parotid gland swelling difficult airway anaesthesia management case presentation MD

mkdir -p /home/daytona/workspace/parotid-airway-case && ls /home/daytona/workspa…

~/parotid-airway-case/generate_pdf.py

from reportlab.lib.pagesizes import A4
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import cm
from reportlab.lib import colors
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    HRFlowable, PageBreak, KeepTogether
)
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.platypus import ListFlowable, ListItem

OUTPUT = "/home/daytona/workspace/parotid-airway-case/Parotid_Swelling_Difficult_Airway_Case_Presentation.pdf"

doc = SimpleDocTemplate(
    OUTPUT,
    pagesize=A4,
    rightMargin=2*cm,
    leftMargin=2*cm,
    topMargin=2*cm,
    bottomMargin=2*cm,
    title="Case Presentation: Parotid Swelling with Difficult Airway - Anaesthesia MD",
    author="Orris AI Medical Assistant"
)

styles = getSampleStyleSheet()

# Custom styles
title_style = ParagraphStyle(
    'CustomTitle',
    parent=styles['Title'],
    fontSize=18,
    textColor=colors.HexColor('#1a237e'),
    spaceAfter=6,
    spaceBefore=0,
    alignment=TA_CENTER,
    fontName='Helvetica-Bold'
)

subtitle_style = ParagraphStyle(
    'Subtitle',
    parent=styles['Normal'],
    fontSize=11,
    textColor=colors.HexColor('#37474f'),
    spaceAfter=4,
    alignment=TA_CENTER,
    fontName='Helvetica'
)

h1_style = ParagraphStyle(
    'H1',
    parent=styles['Heading1'],
    fontSize=13,
    textColor=colors.white,
    spaceBefore=14,
    spaceAfter=4,
    fontName='Helvetica-Bold',
    backColor=colors.HexColor('#1a237e'),
    leftIndent=-10,
    rightIndent=-10,
    borderPad=5,
)

h2_style = ParagraphStyle(
    'H2',
    parent=styles['Heading2'],
    fontSize=11,
    textColor=colors.HexColor('#1a237e'),
    spaceBefore=10,
    spaceAfter=3,
    fontName='Helvetica-Bold',
    borderPad=2,
)

h3_style = ParagraphStyle(
    'H3',
    parent=styles['Heading3'],
    fontSize=10,
    textColor=colors.HexColor('#0d47a1'),
    spaceBefore=7,
    spaceAfter=2,
    fontName='Helvetica-Bold',
)

body_style = ParagraphStyle(
    'Body',
    parent=styles['Normal'],
    fontSize=9.5,
    leading=14,
    spaceAfter=4,
    spaceBefore=1,
    fontName='Helvetica',
    alignment=TA_JUSTIFY,
)

bullet_style = ParagraphStyle(
    'Bullet',
    parent=styles['Normal'],
    fontSize=9.5,
    leading=13,
    spaceAfter=2,
    spaceBefore=1,
    leftIndent=14,
    fontName='Helvetica',
)

sub_bullet_style = ParagraphStyle(
    'SubBullet',
    parent=styles['Normal'],
    fontSize=9,
    leading=12,
    spaceAfter=1,
    spaceBefore=0,
    leftIndent=28,
    fontName='Helvetica',
    textColor=colors.HexColor('#333333'),
)

quote_style = ParagraphStyle(
    'Quote',
    parent=styles['Normal'],
    fontSize=9,
    leading=13,
    spaceAfter=4,
    spaceBefore=4,
    leftIndent=16,
    rightIndent=8,
    fontName='Helvetica-Oblique',
    textColor=colors.HexColor('#1565C0'),
    backColor=colors.HexColor('#E3F2FD'),
    borderPad=6,
    borderColor=colors.HexColor('#1565C0'),
    borderWidth=1,
    borderRadius=3,
)

highlight_style = ParagraphStyle(
    'Highlight',
    parent=styles['Normal'],
    fontSize=9.5,
    leading=13,
    spaceAfter=3,
    spaceBefore=3,
    leftIndent=8,
    rightIndent=8,
    fontName='Helvetica-Bold',
    textColor=colors.HexColor('#B71C1C'),
    backColor=colors.HexColor('#FFEBEE'),
    borderPad=5,
)

table_header_style = ParagraphStyle(
    'TableHeader',
    fontSize=9,
    fontName='Helvetica-Bold',
    textColor=colors.white,
    alignment=TA_CENTER,
    leading=11,
)

table_cell_style = ParagraphStyle(
    'TableCell',
    fontSize=8.5,
    fontName='Helvetica',
    textColor=colors.black,
    leading=11,
    alignment=TA_LEFT,
)

story = []

# ── TITLE PAGE ──────────────────────────────────────────────────────────────
story.append(Spacer(1, 1.2*cm))
story.append(Paragraph("CASE PRESENTATION", title_style))
story.append(Paragraph("Parotid Swelling with Difficult Airway", ParagraphStyle(
    'MainTitle', parent=title_style, fontSize=15, textColor=colors.HexColor('#0d47a1'), spaceAfter=4
)))
story.append(Paragraph("Anaesthesia MD Examination", subtitle_style))
story.append(HRFlowable(width="100%", thickness=2, color=colors.HexColor('#1a237e'), spaceAfter=8))
story.append(Spacer(1, 0.3*cm))

# ── CASE VIGNETTE ──────────────────────────────────────────────────────────
story.append(Paragraph("CASE VIGNETTE", h1_style))
story.append(Spacer(1, 0.15*cm))

vignette_data = [
    [Paragraph("<b>Patient</b>", table_cell_style), Paragraph("45-year-old male", table_cell_style)],
    [Paragraph("<b>Presenting Complaint</b>", table_cell_style), Paragraph("Progressively enlarging right parotid swelling for 2 years, now causing restricted mouth opening and neck stiffness", table_cell_style)],
    [Paragraph("<b>Referred for</b>", table_cell_style), Paragraph("Superficial parotidectomy under general anaesthesia", table_cell_style)],
]
vt = Table(vignette_data, colWidths=[4.5*cm, 12*cm])
vt.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (0,-1), colors.HexColor('#E8EAF6')),
    ('BACKGROUND', (1,0), (1,-1), colors.HexColor('#FAFAFA')),
    ('GRID', (0,0), (-1,-1), 0.5, colors.HexColor('#9FA8DA')),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 5),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
]))
story.append(vt)

# ── SECTION 1: HISTORY ──────────────────────────────────────────────────────
story.append(Paragraph("1. HISTORY", h1_style))

story.append(Paragraph("Chief Complaint", h2_style))
story.append(Paragraph(
    "Slow-growing, painless mass in the right pre-auricular/parotid region for 18-24 months. "
    "Recent complaint of trismus (mouth opening limited to ~2 cm).",
    body_style
))

story.append(Paragraph("History of Present Illness", h2_style))
bullets_hpi = [
    "Mass is firm, non-tender, fixed in later stage / mobile in early stage",
    "No fever, no pus, no skin erythema (features against acute parotitis)",
    "Dysphagia or dysphonia: absent / present (note if present — indicates deep lobe or parapharyngeal extension)",
    "No facial nerve weakness (malignancy less likely, but must rule out)",
    "No recent weight loss, no cervical lymphadenopathy",
]
for b in bullets_hpi:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("Past History", h2_style))
bullets_past = [
    "No prior head/neck surgery or radiotherapy (important: radiation makes mask ventilation difficult)",
    "No diabetes, hypertension, immunosuppression",
]
for b in bullets_past:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("Airway-Relevant History", h2_style))
bullets_airway = [
    "Snoring / OSA symptoms",
    "Previous anaesthesia and intubation difficulty",
    "Neck mobility, dental status",
]
for b in bullets_airway:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

# ── SECTION 2: PHYSICAL EXAMINATION ─────────────────────────────────────────
story.append(Paragraph("2. PHYSICAL EXAMINATION", h1_style))

story.append(Paragraph("General", h2_style))
story.append(Paragraph(
    "Vitals stable; SpO\u2082 on room air: 98%. Anxious but cooperative.",
    body_style
))

story.append(Paragraph("Airway Assessment (MUST document all of the following)", h2_style))

airway_data = [
    [Paragraph("<b>Parameter</b>", table_header_style), Paragraph("<b>Finding in This Patient</b>", table_header_style)],
    [Paragraph("Mouth opening", table_cell_style), Paragraph("< 2.5 cm (trismus) — GRADE III DIFFICULT", table_cell_style)],
    [Paragraph("Mallampati class", table_cell_style), Paragraph("III–IV", table_cell_style)],
    [Paragraph("Thyromental distance", table_cell_style), Paragraph("< 6 cm (concern)", table_cell_style)],
    [Paragraph("Sternomental distance", table_cell_style), Paragraph("< 12.5 cm", table_cell_style)],
    [Paragraph("Neck extension", table_cell_style), Paragraph("Limited if large mass", table_cell_style)],
    [Paragraph("Upper lip bite test", table_cell_style), Paragraph("Class II–III", table_cell_style)],
    [Paragraph("Neck circumference", table_cell_style), Paragraph("Note any obesity", table_cell_style)],
    [Paragraph("Buck teeth / macroglossia", table_cell_style), Paragraph("Note", table_cell_style)],
]
at = Table(airway_data, colWidths=[5*cm, 11.5*cm])
at.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), colors.HexColor('#1a237e')),
    ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.HexColor('#F5F5F5'), colors.white]),
    ('GRID', (0,0), (-1,-1), 0.5, colors.HexColor('#9FA8DA')),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('TOPPADDING', (0,0), (-1,-1), 4),
    ('BOTTOMPADDING', (0,0), (-1,-1), 4),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
]))
story.append(at)
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph(
    '"Other clues to a potentially difficult laryngoscopy include limited neck extension (&lt;35°), a distance between '
    'the tip of the patient\'s mandible and hyoid bone of less than 7 cm, a sternomental distance of less than 12.5 cm '
    'with the head fully extended and the mouth closed, and a poorly visualized uvula during voluntary tongue protrusion." '
    '— Morgan &amp; Mikhail\'s Clinical Anesthesiology, 7e',
    quote_style
))

story.append(Paragraph("Local Examination — Parotid", h2_style))
bullets_local = [
    "Right pre-auricular swelling, ~5 x 4 cm, firm, non-tender, non-pulsatile",
    "Overlying skin normal, no tethering",
    "Facial nerve: all branches intact (House-Brackmann Grade I)",
    "No Stensen's duct discharge",
    "No cervical nodes",
]
for b in bullets_local:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("ENT Examination", h2_style))
story.append(Paragraph(
    "\u2022  Oropharyngeal bulk / tonsillar displacement if deep lobe extension",
    bullet_style
))

# ── SECTION 3: INVESTIGATIONS ────────────────────────────────────────────────
story.append(Paragraph("3. INVESTIGATIONS", h1_style))

story.append(Paragraph("Imaging (Critical for Anaesthesia Planning)", h2_style))
story.append(Paragraph("CT Neck (with contrast) / MRI:", h3_style))
bullets_imaging = [
    "Delineates extent of mass: superficial vs. deep lobe vs. parapharyngeal extension",
    "Airway displacement: \"The physical examination should look for tumor displacement of the airway, as well as impaired "
    "temporomandibular joint (TMJ) mobility and other predictors of airway difficulties. Available head and neck CT scans "
    "or MRI studies should be reviewed with the surgical team, with a focus on airway issues.\" — Miller's Anesthesia, 10e",
    "Assess parapharyngeal space involvement",
]
for b in bullets_imaging:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("USG Parotid + FNAC:", h3_style))
bullets_fnac = [
    "Pleomorphic adenoma: most common benign parotid neoplasm (85% in parotid, 90% in tail of superficial lobe) — slow-growing, painless, firm",
    "Cytology: epithelial + mesenchymal elements",
]
for b in bullets_fnac:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("Routine Labs", h2_style))
story.append(Paragraph(
    "\u2022  CBC, RFT, LFT, coagulation, blood grouping; ECG, CXR (PA view); Thyroid function if suspicion",
    bullet_style
))

# ── SECTION 4: PREOPERATIVE ANAESTHESIA ASSESSMENT ───────────────────────────
story.append(Paragraph("4. PREOPERATIVE ANAESTHESIA ASSESSMENT", h1_style))

story.append(Paragraph("ASA Physical Status", h2_style))
story.append(Paragraph(
    "ASA II (healthy adult, no comorbidities) or ASA III if OSA/HTN present.",
    body_style
))

story.append(Paragraph("Difficult Airway Predictors — LEMON Mnemonic", h2_style))
lemon_data = [
    [Paragraph("<b>Letter</b>", table_header_style), Paragraph("<b>Parameter</b>", table_header_style), Paragraph("<b>Finding</b>", table_header_style)],
    [Paragraph("L", table_cell_style), Paragraph("Look externally", table_cell_style), Paragraph("Parotid mass, neck swelling, limited mouth opening", table_cell_style)],
    [Paragraph("E", table_cell_style), Paragraph("Evaluate 3-3-2 rule", table_cell_style), Paragraph("Mouth opening <3 fingers, hyoid-chin <3 fingers, thyroid-mouth floor <2 fingers", table_cell_style)],
    [Paragraph("M", table_cell_style), Paragraph("Mallampati", table_cell_style), Paragraph("Class III–IV", table_cell_style)],
    [Paragraph("O", table_cell_style), Paragraph("Obstruction", table_cell_style), Paragraph("No frank obstruction but trismus limits access", table_cell_style)],
    [Paragraph("N", table_cell_style), Paragraph("Neck mobility", table_cell_style), Paragraph("Possibly restricted by mass", table_cell_style)],
]
lt = Table(lemon_data, colWidths=[1.5*cm, 4.5*cm, 10.5*cm])
lt.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), colors.HexColor('#1a237e')),
    ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.HexColor('#FFF8E1'), colors.white]),
    ('GRID', (0,0), (-1,-1), 0.5, colors.HexColor('#9FA8DA')),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('TOPPADDING', (0,0), (-1,-1), 4),
    ('BOTTOMPADDING', (0,0), (-1,-1), 4),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
    ('ALIGN', (0,0), (0,-1), 'CENTER'),
    ('FONTNAME', (0,1), (0,-1), 'Helvetica-Bold'),
    ('TEXTCOLOR', (0,1), (0,-1), colors.HexColor('#1a237e')),
]))
story.append(lt)
story.append(Spacer(1, 0.2*cm))

story.append(Paragraph(
    "CONCLUSION: This is an ANTICIPATED DIFFICULT AIRWAY — the critical distinction that drives all anaesthetic planning.",
    highlight_style
))

# ── SECTION 5: ANAESTHETIC PLAN ─────────────────────────────────────────────
story.append(Paragraph("5. ANAESTHETIC PLAN", h1_style))

story.append(Paragraph("Pre-operative Preparation", h2_style))
preop_bullets = [
    "Informed consent including risk of awake intubation, tracheostomy, facial nerve injury",
    "Multidisciplinary team: Anaesthesiologist + ENT Surgeon (scrubbed and ready for surgical airway)",
    "Equipment checklist:",
    "   - Flexible fiberoptic bronchoscope (primary tool)",
    "   - Video laryngoscope (McGrath / GlideScope / C-MAC)",
    "   - Bougie, multiple ETT sizes (6.0, 6.5, 7.0)",
    "   - Supraglottic airway devices: LMA ProSeal / i-gel (backup)",
    "   - Emergency surgical airway kit (cricothyrotomy/tracheostomy set) — opened and ready",
    "   - Anterior commissure (Hollinger) laryngoscope",
    "Neck prepped and draped before induction",
    "IV access: Two large-bore IVs",
    "Monitors: SpO\u2082, ETCO\u2082, ECG, NIBP, temperature, nerve stimulator (facial nerve monitoring — therefore muscle relaxants avoided after intubation)",
]
for i, b in enumerate(preop_bullets):
    if b.startswith("   -"):
        story.append(Paragraph(f"     {b.strip()}", sub_bullet_style))
    else:
        story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("Pre-medication", h2_style))
premed_bullets = [
    "Tab. Diazepam 5 mg oral night before (anxiolysis — use carefully if airway concern)",
    "Inj. Glycopyrrolate 0.2 mg IM 30 min prior: dries secretions, antisialagogue, does NOT cross blood-brain barrier",
    "Avoid: Heavy parenteral sedation — risk of losing airway",
]
for b in premed_bullets:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph(
    '"Glycopyrrolate would be a good choice of premedication because it minimizes upper airway secretions without crossing '
    'the blood-brain barrier. Parenteral sedatives should be very carefully titrated. Dexmedetomidine and ketamine could '
    'be used as sedatives and preserve respiratory effort." — Morgan &amp; Mikhail\'s Clinical Anesthesiology, 7e',
    quote_style
))

story.append(Paragraph("Airway Strategy: AWAKE FIBEROPTIC INTUBATION (AFOI)", h2_style))
story.append(Paragraph(
    "This is the gold standard for anticipated difficult airway with trismus.",
    highlight_style
))
story.append(Spacer(1, 0.2*cm))
story.append(Paragraph(
    '"Induction of anesthesia should be delayed until after the airway has been secured. Useful alternatives include '
    'awake fiberoptic intubation, awake video laryngoscopy, or awake use of optical stylets." '
    '— Morgan &amp; Mikhail\'s Clinical Anesthesiology, 7e',
    quote_style
))

story.append(Paragraph("Step 1 — Topical Airway Anaesthesia", h3_style))
step1_bullets = [
    "Nebulised 4% lignocaine (4 mL) for oropharynx and upper airway",
    "Gargle with 4% lignocaine",
    "10% lignocaine spray to posterior pharynx",
    "Bilateral glossopharyngeal nerve blocks: 2 mL of 2% lignocaine injected into base of palatoglossal arch (anterior tonsillar pillar) with 25G spinal needle — blocks posterior 1/3 tongue and oropharynx sensation",
    "Superior laryngeal nerve (SLN) block (bilateral): 3 mL of 2% lignocaine injected 1 cm below greater cornu of hyoid bone, through thyrohyoid membrane — anaesthetises infraglottic larynx",
    "Transtracheal block: 3 mL of 2% lignocaine injected through cricothyroid membrane; patient asked to inhale-cough to spray subglottically",
    "TOTAL LIGNOCAINE DOSE MUST NOT EXCEED 3 mg/kg (toxicity risk)",
]
for b in step1_bullets:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph(
    '"Bilateral superior laryngeal nerve blocks and a trans tracheal block would anesthetize the airway below the epiglottis. '
    'The hyoid bone is located, and 3 mL of 2% lidocaine is infiltrated 1 cm below each greater cornu, where the internal '
    'branch of the superior laryngeal nerves penetrates the thyrohyoid membrane." — Morgan &amp; Mikhail\'s Clinical Anesthesiology, 7e',
    quote_style
))

story.append(Paragraph("Step 2 — Conscious Sedation (with airway preservation)", h3_style))
step2_bullets = [
    "Inj. Dexmedetomidine: 1 mcg/kg IV over 10 min (loading), then 0.3–0.7 mcg/kg/hr infusion — provides sedation, analgesia, anxiolysis; preserves respiratory effort and airway tone",
    "Alternatively: Ketamine 0.5 mg/kg IV (preserves airway reflexes and spontaneous ventilation)",
    "Supplemental O\u2082 via nasal cannula (THRIVE — Transnasal Humidified Rapid Insufflation Ventilatory Exchange, if available) — prolongs safe apnoea time",
]
for b in step2_bullets:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("Step 3 — AFOI Execution (Nasal route preferred when mouth opening is very limited)", h3_style))
step3_bullets = [
    "Lubricate and vasoconstrict nostril: Xylometazoline drops + 4% lignocaine to nasal mucosa",
    "Pass warmed, lubricated 6.0 or 6.5 mm cuffed ETT over bronchoscope",
    "Advance fiberoptic scope through nostril → nasopharynx → visualise epiglottis → pass through glottis → confirm tracheal rings and carina",
    "Railroad ETT over the bronchoscope into trachea",
    "Confirm position with ETCO\u2082 waveform + bilateral breath sounds",
    "Secure tube, inflate cuff",
]
for b in step3_bullets:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("Step 4 — Induction after Secure Airway", h3_style))
step4_bullets = [
    "Once intubation confirmed:",
    "Inj. Propofol 1–2 mg/kg IV (titrated) OR Inj. Thiopentone 3–5 mg/kg",
    "Single intubating dose: Inj. Succinylcholine 1.5 mg/kg OR Inj. Rocuronium 0.6 mg/kg — for induction ONLY",
    "NO FURTHER MUSCLE RELAXANTS intraoperatively (facial nerve monitoring requirement)",
]
for b in step4_bullets:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("Intraoperative Maintenance", h2_style))
maint_bullets = [
    "TIVA (Total IV Anaesthesia): Propofol infusion 50–150 mcg/kg/min + Remifentanil 0.1 mcg/kg/min",
    "OR: Sevoflurane 1–2% in O\u2082/air + Remifentanil infusion",
    "Avoid neuromuscular blockers after intubation — surgeon must use facial nerve stimulator",
    "Patient position: head-up 15–20° (reduces venous ooze), head turned to LEFT (operative side up — right parotid surgery)",
    "Throat pack inserted (document and remove at end of surgery)",
    "Eyes protected with padding/tape",
]
for b in maint_bullets:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph(
    '"For this reason, the surgical team usually requests that muscle relaxants be avoided after endotracheal intubation '
    'has been achieved... A single, small dose of rocuronium to facilitate endotracheal intubation is often employed, '
    'followed by sevoflurane anesthesia in conjunction with a remifentanil infusion (e.g., 0.1 mcg/kg/min) to provide '
    'immobility." — Miller\'s Anesthesia, 10e',
    quote_style
))

story.append(Paragraph("Monitoring", h2_style))
monitor_bullets = [
    "Standard ASA monitors + ETCO\u2082",
    "Neuromuscular monitoring (Train-of-Four) to confirm reversal",
    "Facial nerve integrity monitoring by surgeon (requires zero paralysis)",
    "Temperature, urine output",
]
for b in monitor_bullets:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

