DNB Anaesthesia — 10-Mark Model Answers

const {
  Document, Packer, Paragraph, TextRun, Table, TableRow, TableCell,
  HeadingLevel, AlignmentType, BorderStyle, WidthType, VerticalAlign,
  PageNumber, Footer, Header, TabStopType, TabStopPosition, PageBreak,
  ShadingType, UnderlineType
} = require('docx');
const fs = require('fs');

// ─── Style helpers ───────────────────────────────────────────────────────────

function h1(text) {
  return new Paragraph({
    text,
    heading: HeadingLevel.HEADING_1,
    spacing: { before: 400, after: 120 },
    border: { bottom: { style: BorderStyle.SINGLE, size: 6, color: '2E4057', space: 4 } }
  });
}

function h2(text) {
  return new Paragraph({
    text,
    heading: HeadingLevel.HEADING_2,
    spacing: { before: 280, after: 80 },
  });
}

function h3(text) {
  return new Paragraph({
    text,
    heading: HeadingLevel.HEADING_3,
    spacing: { before: 200, after: 60 },
  });
}

function h4(text) {
  return new Paragraph({
    children: [new TextRun({ text, bold: true, underline: { type: UnderlineType.SINGLE }, size: 22 })],
    spacing: { before: 160, after: 40 },
  });
}

function para(text, opts = {}) {
  return new Paragraph({
    children: [new TextRun({ text, size: 20, ...opts })],
    spacing: { before: 60, after: 60 },
  });
}

function bullet(text, level = 0) {
  return new Paragraph({
    children: [new TextRun({ text, size: 20 })],
    bullet: { level },
    spacing: { before: 40, after: 40 },
  });
}

function bold(text) {
  return new TextRun({ text, bold: true, size: 20 });
}

function run(text) {
  return new TextRun({ text, size: 20 });
}

function mixedPara(runs) {
  return new Paragraph({ children: runs, spacing: { before: 60, after: 60 } });
}

function pageBreak() {
  return new Paragraph({ children: [new PageBreak()] });
}

function note(text) {
  return new Paragraph({
    children: [new TextRun({ text, italics: true, color: '555555', size: 18 })],
    spacing: { before: 40, after: 60 },
  });
}

function divider() {
  return new Paragraph({
    border: { bottom: { style: BorderStyle.SINGLE, size: 4, color: 'CCCCCC', space: 4 } },
    spacing: { before: 80, after: 80 },
    text: ''
  });
}

// ─── Table helper ────────────────────────────────────────────────────────────

function makeTable(headers, rows, colWidths) {
  const totalWidth = 9000;
  const numCols = headers.length;
  const widths = colWidths || headers.map(() => Math.floor(totalWidth / numCols));

  const headerCells = headers.map((h, i) =>
    new TableCell({
      children: [new Paragraph({
        children: [new TextRun({ text: h, bold: true, size: 18, color: 'FFFFFF' })],
        alignment: AlignmentType.CENTER,
      })],
      width: { size: widths[i], type: WidthType.DXA },
      shading: { type: ShadingType.SOLID, color: '2E4057' },
      verticalAlign: VerticalAlign.CENTER,
      margins: { top: 60, bottom: 60, left: 80, right: 80 },
    })
  );

  const dataRows = rows.map((row, ri) =>
    new TableRow({
      children: row.map((cell, ci) =>
        new TableCell({
          children: [new Paragraph({
            children: [new TextRun({ text: String(cell), size: 18 })],
          })],
          width: { size: widths[ci], type: WidthType.DXA },
          shading: ri % 2 === 0
            ? { type: ShadingType.SOLID, color: 'F0F4F8' }
            : { type: ShadingType.SOLID, color: 'FFFFFF' },
          margins: { top: 60, bottom: 60, left: 80, right: 80 },
          verticalAlign: VerticalAlign.CENTER,
        })
      ),
    })
  );

  return new Table({
    rows: [new TableRow({ children: headerCells, tableHeader: true }), ...dataRows],
    width: { size: totalWidth, type: WidthType.DXA },
    margins: { top: 0, bottom: 200, left: 0, right: 0 },
  });
}

// ─── Cover page ──────────────────────────────────────────────────────────────

const cover = [
  new Paragraph({ spacing: { before: 1200 } }),
  new Paragraph({
    children: [new TextRun({ text: 'DNB ANAESTHESIA', bold: true, size: 56, color: '2E4057' })],
    alignment: AlignmentType.CENTER,
  }),
  new Paragraph({
    children: [new TextRun({ text: 'Model Answers — 10 Questions (10 Marks Each)', bold: true, size: 32, color: '048A81' })],
    alignment: AlignmentType.CENTER,
    spacing: { before: 120, after: 120 },
  }),
  new Paragraph({
    children: [new TextRun({ text: 'References: Miller\'s Anesthesia 10e  |  Morgan & Mikhail 7e  |  Barash Clinical Anesthesia 9e', size: 22, italics: true, color: '555555' })],
    alignment: AlignmentType.CENTER,
    spacing: { before: 80, after: 80 },
  }),
  new Paragraph({
    children: [new TextRun({ text: 'Creasy & Resnik\'s Maternal-Fetal Medicine  |  SSC Guidelines 2021', size: 22, italics: true, color: '555555' })],
    alignment: AlignmentType.CENTER,
    spacing: { before: 40, after: 400 },
  }),
  divider(),
  new Paragraph({
    children: [new TextRun({ text: 'CONTENTS', bold: true, size: 26, color: '2E4057' })],
    alignment: AlignmentType.CENTER,
    spacing: { before: 200, after: 160 },
  }),
  ...[
    'Q1.  Resuscitation in Pregnant Women & Surviving Sepsis Guidelines',
    'Q2.  LFTs and Their Significance; Child-Pugh Score',
    'Q3.  USG-Guided Adductor Canal Block & Renal Replacement Therapy',
    'Q4.  Types of Labour Analgesia & Pain Pathway in Labour Pain',
    'Q5.  Anaesthesia Challenges & Management of Posterior Fossa Tumour',
    'Q6.  Airway Management of Maxillofacial Trauma + MILS',
    'Q7.  Anaesthesia for 2-Year-Old Paediatric with Foreign Body (Emergency)',
    'Q8.  Biochemical Changes of Stored Blood; Blood Transfusion',
    'Q9.  Link 25 & Electrical Safety in the Operating Theatre',
    'Q10. Post-op Analgesia for Paediatric — Lower Abdominal & Thoracotomy',
  ].map(line => new Paragraph({
    children: [new TextRun({ text: line, size: 20 })],
    spacing: { before: 60, after: 60 },
    indent: { left: 720 },
  })),
  pageBreak(),
];

// ─── Q1 ──────────────────────────────────────────────────────────────────────

const q1 = [
  h1('Q1. Resuscitation in Pregnant Women & Surviving Sepsis Guidelines'),
  note('References: Miller\'s Anesthesia Ch. 80; Creasy & Resnik Ch. 18, 48; SSC 2021'),

  h2('PART A — Resuscitation in Pregnant Women (Maternal Cardiac Arrest)'),

  h3('1. Physiological Considerations'),
  bullet('Aortocaval compression by gravid uterus (>20 wks) reduces CO by up to 30%'),
  bullet('Increased O₂ consumption + reduced FRC → rapid desaturation during apnoea'),
  bullet('Difficult airway: Mallampati increases by one class; aspiration risk (reduced LOS tone)'),
  bullet('Physiological hypercoagulability; oedematous upper airway'),

  h3('2. Causes — "BEAUCHOPS"'),
  makeTable(
    ['Letter', 'Cause'],
    [
      ['B', 'Bleeding / DIC'],
      ['E', 'Embolism (AFE / PE)'],
      ['A', 'Anaesthetic complications (failed airway, high spinal)'],
      ['U', 'Uterine atony / rupture'],
      ['C', 'Cardiac (MI, peripartum cardiomyopathy)'],
      ['H', 'Hypertension / Eclampsia'],
      ['O', 'Other: Hypoxia, sepsis, magnesium toxicity'],
      ['P', 'Placenta praevia / abruption'],
      ['S', 'Sepsis'],
    ],
    [1200, 7800]
  ),

  h3('3. Modifications to Standard BLS/ALS'),
  bullet('Left Uterine Displacement (LUD): most critical modification — manual LUD, NOT wedge under patient'),
  bullet('Hand position: slightly higher on sternum (diaphragm elevation)'),
  bullet('Early intubation: most skilled operator; smaller ETT (6.5–7.0 mm); suction ready'),
  bullet('IV access: ABOVE diaphragm (antecubital/central); subdiaphragmatic drugs may not reach circulation'),
  bullet('Defibrillation: standard energies; remove fetal monitors before shock'),
  bullet('Drugs: epinephrine 1 mg IV q3–5 min; standard ACLS protocol unchanged'),

