const pptxgen = require("pptxgenjs");
const { execSync } = require("child_process");

const pres = new pptxgen();
pres.layout = "LAYOUT_WIDE";
pres.title = "Monitoring During Neurosurgery";
pres.author = "MD Anesthesia";

// ─── Color palette ───────────────────────────────────────────────────────────
const C = {
  navy:    "0D1B3E",   // dominant dark background
  teal:    "1A8C8C",   // accent / headers
  tealLt:  "2EC4B6",   // sub-accent
  gold:    "F4A261",   // highlight / callout
  white:   "FFFFFF",
  ltGray:  "E8EEF4",
  mdGray:  "9AAFC4",
  slate:   "1E2F45",   // slide bodies
  red:     "E63946",
};

// ─── Master helpers ──────────────────────────────────────────────────────────
function addSlide(bg) {
  const s = pres.addSlide();
  s.background = { color: bg || C.navy };
  return s;
}

function slideHeader(s, title, subtitle) {
  // Accent bar left
  s.addShape(pres.ShapeType.rect, { x: 0, y: 0, w: 0.08, h: 5.625, fill: { color: C.teal } });
  s.addText(title, {
    x: 0.2, y: 0.15, w: 12.9, h: 0.65,
    fontSize: 26, bold: true, color: C.white, fontFace: "Calibri",
    margin: 0,
  });
  if (subtitle) {
    s.addText(subtitle, {
      x: 0.2, y: 0.82, w: 12.9, h: 0.35,
      fontSize: 14, color: C.tealLt, fontFace: "Calibri", italic: true, margin: 0,
    });
  }
  // thin separator
  s.addShape(pres.ShapeType.rect, { x: 0.2, y: 1.18, w: 12.9, h: 0.04, fill: { color: C.teal } });
}

function bullet(text, level, sub) {
  return {
    text,
    options: {
      bullet: level === 0 ? { type: "bullet", code: "2022" } : { type: "bullet", indent: 30, code: "25B8" },
      color: level === 0 ? C.white : C.ltGray,
      fontSize: level === 0 ? 16 : 14,
      bold: level === 0 && !sub,
      breakLine: true,
      indentLevel: level,
    }
  };
}

function addBulletBox(s, items, x, y, w, h) {
  s.addText(items, { x, y, w, h, fontFace: "Calibri", valign: "top", margin: 6 });
}

function footerSlide(s, src) {
  s.addText(src || "Source: Barash Clinical Anesthesia 9e | Miller's Anesthesia 10e", {
    x: 0.2, y: 5.3, w: 12.9, h: 0.25, fontSize: 9, color: C.mdGray, fontFace: "Calibri", italic: true, margin: 0,
  });
}

// ─── SLIDE 1: TITLE ──────────────────────────────────────────────────────────
{
  const s = addSlide(C.navy);
  // Large decorative block
  s.addShape(pres.ShapeType.rect, { x: 0, y: 0, w: 5.2, h: 5.625, fill: { color: C.slate } });
  s.addShape(pres.ShapeType.rect, { x: 0, y: 0, w: 0.18, h: 5.625, fill: { color: C.teal } });
  s.addShape(pres.ShapeType.rect, { x: 5.2, y: 4.5, w: 8.1, h: 0.1, fill: { color: C.gold } });

  s.addText("MONITORING\nDURING\nNEUROSURGERY", {
    x: 0.35, y: 0.6, w: 4.7, h: 3.2,
    fontSize: 36, bold: true, color: C.white, fontFace: "Calibri",
    charSpacing: 2, valign: "top", margin: 0,
  });
  s.addText("A Comprehensive Guide for\nMD Anesthesia", {
    x: 0.35, y: 3.9, w: 4.7, h: 0.9,
    fontSize: 16, color: C.tealLt, fontFace: "Calibri", italic: true, margin: 0,
  });

  // Right column key topics
  s.addText("KEY TOPICS", {
    x: 5.5, y: 0.5, w: 7.5, h: 0.45,
    fontSize: 13, bold: true, color: C.gold, fontFace: "Calibri", charSpacing: 4, margin: 0,
  });
  const topics = [
    "Cerebral Physiology Review",
    "Standard Intraoperative Monitoring",
    "Neurophysiological Monitoring (IONM)",
    "Cerebral Perfusion Monitoring",
    "Depth of Anesthesia Monitoring",
    "ICP Monitoring",
    "Effect of Anesthetic Agents on Monitoring",
    "Specific Procedures",
  ];
  topics.forEach((t, i) => {
    s.addShape(pres.ShapeType.rect, { x: 5.5, y: 1.1 + i * 0.52, w: 0.08, h: 0.35, fill: { color: C.teal } });
    s.addText(t, {
      x: 5.72, y: 1.1 + i * 0.52, w: 7.2, h: 0.38,
      fontSize: 14, color: C.white, fontFace: "Calibri", valign: "middle", margin: 0,
    });
  });
}

