from reportlab.lib import colors
from reportlab.lib.enums import TA_LEFT, TA_CENTER
from reportlab.lib.pagesizes import letter
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import inch
from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, KeepTogether
from reportlab.pdfbase.pdfmetrics import stringWidth

OUT = '/tmp/workspace/epidural-placement-reference/output/Epidural_Placement_Levels_Quick_Reference.pdf'

PAGE_W, PAGE_H = letter
MARGIN = 0.42 * inch
ACCENT = colors.HexColor('#0E5A74')
DARK = colors.HexColor('#16313E')
PALE = colors.HexColor('#EAF4F7')
PALE2 = colors.HexColor('#F6F9FA')
WARNING = colors.HexColor('#FFF3D6')
GRID = colors.HexColor('#B8CAD1')

styles = getSampleStyleSheet()
styles.add(ParagraphStyle(name='TitleRef', parent=styles['Title'], fontName='Helvetica-Bold', fontSize=17, leading=20, textColor=DARK, alignment=TA_LEFT, spaceAfter=2))
styles.add(ParagraphStyle(name='SubRef', parent=styles['Normal'], fontName='Helvetica', fontSize=8.6, leading=10.5, textColor=colors.HexColor('#4B6470'), spaceAfter=7))
styles.add(ParagraphStyle(name='H', parent=styles['Heading2'], fontName='Helvetica-Bold', fontSize=10.3, leading=12.5, textColor=ACCENT, spaceBefore=5, spaceAfter=3))
styles.add(ParagraphStyle(name='BodyRef', parent=styles['Normal'], fontName='Helvetica', fontSize=7.65, leading=9.15, textColor=DARK))
styles.add(ParagraphStyle(name='SmallRef', parent=styles['Normal'], fontName='Helvetica', fontSize=6.8, leading=8.1, textColor=DARK))
styles.add(ParagraphStyle(name='Cell', parent=styles['Normal'], fontName='Helvetica', fontSize=7.2, leading=8.4, textColor=DARK))
styles.add(ParagraphStyle(name='CellBold', parent=styles['Normal'], fontName='Helvetica-Bold', fontSize=7.25, leading=8.4, textColor=DARK))
styles.add(ParagraphStyle(name='HeadCell', parent=styles['Normal'], fontName='Helvetica-Bold', fontSize=7.3, leading=8.3, textColor=colors.white, alignment=TA_CENTER))
styles.add(ParagraphStyle(name='Footer', parent=styles['Normal'], fontName='Helvetica-Oblique', fontSize=6.4, leading=7.3, textColor=colors.HexColor('#506871')))

def P(text, style='BodyRef'):
    return Paragraph(text, styles[style])

doc = SimpleDocTemplate(OUT, pagesize=letter, leftMargin=MARGIN, rightMargin=MARGIN, topMargin=0.34*inch, bottomMargin=0.32*inch)
story = []
story.append(P('Epidural Placement Levels', 'TitleRef'))
story.append(P('Adult perioperative quick reference. Choose a catheter level that is congruent with the incision and anticipated visceral-pain dermatomes.', 'SubRef'))

# Core rule callout
rule = Table([[P('<b>Core rule:</b> Place the catheter near the <b>midpoint of the dermatomes to be covered</b>, then titrate and clinically test sensory spread before incision.', 'BodyRef')]], colWidths=[7.66*inch])
rule.setStyle(TableStyle([
    ('BACKGROUND',(0,0),(-1,-1), PALE), ('BOX',(0,0),(-1,-1),0.6,ACCENT),
    ('LEFTPADDING',(0,0),(-1,-1),8),('RIGHTPADDING',(0,0),(-1,-1),8),('TOPPADDING',(0,0),(-1,-1),6),('BOTTOMPADDING',(0,0),(-1,-1),6),
]))
story += [rule, Spacer(1, 5)]