  h3('4. Perimortem Caesarean Section (PMCS)'),
  bullet('If no ROSC within 4 minutes → begin PMCS immediately; deliver by 5 minutes ("4–5 minute rule")'),
  bullet('Performed at bedside — do NOT transfer patient'),
  bullet('Rationale: Relieves aortocaval compression → ↑ venous return → ↑ CPR efficacy'),
  bullet('Improves BOTH maternal AND neonatal survival'),

  h3('5. Post-ROSC Care'),
  bullet('Targeted temperature management 33–36°C if unconscious (after ROSC)'),
  bullet('Treat reversible causes: magnesium toxicity → calcium gluconate IV; eclampsia → IV magnesium'),
  bullet('Continuous fetal monitoring; multidisciplinary ICU care'),

  divider(),
  h2('PART B — Surviving Sepsis Campaign (SSC) Guidelines 2021'),

  h3('1. Definitions'),
  bullet('Sepsis: Life-threatening organ dysfunction (SOFA ≥2) from dysregulated host response to infection'),
  bullet('Septic shock: Sepsis + vasopressor requirement + lactate >2 mmol/L despite adequate resuscitation'),

  h3('2. Common Sources in Pregnancy'),
  bullet('Chorioamnionitis, pyelonephritis, endometritis, pneumonia, wound infection'),
  bullet('Signs may be masked: tachycardia + elevated WBC are physiologically normal in pregnancy'),

  h3('3. SSC Hour-1 Bundle'),
  makeTable(
    ['Action', 'Target / Detail'],
    [
      ['Measure serum lactate', 'Remeasure if initial >2 mmol/L'],
      ['Blood cultures', 'Before antibiotics (×2 sets)'],
      ['Broad-spectrum IV antibiotics', 'Within 1 hour of recognition'],
      ['IV crystalloid bolus', '30 mL/kg for hypotension or lactate ≥4 mmol/L'],
      ['Vasopressors (if hypotensive)', 'MAP ≥65 mmHg — norepinephrine first-line'],
    ],
    [3500, 5500]
  ),

  h3('4. Fluid Resuscitation'),
  bullet('Balanced crystalloids (Ringer\'s Lactate) preferred over 0.9% saline'),
  bullet('Dynamic fluid responsiveness assessment — avoid pulmonary oedema (↓ colloid osmotic pressure in pregnancy)'),
  bullet('Albumin considered when large-volume crystalloid required'),

  h3('5. Vasopressors'),
  makeTable(
    ['Agent', 'Role', 'Dose'],
    [
      ['Norepinephrine', 'First-line', '0.01–3 mcg/kg/min, titrate to MAP ≥65'],
      ['Vasopressin', 'Add to reduce NE dose', '0.03 units/min fixed'],
      ['Hydrocortisone', 'If haemodynamically unstable despite fluids + vasopressors', '200 mg/day IV (also promotes fetal lung maturity <34 wks)'],
      ['Epinephrine', 'Refractory shock', '0.01–0.3 mcg/kg/min'],
    ],
    [2500, 3500, 3000]
  ),

  h3('6. Antimicrobials'),
  bullet('Empiric broad-spectrum within 1 hour; de-escalate based on culture sensitivity'),
  bullet('Duration 7–10 days; procalcitonin-guided de-escalation recommended'),
  bullet('Consider delivery if intrauterine source (chorioamnionitis) causing refractory sepsis'),

  h3('7. Ventilation'),
  bullet('Tidal volume 6 mL/kg IBW (lung-protective)'),
  bullet('Permissive hypercapnia acceptable; HOB 30–45°'),
  bullet('SpO₂ target 92–96%'),

  h3('8. Monitoring'),
  bullet('Central venous access + arterial line; urine output >0.5 mL/kg/hr'),
  bullet('Continuous fetal heart rate monitoring if viable gestation'),
  bullet('Glucose target 7.8–10 mmol/L; insulin infusion if >10 mmol/L'),

  pageBreak(),
];

// ─── Q2 ──────────────────────────────────────────────────────────────────────

const q2 = [
  h1('Q2. LFTs and Their Significance; Child-Pugh Score'),
  note('References: Miller\'s Anesthesia Ch. 18; Morgan & Mikhail Ch. 34; Barash Ch. 20'),

  h2('PART A — Liver Function Tests (LFTs) and Anaesthetic Significance'),

  h3('1. Tests and Interpretation'),
  makeTable(
    ['Test', 'Normal', 'Elevated in'],
    [
      ['Total Bilirubin', '<1 mg/dL', 'Hepatocellular damage, cholestasis; jaundice >3 mg/dL'],
      ['Direct (conjugated)', '<0.3 mg/dL', 'Obstructive/hepatocellular cause'],
      ['Indirect (unconjugated)', '<0.8 mg/dL', 'Haemolysis, Gilbert\'s syndrome'],
      ['ALT (SGPT)', '7–56 U/L', 'Most specific for hepatocellular injury'],
      ['AST (SGOT)', '10–40 U/L', 'Less specific; also MI, muscle injury'],
      ['AST:ALT ratio', '—', '<1 viral hepatitis; >2 alcoholic liver disease'],
      ['ALP (Alkaline Phosphatase)', '44–147 U/L', 'Cholestasis, bone disease, pregnancy'],
      ['GGT (Gamma-GT)', '<50 U/L', 'Alcohol use, enzyme induction, cholestasis'],
      ['Albumin', '3.5–5 g/dL', 'Reduced in chronic liver failure (T½ = 21 days)'],
      ['PT / INR', 'INR <1.2', 'Best ACUTE indicator of synthetic function (T½ hours)'],
    ],
    [2200, 1500, 5300]
  ),

  h3('2. Anaesthetic Significance of Abnormal LFTs'),
  bullet('Drug metabolism: ↓ hepatic blood flow + ↓ enzyme activity → prolonged effect of morphine, benzodiazepines, LA'),
  bullet('Coagulation: INR >1.5 or platelets <80,000 → avoid neuraxial anaesthesia without correction'),
  bullet('Albumin: Reduced protein binding → ↑ free drug fraction → enhanced drug effect; reduce doses'),
  bullet('Renal: Hepatorenal syndrome risk; monitor UO meticulously'),
  bullet('Ascites/pleural effusion: Diaphragm elevation → reduced FRC, V/Q mismatch, hypoxia'),
  bullet('Encephalopathy: Avoid benzodiazepines; aspiration risk; rapid sequence induction'),
  bullet('Portal hypertension: Varices → haemorrhage; splenomegaly → thrombocytopaenia'),
  bullet('Hyperdynamic circulation: ↑ CO, ↓ SVR — induction doses must be adjusted'),
  bullet('Pseudo-cholinesterase: Reduced → prolonged succinylcholine / mivacurium action'),

  divider(),
  h2('PART B — Child-Pugh Score'),

  h3('1. Scoring Table'),
  makeTable(
    ['Parameter', '1 Point', '2 Points', '3 Points'],
    [
      ['Serum Bilirubin (mg/dL)', '<2', '2–3', '>3'],
      ['Serum Albumin (g/dL)', '>3.5', '2.8–3.5', '<2.8'],
      ['PT prolongation (s) / INR', '<4 s / <1.7', '4–6 s / 1.7–2.3', '>6 s / >2.3'],
      ['Ascites', 'Absent', 'Mild/Moderate', 'Severe/Refractory'],
      ['Hepatic Encephalopathy', 'Absent', 'Grade I–II', 'Grade III–IV'],
    ],
    [3200, 1950, 1950, 1900]
  ),

  h3('2. Classification and Surgical Risk'),
  makeTable(
    ['Class', 'Score', '1-Year Survival', '2-Year Survival', 'Perioperative Mortality'],
    [
      ['A', '5–6', '100%', '85%', '2–10%'],
      ['B', '7–9', '80%', '57%', '10–30%'],
      ['C', '10–15', '45%', '35%', '>50%'],
    ],
    [1200, 1200, 1700, 1700, 3200]
  ),

  h3('3. Anaesthetic Implications'),
  bullet('Class A: Acceptable operative risk; standard precautions'),
  bullet('Class B: Significant risk; optimise preoperatively; prefer regional if possible; avoid elective if score >9'),
  bullet('Class C: Very high risk; elective surgery contraindicated; if emergency, aggressive ICU support; transplant assessment'),
  bullet('INR >1.5: Give FFP before procedure; platelets <50,000 → transfuse before major surgery'),

  h3('4. MELD Score (Modern Alternative)'),
  bullet('MELD = 3.78 × ln[Bilirubin] + 11.2 × ln[INR] + 9.57 × ln[Creatinine] + 6.43'),
  bullet('MELD ≥15: Mortality risk increases sharply; preferred for transplant prioritisation'),
  bullet('MELD-Na incorporates serum sodium for better accuracy'),

  pageBreak(),
];

