HIGH-YIELD RESPIRATORY MEDICINE NOTES

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/respiratory-notes/Respiratory_Medicine_HighYield_Notes.pdf"

# ── Styles ──────────────────────────────────────────────────────────────────
styles = getSampleStyleSheet()

NAVY   = colors.HexColor("#1a3a5c")
TEAL   = colors.HexColor("#1a7fa8")
GOLD   = colors.HexColor("#e8a020")
LIGHT  = colors.HexColor("#eaf4fb")
WHITE  = colors.white
RED    = colors.HexColor("#c0392b")
GREEN  = colors.HexColor("#1e8449")
GREY_BG = colors.HexColor("#f5f5f5")

title_style = ParagraphStyle("TitleStyle", parent=styles["Title"],
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    spaceAfter=4, fontName="Helvetica-Bold", leading=28)

subtitle_style = ParagraphStyle("SubtitleStyle", parent=styles["Normal"],
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h1_style = ParagraphStyle("H1", parent=styles["Heading1"],
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h3_style = ParagraphStyle("H3", parent=styles["Heading3"],
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body_style = ParagraphStyle("Body", parent=styles["Normal"],
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bullet_style = ParagraphStyle("Bullet", parent=body_style,
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note_style = ParagraphStyle("Note", parent=body_style,
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source_style = ParagraphStyle("Source", parent=body_style,
    fontSize=7.5, textColor=colors.grey, fontName="Helvetica-Oblique",
    alignment=TA_CENTER)

# ── Helpers ──────────────────────────────────────────────────────────────────
def section_header(num, title):
    """Navy banner with white text."""
    data = [[Paragraph(f"{num}. {title}", h1_style)]]
    t = Table(data, colWidths=[17*cm])
    t.setStyle(TableStyle([
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def sub_header(text):
    """Teal left-border heading."""
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def bullet(text):
    return Paragraph(f"• {text}", bullet_style)

def bold(text):
    return f"<b>{text}</b>"

def colored_table(header_row, data_rows, col_widths=None):
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def highlight_box(text, bg=colors.HexColor("#fff3cd"), border=GOLD):
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    ]))
    return t

sp = lambda h=6: Spacer(1, h)

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

# Cover Banner
cover_data = [[
    Paragraph("HIGH-YIELD RESPIRATORY MEDICINE NOTES", title_style),
    Paragraph("KUHS University &amp; NEET PG Preparation", subtitle_style),
    Paragraph("Based on: Harrison's Principles of Internal Medicine 22E (2025) &amp; Murray &amp; Nadel's Textbook of Respiratory Medicine", subtitle_style),
]]
cover_table = Table([[
    Paragraph("HIGH-YIELD RESPIRATORY MEDICINE NOTES", title_style),
]], colWidths=[17*cm])
cover_table.setStyle(TableStyle([
    ("BACKGROUND",    (0,0), (-1,-1), NAVY),
    ("TOPPADDING",    (0,0), (-1,-1), 18),
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    ("LEFTPADDING",   (0,0), (-1,-1), 14),
    ("RIGHTPADDING",  (0,0), (-1,-1), 14),
]))

cover_sub = Table([[
    Paragraph("KUHS University &amp; NEET PG Preparation", subtitle_style),
]], colWidths=[17*cm])
cover_sub.setStyle(TableStyle([
    ("BACKGROUND",    (0,0), (-1,-1), TEAL),
    ("TOPPADDING",    (0,0), (-1,-1), 6),
    ("BOTTOMPADDING", (0,0), (-1,-1), 6),
    ("LEFTPADDING",   (0,0), (-1,-1), 14),
    ("RIGHTPADDING",  (0,0), (-1,-1), 14),
]))
cover_sub2 = Table([[
    Paragraph("Based on: Harrison's Principles of Internal Medicine 22E (2025) | Murray &amp; Nadel's Textbook of Respiratory Medicine", subtitle_style),
]], colWidths=[17*cm])
cover_sub2.setStyle(TableStyle([
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    ("TOPPADDING",    (0,0), (-1,-1), 2),
    ("BOTTOMPADDING", (0,0), (-1,-1), 10),
    ("LEFTPADDING",   (0,0), (-1,-1), 14),
    ("RIGHTPADDING",  (0,0), (-1,-1), 14),
]))

story += [cover_table, cover_sub, cover_sub2, sp(14)]