story.append(P('Suggested catheter insertion regions', 'H'))
data = [
    [P('Operative region / examples','HeadCell'), P('Typical insertion region','HeadCell'), P('Placement logic','HeadCell')],
    [P('<b>Thoracic</b><br/>Thoracotomy, lung resection, thymectomy, radical mastectomy','Cell'), P('<b>T4-T8</b>','CellBold'), P('Choose near the incision and chest-tube distribution.','Cell')],
    [P('<b>Upper abdomen</b><br/>Open cholecystectomy, gastrectomy, hepatic resection, Whipple, esophagectomy','Cell'), P('<b>T6-T8</b>','CellBold'), P('Congruent for upper abdominal incision and visceral pain.','Cell')],
    [P('<b>Middle abdomen / flank</b><br/>Nephrectomy, cystoprostatectomy','Cell'), P('<b>T7-T10</b>','CellBold'), P('Select according to flank and abdominal-incision extent.','Cell')],
    [P('<b>Lower abdomen / pelvis</b><br/>AAA repair, colectomy, radical prostatectomy, total abdominal hysterectomy','Cell'), P('<b>T8-T11</b>','CellBold'), P('Adjust cephalad for a long upper midline incision or extensive peritoneal work.','Cell')],
    [P('<b>Colectomy / anterior resection</b>','Cell'), P('<b>Lower thoracic, often T6-T8</b>','CellBold'), P('Plan for broad visceral coverage; assess actual spread as it may be greater cephalad than caudad.','Cell')],
    [P('<b>Lower extremity</b><br/>Hip or knee arthroplasty, femoropopliteal bypass','Cell'), P('<b>L1-L4</b>','CellBold'), P('Lumbar placement targets lower-limb roots while avoiding an unnecessary thoracic block.','Cell')],
    [P('<b>Labor analgesia</b>','Cell'), P('<b>L2-L3 or L3-L4</b>','CellBold'), P('First stage: T10-L1. Extend to S2-S4 for second-stage perineal analgesia.','Cell')],
    [P('<b>Cesarean delivery</b>','Cell'), P('<b>L2-L3 or L3-L4</b>','CellBold'), P('Lumbar access is standard; titrate to a tested sensory level of T4 for surgery.','Cell')],
]
t = Table(data, colWidths=[3.45*inch, 1.3*inch, 2.91*inch], repeatRows=1)
t.setStyle(TableStyle([
    ('BACKGROUND',(0,0),(-1,0), ACCENT), ('TEXTCOLOR',(0,0),(-1,0), colors.white),
    ('VALIGN',(0,0),(-1,-1),'MIDDLE'), ('GRID',(0,0),(-1,-1),0.35,GRID),
    ('BACKGROUND',(0,1),(-1,-1),PALE2), ('ROWBACKGROUNDS',(0,1),(-1,-1),[colors.white, PALE2]),
    ('LEFTPADDING',(0,0),(-1,-1),5),('RIGHTPADDING',(0,0),(-1,-1),5),('TOPPADDING',(0,0),(-1,-1),4),('BOTTOMPADDING',(0,0),(-1,-1),4),
]))
story += [t, Spacer(1, 5)]

left = [
    P('Before choosing the level', 'H'),
    P('1. Map the <b>skin incision</b> and anticipated deep or visceral pain.<br/>2. Include chest tubes, drains, stoma, donor sites, and extension of the incision.<br/>3. Choose a point near the <b>center</b> of the required dermatomal band.<br/>4. Plan dose and concentration for the intended endpoint: analgesia versus surgical anesthesia.<br/>5. Assess bilateral sensory level and hemodynamics before incision.', 'BodyRef'),
]
right = [
    P('Important cautions', 'H'),
    P('<b>Insertion level is not the final block level.</b> Epidural spread varies with dose, volume, catheter position, patient characteristics, and anatomy.<br/><br/><b>Do not rely on a table alone.</b> Confirm the clinical block, use institutional anticoagulation and infection precautions, and follow local protocols. Thoracic epidural placement requires appropriate expertise.', 'BodyRef'),
]
box = Table([[left, right]], colWidths=[3.83*inch,3.83*inch])
box.setStyle(TableStyle([
    ('VALIGN',(0,0),(-1,-1),'TOP'), ('BOX',(0,0),(-1,-1),0.45,GRID),('LINEBEFORE',(1,0),(1,0),0.45,GRID),
    ('BACKGROUND',(1,0),(1,0),WARNING),
    ('LEFTPADDING',(0,0),(-1,-1),7),('RIGHTPADDING',(0,0),(-1,-1),7),('TOPPADDING',(0,0),(-1,-1),3),('BOTTOMPADDING',(0,0),(-1,-1),5),
]))
story += [box, Spacer(1, 5)]