// ─── SLIDE 2: CEREBRAL PHYSIOLOGY ───────────────────────────────────────────
{
  const s = addSlide(C.slate);
  slideHeader(s, "Cerebral Physiology — The Foundation", "Understanding physiology before monitoring");

  const data = [
    ["Parameter", "Normal Value"],
    ["Cerebral Blood Flow (CBF)", "50 mL/100 g/min (750 mL/min total)"],
    ["CMRO₂", "3 – 3.8 mL/100 g/min"],
    ["CPP", "MAP – ICP (or CVP, whichever higher)"],
    ["Autoregulation Range (MAP)", "60 – 160 mmHg"],
    ["Normal ICP", "5 – 15 mmHg"],
    ["Brain % of body weight", "2% body weight → 20% O₂ consumption"],
  ];

  s.addTable(data, {
    x: 0.3, y: 1.35, w: 6.5, h: 3.6,
    fontFace: "Calibri", fontSize: 13,
    rowH: 0.46,
    firstRowH: 0.46,
    border: { type: "solid", pt: 1, color: C.teal },
    fill: C.slate,
    color: C.white,
    bold: false,
    autoPage: false,
    colW: [3.2, 3.3],
  });

  // Right panel
  s.addShape(pres.ShapeType.rect, { x: 7.1, y: 1.35, w: 5.8, h: 3.9, fill: { color: C.navy }, line: { color: C.teal, pt: 1 } });
  s.addText("KEY PRINCIPLES", { x: 7.2, y: 1.4, w: 5.6, h: 0.4, fontSize: 13, bold: true, color: C.gold, fontFace: "Calibri", margin: 0 });
  const pts = [
    "Flow-Metabolism Coupling: CBF matches CMRO₂ in seconds",
    "CO₂ Reactivity: ↑PaCO₂ → ↑CBF; ΔPaCO₂ 1 mmHg ≈ Δ1–2 mL/100g/min",
    "Ischemia: Irreversible injury after only 4–5 min global ischemia",
    "Monro-Kellie Doctrine: Brain + CSF + Blood = fixed volume; ↑one → ↑ICP",
    "CPP = MAP – ICP; maintain CPP ≥ 60 mmHg",
  ];
  addBulletBox(s, pts.map((p, i) => bullet(p, 0)), 7.2, 1.85, 5.6, 3.2);
  footerSlide(s);
}

// ─── SLIDE 3: OVERVIEW — MONITORING CATEGORIES ──────────────────────────────
{
  const s = addSlide(C.navy);
  slideHeader(s, "Overview: Monitoring Categories in Neuroanesthesia", "");

  const boxes = [
    { title: "Standard Monitoring", icon: "♥", color: C.teal, x: 0.2, y: 1.35,
      items: ["ECG (5-lead)", "SpO₂", "NIBP / IBP", "EtCO₂", "Temperature", "Urine output", "CVP / PA line (selected)"] },
    { title: "Neurophysiological (IONM)", icon: "⚡", color: C.gold, x: 3.6, y: 1.35,
      items: ["EEG", "Somatosensory EPs (SSEP)", "Motor EPs (MEP)", "Brainstem AEPs (BAEP)", "Visual EPs (VEP)", "EMG (free-run / triggered)"] },
    { title: "Cerebral Perfusion", icon: "🩸", color: C.tealLt, x: 7.0, y: 1.35,
      items: ["Transcranial Doppler (TCD)", "Near-Infrared Spectroscopy (NIRS)", "Laser Doppler Flowmetry", "Jugular bulb O₂ sat (SjvO₂)"] },
    { title: "ICP / Brain Compliance", icon: "📊", color: "#C77DFF", x: 10.4, y: 1.35,
      items: ["Ventriculostomy (gold standard)", "Intraparenchymal probe", "Subdural / epidural devices", "Optic nerve sheath diam."] },
  ];

  boxes.forEach(b => {
    s.addShape(pres.ShapeType.rect, { x: b.x, y: b.y, w: 3.2, h: 3.9, fill: { color: C.slate }, line: { color: b.color, pt: 2 } });
    s.addText(b.title, { x: b.x + 0.1, y: b.y + 0.08, w: 3.0, h: 0.45, fontSize: 14, bold: true, color: b.color, fontFace: "Calibri", margin: 0 });
    addBulletBox(s, b.items.map(i => bullet(i, 0)), b.x + 0.1, b.y + 0.55, 3.0, 3.2);
  });
  footerSlide(s);
}