# ============================================================
# SECTION 1: COMMUNITY-ACQUIRED PNEUMONIA
# ============================================================
story += [section_header("1", "COMMUNITY-ACQUIRED PNEUMONIA (CAP)"), sp(6)]

story += [sub_header("Definition & Classification"), sp(4)]
story += [
    bullet("Pneumonia = infection of pulmonary <b>parenchyma</b>"),
    bullet("Categories: <b>CAP</b> (community), <b>HAP</b> (hospital), <b>VAP</b> (ventilator-associated)"),
    bullet("<b>HCAP (healthcare-associated) category is discontinued</b> — assess each patient individually for drug-resistant organism risk"),
    sp(4),
]

story += [sub_header("Causative Organisms — HIGH YIELD"), sp(4)]
org_table = colored_table(
    ["Setting", "Organisms"],
    [
        ["CAP (typical)", "S. pneumoniae (MC), H. influenzae, M. catarrhalis"],
        ["CAP (atypical)", "Mycoplasma, Chlamydophila pneumoniae, Legionella"],
        ["HAP / VAP", "Pseudomonas, MRSA, Klebsiella, Gram-negative rods"],
        ["Aspiration", "Anaerobes (Fusobacterium, Peptostreptococcus)"],
        ["Alcoholics", "Klebsiella pneumoniae (currant jelly sputum)"],
        ["Immunocompromised", "PCP (P. jirovecii), CMV, fungi"],
    ],
    [6*cm, 11*cm]
)
story += [org_table, sp(6)]

story += [sub_header("CURB-65 Score — CAP Severity"), sp(4)]
story += [
    highlight_box("<b>C</b> = Confusion | <b>U</b> = Urea &gt;7 mmol/L | <b>R</b> = RR ≥30/min | <b>B</b> = BP &lt;90 systolic | <b>65</b> = Age ≥65 yrs"),
    sp(3),
]
curb_table = colored_table(
    ["Score", "Action"],
    [
        ["0–1", "Outpatient treatment"],
        ["2", "Hospitalization"],
        ["≥3", "Consider ICU admission"],
    ],
    [4*cm, 13*cm]
)
story += [curb_table, sp(6)]

story += [sub_header("Treatment"), sp(4)]
story += [
    bullet("<b>Mild CAP (outpatient):</b> Amoxicillin OR azithromycin / doxycycline"),
    bullet("<b>Moderate CAP (inpatient, non-ICU):</b> Beta-lactam + macrolide OR respiratory fluoroquinolone (levofloxacin / moxifloxacin)"),
    bullet("<b>Severe CAP (ICU):</b> Beta-lactam + azithromycin OR beta-lactam + fluoroquinolone"),
    bullet("<b>Legionella:</b> Fluoroquinolone or azithromycin"),
    bullet("<b>Aspiration site:</b> Posterior segment RUL (upright) or superior segment RLL (supine)"),
    sp(8),
]

# ============================================================
# SECTION 2: TUBERCULOSIS
# ============================================================
story += [section_header("2", "TUBERCULOSIS (TB)"), sp(6)]

story += [sub_header("Microbiology & Transmission"), sp(4)]
story += [
    bullet("M. tuberculosis — obligate aerobe, slow-growing, <b>acid-fast bacillus (AFB)</b>"),
    bullet("Transmission: <b>airborne</b> droplet nuclei (&lt;5 microns)"),
    bullet("Isolation: <b>negative-pressure room</b>, N95 respirator (filters 95% airborne particles)"),
    bullet("IGRA preferred over TST for latent TB — higher PPV, not affected by BCG vaccination"),
    sp(4),
]