// ─── Q3 ──────────────────────────────────────────────────────────────────────

const q3 = [
  h1('Q3. USG-Guided Adductor Canal Block & Renal Replacement Therapy'),
  note('References: Miller\'s Anesthesia Ch. 74; Morgan & Mikhail Ch. 46; Barash Ch. 36'),

  h2('PART A — USG-Guided Adductor Canal Block'),

  h3('1. Anatomy of the Adductor Canal (Hunter\'s Canal)'),
  bullet('Aponeurotic tunnel in mid-thigh containing saphenous nerve, nerve to vastus medialis, femoral artery and vein'),
  bullet('Bounded by: Vastus medialis (anterolateral), Adductor longus/magnus (posteromedial), Sartorius (anterior roof)'),
  bullet('"True" adductor canal: mid-thigh under sartorius — best determined by USG'),

  h3('2. Rationale and Indications'),
  bullet('Motor-sparing block: preserves quadriceps (unlike femoral nerve block)'),
  bullet('Indications: Total knee arthroplasty (TKA), ACL repair, distal femur/proximal tibia surgery, foot/ankle surgery'),
  bullet('Enables early post-op ambulation — preferred in enhanced recovery protocols'),

  h3('3. USG-Guided Technique'),
  makeTable(
    ['Step', 'Detail'],
    [
      ['Position', 'Supine, hip externally rotated, knee slightly flexed'],
      ['Probe', 'High-frequency linear probe (10–15 MHz)'],
      ['Location', 'Transversely at mid-thigh (midpoint ASIS to superior patellar border)'],
      ['Identify', 'Femoral artery (pulsatile) deep to sartorius; saphenous nerve lateral/anterolateral to artery'],
      ['Needle', '22G, 50–100 mm; in-plane approach (preferred)'],
      ['Volume', '15–20 mL of 0.25–0.5% bupivacaine or 0.2% ropivacaine'],
      ['Endpoint', 'Circumferential spread around saphenous nerve within fascial envelope under sartorius'],
    ],
    [2000, 7000]
  ),

  h3('4. Complications'),
  bullet('Intravascular injection (proximity of femoral artery/vein) — always aspirate before injection'),
  bullet('Haematoma at puncture site'),
  bullet('Inadvertent femoral nerve block → quadriceps weakness and fall risk'),
  bullet('Failed block if too distal (only saphenous) or too proximal (femoral nerve territory)'),

  h3('5. Evidence'),
  para('Adductor canal block provides equivalent analgesia to femoral nerve block for TKA with superior quadriceps preservation, enabling early ambulation. (Miller\'s Anesthesia, Chapter 74)'),

  divider(),
  h2('PART B — Renal Replacement Therapy (RRT)'),

  h3('1. Indications (AEIOU)'),
  makeTable(
    ['Letter', 'Indication', 'Threshold'],
    [
      ['A', 'Acidosis', 'pH <7.15 refractory to treatment'],
      ['E', 'Electrolytes', 'K⁺ >6.5 mEq/L despite treatment'],
      ['I', 'Intoxication', 'Dialysable toxins: methanol, ethylene glycol, salicylates, lithium'],
      ['O', 'Overload', 'Fluid overload refractory to diuretics (pulmonary oedema)'],
      ['U', 'Uraemia', 'Uraemic encephalopathy, pericarditis, coagulopathy'],
    ],
    [800, 2200, 6000]
  ),

  h3('2. Modalities'),
  makeTable(
    ['Modality', 'Mechanism', 'Indication'],
    [
      ['IHD (Intermittent Haemodialysis)', 'Diffusion (dialysis)', 'Haemodynamically stable; rapid solute clearance'],
      ['CRRT (Continuous RRT)', 'Slow convection/diffusion', 'Haemodynamically unstable (ICU)'],
      ['SLEDD (Sustained Low-Efficiency DD)', 'Hybrid IHD+CRRT', 'Intermediate stability (HDU)'],
      ['PD (Peritoneal Dialysis)', 'Diffusion via peritoneum', 'Paediatric; no vascular access'],
    ],
    [2800, 2400, 3800]
  ),

  h3('3. CRRT Subtypes'),
  bullet('CVVH: Continuous Venovenous Haemofiltration (convection — solute drag with ultrafiltrate)'),
  bullet('CVVHD: Continuous Venovenous Haemodialysis (diffusion)'),
  bullet('CVVHDF: Combines both mechanisms — preferred for ICU'),

  h3('4. Access and Anticoagulation'),
  bullet('Double-lumen catheter (13–14 Fr): Right IJV preferred > Femoral > Subclavian (avoid — risk of stenosis)'),
  bullet('Anticoagulation: UFH (standard) or regional citrate anticoagulation (preferred in CRRT — lower bleeding risk)'),

  h3('5. Anaesthetic Considerations'),
  bullet('Drug dosing: water-soluble drugs cleared by CRRT — increase doses of vancomycin, aminoglycosides'),
  bullet('Electrolyte monitoring: K⁺, Mg²⁺, Ca²⁺, phosphate must be replaced'),
  bullet('Haemodynamic monitoring critical — avoid hypotension during sessions'),

  pageBreak(),
];

// ─── Q4 ──────────────────────────────────────────────────────────────────────

const q4 = [
  h1('Q4. Types of Labour Analgesia & Pain Pathway in Labour Pain'),
  note('References: Miller\'s Anesthesia Ch. 62; Morgan & Mikhail Ch. 43; Barash Ch. 58'),

  h2('PART A — Pain Pathways in Labour Pain'),

  h3('1. First Stage of Labour (0–10 cm dilatation)'),
  bullet('Source: Uterine contractions + cervical dilation'),
  bullet('Fibres: Visceral C-fibres (slow, poorly localised)'),
  bullet('Path: Uterine/cervical plexus → paracervical ganglia → inferior hypogastric plexus → superior hypogastric plexus → lumbar sympathetic chain → T10–L1 dorsal roots → dorsal horn → spinothalamic tract → thalamus → cortex'),
  bullet('Referred pain: Lower abdomen, back, anterior thighs (T10–L1 dermatomes)'),

  h3('2. Second Stage of Labour (full dilation → delivery)'),
  bullet('Source: Vaginal/perineal distension, pelvic floor stretching'),
  bullet('Fibres: Somatic Aδ-fibres (sharp, well-localised) + C-fibres'),
  bullet('Path: Pudendal nerve (S2–S4) → sacral plexus → posterior columns → spinothalamic tract → thalamus → cortex'),
  bullet('Pain: Intense, somatic, perineal'),

  h3('3. Segmental Innervation Summary'),
  makeTable(
    ['Stage', 'Stimulus', 'Segments'],
    [
      ['First stage (early)', 'Uterine contractions', 'T11–T12'],
      ['First stage (late)', 'Cervical dilation', 'T10–L1'],
      ['Second stage', 'Perineal/vaginal distension', 'S2–S4 (pudendal)'],
    ],
    [3000, 3000, 3000]
  ),

  divider(),
  h2('PART B — Types of Labour Analgesia'),

  h3('1. Regional Analgesia (Gold Standard)'),

  h4('A. Epidural Analgesia'),
  bullet('Most effective method; PCEA (Patient-Controlled Epidural Analgesia) now standard of care'),
  bullet('Technique: L2–L3 or L3–L4; 18G Tuohy needle; catheter 3–4 cm into epidural space'),
  bullet('Agents: 0.0625–0.1% Bupivacaine + Fentanyl 2 mcg/mL (or Sufentanil 0.5 mcg/mL)'),
  bullet('PCEA: Background 5–10 mL/hr + bolus 5–10 mL q 10–20 min'),
  bullet('Covers first and second stage; can be topped up for caesarean section'),
  bullet('Complications: Dural puncture (PDPH), hypotension, motor block, inadequate block'),

  h4('B. Combined Spinal-Epidural (CSE)'),
  bullet('Needle-through-needle technique: spinal component for rapid onset + epidural catheter for maintenance'),
  bullet('Spinal: Fentanyl 25 mcg ± Bupivacaine 2.5 mg intrathecally'),
  bullet('Advantages: Faster onset, better sacral coverage, less motor block than epidural alone'),

  h4('C. Pudendal Nerve Block'),
  bullet('Blocks S2–S4 (pudendal nerve) at ischial spine; covers perineum for second stage only'),
  bullet('10 mL of 1% lignocaine per side; used for forceps delivery, episiotomy repair'),