// ─── SLIDE 4: EEG ────────────────────────────────────────────────────────────
{
  const s = addSlide(C.slate);
  slideHeader(s, "Electroencephalography (EEG)", "Continuous cortical electrical activity monitoring");

  addBulletBox(s, [
    bullet("Principle", 0),
    bullet("Records spontaneous electrical activity of cerebral cortex", 1),
    bullet("Reflects cerebral metabolic and perfusion status in real-time", 1),
    bullet("Indications", 0),
    bullet("Carotid endarterectomy (CEA) — detecting ischemia during cross-clamp", 1),
    bullet("Epilepsy surgery — cortical mapping; seizure focus localization", 1),
    bullet("Barbiturate coma monitoring — burst suppression endpoint", 1),
    bullet("Aneurysm surgery with temporary clip application", 1),
    bullet("EEG Patterns", 0),
    bullet("Normal awake: Fast, low amplitude (beta/alpha)", 1),
    bullet("Light anesthesia: Increased amplitude, slowing", 1),
    bullet("Deep anesthesia: Burst suppression", 1),
    bullet("Ischemia / anoxia: Slowing → flat (isoelectric)", 1),
    bullet("Advantages", 0),
    bullet("Non-invasive, continuous, real-time cortical assessment", 1),
    bullet("Processed EEG (BIS, Entropy) widely used for anesthetic depth", 1),
  ], 0.2, 1.35, 6.5, 4.0);

  // Right: Anesthetic effect box
  s.addShape(pres.ShapeType.rect, { x: 7.0, y: 1.35, w: 6.1, h: 3.95, fill: { color: C.navy }, line: { color: C.gold, pt: 1.5 } });
  s.addText("⚠  ANESTHETIC DRUG EFFECTS ON EEG", { x: 7.1, y: 1.42, w: 5.9, h: 0.4, fontSize: 13, bold: true, color: C.gold, fontFace: "Calibri", margin: 0 });

  const drugRows = [
    ["Drug / Agent", "EEG Effect"],
    ["Volatile agents (dose↑)", "Burst suppression → isoelectric"],
    ["Propofol", "High-freq → burst suppression"],
    ["Ketamine", "↑ High-frequency activity; activates"],
    ["Benzodiazepines", "Beta activation → slow/suppress"],
    ["Etomidate", "Burst suppression"],
    ["N₂O", "↑ Frequency; little suppression alone"],
    ["Opioids", "Mild slowing; minimal effect"],
  ];
  s.addTable(drugRows, {
    x: 7.1, y: 1.9, w: 5.9, h: 3.2,
    fontFace: "Calibri", fontSize: 12,
    rowH: 0.37,
    border: { type: "solid", pt: 0.5, color: C.teal },
    fill: C.slate,
    color: C.white,
    colW: [2.9, 3.0],
  });
  footerSlide(s);
}

// ─── SLIDE 5: SSEP ───────────────────────────────────────────────────────────
{
  const s = addSlide(C.navy);
  slideHeader(s, "Somatosensory Evoked Potentials (SSEP)", "Monitoring dorsal column / medial lemniscal pathways");

  addBulletBox(s, [
    bullet("Principle", 0),
    bullet("Peripheral nerve stimulated → cortical response recorded", 1),
    bullet("Monitors SENSORY pathways (posterior spinal cord / thalamocortical tracts)", 1),
    bullet("Upper limb: median/ulnar nerve → contralateral cortex", 1),
    bullet("Lower limb: tibial/peroneal nerve → cortex", 1),
    bullet("Indications", 0),
    bullet("Spinal cord surgeries (scoliosis, tumor, vascular)", 1),
    bullet("Cerebral aneurysm / AVM surgery", 1),
    bullet("Carotid endarterectomy", 1),
    bullet("Posterior fossa tumors", 1),
    bullet("Alert Criteria (50-10 rule)", 0),
    bullet("⚠ ≥50% decrease in AMPLITUDE or ≥10% increase in LATENCY", 1),
    bullet("Prompt surgical / anesthetic corrective action required", 1),
  ], 0.2, 1.35, 6.5, 4.0);

  s.addShape(pres.ShapeType.rect, { x: 7.0, y: 1.35, w: 6.1, h: 3.95, fill: { color: C.slate }, line: { color: C.tealLt, pt: 1.5 } });
  s.addText("ANESTHETIC EFFECTS ON SSEP", { x: 7.1, y: 1.42, w: 5.9, h: 0.4, fontSize: 13, bold: true, color: C.tealLt, fontFace: "Calibri", margin: 0 });

  addBulletBox(s, [
    bullet("Volatile Agents: Dose-dependent ↓ amplitude, ↑ latency", 0),
    bullet("Preferred: ≤0.5 MAC; avoid >1 MAC during critical periods", 1),
    bullet("Propofol (TIVA): Minimal effect; preferred for SSEP monitoring", 0),
    bullet("N₂O: Significant ↓ amplitude (additive with volatiles)", 0),
    bullet("Opioids: Minimal effect on cortical SSEP", 0),
    bullet("NMBs: No direct effect (peripheral origin of stimulus)", 0),
    bullet("Hypothermia: ↑ latency (1°C drop → ~5% latency increase)", 0),
    bullet("Hypotension: ↓ amplitude; MAP > 60–65 mmHg target", 0),
    bullet("TIVA (propofol + remifentanil): GOLD STANDARD for SSEP monitoring", 0),
  ], 7.1, 1.9, 5.9, 3.3);
  footerSlide(s);
}