story += [sub_header("Primary vs. Reactivation TB"), sp(4)]
tb_comp = colored_table(
    ["Feature", "Primary TB", "Reactivation TB"],
    [
        ["Location", "Lower / middle lobe + hilar LN", "Apices (upper lobe) — classic"],
        ["Ghon complex", "Present (Ghon focus + hilar LN)", "Absent"],
        ["Cavitation", "Rare", "Common"],
        ["Immunity", "None / little", "Present"],
    ],
    [5*cm, 6*cm, 6*cm]
)
story += [tb_comp, sp(6)]

story += [sub_header("First-Line Drug Side Effects — VERY HIGH YIELD"), sp(4)]
drug_table = colored_table(
    ["Drug", "Key Side Effects", "Monitor"],
    [
        ["Isoniazid (H)", "Peripheral neuropathy (give B6/pyridoxine), hepatitis, lupus-like", "LFT, neurology"],
        ["Rifampicin (R)", "Orange discoloration urine/tears, hepatitis, CYP450 inducer (drug interactions)", "LFT"],
        ["Pyrazinamide (Z)", "Hyperuricemia, hepatitis, arthralgia", "Uric acid, LFT"],
        ["Ethambutol (E)", "Optic neuritis (red-green color blindness, ↓visual acuity)", "Visual acuity"],
    ],
    [4*cm, 8.5*cm, 4.5*cm]
)
story += [drug_table, sp(4)]

story += [
    highlight_box("<b>Standard regimen:</b> 2HRZE / 4HR — 2 months (INH + Rifampicin + Pyrazinamide + Ethambutol), then 4 months (INH + Rifampicin)"),
    sp(4),
]

story += [sub_header("MDR-TB Treatment (WHO 2022)"), sp(4)]
mdr_table = colored_table(
    ["Group", "Drugs"],
    [
        ["Group A (all 3 included)", "Levofloxacin/Moxifloxacin + Bedaquiline + Linezolid"],
        ["Group B (at least 1)", "Clofazimine, Cycloserine/Terizidone"],
        ["Group C (complete regimen)", "Ethambutol, Delamanid, Pyrazinamide, Carbapenems, Amikacin, PAS"],
    ],
    [5*cm, 12*cm]
)
story += [mdr_table, sp(8)]

# ============================================================
# SECTION 3: ASTHMA
# ============================================================
story += [section_header("3", "ASTHMA"), sp(6)]

story += [sub_header("Definition & Pathophysiology"), sp(4)]
story += [
    bullet("Chronic <b>inflammatory</b> airway disease with <b>airway hyperresponsiveness (AHR)</b> and reversible obstruction"),
    bullet("Hallmark: episodic wheezing, dyspnea, chest tightness, cough — worse <b>nocturnal / early morning</b>"),
    bullet("Mechanism: Mast cell → histamine, leukotrienes (LTC4, LTD4, LTE4), IL-4, IL-5, IL-13 → eosinophilic type 2 inflammation"),
    bullet("Remodeling: subepithelial fibrosis, smooth muscle hypertrophy, goblet cell metaplasia"),
    sp(4),
]

story += [sub_header("Diagnosis"), sp(4)]
story += [
    bullet("Spirometry: FEV1/FVC &lt;0.70 (obstructive pattern)"),
    bullet("<b>Bronchodilator reversibility: ≥12% AND ≥200 mL increase in FEV1</b> post-bronchodilator"),
    bullet("<b>Methacholine challenge</b>: PC20 &lt;8 mg/mL = positive AHR (when spirometry is normal)"),
    bullet("Peak flow variability &gt;20% = suggestive of asthma"),
    sp(4),
]

story += [sub_header("GINA Severity Classification"), sp(4)]
sev_table = colored_table(
    ["Severity", "Symptoms", "Night symptoms", "FEV1 % predicted"],
    [
        ["Mild intermittent", "<2 days/week", "≤2/month", "≥80%"],
        ["Mild persistent", ">2 days/week, not daily", "3–4/month", "≥80%"],
        ["Moderate persistent", "Daily", ">1/week", "60–80%"],
        ["Severe persistent", "Continuous", "Frequent", "<60%"],
    ],
    [4.5*cm, 4.5*cm, 3.5*cm, 4.5*cm]
)
story += [sev_table, sp(4)]