# ── SECTION 6: ASA DIFFICULT AIRWAY ALGORITHM ────────────────────────────────
story.append(Paragraph("6. ASA DIFFICULT AIRWAY ALGORITHM", h1_style))

story.append(Paragraph("Key Decision Points for This Patient:", h2_style))
algo_bullets = [
    "Anticipated difficult airway → AWAKE INTUBATION pathway (left arm of algorithm)",
    "Assess likelihood of: difficult mask ventilation, difficult SGA, difficult laryngoscopy, difficult intubation, difficult surgical airway",
    "Consider: awake intubation vs. intubation after GA induction; non-invasive vs. invasive; preserve vs. ablate spontaneous ventilation",
    "If awake intubation fails → Cancel case / Invasive airway access (surgical tracheostomy)",
    "Surgical team on standby for emergency surgical airway at all times",
]
for b in algo_bullets:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Spacer(1, 0.2*cm))
story.append(Paragraph(
    "Algorithm Summary (ASA Task Force on Management of the Difficult Airway — Anesthesiology 2003;98:1269–1277 as "
    "reproduced in Morgan &amp; Mikhail's Clinical Anesthesiology, 7e):",
    body_style
))
story.append(Spacer(1, 0.2*cm))

algo_table_data = [
    [Paragraph("<b>AWAKE INTUBATION PATHWAY</b>", table_header_style), Paragraph("<b>INTUBATION AFTER GA INDUCTION</b>", table_header_style)],
    [
        Paragraph(
            "1. Airway approached by noninvasive intubation\n"
            "   - SUCCEED* → proceed\n"
            "   - FAIL → Cancel / Other options / Invasive access\n\n"
            "2. Invasive airway access*",
            table_cell_style
        ),
        Paragraph(
            "If initial intubation SUCCESSFUL* → proceed\n\n"
            "If UNSUCCESSFUL → Consider:\n"
            "  1. Call for help\n"
            "  2. Return to spontaneous ventilation\n"
            "  3. Awaken patient\n\n"
            "  Then: Face mask ventilation adequate?\n"
            "   YES → Nonemergency pathway\n"
            "       → Alternative intubation approaches\n"
            "       → FAIL after multiple attempts: Invasive access / other options / awaken\n"
            "   NO → Consider/Attempt SGA\n"
            "       → SGA ADEQUATE* → Nonemergency\n"
            "       → SGA NOT ADEQUATE → EMERGENCY PATHWAY\n"
            "         → Call for help → Emergency noninvasive ventilation\n"
            "         → FAIL → Emergency invasive airway access*",
            table_cell_style
        )
    ]
]
algo_tbl = Table(algo_table_data, colWidths=[8.25*cm, 8.25*cm])
algo_tbl.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), colors.HexColor('#1a237e')),
    ('BACKGROUND', (0,1), (0,1), colors.HexColor('#E8F5E9')),
    ('BACKGROUND', (1,1), (1,1), colors.HexColor('#FFF3E0')),
    ('GRID', (0,0), (-1,-1), 0.5, colors.HexColor('#9FA8DA')),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 5),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
]))
story.append(algo_tbl)
story.append(Paragraph(
    "* Confirm ventilation, tracheal intubation, or SGA placement with exhaled CO\u2082. "
    "Invasive airway access includes surgical or percutaneous airway, jet ventilation, and retrograde intubation.",
    ParagraphStyle('AlgoNote', parent=body_style, fontSize=8, textColor=colors.HexColor('#555555'), spaceBefore=3)
))

# ── SECTION 7: CICO PROTOCOL ─────────────────────────────────────────────────
story.append(Paragraph("7. CANNOT INTUBATE - CANNOT OXYGENATE (CICO) PROTOCOL", h1_style))

story.append(Paragraph(
    "If ALL intubation attempts fail and SpO\u2082 is falling:",
    body_style
))
cico_steps = [
    "Call for help IMMEDIATELY",
    "Attempt LMA / i-gel insertion as rescue oxygenation (Supraglottic Airway Device)",
    "If SGA fails → Emergency Front-of-Neck Access (FONA):",
    "   - Cricothyrotomy (needle/surgical) — fastest route",
    "   - Emergency Tracheostomy by ENT surgeon (preferred if already scrubbed and ready)",
]
for s in cico_steps:
    if s.startswith("   -"):
        story.append(Paragraph(f"     {s.strip()}", sub_bullet_style))
    else:
        story.append(Paragraph(f"\u2022  {s}", bullet_style))

story.append(Paragraph(
    '"Once a \'cannot intubate, cannot ventilate\' situation has been identified, immediate consideration should be '
    'given to providing surgical airway access." — Cummings Otolaryngology Head and Neck Surgery',
    quote_style
))

# ── SECTION 8: POSTOPERATIVE MANAGEMENT ──────────────────────────────────────
story.append(Paragraph("8. POSTOPERATIVE MANAGEMENT", h1_style))

story.append(Paragraph("Extubation Strategy (equally important — 'Difficult Extubation')", h2_style))
extub_bullets = [
    "Extubate ONLY when patient is fully awake, following commands, with adequate neuromuscular reversal (TOF ratio > 0.9)",
    "Consider: Airway Exchange Catheter (AEC) left in situ before extubation — allows reintubation if needed",
    "Patient positioned head-up 30–45°",
    "Inj. Dexamethasone 8 mg IV given intraoperatively — reduces postoperative oedema",
    "Post-extubation monitoring in High Dependency Unit (HDU) for minimum 4 hours",
]
for b in extub_bullets:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("Analgesia — Multimodal", h2_style))
analg_bullets = [
    "Inj. Paracetamol 1 g IV 8 hourly",
    "Inj. Ketorolac 30 mg IV (avoid if risk of bleeding)",
    "Inj. Morphine 0.1 mg/kg IV PRN (with antiemetic cover)",
    "Wound infiltration by surgeon with 0.25% Bupivacaine",
]
for b in analg_bullets:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("PONV Prophylaxis", h2_style))
ponv_bullets = [
    "Inj. Ondansetron 4 mg IV at end of surgery",
    "Inj. Dexamethasone 8 mg IV (also reduces oedema — dual benefit)",
    "Head-up position; avoid opioid excess",
]
for b in ponv_bullets:
    story.append(Paragraph(f"\u2022  {b}", bullet_style))

story.append(Paragraph("Complications to Watch For", h2_style))
comp_data = [
    [Paragraph("<b>Complication</b>", table_header_style), Paragraph("<b>Notes</b>", table_header_style)],
    [Paragraph("Haematoma", table_cell_style), Paragraph("Can cause RAPID airway compromise — emergency reintubation / surgical evacuation required", table_cell_style)],
    [Paragraph("Facial nerve palsy", table_cell_style), Paragraph("Temporary (neurapraxia) or permanent (neurotmesis) — House-Brackmann grading", table_cell_style)],
    [Paragraph("Frey's syndrome", table_cell_style), Paragraph("Late complication — auriculotemporal nerve — gustatory sweating over parotid area", table_cell_style)],
    [Paragraph("Sialocele / salivary fistula", table_cell_style), Paragraph("Late complication — collection of saliva under skin flap", table_cell_style)],
    [Paragraph("Anaesthesia mumps", table_cell_style), Paragraph("Rare — acute postoperative parotid swelling (Stensen's duct obstruction / pneumoparotitis) — can compromise airway in severe cases. Self-limiting.", table_cell_style)],
    [Paragraph("Wound infection", table_cell_style), Paragraph("Prophylactic antibiotics, wound care", table_cell_style)],
]
comp_tbl = Table(comp_data, colWidths=[4*cm, 12.5*cm])
comp_tbl.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), colors.HexColor('#1a237e')),
    ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.HexColor('#FFEBEE'), colors.white]),
    ('GRID', (0,0), (-1,-1), 0.5, colors.HexColor('#9FA8DA')),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('TOPPADDING', (0,0), (-1,-1), 4),
    ('BOTTOMPADDING', (0,0), (-1,-1), 4),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
]))
story.append(comp_tbl)

# ── SECTION 9: VIVA DISCUSSION ────────────────────────────────────────────────
story.append(Paragraph("9. DISCUSSION POINTS FOR MD EXAM VIVA", h1_style))

qna = [
    (
        "Q: Why is awake intubation preferred here?",
        "Because trismus from the parotid mass makes any attempt at direct or video laryngoscopy after GA induction dangerous. "
        "Induction abolishes airway tone and may cause complete obstruction. Awake technique preserves spontaneous ventilation "
        "and muscle tone, maintaining the airway at all times."
    ),
    (
        "Q: Why no muscle relaxants intraoperatively?",
        "Facial nerve identification and preservation is central to parotid surgery. Surgeons use a nerve stimulator. If the "
        "patient is paralyzed, stimulation will not produce visible muscle twitch and the nerve cannot be identified, risking permanent facial palsy. "
        "As stated in Miller's Anesthesia 10e: 'preservation of the facial nerve is of prime importance in these operations; consequently, "
        "the surgeon often must identify the facial nerve by using a nerve stimulator. This crucial step is not possible if "
        "neuromuscular blockade is present.'"
    ),
    (
        "Q: What if awake fiberoptic intubation fails?",
        "Per ASA algorithm: cancel case, reassess, consider video laryngoscopy with topical anaesthesia, retrograde intubation, "
        "or elective tracheostomy under local anaesthesia before proceeding. Never attempt the same failed technique repeatedly."
    ),
    (
        "Q: Role of dexmedetomidine in difficult airway management?",
        "Dexmedetomidine is a highly selective alpha-2 adrenoceptor agonist. It provides dose-dependent sedation, analgesia, "
        "and anxiolysis while PRESERVING respiratory drive and airway reflexes. This makes it the sedative of choice for awake "
        "intubation. Patient is calm and cooperative but maintains airway patency and spontaneous ventilation. Loading dose: "
        "1 mcg/kg over 10 minutes; maintenance: 0.3–0.7 mcg/kg/hr."
    ),
    (
        "Q: Common causes of parotid swelling — surgical classification?",
        "Benign neoplasms: Pleomorphic adenoma (most common — 80%, 85% in parotid, 90% in tail of superficial lobe; slow-growing, "
        "painless, firm; may undergo malignant transformation), Warthin's tumour (bilateral in 10%, smokers, males, Tc-99m scan hot). "
        "Malignant: Mucoepidermoid carcinoma (most common malignant), Adenoid cystic carcinoma (perineural invasion, skip lesions), "
        "Acinic cell carcinoma. Inflammatory: Acute bacterial parotitis (dehydration, elderly, Staph. aureus), Mumps (epidemic parotitis, "
        "EBV recurrence), Sjogren's syndrome, Sarcoidosis. Other: HIV parotitis, Lymphoma."
    ),
    (
        "Q: What is 'anaesthesia mumps'?",
        "Rare complication of general anaesthesia: acute bilateral or unilateral parotid swelling occurring intraoperatively or "
        "within 24 hours postoperatively. Caused by: (a) Stensen's duct obstruction due to head position or direct compression, "
        "(b) Retrograde entry of air into duct (pneumoparotitis — increased oral cavity pressure during airway manipulation). "
        "Clinical: tender pre-auricular swelling, mild erythema, no pus. CT may show parapharyngeal involvement. Management: "
        "conservative (hydration, NSAIDs, warm compresses). Can rarely cause airway compromise via parapharyngeal extension — "
        "monitor closely and maintain high index of suspicion."
    ),
    (
        "Q: Sternomental vs. Thyromental distance in airway assessment?",
        "Thyromental distance (Patil's test): distance from thyroid notch to tip of mandible with neck fully extended. "
        "Normal >6.5 cm; <6 cm = difficult intubation predicted. "
        "Sternomental distance: distance from sternum to tip of mandible with neck fully extended and mouth closed. "
        "Normal >12.5 cm; <12.5 cm suggests difficult laryngoscopy (Morgan & Mikhail, 7e)."
    ),
    (
        "Q: What is the Hollinger (anterior commissure) laryngoscope?",
        "Per Cummings Otolaryngology: 'The anterior commissure laryngoscope is arguably the otolaryngologist's most useful tool "
        "in the management of a difficult airway.' It is a straight-bladed laryngoscope that gives an excellent anterior glottic view. "
        "It accommodates only small ETT (5.5 mm or less). If a larger ETT is required, an intubation bougie is first inserted through "
        "the laryngoscope, which is then removed, and the ETT is railroaded over the bougie."
    ),
]

for q, a in qna:
    story.append(Paragraph(q, h3_style))
    story.append(Paragraph(a, body_style))
    story.append(Spacer(1, 0.1*cm))

# ── SECTION 10: SUMMARY TABLE ─────────────────────────────────────────────────
story.append(Paragraph("10. QUICK SUMMARY TABLE", h1_style))

summary_data = [
    [Paragraph("<b>Phase</b>", table_header_style), Paragraph("<b>Key Actions</b>", table_header_style)],
    [Paragraph("Pre-operative", table_cell_style), Paragraph(
        "CT/MRI airway review with surgeon; AFOI decision; Glycopyrrolate premedication; "
        "Dexmedetomidine sedation; equipment checklist; neck prepped; ENT surgeon scrubbed",
        table_cell_style)],
    [Paragraph("Induction", table_cell_style), Paragraph(
        "Awake fiberoptic nasal intubation; topical lignocaine + SLN block + transtracheal block; "
        "nasotracheal 6.0–6.5 mm ETT; confirm ETCO\u2082; then Propofol/Thiopentone induction",
        table_cell_style)],
    [Paragraph("Maintenance", table_cell_style), Paragraph(
        "TIVA (Propofol + Remifentanil) or Sevoflurane + Remifentanil; "
        "NO neuromuscular blockers after induction; head-up 15–20°; facial nerve monitoring",
        table_cell_style)],
    [Paragraph("Emergence", table_cell_style), Paragraph(
        "Fully awake extubation only; TOF >0.9; airway exchange catheter in situ; "
        "head-up 30–45°; HDU monitoring minimum 4 hours",
        table_cell_style)],
    [Paragraph("CICO Rescue", table_cell_style), Paragraph(
        "SGA (LMA/i-gel) → if fails → Emergency Front-of-Neck Access: "
        "Needle/surgical cricothyrotomy or emergency tracheostomy",
        table_cell_style)],
    [Paragraph("Postoperative Watch", table_cell_style), Paragraph(
        "Haematoma (urgent airway risk), facial nerve palsy, Frey's syndrome (late), "
        "sialocele, PONV, pain, anaesthesia mumps",
        table_cell_style)],
]
sum_tbl = Table(summary_data, colWidths=[3.5*cm, 13*cm])
sum_tbl.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), colors.HexColor('#1a237e')),
    ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.HexColor('#E8EAF6'), colors.white]),
    ('GRID', (0,0), (-1,-1), 0.5, colors.HexColor('#9FA8DA')),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 5),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
]))
story.append(sum_tbl)

# ── REFERENCES ────────────────────────────────────────────────────────────────
story.append(Paragraph("KEY TEXTBOOK REFERENCES", h1_style))
refs = [
    "Morgan & Mikhail's Clinical Anesthesiology, 7th Edition — Chapter 19: Airway Management; Difficult Airway Algorithm; Awake Intubation; Nerve Blocks",
    "Miller's Anesthesia, 2-Volume Set, 10th Edition — Chapter: Otolaryngology / Head & Neck Surgery; Parotid and Salivary Gland Surgery (p. 9818)",
    "Cummings Otolaryngology Head and Neck Surgery — Chapter 6: Difficult Airway / Intubation; Surgical Airway Access",
    "Barash, Cullen, and Stoelting's Clinical Anesthesia, 9th Edition — The Difficult Airway",
    "ASA Task Force on Management of the Difficult Airway. Practice Guidelines for Management of the Difficult Airway. Anesthesiology. 2003 May;98(5):1269–1277",
    "Robbins & Kumar Basic Pathology — Diseases of Salivary Glands; Pleomorphic Adenoma",
    "K.J. Lee's Essential Otolaryngology — Salivary Glands: Tumours and Classification",
    "Frontiers in Surgery 2022 — Anesthesia Mumps with Airway Obstruction after Radical Nephrectomy: A Case Report and Literature Review",
]
for i, r in enumerate(refs, 1):
    story.append(Paragraph(f"{i}.  {r}", ParagraphStyle(
        'Ref', parent=body_style, fontSize=8.5, spaceAfter=3, textColor=colors.HexColor('#333333')
    )))

# ── FOOTER NOTE ───────────────────────────────────────────────────────────────
story.append(Spacer(1, 0.4*cm))
story.append(HRFlowable(width="100%", thickness=1, color=colors.HexColor('#9FA8DA'), spaceAfter=6))
story.append(Paragraph(
    "Prepared for Anaesthesia MD Examination | All content sourced from standard anaesthesia and surgical textbooks | "
    "Clinical judgement must always take precedence over any single algorithm or protocol | July 2026",
    ParagraphStyle('Footer', parent=body_style, fontSize=7.5, textColor=colors.HexColor('#777777'), alignment=TA_CENTER)
))

# ── BUILD ─────────────────────────────────────────────────────────────────────
doc.build(story)
print(f"PDF generated: {OUTPUT}")

cd /home/daytona/workspace/parotid-airway-case && python generate_pdf.py 2>&1

ls -lh /home/daytona/workspace/parotid-airway-case/

mkdir -p /home/daytona/workspace/hyperkalemia-guide && echo "ready"

~/hyperkalemia-guide/generate_guide.py

import math
import urllib.request
import os
from reportlab.lib.pagesizes import A4
from reportlab.lib.units import cm, mm
from reportlab.lib import colors
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY, TA_RIGHT
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    HRFlowable, PageBreak, KeepTogether, Image
)
from reportlab.graphics.shapes import (
    Drawing, Rect, String, Line, Polygon, Circle, Path, Group
)
from reportlab.graphics import renderPDF
from reportlab.graphics.charts.lineplots import LinePlot
from reportlab.graphics.widgets.markers import makeMarker
from reportlab.pdfgen import canvas

W, H = A4
OUTPUT = "/home/daytona/workspace/hyperkalemia-guide/Hyperkalemia_ECG_Changes_Study_Guide.pdf"

# ── Download ECG image ─────────────────────────────────────────────────────
ECG_IMG_URL = "https://cdn.orris.care/cdss_images/b676e83606cc2f60f1fb18ad9937e2eec334e88df4df44312d2e4d1e30fe329d.png"
ECG_IMG_PATH = "/home/daytona/workspace/hyperkalemia-guide/ecg_hyperkalemia.png"
if not os.path.exists(ECG_IMG_PATH):
    urllib.request.urlretrieve(ECG_IMG_URL, ECG_IMG_PATH)
    print("ECG image downloaded.")