// ─── SLIDE 6: MEP ────────────────────────────────────────────────────────────
{
  const s = addSlide(C.slate);
  slideHeader(s, "Motor Evoked Potentials (MEP)", "Monitoring corticospinal / anterior spinal cord pathways");

  // Left column
  addBulletBox(s, [
    bullet("Principle", 0),
    bullet("Transcranial electrical stimulation → recording from limb muscles (CMAP)", 1),
    bullet("Monitors MOTOR pathways (anterior corticospinal tract)", 1),
    bullet("Complements SSEP (anterior vs. posterior cord)", 1),
    bullet("Types", 0),
    bullet("TcMEP: Transcranial electrical motor EP (most common)", 1),
    bullet("Direct Cortical: D-wave (epidural electrode) — most sensitive", 1),
    bullet("Indications", 0),
    bullet("Spinal cord surgery (especially anterior pathology)", 1),
    bullet("Intracranial tumor near motor cortex / pyramidal tracts", 1),
    bullet("Cerebrovascular surgery (aneurysm, AVM)", 1),
    bullet("Alert Criteria", 0),
    bullet("⚠ >50% decrease in amplitude = significant warning", 1),
    bullet("Total loss of response = immediate surgical alert", 1),
    bullet("D-wave <50% despite TcMEP loss: transient deficit likely", 1),
  ], 0.2, 1.35, 6.4, 4.0);

  s.addShape(pres.ShapeType.rect, { x: 6.9, y: 1.35, w: 6.2, h: 3.95, fill: { color: C.navy }, line: { color: C.gold, pt: 1.5 } });
  s.addText("CRITICAL ANESTHETIC CONSIDERATIONS", { x: 7.0, y: 1.42, w: 6.0, h: 0.4, fontSize: 12, bold: true, color: C.gold, fontFace: "Calibri", margin: 0 });
  addBulletBox(s, [
    bullet("NMBs: MUST AVOID or use only for intubation (partial block abolishes CMAP)", 0),
    bullet("Volatile agents: Profound dose-dependent suppression; avoid >0.5 MAC", 0),
    bullet("N₂O: Significant suppression; avoid when MEP essential", 0),
    bullet("TIVA (propofol + remifentanil): PREFERRED anesthetic technique", 0),
    bullet("Ketamine (sub-anesthetic dose): May enhance MEP amplitude", 0),
    bullet("Temperature: Hypothermia markedly ↑ latency and ↓ amplitude", 0),
    bullet("Patient Movement: Stimulation can cause sudden movement — bite block essential, secure ETT", 0),
    bullet("Contraindications", 0),
    bullet("Cardiac pacemaker, cochlear implants, cortical electrodes in situ", 1),
    bullet("Epilepsy (relative)", 1),
    bullet("Skull defects near stimulation sites", 1),
  ], 7.0, 1.9, 6.0, 3.3);
  footerSlide(s);
}

// ─── SLIDE 7: BAEP + VEP + EMG ──────────────────────────────────────────────
{
  const s = addSlide(C.navy);
  slideHeader(s, "BAEP | VEP | EMG", "Cranial nerve and auditory pathway monitoring");

  const cols = [
    {
      title: "Brainstem AEP (BAEP)", color: C.teal, x: 0.2,
      items: [
        "Auditory click → cochlear nerve → brainstem waves (I–VII)",
        "Wave I = cochlear nerve; Wave V = inferior colliculus",
        "Indications: Acoustic neuroma, CP angle tumors, posterior fossa surgery",
        "Alert: ≥50% amplitude↓ or ≥1 ms latency prolongation of Wave V",
        "Relatively resistant to anesthetic agents (compared to SSEP/MEP)",
        "Most stable EP modality under anesthesia",
      ]
    },
    {
      title: "Visual EP (VEP)", color: C.tealLt, x: 4.55,
      items: [
        "Flash/LED goggles → visual pathway → occipital cortex",
        "Indications: Pituitary / parasellar surgery, optic nerve-adjacent tumors",
        "Highly variable; most susceptible to anesthetic effects",
        "Alert: Loss of N75 wave or >20 ms latency change",
        "Technically challenging; limited routine use",
        "Growing role with LED-based intraocular stimulation",
      ]
    },
    {
      title: "EMG (Electromyography)", color: C.gold, x: 8.9,
      items: [
        "Free-run EMG: Continuous spontaneous activity → detects nerve irritation",
        "Triggered EMG: Confirms screw/electrode placement near nerve",
        "Cranial nerve monitoring: CN VII (facial), IX, X, XI, XII",
        "Alert: Sustained neurotonic discharge → nerve at risk",
        "NMB: Must avoid for EMG monitoring",
        "Indications: Acoustic neuroma, skull base, posterior fossa",
      ]
    },
  ];

  cols.forEach(c => {
    s.addShape(pres.ShapeType.rect, { x: c.x, y: 1.35, w: 4.2, h: 3.95, fill: { color: C.slate }, line: { color: c.color, pt: 1.5 } });
    s.addText(c.title, { x: c.x + 0.1, y: 1.4, w: 4.0, h: 0.42, fontSize: 14, bold: true, color: c.color, fontFace: "Calibri", margin: 0 });
    addBulletBox(s, c.items.map(i => bullet(i, 0)), c.x + 0.1, 1.88, 4.0, 3.3);
  });
  footerSlide(s);
}