story += [sub_header("Treatment — Step-Up Approach"), sp(4)]
step_table = colored_table(
    ["Step", "Treatment"],
    [
        ["Step 1", "As-needed SABA (salbutamol) OR low-dose ICS/formoterol PRN"],
        ["Step 2", "Low-dose ICS daily + SABA PRN"],
        ["Step 3", "Low-dose ICS/LABA daily"],
        ["Step 4", "Medium/high-dose ICS/LABA"],
        ["Step 5", "Add-on: LAMA, omalizumab (anti-IgE), mepolizumab/reslizumab (anti-IL-5), dupilumab (anti-IL-4Rα)"],
    ],
    [3*cm, 14*cm]
)
story += [step_table, sp(4)]

story += [sub_header("Key Drug Facts — HIGH YIELD"), sp(4)]
story += [
    bullet("<b>SABA (salbutamol):</b> First-line rescue; side effects — tremor, tachycardia"),
    bullet("<b>ICS (budesonide, fluticasone):</b> Local effects — thrush (use spacer + gargle), hoarseness; systemic: osteoporosis, cataracts at high doses"),
    bullet("<b>LABA (salmeterol, formoterol):</b> NOT monotherapy — risk of asthma death; always use with ICS"),
    bullet("<b>Montelukast (CysLT1 antagonist):</b> Good for aspirin-exacerbated disease and exercise-induced; side effect — suicidal ideation (black box)"),
    bullet("<b>Zileuton (5-LO inhibitor):</b> Raises liver enzymes (3%), inhibits CYP1A2"),
    bullet("<b>Omalizumab (anti-IgE):</b> IgE ≥30 IU/mL + perennial allergen sensitization; reduces exacerbations 25–50%"),
    sp(4),
]

story += [
    highlight_box("<b>Samter's Triad (Aspirin-Exacerbated Respiratory Disease):</b> Asthma + Nasal Polyps + Aspirin Sensitivity → excess leukotrienes via COX-1 inhibition"),
    sp(4),
    highlight_box("<b>Status Asthmaticus:</b> Rising PaCO2 = dangerous sign (normal PaCO2 in acute asthma = early fatigue). Tx: IV salbutamol + ipratropium, IV Mg²⁺, IV steroids"),
    sp(8),
]

# ============================================================
# SECTION 4: COPD
# ============================================================
story += [section_header("4", "COPD"), sp(6)]

story += [sub_header("Emphysema vs. Chronic Bronchitis"), sp(4)]
copd_comp = colored_table(
    ["Feature", "Emphysema", "Chronic Bronchitis"],
    [
        ["Definition", "Destruction of alveolar walls", "Productive cough ≥3 months/yr × ≥2 yrs"],
        ["Mechanism", "Elastase-antielastase imbalance", "Mucous gland hypertrophy (Reid index >0.5)"],
        ["Body habitus", "Pink puffer (barrel chest, thin)", "Blue bloater (edematous, cyanotic)"],
        ["PaO2 / PaCO2", "Near normal / Low CO2", "Low O2 / High CO2"],
        ["Breath sounds", "Diminished throughout", "Ronchi / wheezing"],
        ["DLCO", "Reduced", "Normal or mildly reduced"],
    ],
    [4.5*cm, 6.25*cm, 6.25*cm]
)
story += [copd_comp, sp(6)]

story += [sub_header("GOLD Staging (Post-Bronchodilator FEV1/FVC <0.70)"), sp(4)]
gold_table = colored_table(
    ["GOLD Grade", "Severity", "FEV1 % Predicted"],
    [
        ["GOLD 1", "Mild", "≥80%"],
        ["GOLD 2", "Moderate", "50–79%"],
        ["GOLD 3", "Severe", "30–49%"],
        ["GOLD 4", "Very Severe", "<30%"],
    ],
    [4*cm, 6*cm, 7*cm]
)
story += [gold_table, sp(6)]