story.append(P('<b>Evidence source:</b> Recommended procedure ranges: <i>Miller\'s Anesthesia</i>, 10e, Table 77.5, p. 11729. Midpoint principle and differential spread: <i>Morgan and Mikhail\'s Clinical Anesthesiology</i>, 7e, pp. 1801-1802. Educational aid only: not a substitute for clinical judgment, supervision, institutional policy, or patient-specific assessment.', 'Footer'))

doc.build(story)
print(OUT)

from docx import Document
from docx.shared import Inches, Pt, RGBColor
from docx.enum.text import WD_ALIGN_PARAGRAPH
from docx.enum.table import WD_TABLE_ALIGNMENT, WD_CELL_VERTICAL_ALIGNMENT
from docx.oxml import OxmlElement
from docx.oxml.ns import qn
from docx.enum.section import WD_SECTION

OUT = '/tmp/workspace/segmental-neuraxial-block-note/output/Segmental_Neuraxial_Block_Comprehensive_Note.docx'

doc = Document()
sec = doc.sections[0]
sec.top_margin = Inches(0.65); sec.bottom_margin = Inches(0.65)
sec.left_margin = Inches(0.70); sec.right_margin = Inches(0.70)

# Styles
styles = doc.styles
styles['Normal'].font.name = 'Aptos'; styles['Normal']._element.rPr.rFonts.set(qn('w:eastAsia'), 'Aptos')
styles['Normal'].font.size = Pt(10)
styles['Normal'].paragraph_format.space_after = Pt(5)
for name, size, color in [('Title', 24, '17365D'), ('Heading 1', 16, '17365D'), ('Heading 2', 12, '1F5E7A'), ('Heading 3', 10.5, '1F5E7A')]:
    s=styles[name]; s.font.name='Aptos Display' if name=='Title' else 'Aptos'; s.font.size=Pt(size); s.font.bold=True; s.font.color.rgb=RGBColor.from_string(color)
    s.paragraph_format.space_before=Pt(12 if name!='Title' else 0); s.paragraph_format.space_after=Pt(5)

# helpers
def shade(cell, fill):
    tcPr = cell._tc.get_or_add_tcPr(); shd = OxmlElement('w:shd'); shd.set(qn('w:fill'), fill); tcPr.append(shd)
def border_cell(cell, color='B7C9D6'):
    tcPr=cell._tc.get_or_add_tcPr(); borders=OxmlElement('w:tcBorders')
    for edge in ('top','left','bottom','right'):
        el=OxmlElement('w:'+edge); el.set(qn('w:val'),'single'); el.set(qn('w:sz'),'4'); el.set(qn('w:color'),color); borders.append(el)
    tcPr.append(borders)
def set_cell_text(cell, text, bold=False, color=None, size=8.5):
    cell.text=''; p=cell.paragraphs[0]; p.paragraph_format.space_after=Pt(2); r=p.add_run(text); r.bold=bold; r.font.size=Pt(size)
    if color: r.font.color.rgb=RGBColor.from_string(color)
    cell.vertical_alignment=WD_CELL_VERTICAL_ALIGNMENT.CENTER; border_cell(cell)
def table(headers, rows, widths=None):
    t=doc.add_table(rows=1, cols=len(headers)); t.alignment=WD_TABLE_ALIGNMENT.CENTER; t.style='Table Grid'
    for i,h in enumerate(headers): set_cell_text(t.rows[0].cells[i], h, True, 'FFFFFF', 8.5); shade(t.rows[0].cells[i],'1F5E7A')
    for r_i,row in enumerate(rows):
        cells=t.add_row().cells
        for i, val in enumerate(row):
            set_cell_text(cells[i], val, False, None, 8.3)
            if r_i%2==1: shade(cells[i], 'EDF4F8')
    if widths:
        for row in t.rows:
            for i,w in enumerate(widths): row.cells[i].width=Inches(w)
    doc.add_paragraph().paragraph_format.space_after=Pt(1)
    return t
def bullet(text, level=0):
    p=doc.add_paragraph(style='List Bullet' if level==0 else 'List Bullet 2'); p.paragraph_format.space_after=Pt(2); p.add_run(text)
def number(text):
    p=doc.add_paragraph(style='List Number'); p.paragraph_format.space_after=Pt(2); p.add_run(text)
def callout(title, text, fill='EAF3F8'):
    t=doc.add_table(rows=1, cols=1); t.alignment=WD_TABLE_ALIGNMENT.CENTER
    c=t.cell(0,0); shade(c,fill); border_cell(c,'7FA7BC'); c.text=''
    p=c.paragraphs[0]; p.paragraph_format.space_after=Pt(2); r=p.add_run(title+'  '); r.bold=True; r.font.color.rgb=RGBColor.from_string('17365D'); p.add_run(text)
    doc.add_paragraph().paragraph_format.space_after=Pt(1)
def page_break(): doc.add_page_break()