  h4('D. Paracervical Block'),
  bullet('Blocks T10–L1 (uterine/cervical pain) — first stage only'),
  bullet('Risk of fetal bradycardia (direct LA absorption into uterine artery) — largely abandoned'),

  h3('2. Systemic Analgesia'),

  h4('A. Remifentanil PCIA (Patient-Controlled IV Analgesia)'),
  bullet('Most effective systemic opioid for labour pain'),
  bullet('PCA: 0.2–0.4 mcg/kg bolus, lockout 2 minutes'),
  bullet('Rapid onset (1 min), short duration (3–4 min), predictable (no accumulation)'),
  bullet('MANDATORY: Continuous SpO₂ monitoring + 1:1 midwife supervision (risk of apnoea)'),

  h4('B. Pethidine (Meperidine)'),
  bullet('50–100 mg IM q4h; crosses placenta → neonatal respiratory depression'),
  bullet('Active metabolite norpethidine is CNS toxic (seizures) — largely superseded by remifentanil'),

  h4('C. Nitrous Oxide (Entonox — 50:50 N₂O/O₂)'),
  bullet('Self-administered via demand valve; onset 30–45 seconds'),
  bullet('Reduces but does not abolish pain; safe for mother and baby'),
  bullet('Limitations: Nausea, dizziness, environmental pollution'),

  h3('3. Non-Pharmacological Methods'),
  bullet('Water immersion (hydrotherapy) — evidence of reduced epidural request'),
  bullet('TENS (Transcutaneous Electrical Nerve Stimulation)'),
  bullet('Massage, breathing techniques, hypnosis — evidence limited but safe adjuncts'),

  pageBreak(),
];

// ─── Q5 ──────────────────────────────────────────────────────────────────────

const q5 = [
  h1('Q5. Anaesthesia Challenges & Management of Posterior Fossa Tumour'),
  note('References: Miller\'s Anesthesia Ch. 57; Morgan & Mikhail Ch. 27; Barash Ch. 30'),

  h2('1. Types and Anatomy'),
  bullet('Posterior fossa = infratentorial compartment; smallest, least compliant intracranial space'),
  bullet('Adults: Metastases, meningioma, acoustic neuroma, haemangioblastoma'),
  bullet('Children (most common CNS tumour site): Medulloblastoma, ependymoma, cerebellar astrocytoma'),

  h2('2. Key Challenges'),

  h3('A. Raised ICP / Hydrocephalus'),
  bullet('Posterior fossa mass → CSF outflow obstruction → obstructive hydrocephalus'),
  bullet('Signs: Morning headache, vomiting, papilloedema, deteriorating GCS'),
  bullet('Management: Mannitol 0.25–1 g/kg IV; 3% hypertonic saline; dexamethasone; EVD if severe'),

  h3('B. Venous Air Embolism (VAE) — Major Concern'),
  bullet('Incidence: Up to 25–45% in sitting craniotomy; venous sinuses open with negative pressure'),
  bullet('Pathophysiology: Air → right ventricle "air lock" → ↓ pulmonary blood flow → hypoxia → cardiovascular collapse'),
  makeTable(
    ['Monitor', 'Sensitivity', 'Comment'],
    [
      ['Transoesophageal Echocardiography (TOE)', 'Highest (detects 0.02 mL/kg)', 'Gold standard; also detects PFO'],
      ['Precordial Doppler', 'High', 'Best practical monitor; "millwheel" murmur'],
      ['ETCO₂ decrease', 'Moderate', 'Reliable, simple — sudden fall indicates VAE'],
      ['SpO₂', 'Late', 'Indicates significant embolus already occurred'],
      ['CVP increase', 'Moderate', 'Right heart strain; right atrial catheter for aspiration'],
    ],
    [3500, 1700, 3800]
  ),
  h4('Management of VAE'),
  bullet('Notify surgeon → pack/flood surgical field with saline'),
  bullet('Jugular venous compression to reduce venous gradient'),
  bullet('Aspirate air via right atrial catheter (placed at cavoatrial junction)'),
  bullet('100% FiO₂ (avoid N₂O — expands air emboli up to 3× volume)'),
  bullet('Left lateral decubitus + Trendelenburg position'),
  bullet('PEEP cautiously (may open PFO → paradoxical air embolism)'),
  bullet('CPR if cardiac arrest'),

  h3('C. Positioning'),
  bullet('Sitting/semi-sitting: Excellent surgical access; reduces blood in field; but highest VAE risk'),
  bullet('Head flexion limit: ≥2 finger-breadths from chin to chest (prevents cervical cord ischaemia)'),
  bullet('Risks: VAE, pneumocephalus, quadriplegia, haemodynamic instability, peripheral nerve injuries'),
  bullet('Prone: Less VAE risk but poor access for midline lesions'),

  h3('D. Brainstem Proximity'),
  bullet('Manipulation → Cushing\'s response (bradycardia + hypertension), arrhythmias'),
  bullet('Neuromonitoring: SSEP, MEP, BAEP (brainstem auditory evoked potentials), facial EMG'),

  h3('E. Pneumocephalus'),
  bullet('"Mt Fuji sign" on CT: bilateral frontal air collections with bridging veins'),
  bullet('Tension pneumocephalus → neurological deterioration post-op'),
  bullet('Prevention: Avoid N₂O; head-down position before dural closure'),

  h2('3. Anaesthetic Management'),

  h3('A. Preoperative'),
  bullet('Assess ICP (GCS, CT/MRI), hydration, anticonvulsant levels, steroid therapy'),
  bullet('Continue dexamethasone; optimise coagulation; obtain consent for positioning risks'),

  h3('B. Induction'),
  bullet('Propofol (↓ ICP, ↓ CMRO₂) + Fentanyl + Vecuronium (avoid succinylcholine — transient ↑ ICP)'),
  bullet('Avoid ketamine (↑ ICP)'),
  bullet('Lidocaine IV 1.5 mg/kg before laryngoscopy to blunt ICP response'),
  bullet('Secure ETT well (difficult access intraoperatively when positioned)'),

  h3('C. Maintenance'),
  bullet('TIVA with propofol infusion preferred: ↓ CMR, ↓ ICP, antiemetic, rapid offset for neurological assessment'),
  bullet('Alternatively: Volatile ≤1 MAC with air/O₂ (no N₂O)'),
  bullet('Remifentanil infusion: rapid offset → neurological exam immediately post-op'),
  bullet('PaCO₂: Normocapnia (35–40 mmHg); moderate hyperventilation (30–35) if brain tight'),

  h3('D. Monitoring'),
  bullet('Standard + Invasive arterial line (CPP monitoring; CPP = MAP – ICP; target ≥60 mmHg)'),
  bullet('CVP/CVC with right atrial catheter (15–20 cm from right IJ) for VAE aspiration'),
  bullet('Precordial Doppler (best practical VAE monitor)'),
  bullet('SSEP/MEP/BAEP as appropriate to surgical site'),

  h3('E. Emergence'),
  bullet('Smooth emergence critical — coughing spikes ICP; use remifentanil tapering + IV lidocaine'),
  bullet('Extubate fully awake for neurological assessment'),
  bullet('Post-op ITU/HDU; CT scan if any neurological deterioration'),
  bullet('Dexamethasone continued; anticonvulsants maintained'),

  pageBreak(),
];

// ─── Q6 ──────────────────────────────────────────────────────────────────────

const q6 = [
  h1('Q6. Airway Management of Maxillofacial Trauma + Manual Inline Stabilisation'),
  note('References: Miller\'s Anesthesia Ch. 44; Morgan & Mikhail Ch. 19; Barash Ch. 28'),

  h2('1. Challenges in Maxillofacial Trauma'),
  bullet('Distorted anatomy: Mid-face fractures, mandibular fractures, haematomas, oedema'),
  bullet('Blood + secretions: Active bleeding obscures laryngoscopy; high aspiration risk'),
  bullet('Trismus: Masseter spasm, zygoma fracture, haematoma → limited mouth opening'),
  bullet('Cervical spine injury: 1–4% of facial trauma — must be assumed until cleared radiologically'),
  bullet('Difficult mask ventilation: Broken teeth, facial deformity, beard, oedema'),
  bullet('Restricted neck movements due to cervical collar'),
  bullet('Airway burns: If associated fire/blast injury'),

  h2('2. LeFort Fracture Classification'),
  makeTable(
    ['Type', 'Description', 'Airway Implication'],
    [
      ['LeFort I', 'Horizontal fracture of maxilla', 'Moderate instability'],
      ['LeFort II', 'Pyramidal: maxillary-nasal-orbital complex; may involve cribriform plate', 'Nasal intubation CONTRAINDICATED'],
      ['LeFort III', 'Craniofacial separation — full mid-face detachment', 'Nasal intubation ABSOLUTELY CONTRAINDICATED; most serious'],
    ],
    [1600, 4400, 3000]
  ),