story += [sub_header("Treatment — Survival-Improving Interventions"), sp(4)]
story += [
    highlight_box("<b>Three interventions proven to improve survival in COPD:</b><br/>1. Smoking cessation (MOST IMPORTANT) | 2. Long-term O₂ therapy (PaO₂ ≤55 mmHg or SpO₂ ≤88%) | 3. Lung volume reduction surgery (LVRS) in selected emphysema"),
    sp(4),
]
story += [
    bullet("<b>LAMA</b> (tiotropium, aclidinium, glycopyrronium, umeclidinium) — reduces exacerbations more than LABA"),
    bullet("<b>LABA</b> (salmeterol, indacaterol, formoterol, vilanterol)"),
    bullet("<b>LABA + LAMA</b> combination &gt; either alone"),
    bullet("<b>Triple therapy</b> (LABA + LAMA + ICS) — reduces mortality in selected patients"),
    bullet("<b>Roflumilast</b> (PDE4 inhibitor): frequent exacerbators with chronic bronchitis phenotype; side effects — weight loss, nausea, depression"),
    bullet("<b>Azithromycin maintenance</b>: reduces exacerbations; check QT prolongation and hearing"),
    bullet("<b>Controlled O₂</b> in AECOPD: target SpO₂ 88–92% to avoid CO₂ retention"),
    sp(4),
]

story += [sub_header("Alpha-1 Antitrypsin Deficiency"), sp(4)]
story += [
    bullet("MC genetic cause of COPD — <b>panacinar emphysema (lower lobe predominant)</b>"),
    bullet("PiZZ genotype = severe deficiency; also causes liver disease (cirrhosis)"),
    bullet("Treatment: AAT augmentation therapy"),
    sp(8),
]

# ============================================================
# SECTION 5: PULMONARY EMBOLISM
# ============================================================
story += [section_header("5", "PULMONARY EMBOLISM (PE)"), sp(6)]

story += [sub_header("Virchow's Triad"), sp(4)]
story += [
    highlight_box("<b>1. Stasis</b> (immobility, post-op, travel) | <b>2. Hypercoagulability</b> (malignancy, APS, OCP, pregnancy, thrombophilia) | <b>3. Endothelial injury</b> (surgery, trauma)"),
    sp(4),
]

story += [sub_header("Investigations — HIGH YIELD"), sp(4)]
pe_inv = colored_table(
    ["Test", "Finding / Role"],
    [
        ["ECG", "S1Q3T3 (deep S in I, Q in III, inverted T in III); sinus tachycardia most common"],
        ["D-dimer", "High sensitivity, low specificity — RULES OUT PE (high NPV) when negative"],
        ["CTPA", "GOLD STANDARD for diagnosis"],
        ["V/Q scan", "Use when CTPA contraindicated (contrast allergy, renal failure)"],
        ["Echo", "Dilated RV, McConnell sign (apical sparing of RV)"],
        ["ABG", "Hypoxemia + hypocapnia + respiratory alkalosis + increased A-a gradient"],
    ],
    [4.5*cm, 12.5*cm]
)
story += [pe_inv, sp(4)]

story += [sub_header("Wells Score"), sp(4)]
wells_table = colored_table(
    ["Criterion", "Points"],
    [
        ["DVT symptoms/signs", "3"],
        ["PE most likely diagnosis", "3"],
        ["HR >100/min", "1.5"],
        ["Immobilization/surgery in past 4 weeks", "1.5"],
        ["Prior DVT/PE", "1.5"],
        ["Hemoptysis", "1"],
        ["Malignancy", "1"],
        ["Score ≤4 = PE unlikely | Score >4 = PE likely", ""],
    ],
    [13*cm, 4*cm]
)
story += [wells_table, sp(4)]

story += [sub_header("Treatment"), sp(4)]
story += [
    bullet("<b>Anticoagulation:</b> DOACs (rivaroxaban, apixaban, edoxaban) preferred over LMWH/warfarin"),
    bullet("<b>Massive PE (hemodynamically unstable):</b> Systemic thrombolysis (alteplase); catheter-directed thrombolysis; surgical embolectomy"),
    bullet("<b>IVC filter:</b> When anticoagulation is contraindicated"),
    sp(8),
]