# ── Color palette ──────────────────────────────────────────────────────────
C_NAVY   = colors.HexColor('#0D2B55')
C_BLUE   = colors.HexColor('#1565C0')
C_LBLUE  = colors.HexColor('#1E88E5')
C_TEAL   = colors.HexColor('#00838F')
C_RED    = colors.HexColor('#C62828')
C_AMBER  = colors.HexColor('#E65100')
C_GREEN  = colors.HexColor('#2E7D32')
C_BGBLUE = colors.HexColor('#E3F2FD')
C_BGRED  = colors.HexColor('#FFEBEE')
C_BGAMB  = colors.HexColor('#FFF3E0')
C_BGGRN  = colors.HexColor('#E8F5E9')
C_BGPURP = colors.HexColor('#F3E5F5')
C_STRIPE = colors.HexColor('#F5F8FF')
C_GOLD   = colors.HexColor('#F9A825')
C_PURPLE = colors.HexColor('#6A1B9A')
C_GRAY   = colors.HexColor('#546E7A')
C_LGRAY  = colors.HexColor('#ECEFF1')

# ── Styles ─────────────────────────────────────────────────────────────────
ss = getSampleStyleSheet()

def S(name, **kw):
    base = kw.pop('parent', ss['Normal'])
    return ParagraphStyle(name, parent=base, **kw)

TITLE = S('TITLE', fontSize=26, textColor=colors.white, fontName='Helvetica-Bold',
          alignment=TA_CENTER, leading=32, spaceAfter=2)
SUBTITLE = S('SUBTITLE', fontSize=13, textColor=colors.HexColor('#BBDEFB'),
             fontName='Helvetica', alignment=TA_CENTER, leading=18, spaceAfter=2)
BADGE = S('BADGE', fontSize=9, textColor=colors.white, fontName='Helvetica-Bold',
          alignment=TA_CENTER, backColor=C_RED, borderPad=3)

H1 = S('H1', fontSize=13, textColor=colors.white, fontName='Helvetica-Bold',
       spaceBefore=12, spaceAfter=4, backColor=C_NAVY,
       leftIndent=-12, rightIndent=-12, borderPad=6, leading=18)
H2 = S('H2', fontSize=11, textColor=C_NAVY, fontName='Helvetica-Bold',
       spaceBefore=9, spaceAfter=3, leading=15)
H3 = S('H3', fontSize=10, textColor=C_BLUE, fontName='Helvetica-Bold',
       spaceBefore=6, spaceAfter=2, leading=13)

BODY = S('BODY', fontSize=9.5, leading=14, spaceAfter=3, alignment=TA_JUSTIFY,
         fontName='Helvetica')
BULL = S('BULL', fontSize=9.5, leading=13, spaceAfter=2, leftIndent=12,
         fontName='Helvetica')
SBULL = S('SBULL', fontSize=9, leading=12, spaceAfter=1, leftIndent=24,
          fontName='Helvetica', textColor=C_GRAY)

QUOTE = S('QUOTE', fontSize=9, leading=13, spaceAfter=4, spaceBefore=4,
          leftIndent=14, rightIndent=8, fontName='Helvetica-Oblique',
          textColor=C_NAVY, backColor=C_BGBLUE, borderPad=6)

BOX_RED = S('BOX_RED', fontSize=9.5, leading=13, spaceAfter=2, spaceBefore=2,
            leftIndent=8, rightIndent=8, fontName='Helvetica-Bold',
            textColor=C_RED, backColor=C_BGRED, borderPad=5)
BOX_GRN = S('BOX_GRN', fontSize=9.5, leading=13, spaceAfter=2, spaceBefore=2,
            leftIndent=8, rightIndent=8, fontName='Helvetica-Bold',
            textColor=C_GREEN, backColor=C_BGGRN, borderPad=5)
BOX_AMB = S('BOX_AMB', fontSize=9.5, leading=13, spaceAfter=2, spaceBefore=2,
            leftIndent=8, rightIndent=8, fontName='Helvetica', textColor=C_AMBER,
            backColor=C_BGAMB, borderPad=5)

TH = S('TH', fontSize=8.5, fontName='Helvetica-Bold', textColor=colors.white,
       alignment=TA_CENTER, leading=11)
TC = S('TC', fontSize=8.5, fontName='Helvetica', textColor=colors.black,
       alignment=TA_LEFT, leading=11)
TC_C = S('TC_C', fontSize=8.5, fontName='Helvetica', textColor=colors.black,
         alignment=TA_CENTER, leading=11)
TC_B = S('TC_B', fontSize=8.5, fontName='Helvetica-Bold', textColor=C_NAVY,
         alignment=TA_LEFT, leading=11)
FOOT = S('FOOT', fontSize=7.5, textColor=C_GRAY, alignment=TA_CENTER, leading=10)
REF = S('REF', fontSize=8, leading=11, spaceAfter=2, textColor=C_GRAY,
        fontName='Helvetica')

def tbl_style(hdr_color=C_NAVY, row_colors=(C_STRIPE, colors.white)):
    return TableStyle([
        ('BACKGROUND', (0,0), (-1,0), hdr_color),
        ('ROWBACKGROUNDS', (0,1), (-1,-1), row_colors),
        ('GRID', (0,0), (-1,-1), 0.4, colors.HexColor('#B0BEC5')),
        ('VALIGN', (0,0), (-1,-1), 'TOP'),
        ('TOPPADDING', (0,0), (-1,-1), 4),
        ('BOTTOMPADDING', (0,0), (-1,-1), 4),
        ('LEFTPADDING', (0,0), (-1,-1), 5),
        ('RIGHTPADDING', (0,0), (-1,-1), 5),
    ])

def p(text, style=BODY): return Paragraph(text, style)
def sp(h=0.2): return Spacer(1, h*cm)
def hr(): return HRFlowable(width='100%', thickness=1, color=colors.HexColor('#B0BEC5'), spaceAfter=4)
def bull(text): return p(f'\u2022  {text}', BULL)
def sbull(text): return p(f'\u25E6  {text}', SBULL)

# ── ECG waveform drawing ───────────────────────────────────────────────────
def make_ecg_drawing(label, k_level, color, width=130, height=55,
                     peaked_t=False, flat_p=False, wide_qrs=False,
                     sine=False, vf=False, pr_long=False):
    """Draw a stylised ECG trace for a given K+ level."""
    d = Drawing(width, height)
    # background
    d.add(Rect(0, 0, width, height, fillColor=colors.HexColor('#F8FAFE'),
               strokeColor=colors.HexColor('#CFD8DC'), strokeWidth=0.5))
    # grid lines
    for xi in range(0, width, 10):
        d.add(Line(xi, 0, xi, height,
                   strokeColor=colors.HexColor('#E3EAF2'), strokeWidth=0.3))
    for yi in range(0, height, 10):
        d.add(Line(0, yi, width, yi,
                   strokeColor=colors.HexColor('#E3EAF2'), strokeWidth=0.3))

    mid = height * 0.42
    lw = 1.5
    sc = color

    if vf:
        # chaotic VF trace
        import random; random.seed(42)
        pts = []
        for xi in range(0, width, 3):
            amp = random.uniform(-14, 14)
            pts.append((xi, mid + amp))
        for i in range(len(pts)-1):
            d.add(Line(pts[i][0], pts[i][1], pts[i+1][0], pts[i+1][1],
                       strokeColor=sc, strokeWidth=lw))
        d.add(String(4, height-11, 'VF / Asystole', fontSize=7,
                     fillColor=C_RED, fontName='Helvetica-Bold'))
    elif sine:
        # smooth sine wave merging QRS-T
        import math as m
        pts = []
        for xi in range(width):
            y = mid + 16 * m.sin(2 * m.pi * xi / 38)
            pts.append((xi, y))
        for i in range(len(pts)-1):
            d.add(Line(pts[i][0], pts[i][1], pts[i+1][0], pts[i+1][1],
                       strokeColor=sc, strokeWidth=lw))
        d.add(String(4, height-11, 'Sine Wave', fontSize=7,
                     fillColor=C_RED, fontName='Helvetica-Bold'))
    else:
        # build beat sequence: baseline, P, PR, QRS, ST, T, baseline
        def beat(ox, p_amp=5, p_w=8, pr=8, q_d=2, r_h=20, s_d=2,
                 st=6, t_h=7, t_w=14, qrs_w=6):
            segs = []
            x = ox
            # baseline before P
            segs.append((x, mid, x+6, mid))
            x += 6
            # P wave
            if flat_p:
                segs.append((x, mid, x+p_w, mid))
            else:
                segs.append((x, mid, x+p_w//2, mid+p_amp))
                segs.append((x+p_w//2, mid+p_amp, x+p_w, mid))
            x += p_w
            # PR segment
            pr_seg = pr + (6 if pr_long else 0)
            segs.append((x, mid, x+pr_seg, mid))
            x += pr_seg
            # QRS
            qrs_total = qrs_w + (8 if wide_qrs else 0)
            half = qrs_total // 2
            segs.append((x, mid, x+2, mid - 4))       # Q
            segs.append((x+2, mid-4, x+2+half, mid+r_h))  # R up
            segs.append((x+2+half, mid+r_h, x+2+half+2, mid-6))  # S down
            segs.append((x+2+half+2, mid-6, x+qrs_total+2, mid))
            x += qrs_total + 2
            # ST segment
            st_dep = -3 if not peaked_t else 0
            segs.append((x, mid, x+st, mid+st_dep))
            x += st
            # T wave
            t_amp = t_h
            if peaked_t:
                t_amp = int(t_h * 2.5)
                t_w = max(8, t_w - 4)
            segs.append((x, mid+st_dep, x+t_w//2, mid+t_amp))
            segs.append((x+t_w//2, mid+t_amp, x+t_w, mid))
            x += t_w
            # trailing baseline
            segs.append((x, mid, x+8, mid))
            return segs

        all_segs = beat(2)
        ox2 = all_segs[-1][2] + 2
        all_segs += beat(ox2)

        for seg in all_segs:
            d.add(Line(seg[0], seg[1], seg[2], seg[3],
                       strokeColor=sc, strokeWidth=lw))

    # label at bottom-left
    d.add(String(4, 4, label, fontSize=7.5, fillColor=C_NAVY,
                 fontName='Helvetica-Bold'))
    # K+ badge
    badge_bg = C_GREEN if k_level == 'Normal' else (
        C_AMBER if '5' in k_level or '6' in k_level else C_RED)
    d.add(Rect(width-48, height-14, 46, 12, fillColor=badge_bg,
               strokeWidth=0))
    d.add(String(width-46, height-11, f'K\u207a {k_level} mEq/L',
                 fontSize=7, fillColor=colors.white, fontName='Helvetica-Bold'))
    return d

# ── Cover page drawing ─────────────────────────────────────────────────────
def make_cover():
    cw, ch = W, H
    d = Drawing(cw, ch)
    # gradient-like background via stacked rects
    for i in range(80):
        frac = i / 80
        r = int(13 + frac*30)
        g = int(43 + frac*40)
        b = int(85 + frac*60)
        d.add(Rect(0, ch - (i+1)*(ch/80), cw, ch/80+1,
                   fillColor=colors.Color(r/255, g/255, b/255), strokeWidth=0))
    # decorative circles
    d.add(Circle(cw*0.85, ch*0.75, 90,
                 fillColor=colors.Color(1,1,1,0.05), strokeWidth=0))
    d.add(Circle(cw*0.1, ch*0.2, 60,
                 fillColor=colors.Color(1,1,1,0.04), strokeWidth=0))
    # horizontal bands
    d.add(Rect(0, ch*0.38, cw, 3, fillColor=C_GOLD, strokeWidth=0))
    d.add(Rect(0, ch*0.36, cw, 1, fillColor=colors.Color(1,1,1,0.3),
               strokeWidth=0))
    return d

# ── Page numbering ─────────────────────────────────────────────────────────
class NumberedCanvas(canvas.Canvas):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self._saved_page_states = []

    def showPage(self):
        self._saved_page_states.append(dict(self.__dict__))
        self._startPage()

    def save(self):
        num_pages = len(self._saved_page_states)
        for state in self._saved_page_states:
            self.__dict__.update(state)
            self.draw_page_number(num_pages)
            super().showPage()
        super().save()

    def draw_page_number(self, page_count):
        pg = self._pageNumber
        if pg == 1:
            return
        self.saveState()
        self.setFillColor(C_GRAY)
        self.setFont('Helvetica', 7.5)
        txt = f'Hyperkalemia & ECG Changes | Page {pg} of {page_count} | Anaesthesia MD Revision'
        self.drawCentredString(W/2, 1.0*cm, txt)
        self.setStrokeColor(colors.HexColor('#B0BEC5'))
        self.setLineWidth(0.5)
        self.line(2*cm, 1.35*cm, W-2*cm, 1.35*cm)
        self.restoreState()

# ── Build story ────────────────────────────────────────────────────────────
story = []

# ══ PAGE 1: COVER ════════════════════════════════════════════════════════════
cover = make_cover()
story.append(cover)
story.append(Spacer(1, -H + 5.5*cm))   # push text over drawing

cover_title_st = S('CT', fontSize=30, textColor=colors.white,
                   fontName='Helvetica-Bold', alignment=TA_CENTER, leading=36)
cover_sub_st   = S('CS', fontSize=14, textColor=colors.HexColor('#90CAF9'),
                   fontName='Helvetica', alignment=TA_CENTER, leading=20)
cover_tag_st   = S('CTag', fontSize=10, textColor=C_GOLD,
                   fontName='Helvetica-Bold', alignment=TA_CENTER, leading=14)

story.append(p('HYPERKALEMIA', cover_title_st))
story.append(p('&  ECG  CHANGES', cover_title_st))
story.append(sp(0.3))
story.append(p('Complete Exam Study Guide', cover_sub_st))
story.append(sp(0.15))
story.append(p('Anaesthesia MD  \u2022  Internal Medicine  \u2022  Emergency Medicine  \u2022  Nephrology', cover_tag_st))
story.append(sp(0.5))

# mini ECG strip on cover
ecg_strip_data = [
    [make_ecg_drawing('Normal', '4-5', C_GREEN),
     make_ecg_drawing('Peaked T', '5-6', C_LBLUE, peaked_t=True),
     make_ecg_drawing('Flat P / Long PR', '6-7', C_AMBER, flat_p=True, pr_long=True, peaked_t=True),
     make_ecg_drawing('Wide QRS', '7-8', C_AMBER, flat_p=True, wide_qrs=True, peaked_t=True),
    ]
]
strip_tbl = Table(ecg_strip_data, colWidths=[4.2*cm]*4)
strip_tbl.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,-1), colors.Color(1,1,1,0.07)),
    ('BOX', (0,0), (-1,-1), 1, colors.Color(1,1,1,0.2)),
    ('ALIGN', (0,0), (-1,-1), 'CENTER'),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('TOPPADDING', (0,0), (-1,-1), 4),
    ('BOTTOMPADDING', (0,0), (-1,-1), 4),
]))
story.append(strip_tbl)

story.append(sp(0.5))
meta_data = [[
    p('SOURCES', S('MS', fontSize=7.5, textColor=colors.HexColor('#B0BEC5'),
                   fontName='Helvetica-Bold', alignment=TA_CENTER)),
    p("Miller's Anesthesia 10e  \u2022  Harrison's 22e  \u2022  Comprehensive Clinical Nephrology 7e  \u2022  Tintinalli's Emergency Medicine",
      S('MS2', fontSize=8, textColor=colors.HexColor('#E0E0E0'),
        fontName='Helvetica', alignment=TA_CENTER)),
    p('YEAR', S('MS', fontSize=7.5, textColor=colors.HexColor('#B0BEC5'),
                fontName='Helvetica-Bold', alignment=TA_CENTER)),
    p('July 2026', S('MS2', fontSize=8, textColor=colors.HexColor('#E0E0E0'),
                     fontName='Helvetica', alignment=TA_CENTER)),
]]
mt = Table(meta_data, colWidths=[1.5*cm, 12.5*cm, 1.3*cm, 2.2*cm])
mt.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,-1), colors.Color(0,0,0,0.25)),
    ('BOX', (0,0), (-1,-1), 0.5, colors.Color(1,1,1,0.15)),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 5),
    ('LEFTPADDING', (0,0), (-1,-1), 4),
]))
story.append(mt)
story.append(PageBreak())

# ══ PAGE 2-3: CORE CONTENT ════════════════════════════════════════════════

# ── Section 1: Definition & Classification ─────────────────────────────────
story.append(p('1.  DEFINITION & CLASSIFICATION', H1))
story.append(p(
    'Hyperkalemia is defined as serum potassium concentration <b>&gt; 5.0 mEq/L</b> '
    '(normal range: 3.5–5.0 mEq/L). It is the most common electrolyte disorder to cause '
    'life-threatening cardiac arrhythmia.',
    BODY))

class_data = [
    [p('<b>Grade</b>', TH), p('<b>Serum K\u207a (mEq/L)</b>', TH),
     p('<b>ECG Changes</b>', TH), p('<b>Clinical Risk</b>', TH)],
    [p('Mild', TC_B), p('5.0 – 6.0', TC_C),
     p('Usually absent', TC), p('Low — monitor', TC)],
    [p('Moderate', TC_B), p('5.0–6.0 with ECG\nchanges, or\n6.1–6.5 without', TC_C),
     p('Peaked T waves, PR prolongation', TC), p('Moderate — treat', TC)],
    [p('<b>Severe</b>', S('TCS', parent=TC_B, textColor=C_RED)),
     p('<b>&gt; 6.5 mEq/L</b>', S('TCS', parent=TC_C, textColor=C_RED)),
     p('<b>Wide QRS, sine wave, VF risk</b>', S('TCS', parent=TC, textColor=C_RED)),
     p('<b>HIGH — emergency</b>', S('TCS', parent=TC, textColor=C_RED))],
]
ct = Table(class_data, colWidths=[2.5*cm, 4*cm, 6*cm, 4*cm])
ct.setStyle(tbl_style())
ct.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), C_NAVY),
    ('ROWBACKGROUNDS', (0,1), (-1,-1), [C_STRIPE, colors.white]),
    ('BACKGROUND', (0,3), (-1,3), C_BGRED),
    ('GRID', (0,0), (-1,-1), 0.4, colors.HexColor('#B0BEC5')),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('TOPPADDING', (0,0), (-1,-1), 4),
    ('BOTTOMPADDING', (0,0), (-1,-1), 4),
    ('LEFTPADDING', (0,0), (-1,-1), 5),
    ('RIGHTPADDING', (0,0), (-1,-1), 5),
]))
story.append(ct)