# Header/footer
header=sec.header.paragraphs[0]; header.alignment=WD_ALIGN_PARAGRAPH.RIGHT
r=header.add_run('SEGMENTAL NEURAXIAL BLOCK | STUDY NOTE'); r.font.size=Pt(8); r.font.color.rgb=RGBColor.from_string('5A7184')
footer=sec.footer.paragraphs[0]; footer.alignment=WD_ALIGN_PARAGRAPH.CENTER
f=footer.add_run('Educational reference only. Clinical performance requires local protocol, supervision, and patient-specific assessment.'); f.font.size=Pt(8); f.font.color.rgb=RGBColor.from_string('5A7184')

# Title
p=doc.add_paragraph(); p.alignment=WD_ALIGN_PARAGRAPH.CENTER
r=p.add_run('Segmental Neuraxial Block'); r.bold=True; r.font.size=Pt(25); r.font.color.rgb=RGBColor.from_string('17365D')
p=doc.add_paragraph(); p.alignment=WD_ALIGN_PARAGRAPH.CENTER
r=p.add_run('Comprehensive anesthesia note: principles, epidural level selection, assessment, safety, and exam revision'); r.italic=True; r.font.size=Pt(11); r.font.color.rgb=RGBColor.from_string('406A82')
callout('Scope.', 'This note focuses on segmental epidural anesthesia and analgesia in adults. It is a learning aid, not a substitute for institutional anticoagulation policy, drug guidance, or expert supervision.', 'FFF4DD')

doc.add_heading('Learning objectives',1)
for x in ['Define segmental neuraxial block and distinguish it from differential block.', 'Explain why catheter-incision congruence improves the quality and selectivity of epidural analgesia.', 'Choose a practical epidural insertion region from the operative dermatomes.', 'Assess, troubleshoot, and safely respond to inadequate or excessive neuraxial block.'] : bullet(x)

doc.add_heading('1. Definition and terminology',1)
doc.add_heading('Definition',2)
doc.add_paragraph('A segmental neuraxial block is a block confined predominantly to a defined band of spinal nerve roots or dermatomes, with relative sparing above and below that band. In practice, it is most readily achieved with an epidural, particularly thoracic epidural, because drug can be delivered close to the roots serving the operative field. A thoracic epidural can therefore provide upper abdominal analgesia while largely sparing cervical and lower lumbar roots.')
callout('Core principle.', 'For an epidural, place the injection or catheter level near the midpoint of the dermatomes that must be blocked. The final sensory level depends on spread and must be tested, not assumed.')
table(['Term','Meaning','Clinical implication'],[
['Segmental block','Anatomic distribution: a limited band of dermatomes is anesthetized or analgesic.','Aim for incision-congruent catheter placement and limited spread.'],
['Differential block','Functional distribution: sympathetic, sensory, and motor fibers are blocked to differing degrees and heights.','A patient may have analgesia with little motor block, but still have a meaningful sympathectomy.'],
['Epidural analgesia','Usually dilute local anesthetic with or without opioid; pain relief predominates.','Useful for labor and postoperative pain.'],
['Epidural anesthesia','Denser block sufficient for surgery, often with more local anesthetic.','Requires reliable sensory coverage and planning for visceral pain.'],
['Spinal block','Intrathecal injection with rapid, dense block; less easily titrated once injected.','Not usually described as selectively segmental in the same way as an epidural.']
],[1.25,2.3,3.5])

doc.add_heading('2. Applied anatomy and physiology',1)
doc.add_heading('Epidural space and nerve roots',2)
doc.add_paragraph('The epidural space surrounds the dura and contains fat, lymphatics, connective-tissue bands and a venous plexus. Spinal nerve roots travel through this space before exiting through the intervertebral foramina. Local anesthetic bathing these roots inhibits impulse conduction and thereby interrupts somatic and visceral afferent input, as well as motor and autonomic efferent output.')
bullet('Thoracic epidural placement is useful when the operative field is thoracic or upper abdominal because it puts drug near the relevant thoracic roots.')
bullet('Lumbar placement is appropriate for lower-limb, pelvic and obstetric applications, but a low lumbar catheter is often incongruent for thoracic surgery.')
bullet('Connective-tissue bands or septa can contribute to asymmetric or unilateral spread.')