# ============================================================
# SECTION 6: PLEURAL EFFUSION
# ============================================================
story += [section_header("6", "PLEURAL EFFUSION"), sp(6)]

story += [sub_header("Light's Criteria — VERY HIGH YIELD"), sp(4)]
story += [
    highlight_box("<b>Exudate if ≥1 criterion met:</b><br/>1. Pleural fluid protein / serum protein &gt;0.5<br/>2. Pleural fluid LDH / serum LDH &gt;0.6<br/>3. Pleural fluid LDH &gt; 2/3 upper limit of normal serum LDH"),
    sp(4),
]

story += [sub_header("Transudate vs. Exudate"), sp(4)]
eff_table = colored_table(
    ["Feature", "Transudate", "Exudate"],
    [
        ["Mechanism", "Hydrostatic/oncotic imbalance", "Local inflammation / injury"],
        ["Causes", "CHF (MC in USA), cirrhosis, nephrotic syndrome", "Pneumonia, malignancy, TB, PE"],
        ["Glucose", "Normal", "May be low (TB, malignancy, empyema)"],
        ["LDH", "Low", "High"],
    ],
    [4.5*cm, 6.25*cm, 6.25*cm]
)
story += [eff_table, sp(4)]

story += [sub_header("Special Effusions"), sp(4)]
special_eff = colored_table(
    ["Type", "Key Features"],
    [
        ["Empyema", "Pus; pH <7.2, glucose <60, very high LDH; mandates drainage (intercostal tube)"],
        ["Chylothorax", "Milky; triglycerides >110 mg/dL; caused by thoracic duct injury (trauma, malignancy)"],
        ["Hemothorax", "Hematocrit >50% of serum; trauma most common"],
        ["TB pleuritis", "Exudate; lymphocyte-predominant; ADA >40 IU/L (high sensitivity for TB)"],
    ],
    [4.5*cm, 12.5*cm]
)
story += [special_eff, sp(8)]

# ============================================================
# SECTION 7: LUNG CANCER
# ============================================================
story += [section_header("7", "LUNG CANCER"), sp(6)]

story += [sub_header("Classification — HIGH YIELD"), sp(4)]
lc_table = colored_table(
    ["Type", "Location", "Key Features"],
    [
        ["Squamous cell carcinoma", "Central", "Hilar mass, cavitation, paraneoplastic hypercalcemia (PTHrP), Pancoast tumor"],
        ["Adenocarcinoma", "Peripheral", "MC in non-smokers & women; EGFR/ALK mutations; hypertrophic osteoarthropathy"],
        ["Small cell (SCLC)", "Central", "Most aggressive; neuroendocrine; SIADH, Cushing (ectopic ACTH), Lambert-Eaton"],
        ["Large cell carcinoma", "Peripheral", "Poorly differentiated; diagnosis of exclusion"],
    ],
    [4.5*cm, 3.5*cm, 9*cm]
)
story += [lc_table, sp(4)]

story += [sub_header("Paraneoplastic Syndromes — VERY HIGH YIELD"), sp(4)]
para_table = colored_table(
    ["Syndrome", "Associated Cancer"],
    [
        ["SIADH (hyponatremia)", "SCLC"],
        ["Cushing syndrome (ectopic ACTH)", "SCLC"],
        ["Lambert-Eaton syndrome (proximal muscle weakness; VGCC antibodies)", "SCLC"],
        ["Hypercalcemia (PTHrP)", "Squamous cell carcinoma"],
        ["Hypertrophic osteoarthropathy (clubbing + periosteal new bone)", "Adenocarcinoma"],
        ["Superior vena cava (SVC) syndrome", "SCLC, Squamous cell"],
        ["Pancoast tumor (Horner + brachial plexopathy C8-T2)", "Squamous cell (apical)"],
    ],
    [10*cm, 7*cm]
)
story += [para_table, sp(4)]

story += [
    highlight_box("<b>Lambert-Eaton vs. MG:</b> Lambert-Eaton — improves with REPEATED effort (post-tetanic potentiation); proximal weakness; VGCC antibodies | MG — worsens with repeated effort; ACHR antibodies"),
    sp(8),
]