# ── Section 2: Pathophysiology ─────────────────────────────────────────────
story.append(sp(0.2))
story.append(p('2.  PATHOPHYSIOLOGY OF ECG CHANGES', H1))

story.append(p(
    'The resting membrane potential (RMP) of myocardial cells is normally <b>−90 mV</b>, '
    'maintained by a high intracellular-to-extracellular K\u207a gradient. '
    'When extracellular K\u207a rises:',
    BODY))

path_steps = [
    ('<b>Step 1</b>', 'RMP becomes less negative (moves toward zero)', C_BGBLUE),
    ('<b>Step 2</b>', 'Partial depolarisation → fast Na\u207a channels inactivated', C_BGBLUE),
    ('<b>Step 3</b>', 'Slowed conduction velocity → widened QRS, PR prolongation, AV block', C_BGAMB),
    ('<b>Step 4</b>', 'Accelerated Phase 3 repolarisation → tall, narrow, peaked T waves (early change)', C_BGAMB),
    ('<b>Step 5</b>', 'As K\u207a rises further → depolarisation blockade → asystole / VF', C_BGRED),
]
path_tbl_data = [[p(a, S('PS', parent=TC_B, textColor=C_NAVY, alignment=TA_CENTER)),
                  p(b, TC)] for a, b, _ in path_steps]
path_tbl = Table(path_tbl_data, colWidths=[2.5*cm, 14*cm])
path_tbl.setStyle(TableStyle([
    ('ROWBACKGROUNDS', (0,0), (-1,-1), [row[2] for row in path_steps]),
    ('GRID', (0,0), (-1,-1), 0.4, colors.HexColor('#B0BEC5')),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('TOPPADDING', (0,0), (-1,-1), 5),
    ('BOTTOMPADDING', (0,0), (-1,-1), 5),
    ('LEFTPADDING', (0,0), (-1,-1), 5),
]))
story.append(path_tbl)

story.append(p(
    '"Calcium raises the action potential threshold and reduces excitability, without changing the resting membrane potential. '
    'By restoring the difference between resting and threshold potentials, calcium reverses the depolarisation blockade '
    'due to hyperkalemia." — Harrison\'s Principles of Internal Medicine, 22e',
    QUOTE))

# ── Section 3: Sequential ECG Changes ──────────────────────────────────────
story.append(p('3.  SEQUENTIAL ECG CHANGES — LEVEL BY LEVEL', H1))
story.append(p(
    'ECG changes follow a predictable sequence as serum K\u207a rises. However, '
    '<b>the rate of progression can be unpredictable</b> and may not correlate well with '
    'absolute serum K\u207a values. A stat ECG is essential in ALL hyperkalemic patients.',
    BODY))

# ECG drawings row 1
ecg_row1 = [
    [make_ecg_drawing('1. Normal', '4–5', C_GREEN, width=130, height=60),
     make_ecg_drawing('2. Peaked T waves', '5.5–6.5', C_LBLUE, width=130, height=60, peaked_t=True),
     make_ecg_drawing('3. Long PR + Flat P', '6.5–7.5', C_AMBER, width=130, height=60,
                      peaked_t=True, flat_p=True, pr_long=True)],
]
ecg_row2 = [
    [make_ecg_drawing('4. Wide QRS', '7.5–8.5', C_AMBER, width=130, height=60,
                      peaked_t=True, flat_p=True, wide_qrs=True),
     make_ecg_drawing('5. Sine Wave', '> 8.5', C_RED, width=130, height=60, sine=True),
     make_ecg_drawing('6. VF / Asystole', '> 9–10', C_RED, width=130, height=60, vf=True)],
]

for row in [ecg_row1, ecg_row2]:
    et = Table(row, colWidths=[5.5*cm, 5.5*cm, 5.5*cm])
    et.setStyle(TableStyle([
        ('BOX', (0,0), (-1,-1), 0.5, colors.HexColor('#CFD8DC')),
        ('INNERGRID', (0,0), (-1,-1), 0.5, colors.HexColor('#CFD8DC')),
        ('ALIGN', (0,0), (-1,-1), 'CENTER'),
        ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
        ('TOPPADDING', (0,0), (-1,-1), 4),
        ('BOTTOMPADDING', (0,0), (-1,-1), 4),
        ('BACKGROUND', (0,0), (-1,-1), colors.HexColor('#FAFCFF')),
    ]))
    story.append(et)
    story.append(sp(0.1))

# Detailed ECG table
ecg_detail = [
    [p('<b>K\u207a (mEq/L)</b>', TH), p('<b>ECG Change</b>', TH),
     p('<b>Mechanism</b>', TH), p('<b>Clinical Action</b>', TH)],
    [p('4–5\n(Normal)', TC_C),
     p('Normal ECG', TC),
     p('Normal RMP, normal conduction', TC),
     p('No action needed', TC)],
    [p('5.5–6.5', TC_C),
     p('<b>Peaked (tented) T waves</b>\n• Tall, narrow, symmetric\n• Narrow base\n• All leads, esp. precordial', TC),
     p('Accelerated Phase 3 repolarisation; reduced RMP', TC),
     p('Monitor; treat cause; repeat ECG', TC)],
    [p('6.5–7.5', TC_C),
     p('<b>Prolonged PR interval</b> (1° AV block)\n<b>Flattened / absent P waves</b>\n(Atrial standstill)\n<b>ST depression</b>', TC),
     p('Slowed atrial conduction; Na\u207a channel inactivation', TC),
     p('Active treatment: Ca\u00b2\u207a, Insulin-glucose', TC)],
    [p('7.5–8.5', TC_C),
     p('<b>Widened QRS</b> (&gt;120 ms)\nBizarre morphology\nMay mimic BBB', TC),
     p('Slowed intraventricular conduction; partial depolarisation block', TC),
     p('Emergency: IV Calcium immediately', TC)],
    [p('&gt; 8.5', S('K_SEV', parent=TC_C, textColor=C_RED, fontName='Helvetica-Bold')),
     p('<b>SINE WAVE PATTERN</b>\nQRS merges with T wave\nJunctional rhythm', S('ECG_SEV', parent=TC, textColor=C_RED)),
     p('Extreme conduction slowing; QRS-T fusion', TC),
     p('<b>Pre-arrest — call code, prepare defibrillator</b>', S('ACT_SEV', parent=TC, textColor=C_RED, fontName='Helvetica-Bold'))],
    [p('&gt; 9–10', S('K_CRIT', parent=TC_C, textColor=C_RED, fontName='Helvetica-Bold')),
     p('<b>VF / Asystole\nDiastolic arrest</b>', S('ECG_CRIT', parent=TC, textColor=C_RED, fontName='Helvetica-Bold')),
     p('Complete failure of depolarisation; membrane arrest', TC),
     p('<b>CPR + ACLS + Dialysis</b>', S('ACT_CRIT', parent=TC, textColor=C_RED, fontName='Helvetica-Bold'))],
]
edt = Table(ecg_detail, colWidths=[2.2*cm, 5*cm, 4.5*cm, 4.8*cm])
edt.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), C_NAVY),
    ('ROWBACKGROUNDS', (0,1), (-1,-1), [C_BGGRN, C_STRIPE, C_STRIPE, C_BGAMB, C_BGRED, C_BGRED]),
    ('GRID', (0,0), (-1,-1), 0.4, colors.HexColor('#B0BEC5')),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('TOPPADDING', (0,0), (-1,-1), 4),
    ('BOTTOMPADDING', (0,0), (-1,-1), 4),
    ('LEFTPADDING', (0,0), (-1,-1), 5),
    ('RIGHTPADDING', (0,0), (-1,-1), 5),
    ('SPAN', (0,5), (0,6)),
]))
story.append(edt)

story.append(p(
    '"Progressive hyperkalemia results in identifiable changes in the electrocardiogram. These include '
    'peaking of the T wave, flattening of the P wave, prolongation of the PR interval, depression of the ST segment, '
    'prolongation of the QRS complex, and, eventually, progression to a sine wave pattern. '
    'Ventricular fibrillation may occur at ANY TIME during this ECG progression." '
    '— Comprehensive Clinical Nephrology, 7e',
    QUOTE))

# ── Section 4: Reference ECG Image ─────────────────────────────────────────
story.append(p('4.  REFERENCE ECG DIAGRAM (Textbook)', H1))
story.append(p('The following diagram from Comprehensive Clinical Nephrology, 7e (Fig. 10.6) illustrates the '
               'progressive ECG changes with approximate serum potassium levels:', BODY))
story.append(sp(0.1))
if os.path.exists(ECG_IMG_PATH):
    img = Image(ECG_IMG_PATH, width=9*cm, height=11*cm)
    img_tbl = Table([[img]], colWidths=[16.5*cm])
    img_tbl.setStyle(TableStyle([
        ('ALIGN', (0,0), (-1,-1), 'CENTER'),
        ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
        ('BOX', (0,0), (-1,-1), 1, colors.HexColor('#90A4AE')),
        ('TOPPADDING', (0,0), (-1,-1), 6),
        ('BOTTOMPADDING', (0,0), (-1,-1), 6),
        ('BACKGROUND', (0,0), (-1,-1), colors.HexColor('#F8FAFE')),
    ]))
    story.append(img_tbl)
    story.append(p('<i>Fig. 10.6: ECG Changes in Hyperkalemia — Comprehensive Clinical Nephrology, 7e</i>',
                   S('IMGCAP', parent=FOOT, fontSize=8, spaceAfter=4)))

story.append(PageBreak())

# ══ PAGE 3: CAUSES + TREATMENT ════════════════════════════════════════════

# ── Section 5: Causes ──────────────────────────────────────────────────────
story.append(p('5.  CAUSES OF HYPERKALEMIA', H1))

causes_data = [
    [p('<b>Mechanism</b>', TH), p('<b>Specific Causes</b>', TH)],
    [p('Impaired renal\nexcretion', TC_B),
     p('CKD / AKI (most common); Addison\'s disease (mineralocorticoid deficiency); '
       'Hypoaldosteronism; Type IV RTA', TC)],
    [p('Drugs\n(impair excretion)', TC_B),
     p('ACE inhibitors; ARBs; Potassium-sparing diuretics (spironolactone, amiloride, triamterene); '
       'NSAIDs; Direct renin inhibitors; Calcineurin inhibitors (tacrolimus, cyclosporine)', TC)],
    [p('Transcellular\nshift\n(ICF → ECF)', TC_B),
     p('Metabolic acidosis (H\u207a–K\u207a exchange); Insulin deficiency / Hyperglycemia (osmotic shift); '
       'Beta-blockers (block Na\u207a/K\u207a ATPase); Rhabdomyolysis; Massive trauma / burns / tumour lysis; '
       'Digoxin toxicity; <b>Succinylcholine</b> (up to +1 mEq/L — dangerous in burns, denervation, immobility)', TC)],
    [p('Excess intake', TC_B),
     p('Only clinically relevant in patients with impaired excretion (K\u207a supplements, K\u207a-containing salt substitutes, '
       'blood transfusions, TPN)', TC)],
    [p('Pseudo-\nhyperkalemia', TC_B),
     p('<b>No ECG changes</b> (diagnostic clue!); Haemolysed sample; Prolonged tourniquet; '
       'Thrombocytosis (&gt;800,000/\u03bcL); Leukocytosis (&gt;100,000/\u03bcL); '
       'Repeat on fresh sample in fluoride-oxalate tube', TC)],
]
causeT = Table(causes_data, colWidths=[3*cm, 13.5*cm])
causeT.setStyle(tbl_style(hdr_color=C_TEAL, row_colors=(C_BGBLUE, colors.white)))
story.append(causeT)

story.append(sp(0.15))
story.append(p(
    '<b>\u26a0 Succinylcholine warning:</b> In patients with burns, crush injury, denervation, prolonged immobility, '
    'or upper motor neuron lesions, succinylcholine causes massive K\u207a release from upregulated '
    'extrajunctional acetylcholine receptors and can precipitate fatal cardiac arrest. '
    '<b>Use rocuronium instead in these patients.</b>',
    BOX_RED))

# ── Section 6: Clinical Features ───────────────────────────────────────────
story.append(p('6.  CLINICAL FEATURES', H1))

cf_data = [
    [p('<b>System</b>', TH), p('<b>Symptoms &amp; Signs</b>', TH)],
    [p('Cardiac\n(MOST\nIMPORTANT)', TC_B),
     p('Palpitations; bradycardia; irregular rhythm; AV block; VF; diastolic arrest; '
       '<b>ECG changes as above</b> — may be only presentation', TC)],
    [p('Neuromuscular', TC_B),
     p('Generalised weakness; muscle cramps; paresthesias; areflexia; ascending paralysis; '
       'diaphragm weakness → respiratory failure (severe)', TC)],
    [p('GI', TC_B),
     p('Nausea; vomiting; diarrhoea; ileus', TC)],
]
cfT = Table(cf_data, colWidths=[3*cm, 13.5*cm])
cfT.setStyle(tbl_style(hdr_color=C_PURPLE))
story.append(cfT)
story.append(sp(0.1))
story.append(p(
    '<b>\u26a0 Key Point:</b> Mortality risk from hyperkalemia is <b>INDEPENDENT of clinical symptoms</b> '
    'and reflects acute cardiac conduction effects. A patient can be asymptomatic with fatal ECG changes. '
    'Always get a stat ECG. — Comprehensive Clinical Nephrology, 7e',
    BOX_AMB))

# ── Section 7: Treatment ───────────────────────────────────────────────────
story.append(p('7.  TREATMENT — THREE-STEP APPROACH', H1))
story.append(p(
    'Treatment follows three sequential steps, often given simultaneously in severe cases:',
    BODY))

tx_steps = [
    ('STEP 1', 'MEMBRANE STABILISATION\n(Cardiac Protection)',
     C_RED, C_BGRED,
     [
         'Inj. <b>Calcium gluconate 10%</b> — 10 mL IV over 2–3 min (cardiac monitoring)',
         'Mechanism: raises action potential threshold; restores RMP-threshold difference; '
          '<b>does NOT lower serum K\u207a</b>',
         'Onset: 1–3 min; Duration: 30–60 min',
         'Repeat if no ECG improvement or if ECG changes recur',
         '<b>Digoxin caution:</b> If on digoxin, give Ca\u00b2\u207a in 100 mL D5W over 20–30 min '
          '(slow infusion) to avoid acute hypercalcaemia potentiating digoxin toxicity',
     ]),
    ('STEP 2', 'REDISTRIBUTION\n(Shift K\u207a into Cells)',
     C_AMBER, C_BGAMB,
     [
         'Inj. <b>Regular insulin 10 units IV</b> + Inj. <b>50 mL of 50% dextrose (D50W)</b> '
          'immediately after',
         'Onset: 10–20 min; Peak: 30–60 min; Duration: 4–6 h',
         '<b>Monitor glucose</b> closely — hypoglycaemia common; follow with 10% dextrose infusion '
          'at 50–75 mL/h',
         'If glucose \u2265200–250 mg/dL: give insulin WITHOUT glucose',
         'Inj. <b>Salbutamol (Albuterol) 10–20 mg nebulised</b> over 10 min (additive with insulin)',
         '\u2248 20% of ESRD patients are resistant to \u03b2\u2082-agonists — do not use alone',
         'Inj. <b>Sodium bicarbonate</b> — isotonic infusion; delayed effect (4–6 h); '
          'useful in metabolic acidosis; do NOT give as undiluted bolus (hypernatraemia risk)',
     ]),
    ('STEP 3', 'ELIMINATION\n(Remove K\u207a from Body)',
     C_TEAL, C_BGGRN,
     [
         'Inj. <b>Frusemide (Loop diuretic)</b> — promotes urinary K\u207a excretion',
         '<b>Sodium zirconium cyclosilicate (Lokelma)</b> or <b>Patiromer</b> — newer oral K\u207a-binding '
          'resins; well-tolerated',
         '<b>Sodium polystyrene sulphonate (Resonium)</b> — older GI exchange resin',
         '<b>Haemodialysis</b> — most effective and rapid removal; for ESRD, refractory or severe cases',
     ]),
]

for step_label, step_title, hdr_color, bg_color, bullets in tx_steps:
    step_content = [bull(b) for b in bullets]
    title_cell = p(f'<b>{step_label}</b>\n{step_title}',
                   S('StepLabel', parent=TH, fontSize=9.5, leading=14,
                     textColor=colors.white, alignment=TA_CENTER))
    content_table = Table(
        [[title_cell, [p('', BODY)] + step_content]],
        colWidths=[3*cm, 13.5*cm]
    )
    content_table.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (0,0), hdr_color),
        ('BACKGROUND', (1,0), (1,0), bg_color),
        ('BOX', (0,0), (-1,-1), 0.5, colors.HexColor('#B0BEC5')),
        ('INNERGRID', (0,0), (-1,-1), 0.4, colors.HexColor('#CFD8DC')),
        ('VALIGN', (0,0), (-1,-1), 'TOP'),
        ('TOPPADDING', (0,0), (-1,-1), 5),
        ('BOTTOMPADDING', (0,0), (-1,-1), 5),
        ('LEFTPADDING', (0,0), (-1,-1), 5),
        ('RIGHTPADDING', (0,0), (-1,-1), 5),
    ]))
    story.append(content_table)
    story.append(sp(0.1))

story.append(PageBreak())

# ══ PAGE 4: HIGH-YIELD EXAM POINTS ═════════════════════════════════════════

story.append(p('8.  DIAGNOSIS — KEY POINTS', H1))

diag_data = [
    [p('<b>Investigation</b>', TH), p('<b>Purpose &amp; Key Findings</b>', TH)],
    [p('Stat ECG', TC_B),
     p('<b>First test</b> — essential in ALL patients with known or suspected hyperkalemia. '
       'If ECG changes are present, start emergency treatment IMMEDIATELY. '
       'If ECG changes in a dialysis patient with unknown electrolytes → treat for hyperkalemia.', TC)],
    [p('Serum K\u207a', TC_B),
     p('Confirm on a fresh, non-haemolysed sample. If haemolysis present, repeat — '
       'pseudohyperkalemia is excluded by absence of ECG changes.', TC)],
    [p('Serum creatinine\n/ eGFR', TC_B),
     p('Assess renal function — most common cause of true hyperkalemia is renal impairment.', TC)],
    [p('Blood gas (ABG)', TC_B),
     p('Metabolic acidosis → K\u207a shifts out of cells (0.6 mEq/L rise per 0.1 pH fall).', TC)],
    [p('Serum glucose\n/ insulin', TC_B),
     p('Insulin deficiency / hyperglycaemia → hyperkalemia via osmotic shift.', TC)],
    [p('Urine K\u207a', TC_B),
     p('Spot urinary K\u207a &lt;20 mEq/L → renal retention; &gt;20 mEq/L → renal wasting '
       '(unexpected in hyperkalemia — consider redistribution).', TC)],
    [p('Aldosterone\n/ Cortisol', TC_B),
     p('If Addison\'s / hypoaldosteronism suspected.', TC)],
    [p('CPK / Myoglobin', TC_B),
     p('If rhabdomyolysis suspected (trauma, crush, statin use).', TC)],
]
diagT = Table(diag_data, colWidths=[3*cm, 13.5*cm])
diagT.setStyle(tbl_style(hdr_color=C_TEAL))
story.append(diagT)