doc.add_heading('Dermatomes and autonomic outflow',2)
table(['Landmark / region','Approximate segmental relevance','Use in planning'],[
['T4','Nipple line','Often required as the upper sensory level for cesarean delivery; upper thoracic coverage may be needed for some breast procedures.'],
['T6-T8','Upper abdominal region','Common insertion region for upper abdominal surgery.'],
['T10','Umbilical level','A useful surface landmark; first-stage labor pain is predominantly T10-L1.'],
['L1','Inguinal region','Relevant to lower abdominal and groin distribution.'],
['S2-S4','Perineum and pelvic floor','Required for second-stage labor, vaginal/perineal procedures.'],
['T1-L2','Sympathetic outflow','Sympathetic block can cause vasodilation, hypotension and altered cardiac autonomic balance.']
],[1.25,2.0,3.8])

doc.add_heading('Differential blockade',2)
doc.add_paragraph('Local anesthetic concentration declines with increasing distance from the injection site and neural fibers differ in susceptibility. Therefore sympathetic block is generally more cephalad than the sensory level, while motor block is usually less extensive than sensory block. The pattern is clinically important: a modest sensory block may still be accompanied by hypotension from sympathetic blockade.')
callout('Exam line.', 'Segmental block describes WHERE the block is. Differential block describes WHICH functions are blocked and to what extent.')

page_break()
doc.add_heading('3. Pharmacology and determinants of epidural spread',1)
doc.add_heading('Local anesthetics and adjuncts',2)
table(['Component','Primary role','Implications for segmental technique'],[
['Local anesthetic','Produces sensory, sympathetic and, concentration-dependently, motor block.','Volume mainly governs number of segments reached; concentration affects density and motor block. Use the least extensive effective block.'],
['Dilute local anesthetic','Analgesia with reduced motor effect.','Common when mobilization or labor analgesia is desired.'],
['Lipophilic epidural opioid, eg fentanyl','Rapid onset and short duration; substantial systemic uptake may occur.','Useful adjunct but continuous infusion can have less purely segmental effect.'],
['Hydrophilic opioid, eg morphine','Slower onset, longer duration and more spinally mediated effect.','Requires postoperative monitoring for delayed opioid adverse effects according to local policy.'],
['Adjuvants','May alter analgesia and adverse-effect profile.','Use only within institutional protocols.']
],[1.45,2.35,3.25])
doc.add_paragraph('Epidural opioids can improve analgesia without the same degree of motor or sympathetic blockade as local anesthetic. Hydrophilic opioids generally have slower onset and longer duration, whereas lipophilic opioids have faster onset, shorter duration and greater systemic uptake. - Barash, Cullen, and Stoelting’s Clinical Anesthesia, 9e, p. 4698')

doc.add_heading('Factors that determine block level and quality',2)
table(['Factor','Effect / practical consequence'],[
['Insertion site and catheter-tip position','The densest and fastest block is near the injection site. Catheter placement congruent with the incision improves analgesia and reduces unnecessary spread.'],
['Volume and total dose','Increasing volume at the same concentration generally increases the number of segments covered. Dose must be individualized.'],
['Concentration','Higher concentration tends to produce a denser sensory and motor block. Low concentrations can provide analgesia with little motor block.'],
['Bolus versus infusion','Bolus dosing produces a more evident segmental spread; infusions maintain analgesia but may spread or behave differently over time.'],
['Patient and anatomy','Age, height, pregnancy, obesity, epidural anatomy, prior spine surgery and physiological status can alter spread and response.'],
['Position / catheter direction','Catheter migration, unilateral placement or septation can create patchy or one-sided block.'],
['Time','Epidural onset is slower than spinal anesthesia, commonly around 10-20 minutes; assess before incision.']
],[2.05,5.0])
callout('Dose concept.', 'A frequently cited adult starting heuristic is 1-2 mL of local anesthetic per intended segment, but it is not a prescription. Titrate in incremental doses with monitoring and follow local drug protocols.')