# ============================================================
# SECTION 8: INTERSTITIAL LUNG DISEASES
# ============================================================
story += [section_header("8", "INTERSTITIAL LUNG DISEASES (ILD)"), sp(6)]

story += [sub_header("Key ILDs — Summary Table"), sp(4)]
ild_table = colored_table(
    ["Disease", "Key Feature", "HRCT Pattern"],
    [
        ["IPF", "Elderly male, smoker; UIP pattern; poor prognosis; NO steroids", "Honeycombing + traction bronchiectasis (basal/subpleural)"],
        ["Sarcoidosis", "Non-caseating granulomas; bilateral hilar adenopathy; lupus pernio; erythema nodosum", "BHL + upper lobe infiltrates/nodules"],
        ["Hypersensitivity Pneumonitis", "Exposure-related: farmer's lung (actinomycetes), bird fancier's lung", "Ground glass + nodules; upper/mid zones"],
        ["NSIP", "Connective tissue diseases; better prognosis than IPF", "Ground glass opacity (basal, bilateral, symmetric)"],
    ],
    [3.5*cm, 6.5*cm, 7*cm]
)
story += [ild_table, sp(4)]

story += [sub_header("IPF Treatment"), sp(4)]
story += [
    bullet("<b>Pirfenidone</b> (TGF-β inhibitor) and <b>Nintedanib</b> (tyrosine kinase inhibitor) — both reduce rate of FVC decline"),
    bullet("Lung transplant for advanced disease"),
    bullet("<b>Avoid steroids in IPF</b> — worsens outcomes"),
    sp(4),
]

story += [sub_header("Sarcoidosis Staging"), sp(4)]
sarc_table = colored_table(
    ["Stage", "Description"],
    [
        ["Stage I", "Bilateral hilar adenopathy (BHL) only"],
        ["Stage II", "BHL + pulmonary infiltrates"],
        ["Stage III", "Pulmonary infiltrates only (no BHL)"],
        ["Stage IV", "Pulmonary fibrosis"],
    ],
    [4*cm, 13*cm]
)
story += [sarc_table, sp(4)]
story += [
    bullet("Hypercalcemia in sarcoidosis: macrophages produce 1,25-(OH)₂ vitamin D3"),
    bullet("Treatment: corticosteroids if symptomatic or organ-threatening; stages I–II may remit spontaneously"),
    sp(8),
]

# ============================================================
# SECTION 9: RESPIRATORY FAILURE & ARDS
# ============================================================
story += [section_header("9", "RESPIRATORY FAILURE & ARDS"), sp(6)]

story += [sub_header("Type I vs. Type II Respiratory Failure"), sp(4)]
rf_table = colored_table(
    ["Feature", "Type I (Hypoxemic)", "Type II (Hypercapnic)"],
    [
        ["PaO2", "<60 mmHg", "<60 mmHg"],
        ["PaCO2", "Normal or low", ">45 mmHg"],
        ["A-a gradient", "Increased", "Normal (initially)"],
        ["Causes", "Pneumonia, PE, pulmonary edema, ARDS", "COPD, neuromuscular disease, chest wall"],
        ["Mechanism", "V/Q mismatch, shunt, diffusion impairment", "Alveolar hypoventilation"],
    ],
    [4*cm, 6.5*cm, 6.5*cm]
)
story += [rf_table, sp(4)]

story += [sub_header("ARDS — Berlin Definition 2012"), sp(4)]
story += [
    highlight_box("<b>ARDS Criteria:</b> Within 1 week of clinical insult | Bilateral opacities on CXR (not fully explained by fluid/cardiogenic) | Not fully explained by heart failure | PaO₂/FiO₂: Mild 200–300, Moderate 100–200, Severe &lt;100"),
    sp(4),
]
story += [
    bullet("<b>Lung-protective ventilation:</b> Tidal volume 6 mL/kg ideal body weight, plateau pressure &lt;30 cmH₂O"),
    bullet("<b>Prone positioning:</b> For moderate-severe ARDS (PaO₂/FiO₂ &lt;150) — reduces mortality"),
    bullet("<b>PEEP:</b> To prevent atelectrauma"),
    bullet("<b>Neuromuscular blockade</b> in severe cases"),
    bullet("<b>Dexamethasone</b> in COVID-ARDS (RECOVERY trial)"),
    sp(8),
]