// ─── SLIDE 8: CEREBRAL PERFUSION MONITORING ─────────────────────────────────
{
  const s = addSlide(C.slate);
  slideHeader(s, "Cerebral Perfusion Monitoring", "Ensuring adequate cerebral oxygen delivery");

  // TCD box
  s.addShape(pres.ShapeType.rect, { x: 0.2, y: 1.35, w: 6.3, h: 1.95, fill: { color: C.navy }, line: { color: C.teal, pt: 1.5 } });
  s.addText("Transcranial Doppler (TCD)", { x: 0.3, y: 1.38, w: 6.1, h: 0.4, fontSize: 14, bold: true, color: C.teal, fontFace: "Calibri", margin: 0 });
  addBulletBox(s, [
    bullet("Measures MCA blood flow velocity (real-time)", 0),
    bullet("Uses: CEA (detect emboli, test clamp tolerance), vasospasm after SAH, CABG", 0),
    bullet("Detects microemboli (HITS — High Intensity Transient Signals)", 0),
    bullet("Probe: 2 MHz pulsed-wave Doppler through temporal window", 0),
  ], 0.3, 1.8, 6.1, 1.4);

  // NIRS box
  s.addShape(pres.ShapeType.rect, { x: 6.8, y: 1.35, w: 6.3, h: 1.95, fill: { color: C.navy }, line: { color: C.tealLt, pt: 1.5 } });
  s.addText("Near-Infrared Spectroscopy (NIRS / rSO₂)", { x: 6.9, y: 1.38, w: 6.1, h: 0.4, fontSize: 14, bold: true, color: C.tealLt, fontFace: "Calibri", margin: 0 });
  addBulletBox(s, [
    bullet("Non-invasive regional cerebral O₂ saturation (normal ~55–75%)", 0),
    bullet("Alert: >20% drop from baseline OR absolute <50%", 0),
    bullet("Uses: CEA, cardiac surgery, beach chair position", 0),
    bullet("Reflects venous-weighted mixed cortical saturation", 0),
  ], 6.9, 1.8, 6.1, 1.4);

  // SjvO2 box
  s.addShape(pres.ShapeType.rect, { x: 0.2, y: 3.4, w: 6.3, h: 1.9, fill: { color: C.navy }, line: { color: C.gold, pt: 1.5 } });
  s.addText("Jugular Bulb O₂ Saturation (SjvO₂)", { x: 0.3, y: 3.43, w: 6.1, h: 0.4, fontSize: 14, bold: true, color: C.gold, fontFace: "Calibri", margin: 0 });
  addBulletBox(s, [
    bullet("Normal: 55–75%; <50% = cerebral ischemia; >75% = hyperemia / neuronal death", 0),
    bullet("Internal jugular catheter (retrograde) → jugular bulb", 0),
    bullet("Continuous oximetry; guides CPP and ventilation targets", 0),
    bullet("Used in TBI, major neurosurgery, carotid surgery", 0),
  ], 0.3, 3.88, 6.1, 1.35);

  // Brain tissue O2
  s.addShape(pres.ShapeType.rect, { x: 6.8, y: 3.4, w: 6.3, h: 1.9, fill: { color: C.navy }, line: { color: "#C77DFF", pt: 1.5 } });
  s.addText("Brain Tissue O₂ (PbtO₂)", { x: 6.9, y: 3.43, w: 6.1, h: 0.4, fontSize: 14, bold: true, color: "#C77DFF", fontFace: "Calibri", margin: 0 });
  addBulletBox(s, [
    bullet("Licox or Neurovent probe inserted into brain parenchyma", 0),
    bullet("Normal PbtO₂: 20–35 mmHg; critical <15 mmHg; crisis <10 mmHg", 0),
    bullet("Guides O₂ therapy, CPP augmentation in TBI & major surgery", 0),
    bullet("Used in conjunction with ICP monitoring in neurocritical care", 0),
  ], 6.9, 3.88, 6.1, 1.35);
  footerSlide(s);
}

// ─── SLIDE 9: ICP MONITORING ─────────────────────────────────────────────────
{
  const s = addSlide(C.navy);
  slideHeader(s, "Intracranial Pressure (ICP) Monitoring", "Monro-Kellie doctrine in clinical practice");