doc.add_heading('4. Producing a segmental epidural block',1)
doc.add_heading('Planning sequence',2)
for x in ['Define the operative dermatomes: include skin incision, deep muscular and visceral component, drains, chest tubes, stoma, and graft-harvest sites.', 'Select a catheter insertion region close to the midpoint of the required segmental distribution.', 'Perform pre-block assessment: consent, indication, contraindications, baseline neurological findings, coagulation and antithrombotic plan, intravenous access and standard monitoring.', 'Insert and secure the catheter using aseptic technique. Document the insertion level, depth at skin, test-dose approach per local protocol, and baseline observations.', 'Administer incremental medication, monitor haemodynamics, and test sensory distribution before incision. Assess motor function when relevant.', 'Maintain with an appropriately selected regimen and reassess after position changes, boluses, or new pain.'] : number(x)

doc.add_heading('Catheter-incision congruence',2)
doc.add_paragraph('The objective is not merely to obtain a high block. It is to deliver medication to the roots serving the painful field. Compared with incongruent low lumbar placement for thoracic or abdominal surgery, congruent placement may improve analgesia, reduce lower-limb motor block and urinary retention, lower drug requirement, and avoid early catheter removal because of ineffective analgesia. - Miller’s Anesthesia, 10e, pp. 11729-11731')

page_break()
doc.add_heading('5. Procedure-specific insertion regions',1)
doc.add_paragraph('The ranges below are practical starting regions, not fixed rules. Final choice depends on incision extent, surgical approach, expected visceral work, patient anatomy and institutional practice. Confirm the actual sensory block clinically.')
table(['Operative region / examples','Typical epidural insertion region','Rationale and cautions'],[
['Thoracic: thoracotomy, lung resection, thymectomy','T4-T8','Place near incision and chest-tube dermatomes. Thoracic placement is preferred over incongruent lumbar placement.'],
['Breast / chest wall procedures','Often upper thoracic, approximately T2-T6 depending on extent','Match the incision, axillary component and reconstruction plan. High thoracic blocks demand appropriate expertise and monitoring.'],
['Upper abdomen: open cholecystectomy, gastrectomy, liver resection, Whipple, esophagectomy','T6-T8','Targets upper abdominal incision and visceral pain. Esophagectomy may require consideration of thoracic component.'],
['Middle abdomen / flank: nephrectomy, cystoprostatectomy','T7-T10','Adjust to flank extension and incision direction.'],
['Lower abdomen / pelvis: AAA repair, radical prostatectomy, total abdominal hysterectomy','T8-T11','Long upper-midline or extensive peritoneal surgery may require a more cephalad plan.'],
['Colectomy / anterior resection','Often lower thoracic, T6-T8','Choose for incision and visceral distribution; spread may be more cephalad than caudad.'],
['Lower extremity: hip/knee replacement, femoropopliteal bypass','L1-L4','Lumbar placement targets relevant roots and avoids unnecessary thoracic sympathectomy.'],
['Labor analgesia','Lumbar, commonly L2-L3 or L3-L4','First stage: T10-L1. Second stage: extend to S2-S4 for vaginal/perineal pain.'],
['Cesarean delivery','Lumbar epidural access, commonly L2-L3 or L3-L4','Target sensory anesthesia to T4. Prevent and treat hypotension; confirm adequate block before surgery.']
],[2.5,1.25,3.0])
doc.add_paragraph('The procedure-specific ranges for thoracic, upper abdominal, middle abdominal, lower abdominal and lower-extremity surgery are adapted from the recommended catheter insertion sites in Miller’s Anesthesia, 10e, p. 11729.')

doc.add_heading('6. Assessment and troubleshooting',1)
doc.add_heading('Assess before incision and throughout use',2)
table(['Domain','What to assess','Why it matters'],[
['Sensory block','Cold, pinprick or touch bilaterally; record highest and lowest levels.','Confirms coverage and detects unilateral, patchy, or unexpectedly high spread.'],
['Motor block','Leg strength or a recognized motor scale when appropriate.','Avoids unintended motor impairment and informs mobilization decisions.'],
['Haemodynamics','Blood pressure, heart rate, symptoms of reduced perfusion.','Sympathectomy can cause hypotension, especially with high blocks or relative hypovolemia.'],
['Respiratory / neurological status','Dyspnea, upper-limb symptoms, sedation, altered consciousness.','May signal high neuraxial block, opioid effect, or another complication.'],
['Catheter function','Connection, filter, dressing, migration, leak, depth marking.','Mechanical problems can cause sudden analgesic failure.']
],[1.35,3.15,2.35])