  h2('3. Manual Inline Stabilisation (MILS)'),
  h3('Rationale'),
  bullet('Until cervical spine cleared, stabilise to prevent secondary cord injury during airway manipulation'),
  bullet('Cervical collar alone does NOT allow adequate mouth opening; MILS replaces it'),
  h3('Technique'),
  bullet('Assistant stands at patient\'s side, places hands on mastoid processes and mandibular rami'),
  bullet('Maintains head in NEUTRAL position (not traction)'),
  bullet('Cervical collar opened anteriorly → mouth opens → MILS continues'),
  bullet('MILS reduces cervical spine movement by ~50% but worsens Cormack-Lehane grade in ~50% — anticipate difficult airway'),

  h2('4. Airway Management Strategy'),

  h3('A. Immediate (Crash Airway — Cannot Protect/Maintain Airway)'),
  bullet('RSI + MILS: Succinylcholine 1.5 mg/kg (justified despite theoretical concerns)'),
  bullet('Video laryngoscopy (C-MAC, GlideScope, McGrath) with MILS'),
  bullet('If "Can\'t Intubate, Can\'t Oxygenate" → immediate front-of-neck access (FONA): Cricothyrotomy'),

  h3('B. Semi-Elective (Anticipated Difficult Airway)'),
  bullet('Awake Fibreoptic Intubation (AFOI): Gold standard for difficult airway + full stomach'),
  bullet('Airway topicalisation: Nebulised lignocaine 4% + trans-cricoid injection + superior laryngeal nerve blocks'),
  bullet('Sedation: Dexmedetomidine infusion (maintains airway reflexes) or low-dose midazolam/propofol'),
  bullet('Oral route preferred; NASAL ROUTE CONTRAINDICATED in LeFort II/III (cribriform plate fracture)'),

  h3('C. Video Laryngoscopy'),
  bullet('McGrath MAC, C-MAC, GlideScope: Improve view with MILS (but do not eliminate need for it)'),
  bullet('Channelled devices (King Vision, Airtraq): Useful with restricted mouth opening'),
  bullet('Bougie through angulated channel may be required'),

  h3('D. Surgical Airway'),
  bullet('Cricothyrotomy: Emergency — needle or surgical technique; 6.0 ETT or bougie-assisted'),
  bullet('Surgical tracheostomy: Preferred for long-term; performed under local in cooperative patient'),

  h3('E. Nasal Intubation (When Indicated)'),
  bullet('Useful for trismus with intact cervical spine and no basal skull fracture'),
  bullet('Absolutely contraindicated: Basal skull fracture, LeFort II/III, coagulopathy'),
  bullet('Technique: Smaller ETT (6.5 mm); vasoconstrictor pretreatment; gentle passage'),

  h2('5. Post-Intubation Management'),
  bullet('Verify tube position (capnography, bilateral air entry)'),
  bullet('If jaws wired post-op (IMF): wire-cutters at bedside at all times'),
  bullet('Extubation only when fully awake and oedema has subsided; consider delayed extubation in theatre'),
  bullet('Document laryngoscopy grade; notify team of difficult airway'),

  pageBreak(),
];

// ─── Q7 ──────────────────────────────────────────────────────────────────────

const q7 = [
  h1('Q7. Anaesthesia for 2-Year-Old Paediatric with Foreign Body — Emergency'),
  note('References: Miller\'s Anesthesia Ch. 93; Morgan & Mikhail Ch. 44; Barash Ch. 60'),

  h2('1. Clinical Assessment'),
  h3('History'),
  bullet('Type of FB (coin, button battery, peanut), time, site (airway vs. oesophageal), onset of symptoms'),
  bullet('Coughing, stridor, wheeze, cyanosis (airway); drooling, dysphagia, vomiting (oesophageal)'),
  bullet('Last oral intake — always treat as full stomach regardless'),
  bullet('URTI (reactive airway), prematurity, previous anaesthetics'),
  bullet('Weight estimate: Age × 2 + 8 = ~12 kg for 2-year-old'),

  h3('Signs of Airway FB'),
  bullet('Inspiratory stridor: Supraglottic/laryngeal FB'),
  bullet('Expiratory wheeze + unilateral ↓ air entry: Bronchial FB (right main bronchus most common)'),
  bullet('CXR: Hyperinflation, mediastinal shift, atelectasis; radiopaque FB on X-ray'),

  h2('2. Paediatric Physiological Differences'),
  makeTable(
    ['Parameter', '2-Year-Old', 'Anaesthetic Implication'],
    [
      ['Weight', '~12 kg', 'Weight-based drug dosing; small absolute volumes'],
      ['O₂ consumption', '6–8 mL/kg/min (adult: 3–4)', 'Desaturates much faster — rapid preoxygenation essential'],
      ['FRC', 'Small; closes at normal TV', 'Rapid desaturation during apnoea'],
      ['Airway calibre', 'Small; narrowest subglottically', 'FB causes complete obstruction easily'],
      ['Heart rate', '100–120/min', 'Bradycardia = hypoxia — give atropine prophylactically'],
      ['Blood volume', '80 mL/kg = 960 mL', 'Small absolute volume; blood loss significant'],
    ],
    [2200, 2500, 4300]
  ),

  h2('3. Equipment Preparation'),
  bullet('ETT: Uncuffed 4.5 mm (age/4 + 4); Cuffed 4.0 mm (age/4 + 3.5); Uncuffed 4.0 mm as backup'),
  bullet('Laryngoscope: Miller 1 (straight blade preferred in young children)'),
  bullet('Rigid ventilating bronchoscope (Storz): Size 3.5–4.0 mm for 2-year-old'),
  bullet('LMA size 2 (backup); Magill forceps'),
  bullet('Drugs drawn up: Atropine 0.24 mg (0.02 mg/kg); Succinylcholine 24 mg (2 mg/kg); Propofol 36 mg (3 mg/kg)'),

  h2('4. Induction Strategy — Critical Decision'),

  h3('A. Inhalational Induction (Preferred for Airway FB)'),
  bullet('Rationale: Maintains spontaneous ventilation → FB less likely to move; avoids apnoea + complete obstruction'),
  bullet('Agent: Sevoflurane 8% with 100% O₂'),
  bullet('Once deep: IV cannula placed; Atropine IV given (↓ secretions, prevents bradycardia)'),
  bullet('Maintain spontaneous respiration throughout bronchoscopy'),
  bullet('Topical lidocaine 4 mg/kg to larynx before bronchoscopy insertion'),

  h3('B. RSI (Oesophageal FB or Non-Airway Emergency)'),
  bullet('Preoxygenation: High-flow 10 L/min near face (child uncooperative — use distraction)'),
  bullet('Propofol 3 mg/kg IV + Succinylcholine 2 mg/kg IV'),
  bullet('Cricoid pressure (Sellick): 10–15 N in children'),
  bullet('No PPV before intubation; rapid intubation'),

  h2('5. Maintenance During Bronchoscopy'),
  bullet('Sevoflurane 3–4% via sideport of ventilating bronchoscope'),
  bullet('Sanders injector / jet ventilation for older children (not <5 years)'),
  bullet('Avoid muscle relaxants (observe spontaneous movements as guide to depth/position)'),

  h2('6. Complications and Management'),
  makeTable(
    ['Complication', 'Management'],
    [
      ['Complete obstruction (FB pushed distally by PPV)', 'Surgeon ready; STOP PPV; allow spontaneous breathing'],
      ['Laryngospasm', 'Succinylcholine 2 mg/kg IV or Propofol 1 mg/kg IV'],
      ['Bronchospasm', 'Deepen anaesthesia; salbutamol via bronchoscope'],
      ['Hypoxia', 'High-flow O₂; jaw thrust; suction; reposition bronchoscope'],
      ['Oesophageal perforation (FB ingestion)', 'Subcutaneous emphysema, fever → surgical emergency'],
    ],
    [3500, 5500]
  ),

  h2('7. Emergence and Recovery'),
  bullet('Extubate AWAKE (active cough/swallow reflex present) to prevent aspiration'),
  bullet('Post-extubation croup: Racemic epinephrine nebulisation 2.25% 0.5 mL in 2.5 mL saline'),
  bullet('Post-op CXR to confirm FB removal; check for pneumothorax'),
  bullet('IV fluid maintenance: 4:2:1 rule = 40 + (12×2) + (2×1) = 72 mL/hr for 14 kg'),
  bullet('Monitor 24 hours (post-obstructive pulmonary oedema, delayed stridor)'),

  pageBreak(),
];