  // Methods table
  const rows = [
    ["Method", "Location", "Accuracy", "CSF Drain", "Infection Risk"],
    ["Ventriculostomy (EVD)", "Lateral ventricle", "Gold standard", "Yes ✓", "Moderate"],
    ["Intraparenchymal (Codman/Camino)", "Brain tissue", "Excellent", "No", "Low"],
    ["Subdural bolt/screw", "Subdural space", "Good", "No", "Low"],
    ["Epidural transducer", "Epidural space", "Moderate", "No", "Low"],
    ["Non-invasive (ONSD)", "Optic nerve sheath", "Screening only", "No", "None"],
  ];

  s.addTable(rows, {
    x: 0.2, y: 1.35, w: 12.9, h: 3.0,
    fontFace: "Calibri", fontSize: 12.5,
    rowH: 0.45,
    border: { type: "solid", pt: 0.8, color: C.teal },
    fill: C.slate,
    color: C.white,
    colW: [3.0, 2.4, 2.3, 2.0, 2.2],
    autoPage: false,
  });

  // Key principles
  s.addText("TREATMENT THRESHOLDS & TARGETS", { x: 0.2, y: 4.5, w: 6.5, h: 0.35, fontSize: 13, bold: true, color: C.gold, fontFace: "Calibri", margin: 0 });
  addBulletBox(s, [
    bullet("Treat ICP > 20–22 mmHg (BTF guidelines)", 0),
    bullet("Target CPP ≥ 60 mmHg (CPP = MAP – ICP)", 0),
    bullet("Stepwise management: HOB 30°, euvolemia, mannitol, hypertonic saline, hyperventilation (temporary), decompressive craniectomy", 0),
  ], 0.2, 4.88, 6.4, 0.68);

  s.addText("ANESTHESIA EFFECTS ON ICP", { x: 7.0, y: 4.5, w: 6.1, h: 0.35, fontSize: 13, bold: true, color: C.tealLt, fontFace: "Calibri", margin: 0 });
  addBulletBox(s, [
    bullet("Volatiles: ↑ICP (dose-dependent cerebral vasodilation); use ≤0.5 MAC", 0),
    bullet("Propofol: ↓ICP (↓CMRO₂ → ↓CBF); preferred for raised ICP", 0),
    bullet("Ketamine: Traditionally avoided (now controversial — may be safe with controlled ventilation)", 0),
    bullet("Succinylcholine: Transient ↑ICP; avoid if severely raised", 0),
  ], 7.0, 4.88, 6.1, 0.68);
  footerSlide(s);
}

// ─── SLIDE 10: DEPTH OF ANESTHESIA ──────────────────────────────────────────
{
  const s = addSlide(C.slate);
  slideHeader(s, "Depth of Anesthesia Monitoring", "Processed EEG — BIS, Entropy, Narcotrend");

  addBulletBox(s, [
    bullet("Bispectral Index (BIS)", 0),
    bullet("Derived from frontal EEG; scale 0–100 (awake=100; isoelectric=0)", 1),
    bullet("Target range: 40–60 for surgical anesthesia", 1),
    bullet("Critical in neurosurgery: prevents awareness; guides burst suppression (BIS 0–20)", 1),
    bullet("Essential during awake craniotomy — titrate to BIS 60–80 during awake phases", 1),
    bullet("Spectral Entropy (M-Entropy / S-Entropy)", 0),
    bullet("Response Entropy (RE): includes EMG component — detects arousal", 1),
    bullet("State Entropy (SE): pure EEG — reflects hypnotic depth", 1),
    bullet("Target: RE ≈ SE = 40–60 for adequate anesthesia", 1),
    bullet("Limitations of DoA Monitors", 0),
    bullet("Can be falsely suppressed by muscle relaxants (↓ EMG artifact)", 1),
    bullet("High-frequency EEG from ketamine/N₂O may give falsely high BIS", 1),
    bullet("Cannot replace clinical assessment; unreliable in hypothermia", 1),
    bullet("Awake Craniotomy — Special Consideration", 0),
    bullet("Dexmedetomidine + remifentanil ± propofol infusion", 1),
    bullet("Target: patient comfortable, cooperative, able to follow commands", 1),
    bullet("BIS 70–80 during asleep phases; allow arousal for motor/language testing", 1),
  ], 0.2, 1.35, 6.4, 4.0);

  // Right info panel
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  const bisData = [
    ["BIS Range", "Clinical State"],
    ["100", "Fully awake"],
    ["80 – 100", "Sedation (light)"],
    ["60 – 80", "Light anesthesia / sedation"],
    ["40 – 60", "Surgical anesthesia (TARGET)"],
    ["20 – 40", "Deep anesthesia"],
    ["< 20", "Burst suppression / barbiturate coma"],
    ["0", "Isoelectric / flat EEG"],
  ];
  s.addTable(bisData, {
    x: 7.0, y: 1.88, w: 6.0, h: 3.35,
    fontFace: "Calibri", fontSize: 13,
    rowH: 0.42,
    border: { type: "solid", pt: 0.8, color: C.teal },
    fill: C.slate,
    color: C.white,
    colW: [2.5, 3.5],
  });
  footerSlide(s);
}