# ── Section 8: High-Yield Points ───────────────────────────────────────────
story.append(p('9.  HIGH-YIELD EXAM POINTS', H1))

hyp_cols = [
    [
        p('EARLIEST ECG change', H3),
        bull('Peaked (tented) T waves — tall, narrow, symmetric, narrow base, all leads'),
        sp(0.1),
        p('MOST DANGEROUS ECG sign', H3),
        bull('Sine wave pattern = impending cardiac arrest'),
        bull('"The sine wave is a sign of impending cardiac arrest and is often a fatal rhythm." — Miller\'s Anesthesia 10e'),
        sp(0.1),
        p('DRUG THAT DOES NOT LOWER K\u207a', H3),
        bull('IV Calcium — only stabilises the myocardium; does NOT reduce serum K\u207a'),
        sp(0.1),
        p('FASTEST K\u207a-LOWERING TREATMENT', H3),
        bull('Haemodialysis (removes most K\u207a per unit time)'),
        sp(0.1),
        p('ECG CHANGE NOT SEEN IN HYPERKALEMIA', H3),
        bull('U waves (U waves are a feature of hypoKALEMIA)'),
    ],
    [
        p('SUCCINYLCHOLINE RISK', H3),
        bull('Can raise K\u207a by up to +1 mEq/L normally'),
        bull('In burns, denervation, crush injury, UMN lesion: can raise by +5–10 mEq/L → fatal arrest'),
        bull('Use rocuronium instead in at-risk patients'),
        sp(0.1),
        p('DIGOXIN + CALCIUM INTERACTION', H3),
        bull('Hypercalcaemia potentiates digoxin cardiac toxicity'),
        bull('If must give Ca\u00b2\u207a in a patient on digoxin: dilute in D5W, give slowly over 20–30 min'),
        sp(0.1),
        p('ECG + K\u207a CORRELATION CAVEAT', H3),
        bull('"The rate of progression from mild to severe cardiac effects can be unpredictable '
             'and may not correlate well with changes in serum K\u207a." — Nephrology 7e'),
        sp(0.1),
        p('K\u207a \u2265 6.5 mEq/L WITHOUT ECG CHANGES', H3),
        bull('Still requires AGGRESSIVE management — ECG changes are not sensitive enough to rule out cardiac risk'),
    ],
]

hyp_tbl = Table([hyp_cols], colWidths=[8.25*cm, 8.25*cm])
hyp_tbl.setStyle(TableStyle([
    ('BOX', (0,0), (-1,-1), 0.5, colors.HexColor('#CFD8DC')),
    ('INNERGRID', (0,0), (-1,-1), 0.5, colors.HexColor('#CFD8DC')),
    ('VALIGN', (0,0), (-1,-1), 'TOP'),
    ('BACKGROUND', (0,0), (0,0), C_BGBLUE),
    ('BACKGROUND', (1,0), (1,0), C_BGAMB),
    ('TOPPADDING', (0,0), (-1,-1), 6),
    ('BOTTOMPADDING', (0,0), (-1,-1), 6),
    ('LEFTPADDING', (0,0), (-1,-1), 6),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
]))
story.append(hyp_tbl)

# ── Section 9: Memory Mnemonics ─────────────────────────────────────────────
story.append(p('10.  MEMORY AIDS FOR EXAM', H1))

story.append(p('ECG Changes in Order — Mnemonic: <b>"P Waves Disappear, QRS Swells, Then Sines"</b>', H2))
mnemo_data = [
    [p('<b>Letter</b>', TH), p('<b>Change</b>', TH), p('<b>K\u207a Level</b>', TH)],
    [p('P', TC_B), p('Peaked T waves (earliest)', TC), p('5.5–6.5', TC_C)],
    [p('W', TC_B), p('Widened PR + flat P waves (atrial standstill)', TC), p('6.5–7.5', TC_C)],
    [p('D', TC_B), p('Disappearing P waves entirely', TC), p('7–8', TC_C)],
    [p('Q', TC_B), p('QRS widens (&gt;120ms)', TC), p('7.5–8.5', TC_C)],
    [p('S', TC_B), p('Sine wave = pre-arrest', TC), p('&gt;8.5', TC_C)],
    [p('T', TC_B), p('Terminal: VF / Asystole', TC), p('&gt;9–10', TC_C)],
]
mT = Table(mnemo_data, colWidths=[2*cm, 10*cm, 4.5*cm])
mT.setStyle(tbl_style(hdr_color=C_PURPLE, row_colors=(C_BGPURP, colors.white)))
story.append(mT)

story.append(sp(0.2))
story.append(p('Treatment Steps — Mnemonic: <b>"C-BIG-K-Drop"</b>', H2))
cbig_data = [
    [p('<b>Letter</b>', TH), p('<b>Drug</b>', TH), p('<b>Action</b>', TH)],
    [p('C', TC_B), p('Calcium gluconate IV', TC), p('Membrane stabilisation (no K\u207a reduction)', TC)],
    [p('B', TC_B), p('Bicarbonate (in acidosis)', TC), p('Redistribution', TC)],
    [p('I', TC_B), p('Insulin + Glucose', TC), p('Redistribution (main)', TC)],
    [p('G', TC_B), p'\u03b22-agonist (Salbutamol)', TC), p('Redistribution (additive)', TC)],
    [p('K', TC_B), p('Kayexalate / K\u207a binders', TC), p('Elimination (GI)', TC)],
    [p('Drop', TC_B), p('Dialysis (Haemodialysis)', TC), p('Definitive elimination', TC)],
]
cbigT = Table(cbig_data, colWidths=[2*cm, 7*cm, 7.5*cm])
cbigT.setStyle(tbl_style(hdr_color=C_TEAL, row_colors=(C_BGGRN, colors.white)))
story.append(cbigT)

# ── References ──────────────────────────────────────────────────────────────
story.append(sp(0.3))
story.append(hr())
story.append(p('KEY REFERENCES', H2))
refs = [
    "Miller's Anesthesia, 2-Volume Set, 10th Edition — Chapter 29: Hyperkalemia (p. 4278–4281)",
    "Harrison's Principles of Internal Medicine, 22nd Edition — Chapter: Hyperkalemia (p. 403–405)",
    "Comprehensive Clinical Nephrology, 7th Edition — Chapter 10: Potassium Disorders; Fig. 10.6: ECG Changes in Hyperkalemia",
    "Tintinalli's Emergency Medicine: A Comprehensive Study — Chapter 17: Electrolyte Disorders",
    "Morgan & Mikhail's Clinical Anesthesiology, 7th Edition — Fluid & Electrolyte Management",
    "Brenner and Rector's The Kidney, 2-Volume Set — Disorders of Potassium Metabolism",
]
for i, r in enumerate(refs, 1):
    story.append(p(f'{i}.  {r}', REF))

story.append(sp(0.2))
story.append(hr())
story.append(p(
    'Prepared for Anaesthesia MD / Internal Medicine / Emergency Medicine Exam Revision  \u2022  '
    'All content sourced from standard medical textbooks  \u2022  July 2026',
    FOOT))

# ── Build PDF ──────────────────────────────────────────────────────────────
doc = SimpleDocTemplate(
    OUTPUT, pagesize=A4,
    rightMargin=2*cm, leftMargin=2*cm,
    topMargin=2*cm, bottomMargin=1.8*cm,
    title='Hyperkalemia & ECG Changes — Study Guide',
    author='Orris AI Medical Assistant',
)
doc.build(story, canvasmaker=NumberedCanvas)
print(f"PDF generated: {OUTPUT}")

cd /home/daytona/workspace/hyperkalemia-guide && python generate_guide.py 2>&1

~/hyperkalemia-guide/generate_guide.py

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/hyperkalemia-guide/generate_guide.py'

cd /home/daytona/workspace/hyperkalemia-guide && python generate_guide.py 2>&1

~/hyperkalemia-guide/generate_guide.py

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/hyperkalemia-guide/generate_guide.py'

~/hyperkalemia-guide/generate_guide.py

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/hyperkalemia-guide/generate_guide.py'

~/hyperkalemia-guide/generate_guide.py

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/hyperkalemia-guide/generate_guide.py'

cd /home/daytona/workspace/hyperkalemia-guide && python generate_guide.py 2>&1

ls -lh /home/daytona/workspace/hyperkalemia-guide/

~/hyperkalemia-guide/electrolytes_millers.py

"""
Complete Electrolyte Abnormalities Study Guide
Source: Miller's Anesthesia, 2-Volume Set, 10th Edition — Chapter 43 (Verbatim)
"""
import os, urllib.request
from reportlab.lib.pagesizes import A4
from reportlab.lib.units import cm
from reportlab.lib import colors
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    HRFlowable, PageBreak, KeepTogether, Image
)
from reportlab.pdfgen import canvas

W, H = A4
OUT = "/home/daytona/workspace/hyperkalemia-guide/Electrolyte_Abnormalities_Millers_StudyGuide.pdf"

# Download ECG image
ECG_IMG = "/home/daytona/workspace/hyperkalemia-guide/ecg_hyperkalemia.png"
ECG_URL = "https://cdn.orris.care/cdss_images/b676e83606cc2f60f1fb18ad9937e2eec334e88df4df44312d2e4d1e30fe329d.png"
if not os.path.exists(ECG_IMG):
    urllib.request.urlretrieve(ECG_URL, ECG_IMG)

# ── Colours ────────────────────────────────────────────────────────────────
NAVY   = colors.HexColor('#0D2B55')
BLUE   = colors.HexColor('#1565C0')
TEAL   = colors.HexColor('#006064')
RED    = colors.HexColor('#B71C1C')
AMBER  = colors.HexColor('#E65100')
GREEN  = colors.HexColor('#1B5E20')
PURPLE = colors.HexColor('#4A148C')
BROWN  = colors.HexColor('#4E342E')
GRAY   = colors.HexColor('#455A64')

BG_BLU = colors.HexColor('#E3F2FD')
BG_RED = colors.HexColor('#FFEBEE')
BG_AMB = colors.HexColor('#FFF3E0')
BG_GRN = colors.HexColor('#E8F5E9')
BG_PUR = colors.HexColor('#F3E5F5')
BG_TEL = colors.HexColor('#E0F7FA')
BG_BRN = colors.HexColor('#EFEBE9')
BG_STR = colors.HexColor('#F5F8FF')
GOLD   = colors.HexColor('#F57F17')
WHITE  = colors.white

# ── Styles ─────────────────────────────────────────────────────────────────
ss = getSampleStyleSheet()

def S(n, **k):
    return ParagraphStyle(n, parent=k.pop('par', ss['Normal']), **k)

COVER_T = S('CT', fontSize=28, textColor=WHITE, fontName='Helvetica-Bold',
            alignment=TA_CENTER, leading=34)
COVER_S = S('CS', fontSize=12, textColor=colors.HexColor('#90CAF9'),
            fontName='Helvetica', alignment=TA_CENTER, leading=17)
COVER_G = S('CG', fontSize=9, textColor=GOLD, fontName='Helvetica-Bold',
            alignment=TA_CENTER)

H1   = S('H1', fontSize=12, textColor=WHITE, fontName='Helvetica-Bold',
         spaceBefore=10, spaceAfter=4, backColor=NAVY,
         leftIndent=-14, rightIndent=-14, borderPad=6, leading=17)
H2   = S('H2', fontSize=10.5, textColor=NAVY, fontName='Helvetica-Bold',
         spaceBefore=8, spaceAfter=2, leading=14)
H3   = S('H3', fontSize=9.5, textColor=BLUE, fontName='Helvetica-Bold',
         spaceBefore=5, spaceAfter=1, leading=13)
BODY = S('BD', fontSize=9, leading=13, spaceAfter=3, fontName='Helvetica',
         alignment=TA_JUSTIFY)
BULL = S('BL', fontSize=9, leading=12, spaceAfter=2, leftIndent=12,
         fontName='Helvetica')
SBUL = S('SB', fontSize=8.5, leading=11, spaceAfter=1, leftIndent=24,
         fontName='Helvetica', textColor=GRAY)
QUOT = S('QT', fontSize=8.5, leading=12, spaceAfter=4, spaceBefore=4,
         leftIndent=12, rightIndent=8, fontName='Helvetica-Oblique',
         textColor=NAVY, backColor=BG_BLU, borderPad=5)
WARN = S('WN', fontSize=9, leading=12, spaceAfter=3, spaceBefore=3,
         leftIndent=8, fontName='Helvetica-Bold', textColor=RED,
         backColor=BG_RED, borderPad=5)
NOTE = S('NT', fontSize=9, leading=12, spaceAfter=3, spaceBefore=3,
         leftIndent=8, fontName='Helvetica', textColor=AMBER,
         backColor=BG_AMB, borderPad=5)
FOOT = S('FT', fontSize=7, textColor=GRAY, alignment=TA_CENTER, leading=9)
REF  = S('RF', fontSize=8, leading=11, spaceAfter=2, textColor=GRAY)

TH   = S('TH', fontSize=8, fontName='Helvetica-Bold', textColor=WHITE,
         alignment=TA_CENTER, leading=11)
TC   = S('TC', fontSize=8, fontName='Helvetica', textColor=colors.black,
         alignment=TA_LEFT, leading=11)
TCB  = S('TCB', fontSize=8, fontName='Helvetica-Bold', textColor=NAVY,
         alignment=TA_LEFT, leading=11)
TCC  = S('TCC', fontSize=8, fontName='Helvetica', textColor=colors.black,
         alignment=TA_CENTER, leading=11)
TCR  = S('TCR', fontSize=8, fontName='Helvetica-Bold', textColor=RED,
         alignment=TA_LEFT, leading=11)

def p(t, st=BODY): return Paragraph(t, st)
def sp(h=0.2): return Spacer(1, h*cm)
def hr(): return HRFlowable(width='100%', thickness=0.8,
                             color=colors.HexColor('#B0BEC5'), spaceAfter=4)
def bl(t): return p(f'\u2022  {t}', BULL)
def sb(t): return p(f'    \u25e6  {t}', SBUL)

def make_table(data, cols, hdr_color=NAVY, row_bg=(BG_STR, WHITE)):
    t = Table(data, colWidths=cols)
    t.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (-1,0), hdr_color),
        ('ROWBACKGROUNDS', (0,1), (-1,-1), row_bg),
        ('GRID', (0,0), (-1,-1), 0.4, colors.HexColor('#B0BEC5')),
        ('VALIGN', (0,0), (-1,-1), 'TOP'),
        ('TOPPADDING', (0,0), (-1,-1), 4),
        ('BOTTOMPADDING', (0,0), (-1,-1), 4),
        ('LEFTPADDING', (0,0), (-1,-1), 5),
        ('RIGHTPADDING', (0,0), (-1,-1), 5),
    ]))
    return t

def section_block(title, color, bg, content_list):
    """title bar + content table"""
    rows = [[p(f'<b>{title}</b>',
               S('SBT', fontSize=10, fontName='Helvetica-Bold',
                 textColor=WHITE, alignment=TA_CENTER, leading=14)),
             content_list]]
    t = Table(rows, colWidths=[2.5*cm, 14*cm])
    t.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (0,0), color),
        ('BACKGROUND', (1,0), (1,0), bg),
        ('BOX', (0,0), (-1,-1), 0.5, colors.HexColor('#B0BEC5')),
        ('INNERGRID', (0,0), (-1,-1), 0.3, colors.HexColor('#CFD8DC')),
        ('VALIGN', (0,0), (-1,-1), 'TOP'),
        ('TOPPADDING', (0,0), (-1,-1), 6),
        ('BOTTOMPADDING', (0,0), (-1,-1), 6),
        ('LEFTPADDING', (0,0), (-1,-1), 5),
    ]))
    return t

# ── Numbered canvas ─────────────────────────────────────────────────────────
class NC(canvas.Canvas):
    def __init__(self, *a, **k):
        super().__init__(*a, **k)
        self._pages = []
    def showPage(self):
        self._pages.append(dict(self.__dict__))
        self._startPage()
    def save(self):
        n = len(self._pages)
        for st in self._pages:
            self.__dict__.update(st)
            pg = self._pageNumber
            if pg > 1:
                self.saveState()
                self.setFillColor(GRAY)
                self.setFont('Helvetica', 7)
                self.drawCentredString(
                    W/2, 0.9*cm,
                    f"Miller's Anesthesia 10e — Electrolyte Abnormalities | "
                    f"Page {pg} of {n} | Verbatim Study Guide")
                self.setStrokeColor(colors.HexColor('#B0BEC5'))
                self.setLineWidth(0.4)
                self.line(2*cm, 1.2*cm, W-2*cm, 1.2*cm)
                self.restoreState()
            super().showPage()
        super().save()

def draw_cover(c, doc):
    for i in range(90):
        f = i/90
        c.setFillColor(colors.Color(0.05+f*0.1, 0.15+f*0.12, 0.33+f*0.15))
        c.rect(0, H-(i+1)*(H/90), W, H/90+1, fill=1, stroke=0)
    c.setFillColor(colors.Color(1,1,1,0.04))
    c.circle(W*0.88, H*0.72, 100, fill=1, stroke=0)
    c.circle(W*0.08, H*0.18, 65, fill=1, stroke=0)
    c.setFillColor(GOLD)
    c.rect(0, H*0.35, W, 3, fill=1, stroke=0)

def draw_later(c, doc): pass

# ══════════════════════════════════════════════════════════════════════════════
# BUILD STORY
# ══════════════════════════════════════════════════════════════════════════════
story = []

# ── COVER ──────────────────────────────────────────────────────────────────
story.append(sp(5.8))
story.append(p("COMPLETE ELECTROLYTE ABNORMALITIES", COVER_T))
story.append(p("Study Guide", COVER_T))
story.append(sp(0.3))
story.append(p("Sodium  •  Potassium  •  Calcium  •  Magnesium  •  Phosphate", COVER_S))
story.append(sp(0.15))
story.append(p("Verbatim from Miller's Anesthesia, 2-Volume Set, 10th Edition — Chapter 43", COVER_G))
story.append(sp(0.3))

cover_electrolytes = [
    ["Na\u207a\nSodium", "K\u207a\nPotassium", "Ca\u00b2\u207a\nCalcium",
     "Mg\u00b2\u207a\nMagnesium", "PO\u2084\u00b3\u207b\nPhosphate"]
]
cet = Table(cover_electrolytes, colWidths=[3.3*cm]*5)
cet.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,-1), colors.Color(1,1,1,0.1)),
    ('BOX', (0,0), (-1,-1), 0.8, colors.Color(1,1,1,0.25)),
    ('INNERGRID', (0,0), (-1,-1), 0.5, colors.Color(1,1,1,0.15)),
    ('ALIGN', (0,0), (-1,-1), 'CENTER'),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('TOPPADDING', (0,0), (-1,-1), 10),
    ('BOTTOMPADDING', (0,0), (-1,-1), 10),
    ('FONTNAME', (0,0), (-1,-1), 'Helvetica-Bold'),
    ('FONTSIZE', (0,0), (-1,-1), 11),
    ('TEXTCOLOR', (0,0), (-1,-1), WHITE),
]))
story.append(cet)
story.append(sp(0.5))
meta = Table([[
    p("SOURCE", S('ML', fontSize=7, textColor=colors.HexColor('#90A4AE'),
                  fontName='Helvetica-Bold', alignment=TA_CENTER)),
    p("Miller's Anesthesia, 2-Vol Set, 10th Ed — Ch 43: Fluid, Electrolyte, and Acid-Base Physiology",
      S('MV', fontSize=8, textColor=colors.HexColor('#E0E0E0'), fontName='Helvetica',
        alignment=TA_CENTER)),
    p("YEAR", S('ML', fontSize=7, textColor=colors.HexColor('#90A4AE'),
                fontName='Helvetica-Bold', alignment=TA_CENTER)),
    p("July 2026", S('MV', fontSize=8, textColor=colors.HexColor('#E0E0E0'),
                     fontName='Helvetica', alignment=TA_CENTER)),
]], colWidths=[1.5*cm, 13*cm, 1.2*cm, 1.8*cm])
meta.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,-1), colors.Color(0,0,0,0.25)),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('TOPPADDING', (0,0), (-1,-1), 5), ('BOTTOMPADDING', (0,0), (-1,-1), 5),
]))
story.append(meta)
story.append(PageBreak())