// ─── Q8 ──────────────────────────────────────────────────────────────────────

const q8 = [
  h1('Q8. Biochemical Changes of Stored Blood; Indications & Complications of Transfusion'),
  note('References: Miller\'s Anesthesia Ch. 49; Morgan & Mikhail Ch. 51; Barash Ch. 17'),

  h2('PART A — Biochemical Changes in Stored Blood ("Storage Lesion")'),
  para('Blood stored in CPDA-1 solution at 1–6°C for up to 35 days, or in Additive Solutions (AS-1, AS-3, AS-7) for up to 42 days.'),
  makeTable(
    ['Change', 'Mechanism', 'Clinical Effect'],
    [
      ['↑ K⁺ (up to 70–80 mEq/L by day 42)', 'RBC lysis; loss of Na-K ATPase', 'Hyperkalaemia (esp. neonates, rapid infusion)'],
      ['↓ pH (→ 6.5–6.8)', 'RBC metabolism → lactic acid', 'Metabolic acidosis (massive transfusion)'],
      ['↓ 2,3-DPG (→ 0 by day 2–3)', 'Depletion of phosphate stores', 'Left-shift O₂-Hb curve → ↓ O₂ offloading (reverses within 24 hrs post-transfusion)'],
      ['↓ ATP', 'Metabolic depletion', '↓ RBC deformability; spherocytosis; ↓ RBC survival'],
      ['↑ Free haemoglobin', 'RBC haemolysis', 'NO scavenging → vasoconstriction; renal tubular injury'],
      ['Citrate excess', 'Anticoagulant in preservative', 'Hypocalcaemia (chelates Ca²⁺) → myocardial depression with massive transfusion'],
      ['↑ Microaggregates', 'RBC + platelet + fibrin debris', 'Microemboli in pulmonary vasculature'],
      ['Loss of clotting factors V, VIII', 'Labile factors degrade in storage', 'Coagulopathy after massive transfusion'],
      ['Hypothermia', 'Cold storage (4°C)', 'Arrhythmias; impaired coagulation enzyme function'],
    ],
    [2800, 2700, 3500]
  ),

  h3('Clinical Implications'),
  bullet('Use blood warmers for all large transfusions — target normothermia'),
  bullet('Monitor Ca²⁺, K⁺, pH, lactate with massive transfusion'),
  bullet('Massive transfusion protocol: 1:1:1 (PRBC : FFP : Platelets)'),
  bullet('Neonates and renal failure patients: Use freshest blood available (<5 days) for exchange/cardiac surgery'),

  divider(),
  h2('PART B — Indications for Blood Transfusion'),
  makeTable(
    ['Component', 'Indications', 'Threshold'],
    [
      ['PRBC', 'Anaemia with symptoms (dyspnoea, angina, tachycardia); acute haemorrhage (Class III/IV)', 'Restrictive: Hb <7 g/dL (stable); Liberal: Hb <8 g/dL (cardiac, elderly)'],
      ['FFP', 'Massive transfusion; DIC with bleeding; warfarin reversal; TTP (plasma exchange)', 'INR >1.5–2 with bleeding'],
      ['Platelets', 'Active bleeding; major surgery', '<50,000/μL (major surgery); <100,000 (neurosurgery); <10,000 (prophylactic)'],
      ['Cryoprecipitate', 'Hypofibrinogenaemia; Haemophilia A; vWD; DIC', 'Fibrinogen <1.5 g/L with active bleeding'],
    ],
    [1500, 4000, 3500]
  ),

  divider(),
  h2('PART C — Complications of Blood Transfusion'),

  h3('A. Immunological Complications'),
  makeTable(
    ['Reaction', 'Mechanism', 'Features', 'Management'],
    [
      ['AHTR (Acute HTR)', 'ABO incompatibility; IgM + complement', 'Fever, chills, back pain, haemoglobinuria, DIC, renal failure, shock — most fatal', 'Stop transfusion; IV fluids; maintain UO >1 mL/kg/hr; treat DIC'],
      ['DHTR (Delayed HTR)', 'IgG (Rh, Kidd, Duffy); 3–14 days later', 'Mild jaundice, fever, unexplained anaemia', 'Supportive; notify haematology'],
      ['FNHTR', 'WBC antibodies + cytokines', 'Fever ≥1°C rise; chills; no haemolysis', 'Stop → exclude AHTR; paracetamol; restart slowly'],
      ['Allergic/Urticaria', 'IgE against plasma proteins', 'Urticaria, pruritis', 'Stop; antihistamine; restart if mild'],
      ['Anaphylaxis', 'IgA deficiency + anti-IgA antibodies', 'Bronchospasm, hypotension, collapse', 'Stop; Epinephrine 0.5 mg IM; resuscitate'],
      ['TRALI', 'Anti-HLA/anti-neutrophil Abs from donor', 'Bilateral infiltrates within 6 hrs; non-cardiogenic pulmonary oedema', 'Stop; O₂/ventilatory support; no diuretics'],
      ['TA-GvHD', 'Donor T-lymphocytes attack host', 'Fever, rash, diarrhoea, pancytopaenia', 'Prevention: Irradiated blood; >90% fatal once established'],
      ['TACO', 'Volume overload; hydrostatic', 'Bilateral oedema; ↑ BNP; cardiogenic', 'Diuretics; stop/slow transfusion'],
    ],
    [1700, 2000, 3000, 2300]
  ),

  h3('B. Non-Immunological Complications'),
  bullet('Hyperkalaemia: Old blood, rapid infusion, neonates — monitor K⁺, use fresh blood'),
  bullet('Hypocalcaemia: Citrate toxicity → myocardial depression — calcium gluconate 10 mL IV'),
  bullet('Hypothermia: Cold blood → arrhythmias, coagulopathy — use blood warmer'),
  bullet('Metabolic acidosis: Lactic acid in stored blood; monitor ABG'),
  bullet('Dilutional coagulopathy: Massive transfusion — treat with 1:1:1 protocol'),
  bullet('Transfusion-transmitted infections: HIV <1:1.5M, HCV <1:1.2M, HBV <1:1M per unit (current screening)'),
  bullet('Iron overload: Chronic transfusion → haemosiderosis → chelation therapy required'),

  pageBreak(),
];

// ─── Q9 ──────────────────────────────────────────────────────────────────────

const q9 = [
  h1('Q9. Link 25 & Electrical Safety in the Operating Theatre'),
  note('References: Miller\'s Anesthesia Ch. 6; Morgan & Mikhail Ch. 3; Barash Ch. 5'),

  h2('1. Basic Electrical Principles'),
  makeTable(
    ['Term', 'Definition'],
    [
      ['Voltage (V)', 'Electromotive force / potential difference (volts)'],
      ['Current (I)', 'Flow of electrons (amperes); V = IR (Ohm\'s law)'],
      ['Resistance (R)', 'Opposition to current flow (ohms)'],
      ['Power (P)', 'P = I²R — heat generated (basis of diathermy burns)'],
      ['Frequency', 'Mains 50 Hz; lowest threshold for VF at 50–60 Hz'],
    ],
    [2000, 7000]
  ),

  h2('2. Macroshock vs. Microshock'),
  makeTable(
    ['Parameter', 'Macroshock', 'Microshock'],
    [
      ['Definition', 'Current applied to body surface', 'Current applied directly to myocardium (via catheter/pacemaker wire)'],
      ['VF threshold', '100–150 mA', '60–180 μA (1000× more sensitive)'],
      ['Source', 'Faulty equipment touching skin', 'Central line, cardiac catheter acting as conductor'],
      ['Path', 'Skin → heart (high impedance, dispersed)', 'Direct to myocardium (no impedance)'],
    ],
    [2000, 3500, 3500]
  ),

  h3('Human Current Response Thresholds'),
  makeTable(
    ['Current', 'Effect'],
    [
      ['1 mA', 'Perception threshold'],
      ['5–10 mA', '"Let-go" threshold — unable to release conductor'],
      ['50–100 mA', 'Respiratory paralysis'],
      ['100–150 mA', 'Ventricular fibrillation (VF)'],
      ['>1 A', 'Sustained myocardial contraction (defibrillation effect), severe burns'],
    ],
    [2000, 7000]
  ),

  h2('3. Link 25 / Leakage Current Standards (IEC 60601)'),
  makeTable(
    ['Equipment Type', 'Description', 'Max Leakage Current'],
    [
      ['Type B', 'General body-contact equipment', '100 μA'],
      ['Type BF', 'Floating, body-connected (e.g. ECG)', '100 μA'],
      ['Type CF', 'Cardiac floating — intracardiac use (pacemaker leads, cardiac catheters)', '10 μA'],
    ],
    [1800, 4200, 3000]
  ),
  bullet('"Link 25" concept: CF equipment limit of 10 μA provides safety margin well below microshock threshold of 60 μA'),
  bullet('All intracardiac catheters and cardiac pacemaker connections MUST use CF-grade equipment in OT'),