// ─── SLIDE 11: EFFECT OF AGENTS (TABLE) ─────────────────────────────────────
{
  const s = addSlide(C.navy);
  slideHeader(s, "Effect of Anesthetic Agents on IONM", "Critical knowledge for the neuroanesthesiologist");

  const tableData = [
    ["Agent", "EEG", "SSEP", "MEP", "BAEP", "ICP / CBF"],
    ["Propofol", "Burst suppression (high dose)", "Mild ↓amp", "Mild ↓amp", "Minimal", "↓ ICP, ↓ CBF ✓"],
    ["Volatile (Iso/Sevo/Des)", "Dose↑ → burst suppress", "↓ amp ↑ lat", "Major ↓↓", "Minimal", "↑ ICP, ↑ CBF ✗"],
    ["Nitrous Oxide (N₂O)", "↑ frequency", "↓ amp (sig)", "↓ amp (sig)", "Minimal", "↑ CBF (mild)"],
    ["Ketamine", "Activates (β↑)", "Minimal", "↑ or neutral", "Minimal", "↑ ICP (when no ventilation ctrl)"],
    ["Etomidate", "Burst suppression", "↑ amp", "Activates", "Minimal", "↓ ICP, ↓ CBF ✓"],
    ["Dexmedetomidine", "Slowing", "Minimal", "Minimal", "Minimal", "Minimal"],
    ["Opioids (Fentanyl)", "Mild slowing", "Minimal", "Minimal", "Minimal", "Minimal (preferred)"],
    ["NMBs", "No effect", "No effect", "↓↓ ABOLISH", "No effect", "No direct effect"],
    ["Hypothermia", "↑ latency / flat", "↑ latency ↓ amp", "↑ lat ↓ amp", "↑ latency", "↓ CMRO₂ protective"],
  ];

  s.addTable(tableData, {
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    rowH: 0.4,
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    fill: C.slate,
    color: C.white,
    colW: [2.4, 2.0, 2.0, 2.0, 1.9, 2.7],
    autoPage: false,
  });

  s.addText("✓ = favourable for neuroanesthesia   ✗ = caution required   ↓↓ = major suppression", {
    x: 0.2, y: 5.33, w: 12.9, h: 0.22, fontSize: 10, color: C.gold, fontFace: "Calibri", italic: true, margin: 0,
  });
  footerSlide(s, "Source: Miller's Anesthesia 10e | Barash Clinical Anesthesia 9e");
}

// ─── SLIDE 12: SPECIAL PROCEDURES ──────────────────────────────────────────
{
  const s = addSlide(C.slate);
  slideHeader(s, "Monitoring in Specific Neurosurgical Procedures", "");

  const procs = [
    {
      title: "Carotid Endarterectomy (CEA)",
      items: ["EEG/SSEP: ischemia during cross-clamp", "TCD: detect emboli (HITS)", "NIRS (rSO₂): non-invasive option", "Awake technique: gold standard neurologic monitor"],
      x: 0.2, y: 1.35, color: C.teal,
    },
    {
      title: "Cerebral Aneurysm Surgery",
      items: ["SSEP + MEP: during temporary clipping", "TCD: vasospasm surveillance", "EEG: ischemia detection", "BIS: anesthetic depth"],
      x: 6.8, y: 1.35, color: C.gold,
    },
    {
      title: "Spinal Cord Surgery (Scoliosis/Tumor)",
      items: ["SSEP + MEP (combined multimodal IONM)", "Free-run EMG: nerve root irritation", "D-wave: most sensitive for cord integrity", "TIVA mandatory — avoid NMB"],
      x: 0.2, y: 3.25, color: C.tealLt,
    },
    {
      title: "Posterior Fossa / Acoustic Neuroma",
      items: ["BAEP: cochlear nerve monitoring (Wave V)", "Facial EMG (CN VII monitoring)", "Triggered EMG: CN IX, X, XI, XII", "ABR changes → adjust retraction / position"],
      x: 6.8, y: 3.25, color: "#C77DFF",
    },
  ];

  procs.forEach(p => {
    s.addShape(pres.ShapeType.rect, { x: p.x, y: p.y, w: 6.4, h: 1.75, fill: { color: C.navy }, line: { color: p.color, pt: 1.5 } });
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    addBulletBox(s, p.items.map(i => bullet(i, 0)), p.x + 0.1, p.y + 0.46, 6.2, 1.2);
  });
  footerSlide(s);
}

// ─── SLIDE 13: TIVA vs VOLATILE ─────────────────────────────────────────────
{
  const s = addSlide(C.navy);
  slideHeader(s, "TIVA vs. Volatile Anesthesia in Neuroanesthesia", "Choosing the right anesthetic technique");