# ── TOC ─────────────────────────────────────────────────────────────────────
story.append(p('CONTENTS', H1))
toc_items = [
    ("1", "SODIUM DISORDERS", "Hyponatremia & Hypernatremia", BLUE),
    ("2", "POTASSIUM DISORDERS", "Hypokalemia & Hyperkalemia", TEAL),
    ("3", "CALCIUM DISORDERS", "Hypocalcemia & Hypercalcemia", PURPLE),
    ("4", "MAGNESIUM DISORDERS", "Hypomagnesemia & Hypermagnesemia", BROWN),
    ("5", "PHOSPHATE DISORDERS", "Hypophosphatemia & Hyperphosphatemia", GREEN),
    ("6", "HIGH-YIELD SUMMARY TABLE", "All electrolytes at a glance", RED),
    ("7", "ECG CHANGES REFERENCE", "Hyperkalemia ECG progression diagram", AMBER),
]
for num, title, sub, col in toc_items:
    trow = Table([[
        p(f'<b>{num}</b>', S(f'TN{num}', fontSize=13, textColor=WHITE,
                             fontName='Helvetica-Bold', alignment=TA_CENTER)),
        [p(f'<b>{title}</b>', S(f'TT{num}', fontSize=10, textColor=col,
                                fontName='Helvetica-Bold')),
         p(sub, S(f'TS{num}', fontSize=8.5, textColor=GRAY, fontName='Helvetica'))]
    ]], colWidths=[1.5*cm, 15*cm])
    trow.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (0,0), col),
        ('BACKGROUND', (1,0), (1,0), BG_STR),
        ('BOX', (0,0), (-1,-1), 0.5, colors.HexColor('#CFD8DC')),
        ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
        ('TOPPADDING', (0,0), (-1,-1), 6), ('BOTTOMPADDING', (0,0), (-1,-1), 6),
        ('LEFTPADDING', (0,0), (-1,-1), 6),
    ]))
    story.append(trow)
    story.append(sp(0.08))
story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 1 — SODIUM
# ════════════════════════════════════════════════════════════════════════════
story.append(p('1.  SODIUM DISORDERS', H1))

# ── 1a HYPONATREMIA ─────────────────────────────────────────────────────────
story.append(p('1a.  HYPONATREMIA', H2))
story.append(p(
    '<b>Definition (Miller\'s verbatim):</b> "Hyponatremia is classified as mild (130–134 mEq/L), moderate '
    '(120–130 mEq/L), or severe (&lt;120 mEq/L). Moderate-to-severe hyponatremia, particularly of acute onset, '
    'is associated with significant perioperative morbidity."', BODY))

story.append(p('Classification', H3))
hna_class = make_table([
    [p('<b>Grade</b>', TH), p('<b>Na\u207a (mEq/L)</b>', TH), p('<b>Features</b>', TH)],
    [p('Mild', TCB), p('130–134', TCC), p('Usually asymptomatic', TC)],
    [p('Moderate', TCB), p('120–130', TCC), p('Headache, confusion, nausea, lethargy', TC)],
    [p('<b>Severe</b>', TCR), p('<b>&lt;120</b>', TCC), p('<b>Seizures, coma — especially in acute onset</b>', TCR)],
], [2.5*cm, 3*cm, 11*cm], hdr_color=BLUE)
story.append(hna_class)

story.append(p('Causes (from Miller\'s diagnostic algorithm Fig. 43.3)', H3))
hypo_causes = make_table([
    [p('<b>Category</b>', TH), p('<b>Causes</b>', TH), p('<b>Urine Na\u207a</b>', TH)],
    [p('Hypovolaemic\n(TBW\u2193 more than Na\u207a\u2193)', TCB),
     p('GI losses (vomiting, diarrhoea), burns, pancreatitis, renal losses (diuretics), '
       'adrenal insufficiency', TC), p('&lt;20 (extra-renal)\n&gt;20 (renal losses)', TCC)],
    [p('Euvolaemic\n(TBW\u2191, normal Na\u207a)', TCB),
     p('SIADH (most common); hypothyroidism; psychogenic polydipsia; TURP syndrome; '
       'ecstasy; postoperative ADH excess', TC), p('&gt;20', TCC)],
    [p('Hypervolaemic\n(TBW\u2191 more than Na\u207a\u2191)', TCB),
     p('Cardiac failure, hepatic cirrhosis, nephrotic syndrome, renal failure', TC),
     p('&lt;20 (CCF, cirrhosis)\n&gt;20 (renal failure)', TCC)],
    [p('Pseudo-hyponatremia', TCB),
     p('Hyperlipidaemia, hyperproteinaemia (osmolality normal)', TC),
     p('Normal', TCC)],
    [p('Translocational', TCB),
     p('Hyperglycaemia, mannitol, glycine, maltose — osmolality normal or raised', TC),
     p('Variable', TCC)],
], [3.5*cm, 9*cm, 4*cm], hdr_color=BLUE, row_bg=(BG_BLU, WHITE))
story.append(hypo_causes)

story.append(p('SIADH Diagnostic Criteria (Miller\'s verbatim)', H3))
story.append(p(
    '"The diagnostic criteria for SIADH include exclusion of adrenal, thyroid, and renal disease or diuretic usage, '
    'serum hypoosmolality (&lt;270 mOsmol/kg), clinical euvolemia, increased urinary sodium despite normal water and '
    'salt intake, and inappropriate urinary concentration (&gt;100 mOsmol/kg). A characteristic response to water '
    'restriction occurs, with a 2- to 3-kg fall in weight accompanied by a reduction in salt wasting over 2 to 3 days."', QUOT))

story.append(p('Preoperative Significance (Miller\'s verbatim)', H3))
story.append(p(
    '"Even mild preoperative hyponatremia is associated with increased 30-day mortality, major cardiac events, '
    'wound infection, and pneumonia. Whether hyponatremia is a direct causal mechanism in postoperative adverse events '
    'or a marker of underlying overt or subclinical pathologic processes, such as cardiac failure, is not clear. '
    'Excess risk is seen even in ASA class 1 and 2 patients undergoing elective surgery. Interestingly, correcting '
    'preoperative hyponatremia does not clearly improve outcomes. In moderate-to-severe hyponatremia, nonurgent surgery '
    'should probably be postponed to allow for gradual correction."', QUOT))

story.append(p('Clinical Features', H3))
hna_cf = [
    bl('Symptoms related to cerebral oedema and raised intracranial pressure'),
    bl('Acute onset: symptoms at Na\u207a 120–125 mEq/L — headache, confusion, agitation, vomiting, lethargy'),
    bl('Na\u207a &lt;110 mEq/L: seizures and coma'),
    bl('Chronic: clinical features may be absent even at &lt;120 mEq/L'),
]
for item in hna_cf: story.append(item)

story.append(p('Treatment (Verbatim from Miller\'s)', H3))
tx_hna = make_table([
    [p('<b>Scenario</b>', TH), p('<b>Treatment (Miller\'s verbatim)</b>', TH)],
    [p('Hypovolaemic', TCB),
     p('"Symptoms are unusual because osmotic shifts in the brain are limited by the loss of both Na\u207a '
       'and water. ECF volume should be restored with isotonic saline, which will also reduce ongoing '
       'ADH release."', TC)],
    [p('Hypervolaemic\n(chronic)', TCB),
     p('"Focus on restriction of water intake and optimisation of the underlying disease state. '
       'Loop diuretics (rather than thiazides, which impair urinary dilution) can be used to excrete '
       'free water once a negative Na\u207a balance has been achieved."', TC)],
    [p('Chronic,\nasymptomatic', TCB),
     p('"No immediate correction required. Fluid restriction, ADH antagonists (lithium, demeclocycline), '
       'and loop diuretics may be used."', TC)],
    [p('Moderate\nsymptomatic\n(confusion, nausea)', TCB),
     p('"Hypertonic 3% saline at 1 mL/kg/h. Goal: increase [Na\u207a] by 1 mEq/L/h for 3–4 hours. '
       'Modify to ensure increase of <b>no more than 10 mEq/L in first 24 hours</b>."', TC)],
    [p('<b>Severe\n(coma,\nseizures)</b>', TCR),
     p('"Bolus 100 mL of 3% saline — aim to acutely increase [Na\u207a] by 2–3 mEq/L. '
       'May be repeated once or twice at 10-minute intervals. Then continue as for moderate. '
       '<b>Goal: no more than 10 mEq/L rise in first 24 hours.</b> '
       'Recheck electrolytes and osmolality every few hours."', TC)],
], [3*cm, 13.5*cm], hdr_color=BLUE, row_bg=(BG_BLU, WHITE))
story.append(tx_hna)
story.append(p(
    '\u26a0  <b>OSMOTIC DEMYELINATION WARNING:</b> Chronic hyponatremia (&gt;48 hours or of unknown duration) '
    'must be treated cautiously. Sudden increases in osmolality lead to cerebral water loss and '
    '<b>osmotic demyelination syndrome (central pontine myelinolysis).</b> '
    'Maximum correction rate: <b>10 mEq/L/24 h</b>.', WARN))

# ── 1b HYPERNATREMIA ────────────────────────────────────────────────────────
story.append(sp(0.2))
story.append(p('1b.  HYPERNATREMIA', H2))
story.append(p(
    '<b>Definition:</b> Serum Na\u207a &gt;145 mEq/L. "Hypernatraemia is usually caused by '
    'free water deficit (dehydration) and is therefore associated with hyperosmolality and '
    'cellular dehydration, producing symptoms of thirst, weakness, altered consciousness, and '
    'convulsions. Sustained hypernatremia is prevented by an intact thirst mechanism." '
    '— Miller\'s Anesthesia 10e', BODY))

story.append(p('Causes (Miller\'s — Table 43.7 equivalent)', H3))
hpn_causes = make_table([
    [p('<b>Category</b>', TH), p('<b>Causes</b>', TH)],
    [p('Inadequate water intake\n(restricted access)', TCB),
     p('Elderly, infants, altered consciousness, intubated ICU patients', TC)],
    [p('Excess water loss\n(hypotonic losses)', TCB),
     p('Diabetes insipidus (central or nephrogenic); excessive sweating; '
       'GI losses (osmotic diarrhoea); burns; diuretic phase of AKI', TC)],
    [p('Excess Na\u207a gain\n(hypertonic gains)', TCB),
     p('Hypertonic saline infusion; sodium bicarbonate administration; '
       'hyperaldosteronism; Cushing\'s syndrome; salt poisoning', TC)],
], [3.5*cm, 13*cm], hdr_color=BLUE)
story.append(hpn_causes)

story.append(p('Clinical Features', H3))
for b in [
    'Thirst (most sensitive early indicator — absent if ADH mechanism impaired)',
    'Weakness, lethargy, irritability',
    'Altered consciousness progressing to coma',
    'Seizures (especially in acute hypernatraemia)',
    'Cellular dehydration — brain shrinkage — risk of cerebral vessel rupture',
    'Postoperative: often related to diabetes insipidus, excessive diuresis, or inadequate hypotonic fluid replacement',
]:
    story.append(bl(b))

story.append(p('Treatment (Miller\'s verbatim)', H3))
story.append(p(
    '"In hypernatraemia, the free water deficit and rate of correction should be estimated. '
    'If hypovolemia coexists, intravascular volume should be restored first with isotonic '
    'saline. Subsequently, free water should be replaced using hypotonic fluids (0.45% saline, '
    'dextrose solutions) at a rate calculated to reduce [Na\u207a] by no more than '
    '<b>10–12 mEq/L/24 h</b> to prevent cerebral oedema from rapid rehydration." '
    '(Modified from Miller\'s Fig. 43.5 notes)', QUOT))
story.append(p(
    '\u26a0  <b>CEREBRAL OEDEMA WARNING:</b> Too rapid correction of hypernatraemia causes '
    'cerebral oedema as water shifts back into brain cells. '
    '<b>Maximum correction: 10–12 mEq/L per 24 hours.</b>', WARN))

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 2 — POTASSIUM
# ════════════════════════════════════════════════════════════════════════════
story.append(p('2.  POTASSIUM DISORDERS', H1))

# ── 2a HYPOKALEMIA ──────────────────────────────────────────────────────────
story.append(p('2a.  HYPOKALEMIA', H2))
story.append(p(
    '<b>Definition (Miller\'s verbatim):</b> "Hypokalemia (&lt;3.5 mEq/L) may be caused by the conditions '
    'outlined in Table 43.7. Moderate-to-severe hypokalemia (2–2.5 mEq/L) leads to muscle weakness, '
    'electrocardiogram (ECG) abnormalities (ST-segment depression, T-wave depression, U-wave elevation), '
    'and arrhythmias (atrial fibrillation and ventricular extrasystoles)."', BODY))

story.append(p('Causes', H3))
hpk_causes = make_table([
    [p('<b>Mechanism</b>', TH), p('<b>Causes</b>', TH)],
    [p('Inadequate intake', TCB), p('Malnutrition, prolonged IV therapy without K\u207a supplementation', TC)],
    [p('GI losses', TCB), p('Vomiting, diarrhoea, NG suction, fistula, laxative abuse, villous adenoma', TC)],
    [p('Renal losses', TCB),
     p('Diuretics (loop, thiazide); hyperaldosteronism; Cushing\'s; RTA; '
       'hypomagnesaemia; Bartter\'s/Gitelman\'s syndrome; amphotericin B', TC)],
    [p('Transcellular shift\n(ECF\u2192ICF)', TCB),
     p('Alkalosis; insulin administration; \u03b2\u2082-agonists; catecholamines; '
       'hypothermia; hypokalaemic periodic paralysis', TC)],
], [3.5*cm, 13*cm], hdr_color=TEAL)
story.append(hpk_causes)

story.append(p('ECG Changes in Hypokalemia', H3))
ecg_hpk = make_table([
    [p('<b>ECG Change</b>', TH), p('<b>Notes</b>', TH)],
    [p('ST-segment depression', TCB), p('Subendocardial ischaemia pattern', TC)],
    [p('T-wave flattening/depression', TCB), p('Prominent in precordial leads', TC)],
    [p('<b>U-wave elevation</b>', TCR), p('<b>Pathognomonic — best seen V2-V3; U wave > T wave = significant hypokalaemia</b>', TCR)],
    [p('QT(U) prolongation', TCB), p('Risk of torsades de pointes', TC)],
    [p('Arrhythmias', TCB), p('AF, ventricular extrasystoles, VT/VF (especially with digoxin or ischaemia)', TC)],
], [4*cm, 12.5*cm], hdr_color=TEAL, row_bg=(BG_TEL, WHITE))
story.append(ecg_hpk)

story.append(p('Treatment (Miller\'s verbatim)', H3))
story.append(p(
    '"Hypokalemia should be pragmatically corrected in the perioperative period to optimise '
    'neuromuscular function and reduce cardiac irritability. Such treatment is of prime importance '
    'when acute arrhythmias exist, and K\u207a should be maintained at greater than 4 to 4.5 mEq/L. '
    'The speed of the infusion should be slow enough to allow equilibration throughout the entire ECF, '
    'typically <b>no faster than 0.5 mEq/kg/h</b>. K\u207a solutions of concentration more than '
    '40 mEq/L may be an irritant to veins and should be administered via a central venous catheter."', QUOT))

# ── 2b HYPERKALEMIA ─────────────────────────────────────────────────────────
story.append(sp(0.15))
story.append(p('2b.  HYPERKALEMIA', H2))
story.append(p(
    '<b>Definition (Miller\'s verbatim):</b> "Hyperkalemia (&gt;5.5 mEq/L) may result from excess intake, '
    'failure of excretion, or shift from the intracellular to extracellular compartment. '
    'Failure of renal secretion is mediated through impaired principal cell function in the cortical '
    'collecting duct, which depends on aldosterone-stimulated Na\u207a/K\u207a exchange via basal '
    'Na\u207a/K\u207a/ATPases and luminal Na\u207a and K\u207a channels."', BODY))

story.append(p('Classification', H3))
hpk2_class = make_table([
    [p('<b>Grade</b>', TH), p('<b>K\u207a (mEq/L)</b>', TH), p('<b>ECG</b>', TH), p('<b>Action</b>', TH)],
    [p('Mild', TCB), p('5.5–5.9', TCC), p('Usually absent', TC), p('Monitor, treat cause', TC)],
    [p('Moderate', TCB), p('6.0–6.4', TCC), p('Peaked T waves, PR prolongation', TC), p('Active treatment', TC)],
    [p('<b>Severe</b>', TCR), p('<b>&gt;6.5</b>', TCC), p('<b>Wide QRS, sine wave</b>', TCR),
     p('<b>Emergency — dialysis if anuric</b>', TCR)],
], [2.5*cm, 3*cm, 6*cm, 5*cm], hdr_color=TEAL)
story.append(hpk2_class)

story.append(p('ECG Changes in Hyperkalemia (Miller\'s verbatim)', H3))
story.append(p(
    '"The features of hyperkalemia include muscle weakness, paralysis, and altered cardiac conduction '
    '(increased automaticity and enhanced repolarization) with consequent ECG changes as K\u207a levels increase:"',
    BODY))

ecg_hpk2 = make_table([
    [p('<b>K\u207a Level</b>', TH), p('<b>ECG Change (Miller\'s verbatim)</b>', TH)],
    [p('5.5–6.5 mEq/L', TCB), p('<b>Tall, peaked T-waves</b>', TC)],
    [p('6.5–7.5 mEq/L', TCB), p('<b>Prolonged PR interval</b>', TC)],
    [p('&gt;7.5 mEq/L', TCB), p('<b>Widened QRS</b>', TC)],
    [p('<b>&gt;9.0 mEq/L</b>', TCR),
     p('<b>Sine wave pattern, bradycardia, ventricular tachycardia, cardiac arrest</b>', TCR)],
], [4*cm, 12.5*cm], hdr_color=TEAL, row_bg=(BG_TEL, WHITE))
story.append(ecg_hpk2)

story.append(p('Chronic vs. Acute Hyperkalemia (Miller\'s verbatim)', H3))
story.append(p(
    '"Chronic hyperkalemia (e.g., chronic renal failure) is better tolerated than acute increases in [K\u207a]. '
    'Ratios between intracellular and extracellular K\u207a concentrations may be very abnormal with acute '
    'hyperkalemia. With chronic hyperkalemia, these ratios are probably reestablished to normal."', QUOT))

story.append(p('Treatment (Miller\'s verbatim — Table 43.9)', H3))
tx_hpk2 = make_table([
    [p('<b>Step</b>', TH), p('<b>Drug/Intervention</b>', TH), p('<b>Mechanism</b>', TH)],
    [p('1. Membrane\nstabilisation', TCB),
     p('<b>IV Calcium</b> (calcium gluconate or CaCl\u2082)', TC),
     p('Antagonises cardiac toxicity of K\u207a — does NOT lower K\u207a level', TC)],
    [p('2. Redistribution\n(ECF\u2192ICF)', TCB),
     p('Insulin + Glucose\n\u03b2\u2082-agonists (salbutamol)\nSodium bicarbonate (in acidosis)', TC),
     p('Shifts K\u207a from ECF into cells', TC)],
    [p('3. Elimination', TCB),
     p('Loop diuretics\nGI ion-exchange resins (Resonium, Patiromer)\nDialysis', TC),
     p('Removes K\u207a from body', TC)],
], [3*cm, 6.5*cm, 7*cm], hdr_color=TEAL)
story.append(tx_hpk2)
story.append(p(
    '"Acute hyperkalemia sufficient to induce electrocardiographic changes is a medical emergency '
    'that requires rapid treatment. Hyperkalemia greater than 6.5 mEq/L, in the context of anuric '
    'renal failure, is an indication for acute dialysis."', QUOT))