  h2('4. Isolated Power Supply System (IPS)'),
  h3('Purpose: Prevent macroshock in OT'),
  bullet('Normal mains: One conductor earthed — fault touching patient completes circuit through them → shock'),
  bullet('IPS uses isolation transformer: Neither output conductor connected to earth'),
  bullet('Single ground fault does NOT complete circuit through patient — surgery continues safely'),

  h3('Line Isolation Monitor (LIM)'),
  bullet('Continuously measures impedance between isolated circuit and earth'),
  bullet('Alarms if leakage exceeds 2–5 mA (warning, not automatic power cutoff)'),
  bullet('On alarm: investigate and remove faulty equipment; do NOT cut power mid-surgery'),

  h2('5. Equipment Classification (IEC 60601)'),
  makeTable(
    ['Class', 'Insulation', 'Earth Required', 'Safety Basis'],
    [
      ['Class I', 'Basic insulation', 'Yes — earthed metal casing', 'Depends on earth integrity'],
      ['Class II', 'Double insulation', 'No', 'Self-contained (e.g. battery-powered)'],
      ['Class III', 'Extra low voltage (SELV)', 'No', 'Intrinsically safe by low voltage'],
    ],
    [1500, 2500, 2000, 3000]
  ),

  h2('6. Diathermy (Electrosurgery) Safety'),
  makeTable(
    ['Type', 'Mechanism', 'Risk'],
    [
      ['Monopolar', 'High-freq AC current: concentrated at active tip, dispersed at return plate', 'Return plate burns (poor contact); ECG electrode burns; pacemaker interference'],
      ['Bipolar', 'Current only between two forceps tips', 'Less risk; preferred for delicate surgery + pacemaker patients'],
    ],
    [1500, 4500, 3000]
  ),
  bullet('Frequency >100 kHz: Avoids neuromuscular stimulation (higher than nerve conduction bandwidth)'),
  bullet('Pacemaker: Use bipolar if possible; asynchronous mode (DOO/VOO); magnet at bedside'),
  bullet('Fire risk: Supplement O₂ near drapes + diathermy spark → drape fire (head/neck surgery)'),

  h2('7. Electrical Safety Measures in OT'),
  bullet('Regular equipment PAT testing and maintenance (annual biomedical engineering checks)'),
  bullet('IPS + LIM in all OT suites (mandatory by hospital standards)'),
  bullet('Medical-grade power strips only; no domestic extension leads'),
  bullet('Antistatic flooring + equipment (historically for explosive agents; relevant for static spark prevention)'),
  bullet('Staff training in electrical hazard recognition and near-miss reporting'),
  bullet('RCDs (Residual Current Devices) NOT used in OT — they interrupt power; IPS is used instead'),

  pageBreak(),
];

// ─── Q10 ─────────────────────────────────────────────────────────────────────

const q10 = [
  h1('Q10. Post-op Analgesia for Paediatric — Lower Abdominal Surgery & Thoracotomy'),
  note('References: Miller\'s Anesthesia Ch. 93; Morgan & Mikhail Ch. 44; Barash Ch. 60'),

  h2('Principles of Paediatric Post-operative Analgesia'),
  bullet('Multimodal analgesia: Combine analgesics at different mechanisms to reduce opioid requirements'),
  bullet('Components: Paracetamol (baseline) + NSAIDs + Regional technique + Opioids (rescue)'),

  h3('Pain Assessment Tools'),
  makeTable(
    ['Age Group', 'Tool', 'Scale'],
    [
      ['Neonates/Infants', 'NIPS (Neonatal Infant Pain Scale) / CRIES', '0–7 or 0–10'],
      ['1–5 years', 'FLACC (Face, Legs, Activity, Cry, Consolability)', '0–10'],
      ['>5 years', 'Faces Pain Scale / NRS', '0–10'],
    ],
    [2500, 3500, 3000]
  ),
  bullet('Target: FLACC/NRS score <4 for adequate analgesia'),

  divider(),
  h2('PART A — Lower Abdominal Surgery'),
  para('Indications: Inguinal hernia repair, orchidopexy, circumcision, lower laparotomy, appendicectomy'),

  h3('1. Caudal Epidural Block — Workhorse of Paediatric Regional Analgesia'),
  h4('Anatomy and Technique'),
  bullet('Sacral hiatus bounded by sacral cornua; approach via sacrococcygeal ligament'),
  bullet('Position: Lateral decubitus or prone; 22G short-bevel needle at 45–60° through sacrococcygeal membrane'),
  bullet('USG guidance increasingly used — confirms needle position, reduces failure rate'),

  h4('Dosing'),
  makeTable(
    ['Volume (bupivacaine 0.25%)', 'Level Reached', 'Coverage'],
    [
      ['0.5 mL/kg', 'S2–T12', 'Perineal/scrotal surgery'],
      ['1 mL/kg', 'T10', 'Lower abdominal surgery (ideal for hernia/orchidopexy)'],
      ['1.25 mL/kg', 'T6', 'Mid-abdominal (use 0.2% to avoid toxicity)'],
    ],
    [3000, 2000, 4000]
  ),

  h4('Additives to Prolong Duration'),
  makeTable(
    ['Additive', 'Dose', 'Duration Extension', 'Note'],
    [
      ['Clonidine', '1–2 mcg/kg', '4–6 hours', 'Mild sedation; avoid <6 months'],
      ['Dexmedetomidine', '1 mcg/kg', '6–8 hours', 'Growing evidence; sedation'],
      ['Morphine (preservative-free)', '30 mcg/kg', '12–24 hours', 'Monitor for delayed respiratory depression'],
      ['Ketamine (preservative-free)', '0.5 mg/kg', '6 hours', 'Avoid >1 mg/kg (dissociation)'],
    ],
    [2000, 1500, 2000, 3500]
  ),

  bullet('Complications: Dural puncture, intravascular injection, infection (rare), inadvertent intraosseous'),

  h3('2. Ilioinguinal / Iliohypogastric Nerve Block'),
  bullet('Indication: Inguinal hernia, orchidopexy'),
  bullet('USG guided: Between external oblique and internal oblique, 1 cm medial and inferior to ASIS'),
  bullet('0.25% Bupivacaine 0.1–0.2 mL/kg per side; duration 8–12 hours; no motor block'),

  h3('3. TAP (Transversus Abdominis Plane) Block'),
  bullet('Indication: Lower abdominal incisions (appendicectomy, laparotomy, stomas)'),
  bullet('USG guided: Between internal oblique and transversus abdominis in midaxillary triangle of Petit'),
  bullet('0.25% Bupivacaine 0.4 mL/kg per side (max 2 mg/kg per side)'),
  bullet('Covers T10–L1 (somatic pain only — does NOT cover visceral pain)'),

  h3('4. Systemic Analgesia'),
  makeTable(
    ['Drug', 'Dose', 'Route', 'Comment'],
    [
      ['Paracetamol', '20 mg/kg loading, then 15 mg/kg q6h', 'IV', 'Essential base; ceiling effect'],
      ['Ketorolac', '0.5 mg/kg q6h', 'IV', '>6 months; reduces opioid 30–40%; caution renal/bleeding'],
      ['Diclofenac', '1 mg/kg q8h', 'PR/IV', 'Anti-inflammatory; rectal suppository post-op'],
      ['Morphine NCA', '20–40 mcg/kg q1h nurse-controlled', 'IV', 'Age <5 years; nurse/parent key'],
      ['Morphine PCA', '10–20 mcg/kg bolus, 5 min lockout', 'IV', 'Age ≥5–6 years'],
    ],
    [1800, 2200, 1200, 3800]
  ),

  divider(),
  h2('PART B — Thoracotomy Analgesia'),
  para('Thoracotomy is among the most painful surgeries. Inadequate analgesia → splinting → atelectasis → pneumonia. Multimodal approach is essential.'),

  h3('1. Thoracic Epidural Analgesia (TEA) — Gold Standard'),
  bullet('Catheter: T4–T8 level for posterolateral thoracotomy; placed awake or under GA'),
  bullet('Drugs: 0.1% Bupivacaine + Fentanyl 2 mcg/mL at 0.1–0.3 mL/kg/hr'),
  bullet('Benefits: Superior to systemic opioids; reduces pulmonary complications by 50%; enables early extubation'),
  bullet('Paediatric: Caudal-thoracic threading technique — catheter threaded from caudal epidural to thoracic level under fluoroscopy/USG'),
  bullet('Complications: Dural tap, haematoma, hypotension, motor block'),