# ============================================================
# SECTION 10: QUICK-FIRE HIGH-YIELD FACTS
# ============================================================
story += [section_header("10", "QUICK-FIRE HIGH-YIELD FACTS & MNEMONICS"), sp(6)]

qf_table = colored_table(
    ["High-Yield Fact", "Answer"],
    [
        ["MC cause of CAP", "S. pneumoniae"],
        ["Atypical pneumonia — young adults, 'walking pneumonia'", "Mycoplasma pneumoniae"],
        ["Currant jelly sputum", "Klebsiella pneumoniae"],
        ["Legionella clues", "AC exposure, hyponatremia, diarrhea, raised LFTs; Urinary antigen test"],
        ["Samter's Triad", "Asthma + Nasal Polyps + Aspirin sensitivity"],
        ["Reid index >0.5", "Chronic bronchitis (mucous gland/bronchial wall ratio)"],
        ["DLCO reduced in", "Emphysema, IPF, PE; Normal/raised in asthma"],
        ["DLCO increased in", "Polycythemia, pulmonary hemorrhage"],
        ["Pleural ADA >40 U/L", "TB pleuritis (high sensitivity)"],
        ["PTHrP hypercalcemia in lung", "Squamous cell carcinoma"],
        ["SIADH in lung cancer", "SCLC"],
        ["Lambert-Eaton key feature", "Improves with repeated effort; VGCC antibodies"],
        ["PFT in restrictive disease", "FEV1/FVC normal or >70%; TLC reduced"],
        ["PFT in obstructive disease", "FEV1/FVC <0.70; TLC normal or increased (emphysema)"],
        ["IPF drugs (2)", "Pirfenidone, Nintedanib"],
        ["Mesothelioma", "Asbestos exposure; pleural plaques; epithelial type most common"],
        ["Goodpasture syndrome", "Anti-GBM antibodies; pulmonary hemorrhage + glomerulonephritis"],
        ["MC genetic cause of COPD", "Alpha-1 antitrypsin deficiency (PiZZ) — panacinar emphysema, lower lobes"],
        ["McConnell sign (Echo)", "RV apical sparing — classic for PE"],
        ["Normal PaCO2 in acute asthma", "Danger sign — indicates tiring patient (should be low normally)"],
    ],
    [9*cm, 8*cm]
)
story += [qf_table, sp(10)]

# Footer / Source
story += [
    HRFlowable(width="100%", thickness=1, color=TEAL),
    sp(4),
    Paragraph(
        "Sources: Harrison's Principles of Internal Medicine, 22nd Edition (2025, McGraw-Hill) | "
        "Murray &amp; Nadel's Textbook of Respiratory Medicine, 2-Volume Set (Elsevier) | "
        "Goldman-Cecil Medicine International Edition",
        source_style
    ),
    sp(2),
    Paragraph(
        "Prepared for KUHS University &amp; NEET PG Preparation — July 2026",
        source_style
    ),
]

# ── Build PDF ────────────────────────────────────────────────────────────────
doc = SimpleDocTemplate(
    OUTPUT,
    pagesize=A4,
    rightMargin=2*cm,
    leftMargin=2*cm,
    topMargin=2*cm,
    bottomMargin=2*cm,
    title="High-Yield Respiratory Medicine Notes",
    author="Medical Library — Harrison's 22E",
    subject="KUHS & NEET PG Respiratory System",
)

def add_page_number(canvas, doc):
    canvas.saveState()
    canvas.setFont("Helvetica", 8)
    canvas.setFillColor(colors.grey)
    canvas.drawRightString(A4[0] - 2*cm, 1.2*cm, f"Page {doc.page}")
    canvas.drawString(2*cm, 1.2*cm, "High-Yield Respiratory Medicine | KUHS & NEET PG")
    canvas.restoreState()

doc.build(story, onFirstPage=add_page_number, onLaterPages=add_page_number)
print("PDF generated successfully:", OUTPUT)