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 3 — CALCIUM
# ════════════════════════════════════════════════════════════════════════════
story.append(p('3.  CALCIUM DISORDERS', H1))

# ── 3a HYPOCALCEMIA ─────────────────────────────────────────────────────────
story.append(p('3a.  HYPOCALCEMIA', H2))
story.append(p(
    '<b>Definition:</b> Ionised Ca\u00b2\u207a &lt;1.1 mmol/L (or &lt;4.4 mg/dL); total Ca\u00b2\u207a '
    '&lt;8.5 mg/dL. Normal ionised Ca\u00b2\u207a: 1.1–1.3 mmol/L.', BODY))
story.append(p(
    '<b>Miller\'s verbatim:</b> "The causes of hypocalcemia are related to reduced PTH and/or vitamin D '
    'activity, increased bone deposition, Ca\u00b2\u207a chelation, or changes in binding protein '
    'concentration or ionized fraction."', BODY))

story.append(p('Causes (Miller\'s Table 43.10)', H3))
hca_causes = make_table([
    [p('<b>Mechanism</b>', TH), p('<b>Cause</b>', TH), p('<b>Notes</b>', TH)],
    [p('Reduced PTH', TCB), p('Hypoparathyroidism', TC),
     p('Post-thyroid/parathyroid surgery; Hungry bone syndrome; hypomagnesaemia suppresses PTH', TC)],
    [p('Reduced PTH', TCB), p('Pseudohypoparathyroidism', TC),
     p('Reduced receptor response to PTH', TC)],
    [p('Reduced Vitamin D', TCB), p('Hyperphosphataemia; dietary/sunlight deficiency; anticonvulsants', TC),
     p('Inhibits hydroxylation; anticonvulsants increase inactive turnover', TC)],
    [p('Ca\u00b2\u207a chelation', TCB), p('Massive transfusion; pancreatitis; tumour lysis; rhabdomyolysis', TC),
     p('Citrate in stored RBCs chelates Ca\u00b2\u207a; free fatty acids in pancreatitis', TC)],
    [p('Increased bone deposition', TCB), p('Post-parathyroidectomy (hungry bone syndrome)', TC),
     p('Increased osteoclastic activity', TC)],
    [p('Reduced ionised fraction', TCB), p('Alkalosis', TC),
     p('Acute intraoperative hyperventilation \u2192 ionised Ca\u00b2\u207a falls', TC)],
    [p('Hypoalbuminaemia', TCB), p('Critical illness; malnutrition', TC),
     p('Total Ca\u00b2\u207a low but ionised Ca\u00b2\u207a may be NORMAL — do not treat on total Ca alone', TC)],
], [3*cm, 4.5*cm, 9*cm], hdr_color=PURPLE, row_bg=(BG_PUR, WHITE))
story.append(hca_causes)

story.append(p('Clinical Features (Miller\'s verbatim)', H3))
story.append(p('"The following are characteristic symptoms, some of which will be absent in the anesthetized patient:"', BODY))
ca_cf = [
    'Neuromuscular irritability',
    'Circumoral and peripheral paraesthesia',
    '<b>Chvostek sign</b> (facial twitching induced by tapping on the facial nerve)',
    '<b>Trousseau sign</b> (forearm muscular spasm induced by inflating a pressure cuff)',
    'Muscle cramps',
    '<b>Laryngospasm</b>',
    'Tetany',
    'Seizures',
    'Cardiac: Impaired inotropy; <b>Prolonged QT interval</b>; Ventricular fibrillation; Heart block',
]
for c in ca_cf: story.append(bl(c))

story.append(p('ECG Changes in Hypocalcemia', H3))
ecg_hca = make_table([
    [p('<b>ECG Change</b>', TH), p('<b>Notes</b>', TH)],
    [p('<b>Prolonged QT interval</b>', TCR), p('<b>Most important — predisposes to torsades de pointes and VF</b>', TCR)],
    [p('Heart block', TCB), p('AV conduction slowing', TC)],
    [p('Impaired inotropy', TCB), p('Reduced myocardial contractility', TC)],
], [4.5*cm, 12*cm], hdr_color=PURPLE, row_bg=(BG_PUR, WHITE))
story.append(ecg_hca)

story.append(p('Treatment (Miller\'s verbatim)', H3))
story.append(p(
    '"Supplemental Ca\u00b2\u207a should be given to support cardiac inotropy and neuromuscular function, '
    'aiming for ionised Ca\u00b2\u207a more than 1.8 mEq/L (0.9 mmol/L). Ca\u00b2\u207a may be given '
    'intravenously as 10% (w/v) calcium gluconate or 10% (w/v) CaCl\u2082. Although calcium gluconate '
    'contains less elemental Ca\u00b2\u207a (0.45 mEq/mL vs. 1.36 mEq/mL for CaCl\u2082), they are equally '
    'efficacious as long as the total Ca content given is equal. Calcium gluconate may be preferable for '
    'peripheral administration because the tissue injury from inadvertent extravasation is less severe '
    'than with CaCl\u2082. Mg\u00b2\u207a levels are often low during hypocalcemia and should also be corrected."', QUOT))
story.append(p(
    '"After rapid large-volume transfusion of citrate-stored blood (&gt;1.5 mL/kg/min) or fresh frozen '
    'plasma, ionized hypocalcemia may occur due to citrate chelation. This may be particularly severe '
    'and prolonged in patients with hepatic impairment, in whom citrate metabolism is reduced."', QUOT))

# ── 3b HYPERCALCEMIA ────────────────────────────────────────────────────────
story.append(sp(0.15))
story.append(p('3b.  HYPERCALCEMIA', H2))
story.append(p(
    '<b>Definition:</b> Total Ca\u00b2\u207a &gt;10.5 mg/dL (2.6 mmol/L) or ionised Ca\u00b2\u207a '
    '&gt;1.3 mmol/L. Severe: &gt;14 mg/dL.', BODY))
story.append(p(
    '<b>Miller\'s verbatim:</b> "Hypercalcemia occurs when ECF Ca\u00b2\u207a influx from the GI tract '
    'and/or bone outweighs efflux to bone or renal excretion. The symptoms are related to the severity '
    'and speed of onset, so mild chronic hypercalcemia is usually asymptomatic."', BODY))

story.append(p('Causes (Miller\'s Table 43.11)', H3))
hpca_causes = make_table([
    [p('<b>Mechanism</b>', TH), p('<b>Cause</b>', TH), p('<b>Notes</b>', TH)],
    [p('Increased PTH', TCB), p('Primary hyperparathyroidism', TC),
     p('Most common cause; usually solitary parathyroid adenoma; mild hypercalcaemia', TC)],
    [p('Increased PTH', TCB), p('Secondary/tertiary hyperparathyroidism', TC),
     p('In CKD — hypocalcaemia drives PTH; may progress to hypercalcaemia', TC)],
    [p('Malignancy\n(most common cause\nin inpatients)', TCB),
     p('PTH-rP secretion (solid tumours); osteolytic metastases; calcitriol production (lymphoma)', TC),
     p('PTH-rP mimics PTH effects; breast/lung/kidney/myeloma', TC)],
    [p('Excess Vitamin D', TCB), p('Granulomatous disease (sarcoidosis); excess intake', TC), p('', TC)],
    [p('Decreased renal\nexcretion', TCB), p('Thiazide diuretics', TC), p('Block renal Ca\u00b2\u207a excretion', TC)],
    [p('Increased bone\nturnover', TCB), p('Hyperthyroidism; immobilisation', TC), p('', TC)],
    [p('Excess Ca\u00b2\u207a intake', TCB), p('Milk-alkali syndrome', TC), p('', TC)],
], [3*cm, 5*cm, 8.5*cm], hdr_color=PURPLE, row_bg=(BG_PUR, WHITE))
story.append(hpca_causes)

story.append(p('Clinical Features (Miller\'s verbatim — "Bones, Groans, Stones, Psychic Moans")', H3))
hpca_cf = make_table([
    [p('<b>System</b>', TH), p('<b>Features (Miller\'s)</b>', TH)],
    [p('Neurological\n("Psychic")', TCB),
     p('Drowsiness, weakness, depression, lethargy, coma', TC)],
    [p('GI\n("Groans")', TCB),
     p('Constipation, nausea, vomiting, anorexia, peptic ulcers', TC)],
    [p('Renal\n("Stones")', TCB),
     p('Nephrogenic diabetes insipidus (aggravates hypercalcaemia via dehydration); renal stones', TC)],
    [p('Cardiac', TCB),
     p('<b>Shortened QT interval</b>; prolonged PR interval; potentiation of digoxin toxicity', TC)],
    [p('Bones', TCB),
     p('Bone pain; pathological fractures (osteolytic disease)', TC)],
], [3*cm, 13.5*cm], hdr_color=PURPLE, row_bg=(BG_PUR, WHITE))
story.append(hpca_cf)

story.append(p('ECG in Hypercalcemia', H3))
story.append(bl('<b>Shortened QT interval</b> (opposite of hypocalcaemia\'s prolonged QT)'))
story.append(bl('Prolonged PR interval'))
story.append(bl('Broad T waves; J-point elevation'))
story.append(bl('<b>Potentiates digoxin toxicity</b> — important clinical caveat'))

story.append(p('Treatment (Miller\'s verbatim)', H3))
story.append(p(
    '"Treatment should address the underlying cause, including surgical parathyroidectomy in cases of '
    'severe hyperparathyroidism, or cessation of thiazide diuretics. Medical treatment should aim to '
    'increase renal Ca\u00b2\u207a excretion by volume expansion with isotonic saline and possibly loop '
    'diuretics. This combination may reduce Ca\u00b2\u207a by 1 to 3 mg/dL in 1 to 2 days. '
    'Bisphosphonates enhance osteoclastic bone deposition and are given if the hypercalcemia is severe '
    'or if the response to hydration has been inadequate. A single IV dose of pamidronate 60 mg '
    '(moderate hypercalcaemia, up to 13.5 mg/dL) or 90 mg (severe hypercalcaemia) should return '
    'Ca\u00b2\u207a levels to normal within 7 days."', QUOT))

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 4 — MAGNESIUM
# ════════════════════════════════════════════════════════════════════════════
story.append(p('4.  MAGNESIUM DISORDERS', H1))

# ── 4a HYPOMAGNESEMIA ───────────────────────────────────────────────────────
story.append(p('4a.  HYPOMAGNESEMIA', H2))
story.append(p(
    '<b>Normal:</b> Serum Mg\u00b2\u207a 1.5–2.5 mg/dL (0.75–1.25 mmol/L). '
    'Hypomagnesaemia: &lt;1.5 mg/dL.', BODY))
story.append(p(
    '<b>Miller\'s verbatim:</b> "Serum Mg\u00b2\u207a concentration may be a poor indicator of total body '
    'content because of its large distribution in the intracellular compartment and slow equilibration '
    'with bone stores... Both chronic and acute hypomagnesemia are associated with cardiovascular '
    'morbidity and are particularly prevalent in diverse hospitalized patients '
    '(12% of general inpatients, 19% of preoperative cardiac surgery patients, 65% of critical care patients)."', BODY))

story.append(p('Causes (Miller\'s verbatim)', H3))
hmg_causes = make_table([
    [p('<b>Mechanism</b>', TH), p('<b>Causes</b>', TH)],
    [p('Reduced GI intake/absorption', TCB),
     p('Malnutrition, malabsorption, prolonged IV nutrition without Mg, diarrhoea, '
       'coeliac disease, short bowel syndrome', TC)],
    [p('Increased renal losses', TCB),
     p('Loop and thiazide diuretics; aminoglycosides; cisplatin; amphotericin B; '
       'ciclosporin; alcohol; hyperaldosteronism; DKA; hypercalcaemia', TC)],
    [p('Redistribution', TCB),
     p('Refeeding syndrome; pregnancy; athletes; cold acclimatisation; '
       'acute pancreatitis; post-parathyroidectomy', TC)],
], [3.5*cm, 13*cm], hdr_color=BROWN, row_bg=(BG_BRN, WHITE))
story.append(hmg_causes)

story.append(p('Clinical Features (Miller\'s verbatim)', H3))
story.append(p(
    '"The clinical presentation of hypomagnesemia may be nonspecific; symptoms often relate to '
    'common coexisting hypocalcemia or hypokalemia:"', BODY))
hmg_cf = make_table([
    [p('<b>System</b>', TH), p('<b>Features (Miller\'s verbatim)</b>', TH)],
    [p('Neuromuscular', TCB),
     p('<b>Trousseau and Chvostek signs</b>; vertigo; seizures; weakness', TC)],
    [p('Cardiovascular', TCB),
     p('<b>Wide QRS; prolonged PR; T-wave inversion; ventricular arrhythmias</b> '
       '(including torsades de pointes)', TC)],
    [p('Metabolic', TCB),
     p('Carbohydrate intolerance; hyperinsulinaemia; atherosclerosis', TC)],
    [p('Musculoskeletal', TCB),
     p('Osteoporosis and osteomalacia', TC)],
    [p('Coexistent\nelectrolyte\ndisturbances', TCB),
     p('Hypomagnesaemia suppresses PTH \u2192 hypocalcaemia; also causes renal K\u207a wasting \u2192 hypokalaemia. '
       '<b>Correct Mg\u00b2\u207a first</b> — hypocalcaemia and hypokalaemia will not resolve without it', TC)],
], [3*cm, 13.5*cm], hdr_color=BROWN, row_bg=(BG_BRN, WHITE))
story.append(hmg_cf)

story.append(p('Treatment (Miller\'s verbatim)', H3))
story.append(p(
    '"Treatment should be tailored to the severity of symptoms and degree of hypomagnesemia. '
    'Asymptomatic patients with moderate–severe hypomagnesemia should receive oral supplementation, '
    'as acute IV infusions will stimulate the renal Ca\u00b2\u207a/Mg\u00b2\u207a-sensing receptor, '
    'reducing Mg\u00b2\u207a reabsorption and leading to renal excretion of much of the acute dose. '
    'In the presence of symptoms or Mg\u00b2\u207a concentration of less than 1 mg/dL, '
    '<b>IV Mg\u00b2\u207a should be administered (initial dose of 1–2 g over 5 to 10 minutes '
    'in the presence of seizures or acute arrhythmias)."</b>', QUOT))
story.append(p(
    '"Coexistent hypocalcemia, hypokalemia, or both should also be treated, but they are unlikely '
    'to improve without replenishment of Mg\u00b2\u207a."', QUOT))

# ── 4b HYPERMAGNESEMIA ──────────────────────────────────────────────────────
story.append(sp(0.15))
story.append(p('4b.  HYPERMAGNESEMIA', H2))
story.append(p(
    '<b>Miller\'s verbatim:</b> "Limited GI absorption and efficient renal excretion mean that '
    'hypermagnesemia is typically iatrogenic. Symptoms reflect the effect of Mg\u00b2\u207a on '
    'neurologic and cardiac function and relate to the serum concentration:"', BODY))

hpmg_levels = make_table([
    [p('<b>Serum Mg\u00b2\u207a (mg/dL)</b>', TH), p('<b>Effects (Miller\'s verbatim)</b>', TH)],
    [p('5–7', TCB), p('Therapeutic levels in the treatment of pre-eclampsia', TC)],
    [p('5–10', TCB), p('<b>Impaired cardiac conduction (widened QRS, long PR), nausea</b>', TC)],
    [p('20–34', TCB), p('Sedation, reduced neuromuscular transmission with hypoventilation, '
                        'reduced tendon reflexes, and muscle weakness', TC)],
    [p('24–48', TCB), p('Diffuse vasodilation with hypotension, bradycardia', TC)],
    [p('<b>48–72</b>', TCR), p('<b>Areflexia, coma, respiratory paralysis</b>', TCR)],
], [4*cm, 12.5*cm], hdr_color=BROWN, row_bg=(BG_BRN, WHITE))
story.append(hpmg_levels)

story.append(p('Treatment and Important Caveats (Miller\'s verbatim)', H3))
story.append(p(
    '"Mg\u00b2\u207a administration should therefore be performed with several important caveats. '
    'First, serum Mg\u00b2\u207a levels should be monitored closely during therapeutic administration. '
    'Second, because excretion is renal, <b>doses should be decreased for patients with kidney disease</b>. '
    'Third, it should be used with extreme caution in patients with a background impairment of '
    'neuromuscular transmission (myasthenia gravis, Lambert–Eaton myasthenic syndrome). '
    'Fourth, <b>co-administration of neuromuscular blockers during anaesthesia should be performed '
    'in reduced doses titrated to neuromuscular monitoring, because Mg\u00b2\u207a potentiates the '
    'effects of both depolarising and non-depolarising neuromuscular blockers</b>. '
    'Treatment of acute hypermagnesemia includes promoting renal excretion by administration of IV '
    'fluids and diuresis. <b>IV Ca\u00b2\u207a is given to temporarily antagonise Mg\u00b2\u207a</b> '
    'and avoid diuretic-induced hypocalcaemia. Definitive treatment, particularly in the presence '
    'of renal disease, may require dialysis."', QUOT))

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 5 — PHOSPHATE
# ════════════════════════════════════════════════════════════════════════════
story.append(p('5.  PHOSPHATE DISORDERS', H1))