  h3('2. Paravertebral Block (PVB)'),
  bullet('Anatomy: Wedge-shaped space lateral to vertebral body — contains intercostal nerve, rami communicantes'),
  bullet('Technique: USG; needle 2.5 cm lateral to spinous process → transverse process → superior border → advance 1–1.5 cm'),
  bullet('Drugs: Ropivacaine 0.5% bolus 0.5 mL/kg; then catheter infusion 0.2% ropivacaine 0.1 mL/kg/hr'),
  bullet('Advantages: Unilateral block (fewer haemodynamic effects); less motor block; equally effective as TEA; safer with coagulopathy'),

  h3('3. Intercostal Nerve Block'),
  bullet('Bupivacaine 0.25% 0.5–1 mL per level; block 2 levels above and below incision'),
  bullet('Duration 6–12 hours; intraoperative injection by surgeon reduces systemic opioid'),
  bullet('CAUTION: Highest plasma LA levels of any regional technique — stay within 2 mg/kg total'),

  h3('4. Fascial Plane Blocks (Newer Approaches)'),
  bullet('ESPB (Erector Spinae Plane Block): LA between erector spinae and transverse process; T1–T9 coverage via paravertebral spread; Ropivacaine 0.2% 0.5–1 mL/kg'),
  bullet('SAPB (Serratus Anterior Plane Block): Between serratus anterior and latissimus dorsi; T2–T9; lateral thorax'),
  bullet('Advantages: Easier, safer (away from pleura); suitable for all ages'),

  h3('5. Systemic Adjuncts'),
  makeTable(
    ['Drug', 'Dose', 'Benefit'],
    [
      ['Paracetamol IV', '15 mg/kg q6h', 'Essential baseline; synergistic with regional'],
      ['Ketorolac IV', '0.5 mg/kg q6h', 'Reduces opioid 30–40%; anti-inflammatory'],
      ['Ketamine infusion', '0.1–0.2 mg/kg/hr', 'NMDA antagonism → prevents central sensitisation'],
      ['Dexmedetomidine infusion', '0.2–0.7 mcg/kg/hr', 'Opioid-sparing; sedation; reduces emergence agitation'],
      ['Morphine PCA (≥5 yrs)', '10–20 mcg/kg bolus, 5 min lockout', 'Rescue analgesia; patient-controlled'],
    ],
    [2500, 2000, 4500]
  ),

  h3('6. Non-Pharmacological'),
  bullet('Pillow splinting of incision for cough — teach pre-operatively'),
  bullet('Semi-upright positioning (30–45°) — improves respiratory mechanics'),
  bullet('Chest physiotherapy within 6 hours post-surgery'),
  bullet('Incentive spirometry once alert — prevents atelectasis'),

  divider(),
  h3('Summary — Analgesic Regimen'),
  makeTable(
    ['Surgery', 'First Choice Regional', 'Systemic Base', 'Rescue Opioid'],
    [
      ['Inguinal hernia/orchidopexy', 'Caudal 0.5 mL/kg 0.25% bupivacaine OR IliIng/IliHypo block', 'Paracetamol + Ketorolac', 'Morphine NCA/PCA'],
      ['Lower abdominal laparotomy', 'Caudal 1 mL/kg OR bilateral TAP block', 'Paracetamol + Ketorolac', 'Morphine NCA/PCA'],
      ['Thoracotomy', 'Thoracic epidural (gold standard) OR Paravertebral block', 'Paracetamol + Ketamine infusion + Ketorolac', 'Morphine PCA (≥5 yrs)'],
    ],
    [2000, 3000, 2200, 1800]
  ),

  pageBreak(),
];

// ─── References page ─────────────────────────────────────────────────────────

const refs = [
  h1('References'),
  h3('Primary Textbooks'),
  bullet('Miller\'s Anesthesia, 10th Edition. Gropper MA et al. Elsevier, 2023. Chapters: 6, 18, 44, 49, 57, 62, 74, 80, 91, 93'),
  bullet('Morgan & Mikhail\'s Clinical Anesthesiology, 7th Edition. Butterworth JF et al. McGraw-Hill, 2022. Chapters: 3, 19, 21, 27, 34, 40, 43, 44, 46, 51'),
  bullet('Barash Clinical Anesthesia, 9th Edition. Barash PG et al. Wolters Kluwer, 2023. Chapters: 5, 14, 17, 20, 28, 30, 32, 36, 58, 60'),
  bullet('Creasy & Resnik\'s Maternal-Fetal Medicine, 9th Edition. Chapters 18, 48'),

  h3('Guidelines'),
  bullet('Surviving Sepsis Campaign International Guidelines 2021. Evans L et al. Intensive Care Med. 2021;47(11):1181–1247'),
  bullet('ILCOR/AHA Special Circumstances Guidelines: Cardiac Arrest in Pregnancy 2023'),
  bullet('Obstetric Anaesthetists\' Association / Association of Anaesthetists: Guidelines for Obstetric Anaesthesia (UK, 2021)'),
  bullet('American Society of Regional Anesthesia (ASRA): Regional Anesthesia Practice Advisories 2022'),
  bullet('IEC 60601-1: Medical Electrical Equipment Safety Standards (3rd Edition)'),

  divider(),
  new Paragraph({
    children: [new TextRun({ text: 'Document prepared for DNB Anaesthesia examination preparation. May 2026.', italics: true, size: 18, color: '888888' })],
    alignment: AlignmentType.CENTER,
    spacing: { before: 200 },
  }),
];

// ─── Build document ───────────────────────────────────────────────────────────

const doc = new Document({
  creator: 'Orris AI',
  title: 'DNB Anaesthesia — 10 Model Answers',
  description: 'Comprehensive model answers for DNB Anaesthesia examination, referenced from Miller\'s, Morgan & Mikhail, and Barash.',
  styles: {
    default: {
      document: {
        run: { font: 'Calibri', size: 20 },
      },
    },
    paragraphStyles: [
      {
        id: 'Heading1',
        name: 'Heading 1',
        basedOn: 'Normal',
        next: 'Normal',
        run: { bold: true, size: 32, color: '2E4057', font: 'Calibri' },
        paragraph: { spacing: { before: 400, after: 120 } },
      },
      {
        id: 'Heading2',
        name: 'Heading 2',
        basedOn: 'Normal',
        next: 'Normal',
        run: { bold: true, size: 26, color: '048A81', font: 'Calibri' },
        paragraph: { spacing: { before: 280, after: 80 } },
      },
      {
        id: 'Heading3',
        name: 'Heading 3',
        basedOn: 'Normal',
        next: 'Normal',
        run: { bold: true, size: 22, color: '2E4057', font: 'Calibri' },
        paragraph: { spacing: { before: 200, after: 60 } },
      },
    ],
  },
  sections: [
    {
      properties: {
        page: {
          margin: { top: 1080, bottom: 1080, left: 1080, right: 1080 },
        },
      },
      headers: {
        default: new Header({
          children: [
            new Paragraph({
              children: [
                new TextRun({ text: 'DNB Anaesthesia — Model Answers', bold: true, size: 18, color: '2E4057' }),
                new TextRun({ text: '\t\t', size: 18 }),
                new TextRun({ text: 'Miller\'s | Morgan & Mikhail | Barash', italics: true, size: 16, color: '888888' }),
              ],
              tabStops: [{ type: TabStopType.RIGHT, position: 8640 }],
              border: { bottom: { style: BorderStyle.SINGLE, size: 4, color: 'CCCCCC', space: 4 } },
            }),
          ],
        }),
      },
      footers: {
        default: new Footer({
          children: [
            new Paragraph({
              children: [
                new TextRun({ text: 'Page ', size: 16, color: '888888' }),
                new PageNumber(),
                new TextRun({ text: '  |  DNB Anaesthesia Exam Preparation', size: 16, color: '888888' }),
              ],
              alignment: AlignmentType.CENTER,
              border: { top: { style: BorderStyle.SINGLE, size: 4, color: 'CCCCCC', space: 4 } },
            }),
          ],
        }),
      },
      children: [
        ...cover,
        ...q1, ...q2, ...q3, ...q4, ...q5,
        ...q6, ...q7, ...q8, ...q9, ...q10,
        ...refs,
      ],
    },
  ],
});

Packer.toBuffer(doc).then(buffer => {
  fs.writeFileSync('/home/daytona/workspace/dnb-anaesthesia/DNB_Anaesthesia_Model_Answers.docx', buffer);
  console.log('SUCCESS: Document written.');
}).catch(err => {
  console.error('ERROR:', err.message);
  process.exit(1);
});