table(['Problem','Likely causes','Structured response'],[
['Patchy or inadequate block','Incongruent placement, insufficient dose/spread, catheter malposition, poor epidural distribution.','Reassess dermatomes and catheter depth; exclude intravascular or intrathecal signs; use cautious clinician-directed adjustment or replace if persistently ineffective.'],
['Unilateral block','Catheter directed laterally, septation, lateral positioning.','Check catheter depth and patient position; consider withdrawal/repositioning or replacement according to protocol.'],
['Sudden loss of analgesia','Catheter migration/dislodgement, empty pump, disconnection, change in surgical pain.','Inspect system, check insertion marking, assess block, and do not simply escalate dose without diagnosis.'],
['Excessively high block','Excessive dose/spread, unrecognized intrathecal/subdural placement, altered anatomy.','Stop dosing, call for help, support airway and ventilation, treat hypotension/bradycardia, and prepare for intubation if needed.'],
['Local anesthetic systemic toxicity','Intravascular injection or excessive systemic absorption.','Stop injection, call for help, manage airway/seizures/circulation and follow local LAST lipid-emulsion protocol.']
],[1.35,2.45,3.05])
callout('Safety rule.', 'New severe back pain, progressive motor weakness, sensory loss after expected regression, sphincter disturbance, or fever with neurological signs requires urgent evaluation for neuraxial hematoma or infection. Time-sensitive escalation is essential.', 'FDE9E7')

page_break()
doc.add_heading('7. Contraindications, complications, and safety',1)
doc.add_heading('Contraindications and precautions',2)
table(['Category','Examples / action'],[
['Do not proceed without resolution or specialist decision','Patient refusal; infection at puncture site; clinically significant coagulopathy or unacceptable antithrombotic timing; severe uncorrected haemodynamic instability.'],
['Require individualized risk-benefit assessment','Systemic infection/sepsis, thrombocytopenia, anticoagulant or antiplatelet treatment, pre-existing neurological disease, spinal abnormality or prior spinal surgery, raised intracranial pressure due to mass lesion, severe valvular disease or fixed cardiac output state.'],
['Planning requirements','Use current institutional and specialty-society guidance for neuraxial procedures with antithrombotic drugs, including both insertion and catheter removal. Document neurological baseline and escalation plan.']
],[2.2,4.65])
doc.add_paragraph('Commonly cited contraindications to neuraxial anesthesia include refusal, coagulopathy, haemodynamic instability and infection at the injection site. - Barash, Cullen, and Stoelting’s Clinical Anesthesia, 9e, p. 3651')

doc.add_heading('Complications',2)
table(['Type','Examples','Prevention / first response'],[
['Expected physiological effects','Hypotension, bradycardia, motor weakness, urinary retention, pruritus or nausea depending on regimen.','Use incremental dosing, monitor and treat haemodynamic effects promptly; choose an appropriate concentration and regimen.'],
['Technical / mechanical','Dural puncture and post-dural puncture headache, vascular puncture, failed/patchy block, catheter migration, knotting or breakage.','Meticulous technique, careful documentation, reassessment, and early troubleshooting.'],
['Drug-related','Intravascular injection, local anesthetic systemic toxicity, medication error, opioid-related sedation or respiratory depression.','Incremental dosing, aspiration/test-dose policy, monitoring and readiness to manage LAST or opioid toxicity.'],
['Serious neurological / infectious','High or total spinal, epidural hematoma, epidural abscess, meningitis, direct neural injury.','Appropriate patient selection, asepsis, antithrombotic management, frequent neurological assessment and urgent escalation of red flags.']
],[1.45,2.7,2.7])

doc.add_heading('High or total neuraxial block: immediate priorities',2)
for x in ['Stop epidural injection or infusion and call for experienced help.', 'Maintain oxygenation and ventilation. Prepare for airway control and intubate if there is respiratory failure, loss of consciousness, or inability to protect the airway.', 'Treat hypotension and bradycardia with positioning, intravenous fluid as appropriate, and vasopressors according to local practice.', 'Continue close monitoring until the block regresses and identify the likely mechanism before any further neuraxial dosing.'] : number(x)