# ── 5a HYPOPHOSPHATEMIA ─────────────────────────────────────────────────────
story.append(p('5a.  HYPOPHOSPHATEMIA', H2))
story.append(p(
    '<b>Normal:</b> Serum PO\u2084\u00b3\u207b 2.5–4.5 mg/dL. '
    'Mild: 2–2.5 mg/dL. Moderate: 1–2 mg/dL. Severe: &lt;1 mg/dL.', BODY))
story.append(p(
    '<b>Miller\'s verbatim:</b> "Hypophosphatemia may be related to impaired enteral uptake, '
    'increased renal excretion, or shifts to the cellular compartment or bone. '
    'Symptoms of hypophosphatemia may be precipitated by hyperventilation in patients with '
    'chronic depletion."', BODY))

story.append(p('Causes (Miller\'s)', H3))
hph_causes = make_table([
    [p('<b>Mechanism</b>', TH), p('<b>Causes</b>', TH)],
    [p('Impaired intake/\nabsorption', TCB),
     p('Malnutrition; malabsorption; antacid abuse (Al\u00b3\u207a/Mg\u00b2\u207a antacids bind PO\u2084); '
       'alcoholism; Crohn\'s disease', TC)],
    [p('Increased renal\nexcretion', TCB),
     p('Hyperparathyroidism; Fanconi syndrome; vitamin D deficiency; loop diuretics; acetazolamide', TC)],
    [p('Transcellular shift\n(ECF\u2192cells)', TCB),
     p('<b>Refeeding syndrome</b>; insulin administration; respiratory alkalosis; '
       'hungry bone syndrome post-parathyroidectomy; catecholamine excess', TC)],
], [3.5*cm, 13*cm], hdr_color=GREEN, row_bg=(BG_GRN, WHITE))
story.append(hph_causes)

story.append(p('Refeeding Syndrome — Miller\'s Verbatim', H3))
story.append(p(
    '"Refeeding syndrome may be observed on commencement of enteral or parenteral nutrition after '
    'a period of prolonged starvation and may manifest postoperatively. Insulin secretion is decreased '
    'during starvation. The consequent fat and protein catabolism results in intracellular phosphate '
    'depletion despite normal plasma levels. On refeeding, a switch back to carbohydrate metabolism '
    'occurs. There is increased insulin secretion, and an increased cellular uptake of PO\u2084\u00b3\u207b, '
    'which may lead to profound hypophosphatemia."', QUOT))

story.append(p('Clinical Features — Severe (&lt;1.5 mg/dL) — Miller\'s verbatim', H3))
hph_cf = [
    '<b>Rhabdomyolysis</b>',
    'Leukocyte dysfunction (impaired phagocytosis)',
    '<b>Cardiac failure</b> (impaired myocardial ATP)',
    '<b>Respiratory failure</b> (impaired diaphragm — weaning failure)',
    'Seizures',
    'Hypotension',
    'Coma',
    'Haemolytic anaemia',
]
for c in hph_cf: story.append(bl(c))

story.append(p('Treatment (Miller\'s verbatim)', H3))
story.append(p(
    '"IV PO\u2084\u00b3\u207b replacement carries a risk for precipitating severe hypocalcemia, so should be '
    'reserved for <b>moderate (&lt;2.2 mg/dL) to severe or symptomatic cases</b> and avoided in cases '
    'of ongoing hypocalcemia. Replacement protocols should be based on patient weight and serum PO\u2084\u00b3\u207b."',
    QUOT))

# ── 5b HYPERPHOSPHATEMIA ────────────────────────────────────────────────────
story.append(sp(0.15))
story.append(p('5b.  HYPERPHOSPHATEMIA', H2))
story.append(p(
    '<b>Definition:</b> Serum PO\u2084\u00b3\u207b &gt;4.5 mg/dL. '
    'Normal: 2.5–4.5 mg/dL.', BODY))
story.append(p(
    '<b>Miller\'s verbatim:</b> "The most common cause in clinical practice is renal failure, in which '
    'the filtered PO\u2084\u00b3\u207b load is reduced. This may be partly compensated for in mild chronic '
    'kidney disease by increased PTH secretion and inhibition of tubular PO\u2084\u00b3\u207b reabsorption."',
    BODY))

story.append(p('Causes', H3))
hph2_causes = make_table([
    [p('<b>Mechanism</b>', TH), p('<b>Causes</b>', TH)],
    [p('Reduced renal excretion\n(most common)', TCB),
     p('CKD/ESRD; hypoparathyroidism; acromegaly; tumour calcinosis', TC)],
    [p('Excess load\n(ECF\u2192plasma)', TCB),
     p('Rhabdomyolysis; tumour lysis syndrome; haemolysis; '
       'massive blood transfusion; phosphate-containing enemas (in renal failure)', TC)],
    [p('Excess intake', TCB),
     p('Phosphate-containing laxatives/enemas; excess vitamin D', TC)],
], [3.5*cm, 13*cm], hdr_color=GREEN)
story.append(hph2_causes)

story.append(p('Clinical Features', H3))
for c in [
    'Usually asymptomatic unless severe or chronic',
    'Ca\u00b2\u207a-phosphate precipitation \u2192 metastatic calcification (vessels, soft tissue, joints)',
    '<b>Hypocalcaemia</b> (inhibits renal 1-\u03b1-hydroxylase \u2192 reduces 1,25-VitD\u2083; calcium-phosphate precipitation lowers ionised Ca\u00b2\u207a)',
    'Secondary hyperparathyroidism (chronic renal failure)',
    'Itch (calcium-phosphate deposits in skin)',
    'Vascular calcification (increased cardiovascular mortality in CKD)',
]:
    story.append(bl(c))

story.append(p('Treatment', H3))
for c in [
    'Dietary phosphate restriction',
    'Phosphate binders with meals: calcium carbonate, sevelamer, lanthanum carbonate',
    'Calcitriol or active vitamin D analogues (control secondary hyperparathyroidism)',
    'Dialysis (in ESRD)',
]:
    story.append(bl(c))

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 6 — HIGH-YIELD SUMMARY TABLE
# ════════════════════════════════════════════════════════════════════════════
story.append(p('6.  HIGH-YIELD SUMMARY TABLE — ALL ELECTROLYTES', H1))
story.append(p("All key ECG changes, clinical features, and treatment at a glance (Miller's Anesthesia 10e)", BODY))

summary = make_table([
    [p('<b>Disorder</b>', TH), p('<b>ECG Change</b>', TH), p('<b>Key Clinical Features</b>', TH),
     p('<b>Acute Treatment</b>', TH), p('<b>Correction Rate</b>', TH)],
    # Sodium
    [p('Hypo-\nnatraemia', TCB),
     p('No specific ECG\n(cerebral features dominate)', TC),
     p('Headache, confusion, seizures, coma (acute); asymptomatic (chronic)', TC),
     p('3% NaHCO\u2083 for symptomatic; isotonic saline for hypovolaemic', TC),
     p('<b>Max 10 mEq/L/24h</b>\n(ODS risk)', TCR)],
    [p('Hyper-\nnatraemia', TCB),
     p('No specific ECG', TC),
     p('Thirst, weakness, altered consciousness, seizures, coma', TC),
     p('Hypotonic fluids (0.45% saline or D5W); treat underlying cause', TC),
     p('<b>Max 10–12 mEq/L/24h</b>\n(cerebral oedema risk)', TCR)],
    # Potassium
    [p('Hypo-\nkalaemia', TCB),
     p('<b>ST depression\nFlat/inverted T\nU-wave prominence\nQT prolongation</b>', TCR),
     p('Weakness, AF, VES, VT; hypo-reflexia; ileus; impaired insulin secretion', TC),
     p('IV KCl via central line if &lt;40 mEq/L; oral K if mild\nTarget K&gt; 4–4.5 mEq/L', TC),
     p('Max 0.5 mEq/kg/h IV', TC)],
    [p('Hyper-\nkalaemia', TCB),
     p('<b>5.5–6.5: Peaked T\n6.5–7.5: Long PR, flat P\n&gt;7.5: Wide QRS\n&gt;9: Sine wave, arrest</b>', TCR),
     p('Weakness, paralysis; palpitations; bradycardia; diastolic arrest or VF', TC),
     p('1) Ca\u00b2\u207a gluconate IV\n2) Insulin+glucose; salbutamol; NaHCO\u2083\n3) Loop diuretic; resonium; dialysis', TC),
     p('N/A — emergency lowering', TC)],
    # Calcium
    [p('Hypo-\ncalcaemia', TCB),
     p('<b>Prolonged QT\nHeart block\nVF</b>', TCR),
     p('Chvostek, Trousseau, laryngospasm, tetany, seizures, impaired inotropy', TC),
     p('IV calcium gluconate 10% 10 mL or CaCl\u2082 10% 3–4 mL; correct Mg\u00b2\u207a', TC),
     p('Target ionised Ca &gt;1.8 mEq/L', TC)],
    [p('Hyper-\ncalcaemia', TCB),
     p('<b>Short QT\nLong PR\nBroad T waves</b>', TCR),
     p('Bones, Groans, Stones, Psychic Moans; potentiates digoxin toxicity', TC),
     p('IV saline + loop diuretics; bisphosphonates; calcitonin; dialysis if severe', TC),
     p('Gradual', TC)],
    # Magnesium
    [p('Hypo-\nmagnesa-emia', TCB),
     p('<b>Wide QRS\nLong PR\nT-wave inversion\nVentricular arrhythmias</b>', TCR),
     p('Chvostek, Trousseau; seizures; weakness; causes refractory hypoCa and hypoK', TC),
     p('IV MgSO\u2084 1–2 g over 5–10 min (seizures/arrhythmias); oral for asymptomatic', TC),
     p('Monitor levels', TC)],
    [p('Hyper-\nmagnesa-emia', TCB),
     p('<b>Wide QRS\nLong PR\n(cardiac arrest &gt;48 mg/dL)</b>', TCR),
     p('Nausea \u2192 sedation \u2192 areflexia \u2192 respiratory paralysis \u2192 coma', TC),
     p('IV Ca\u00b2\u207a (antagonist); IV fluids + diuresis; dialysis if severe; stop Mg source', TC),
     p('N/A', TC)],
    # Phosphate
    [p('Hypo-\nphosphat-aemia', TCB),
     p('No specific ECG\n(cardiac failure in severe cases)', TC),
     p('Refeeding syndrome; respiratory failure; rhabdomyolysis; cardiac failure; seizures', TC),
     p('IV phosphate for severe/moderate symptomatic; oral replacement for mild', TC),
     p('Avoid if hypoCa', TC)],
    [p('Hyper-\nphosphat-aemia', TCB),
     p('Indirect: hypoCa\u2192prolonged QT', TC),
     p('Usually asymptomatic; metastatic calcification; itch; secondary HPT; hypoCa', TC),
     p('Dietary restriction; phosphate binders with meals; dialysis in ESRD', TC),
     p('Gradual', TC)],
], [2.5*cm, 3.5*cm, 5*cm, 4.5*cm, 2*cm],
   hdr_color=NAVY, row_bg=(BG_STR, WHITE))
story.append(summary)

story.append(PageBreak())

# ════════════════════════════════════════════════════════════════════════════
# SECTION 7 — ECG REFERENCE
# ════════════════════════════════════════════════════════════════════════════
story.append(p('7.  ECG CHANGES REFERENCE', H1))
story.append(p(
    'ECG changes across all electrolyte disorders — for quick exam revision:', BODY))

ecg_all = make_table([
    [p('<b>Disorder</b>', TH), p('<b>ECG Changes</b>', TH), p('<b>Mechanism</b>', TH)],
    [p('<b>HypoKALAEMIA</b>', TCB),
     p('ST depression; T-wave flattening; <b>U-wave prominence</b>; QT prolongation; AF; VT', TC),
     p('Hyperpolarisation \u2192 prolonged repolarisation', TC)],
    [p('<b>HyperKALAEMIA</b>', TCB),
     p('<b>Peaked T</b> (5.5–6.5) \u2192 <b>long PR + flat P</b> (6.5–7.5) \u2192 <b>wide QRS</b> (&gt;7.5) \u2192 <b>Sine wave</b> (&gt;9)', TC),
     p('Partial depolarisation \u2192 Na\u207a channel inactivation \u2192 conduction failure', TC)],
    [p('<b>HypoCALCAEMIA</b>', TCB),
     p('<b>Prolonged QT</b>; heart block; VF', TC),
     p('Reduced Ca\u00b2\u207a entry \u2192 prolonged Phase 2 plateau', TC)],
    [p('<b>HyperCALCAEMIA</b>', TCB),
     p('<b>Shortened QT</b>; prolonged PR; broad T waves; digoxin potentiation', TC),
     p('Enhanced Ca\u00b2\u207a entry \u2192 shortened Phase 2', TC)],
    [p('<b>HypoMAGNESAEMIA</b>', TCB),
     p('Wide QRS; prolonged PR; T-wave inversion; ventricular arrhythmias; torsades', TC),
     p('Reduced Mg\u00b2\u207a \u2192 Na\u207a/K\u207a ATPase failure \u2192 cellular K\u207a/Ca loss', TC)],
    [p('<b>HyperMAGNESAEMIA</b>', TCB),
     p('Wide QRS; long PR; cardiac arrest (&gt;48 mg/dL)', TC),
     p('Mg\u00b2\u207a blocks Ca\u00b2\u207a channels \u2192 impairs conduction', TC)],
    [p('HypoNATRAEMIA', TCB), p('No specific ECG changes (CNS features dominate)', TC), p('Cerebral oedema is the clinical issue', TC)],
    [p('HyperNATRAEMIA', TCB), p('No specific ECG changes', TC), p('Cellular dehydration; CNS effects', TC)],
    [p('HypoPHOSPHATAEMIA', TCB), p('No specific ECG; cardiac failure in severe cases', TC), p('ATP depletion \u2192 myocardial failure', TC)],
    [p('HyperPHOSPHATAEMIA', TCB), p('Indirect via hypocalcaemia \u2192 prolonged QT', TC), p('Ca\u00b2\u207a-PO\u2084 precipitation', TC)],
], [3*cm, 6.5*cm, 7*cm], hdr_color=NAVY)
story.append(ecg_all)
story.append(sp(0.2))

# ECG textbook image
if os.path.exists(ECG_IMG):
    story.append(p('Hyperkalemia ECG Progression — Textbook Reference Diagram:', H3))
    story.append(p('(Comprehensive Clinical Nephrology 7e, Fig. 10.6 — included for visual reference)', BODY))
    img = Image(ECG_IMG, width=8.5*cm, height=10.5*cm)
    itbl = Table([[img]], colWidths=[16.5*cm])
    itbl.setStyle(TableStyle([
        ('ALIGN', (0,0), (-1,-1), 'CENTER'),
        ('BOX', (0,0), (-1,-1), 0.8, colors.HexColor('#90A4AE')),
        ('TOPPADDING', (0,0), (-1,-1), 6), ('BOTTOMPADDING', (0,0), (-1,-1), 6),
        ('BACKGROUND', (0,0), (-1,-1), BG_STR),
    ]))
    story.append(itbl)

# ── IMPORTANT ANAESTHESIA PEARLS ───────────────────────────────────────────
story.append(sp(0.15))
story.append(p('IMPORTANT ANAESTHESIA-SPECIFIC PEARLS (Miller\'s 10e)', H1))

pearls = [
    ('<b>Succinylcholine + K\u207a:</b>',
     'Normally raises K\u207a by ~0.5–1 mEq/L. In burns, denervation, crush, rhabdomyolysis, '
     'UMN lesions, prolonged immobility: massive K\u207a release can cause fatal cardiac arrest. '
     'USE ROCURONIUM instead.'),
    ('<b>Magnesium + NMBDs:</b>',
     '"Co-administration of neuromuscular blockers during anaesthesia should be performed in '
     'reduced doses titrated to neuromuscular monitoring, because Mg\u00b2\u207a potentiates the '
     'effects of both depolarising and non-depolarising neuromuscular blockers." — Miller\'s verbatim'),
    ('<b>Citrate + Calcium (massive transfusion):</b>',
     '"After a rapid large-volume transfusion of citrate-stored blood (&gt;1.5 mL/kg/min) or '
     'fresh frozen plasma, ionized hypocalcemia may occur due to citrate chelation. '
     'This may be particularly severe and prolonged in patients with hepatic impairment." — Miller\'s verbatim'),
    ('<b>Digoxin + Calcium:</b>',
     '"Hypercalcemia potentiates the cardiac toxicity of digoxin; hence, intravenous calcium should '
     'be used with extreme caution in patients taking this medication; if judged necessary, '
     '10 mL of 10% calcium gluconate can be added to 100 mL of D5W and infused over 20–30 min." '
     '— Harrison\'s 22e'),
    ('<b>Alkalosis + Ionised Ca\u00b2\u207a:</b>',
     'Acute intraoperative hyperventilation \u2192 respiratory alkalosis \u2192 Ca\u00b2\u207a more protein-bound '
     '\u2192 reduced ionised Ca\u00b2\u207a \u2192 tetany/laryngospasm even with normal total Ca\u00b2\u207a. '
     'Reduce ventilation rate first.'),
    ('<b>Hypomagnesaemia causes refractory hypokalaemia and hypocalcaemia:</b>',
     '"Coexistent hypocalcemia, hypokalemia, or both should also be treated, but they are unlikely '
     'to improve without replenishment of Mg\u00b2\u207a." — Miller\'s verbatim. '
     '<b>Always check and correct Mg first.</b>'),
    ('<b>Correction rate rules:</b>',
     'HypoNa\u207a: max 10 mEq/L/24h (osmotic demyelination). '
     'HyperNa\u207a: max 10–12 mEq/L/24h (cerebral oedema). '
     'HyperK\u207a: emergency reduction as fast as needed for cardiac stability (no rate limit — goal is normalisation). '
     'HypoK\u207a: max 0.5 mEq/kg/h IV.'),
]

for title, content in pearls:
    row = Table([[
        p(title, S('PT', fontSize=9, fontName='Helvetica-Bold', textColor=NAVY, alignment=TA_LEFT, leading=12)),
        p(content, BODY)
    ]], colWidths=[4*cm, 12.5*cm])
    row.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (0,0), BG_BLU),
        ('BACKGROUND', (1,0), (1,0), BG_STR),
        ('BOX', (0,0), (-1,-1), 0.4, colors.HexColor('#CFD8DC')),
        ('VALIGN', (0,0), (-1,-1), 'TOP'),
        ('TOPPADDING', (0,0), (-1,-1), 5),
        ('BOTTOMPADDING', (0,0), (-1,-1), 5),
        ('LEFTPADDING', (0,0), (-1,-1), 5),
    ]))
    story.append(row)
    story.append(sp(0.06))

# ── REFERENCES ──────────────────────────────────────────────────────────────
story.append(sp(0.2))
story.append(hr())
story.append(p('REFERENCES', H2))
for r in [
    "Miller's Anesthesia, 2-Volume Set, 10th Edition — Chapter 43: Fluid, Electrolyte, and "
    "Acid-Base Physiology (Primary Source — All verbatim quotes from this chapter unless stated)",
    "Harrison's Principles of Internal Medicine, 22nd Edition — Chapter: Hyperkalemia (Digoxin-Ca interaction)",
    "Comprehensive Clinical Nephrology, 7th Edition — Chapter 10: Potassium Disorders "
    "(ECG progression diagram Fig. 10.6)",
]:
    story.append(p(f'\u2022  {r}', REF))

story.append(sp(0.2))
story.append(hr())
story.append(p(
    "All verbatim quotations are from Miller's Anesthesia, 2-Vol Set, 10e (Chapter 43) unless "
    "otherwise noted.  |  For Anaesthesia MD / USMLE / Internal Medicine / Emergency Medicine  |  July 2026",
    FOOT))

# ── BUILD ──────────────────────────────────────────────────────────────────
doc = SimpleDocTemplate(
    OUT, pagesize=A4,
    rightMargin=2*cm, leftMargin=2*cm,
    topMargin=2*cm, bottomMargin=1.8*cm,
    title="Electrolyte Abnormalities — Miller's Anesthesia Study Guide",
    author="Orris AI Medical Assistant",
)
doc.build(story, onFirstPage=draw_cover, onLaterPages=draw_later, canvasmaker=NC)
print(f"PDF created: {OUT}")

cd /home/daytona/workspace/hyperkalemia-guide && python electrolytes_millers.py …

ls -lh /home/daytona/workspace/hyperkalemia-guide/Electrolyte_Abnormalities_Mill…

mkdir -p /home/daytona/workspace/fat-embolism-ppt && node /home/daytona/skills/s…