doc.add_heading('8. Epidural versus spinal: segmental perspective',1)
table(['Feature','Epidural','Single-shot spinal'],[
['Onset','Usually slower, commonly 10-20 minutes.','Rapid.'],
['Titration','Catheter permits boluses, infusion and adjustment.','Limited once intrathecal dose is injected.'],
['Segmental selectivity','Can be localized around injection/catheter level, especially thoracically.','Dense block but less easily confined or adjusted segmentally.'],
['Motor block','Can range from absent to complete depending on solution and dose.','Usually more dense for a surgical dose.'],
['Best conceptual use','Targeted analgesia/anesthesia and prolonged postoperative pain management.','Rapid anesthesia for selected surgery or as part of combined spinal-epidural techniques.']
],[1.55,3.2,2.25])

page_break()
doc.add_heading('9. Exam-focused revision',1)
doc.add_heading('High-yield points',2)
for x in [
'Segmental block is mainly an epidural concept: a band of dermatomes is blocked while roots above and below are relatively spared.',
'The epidural catheter should be placed near the midpoint of dermatomes requiring analgesia or anesthesia.',
'Catheter-incision congruence gives denser relevant analgesia with less drug and fewer off-target effects such as lower-limb motor block.',
'Do not confuse a segmental block with differential block. Segmental = anatomic distribution; differential = sympathetic, sensory and motor effects differ.',
'Volume chiefly influences longitudinal spread; concentration influences block density and motor effect.',
'Sympathetic block may extend more cephalad than the sensory level. Monitor blood pressure even when motor function is preserved.',
'Thoracic epidural is usually more appropriate than low lumbar epidural for thoracic and upper abdominal procedures.',
'Always test bilateral sensory level before surgical incision. A dermatome target is an endpoint, not a substitute for clinical assessment.',
'Persistent block failure, unexpectedly high block, or new neurological deficit must prompt diagnosis rather than repeated blind dosing.',
'Antithrombotic timing matters for both insertion and removal of an epidural catheter.'
]: bullet(x)

doc.add_heading('Common viva questions with model answers',2)
table(['Question','Model answer'],[
['Define segmental epidural block.','It is an epidural block concentrated in a limited, clinically relevant band of nerve roots or dermatomes, relatively sparing segments above and below.'],
['How do you choose insertion level?','Map the expected somatic and visceral dermatomes, then place the catheter near the midpoint of the required field. Consider incision length, surgical approach, drains and catheter tip position.'],
['Why is thoracic placement used for upper abdominal surgery?','It provides incision-congruent delivery to thoracic roots, improving relevant analgesia while reducing the need for high-volume spread from a lumbar catheter.'],
['What is differential blockade?','The unequal effects of neuraxial local anesthetic on sympathetic, sensory and motor function. Sympathetic block is generally highest, sensory intermediate, and motor lowest.'],
['Why may an epidural be unilateral?','A laterally directed catheter, asymmetric epidural anatomy or septation, and patient position can limit spread to one side.'],
['What are red flags for hematoma or abscess?','Severe back pain, progressive motor or sensory deficit, sphincter dysfunction, fever or systemic illness, and delayed regression. These require urgent assessment.']
],[2.35,4.65])

doc.add_heading('One-minute answer framework',2)
callout('If asked to explain segmental neuraxial block in an exam:', 'Define it as a focused epidural block of selected dermatomes. State that the catheter is placed near the midpoint of the operative dermatomes. Explain that volume controls spread and concentration controls density/motor effect. Distinguish it from differential block. Give a thoracic epidural example for upper abdominal surgery. Finish with testing of sensory level, haemodynamic monitoring, and vigilance for high block, hematoma and infection.', 'EAF3F8')

doc.add_heading('Selected sources',1)
for x in [
'Morgan and Mikhail’s Clinical Anesthesiology, 7e: regional and epidural anesthesia, pp. 1801, 1832-1834.',
'Miller’s Anesthesia, 10e: recommended catheter insertion sites and catheter-incision congruence, pp. 11729-11731.',
'Barash, Cullen, and Stoelting’s Clinical Anesthesia, 9e: neuraxial analgesia and epidural opioid pharmacology, pp. 4697-4698.',
'NYSORA: Epidural Anesthesia and Analgesia, sections on dermatomal congruence, contraindications and complications.',
'Recent evidence update: systematic reviews of perioperative epidural analgesia include PMIDs 42439462 and 40164382. Procedure-specific benefit relative to other analgesic strategies is context-dependent.'
]: bullet(x)

doc.save(OUT)
print(OUT)