  // TIVA column
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  s.addText("✓  TIVA (Propofol + Remifentanil)", { x: 0.3, y: 1.4, w: 6.1, h: 0.45, fontSize: 15, bold: true, color: C.teal, fontFace: "Calibri", margin: 0 });
  addBulletBox(s, [
    bullet("Minimal effect on SSEP amplitude/latency", 0),
    bullet("Preserves MEP responses — preferred for spinal cord surgery", 0),
    bullet("Decreases ICP and CMRO₂", 0),
    bullet("Maintains cerebrovascular autoregulation and CO₂ reactivity", 0),
    bullet("Required when reliable IONM is essential", 0),
    bullet("Smooth, predictable emergence for early neurologic assessment", 0),
    bullet("Disadvantage: Risk of TIVA awareness if not monitored (use BIS)", 0),
    bullet("Propofol infusion syndrome (PRIS) — rare but monitor with long infusions", 0),
  ], 0.3, 1.92, 6.1, 3.2);

  // Volatile column
  s.addShape(pres.ShapeType.rect, { x: 6.8, y: 1.35, w: 6.3, h: 3.9, fill: { color: C.slate }, line: { color: C.gold, pt: 2 } });
  s.addText("⚠  Volatile (Iso / Sevo / Des)", { x: 6.9, y: 1.4, w: 6.1, h: 0.45, fontSize: 15, bold: true, color: C.gold, fontFace: "Calibri", margin: 0 });
  addBulletBox(s, [
    bullet("Acceptable at ≤0.5 MAC with N₂O-free technique", 0),
    bullet("Suppresses SSEP (dose-dependent ↓ amplitude)", 0),
    bullet("MEP severely impaired — AVOID if MEP monitoring required", 0),
    bullet("Dose-dependent ↑ CBF and ↑ ICP (especially >1 MAC)", 0),
    bullet("Impairs cerebral autoregulation at higher concentrations", 0),
    bullet("Advantage: Ease of administration; hemodynamic stability", 0),
    bullet("Isoflurane: preferred volatile (EEG burst suppression at high dose — neuroprotective)", 0),
    bullet("Desflurane: ↑ CBF acutely; ↑ ICP — use with caution", 0),
  ], 6.9, 1.92, 6.1, 3.2);
  footerSlide(s);
}

// ─── SLIDE 14: POSITIONING & SPECIAL CONSIDERATIONS ─────────────────────────
{
  const s = addSlide(C.slate);
  slideHeader(s, "Positioning & Special Monitoring Considerations", "Sitting position | Posterior fossa | Awake craniotomy");

  addBulletBox(s, [
    bullet("Sitting / Semi-Sitting (Beach Chair) Position", 0),
    bullet("↑ Risk of VAE (Venous Air Embolism) — monitor with precordial Doppler (most sensitive) + TEE", 1),
    bullet("NIRS: Bilateral cerebral oxygenation monitoring — 20% ↓ from baseline = concerning", 1),
    bullet("TCD: Detect air emboli in MCA", 1),
    bullet("Precordial Doppler: simple, sensitive, continuous", 1),
    bullet("ETCO₂: Sudden ↓ = large VAE; N₂ detectable if N₂O avoided", 1),
    bullet("IBP mandatory; CVP line for aspiration of air from right atrium", 1),
    bullet("Venous Air Embolism (VAE) Management", 0),
    bullet("Flood field with saline, compress jugular veins, lower head, aspirate CVP, 100% O₂, vasopressors", 1),
    bullet("Paradoxical embolism risk if PFO present — TOE/TEE assessment pre-op", 1),
    bullet("Posterior Fossa Surgery", 0),
    bullet("CN monitoring (BAEP, EMG CN VII/IX/X)", 1),
    bullet("SSEP monitoring for sensory tracts", 1),
    bullet("VAE monitoring (position-dependent)", 1),
    bullet("Awake Craniotomy", 0),
    bullet("Asleep-awake-asleep technique: Dexmedetomidine + Remifentanil + Propofol (bolus)", 1),
    bullet("Language and motor mapping during awake phase — SSEP/MEP supplement", 1),
    bullet("No NMBs; airway must be secured (LMA or ETT)", 1),
  ], 0.2, 1.35, 6.4, 4.0);

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  s.addText("VAE DETECTION SENSITIVITY", { x: 7.0, y: 1.42, w: 6.0, h: 0.38, fontSize: 13, bold: true, color: C.tealLt, fontFace: "Calibri", margin: 0 });

  const vaeData = [
    ["Monitor", "Sensitivity"],
    ["TEE (Transoesophageal Echo)", "Most sensitive (0.02 mL/kg)"],
    ["Precordial Doppler", "Highly sensitive (0.05 mL/kg)"],
    ["PA Catheter", "Moderate"],
    ["EtCO₂ ↓", "Moderate — delayed"],
    ["EtN₂ ↑", "Sensitive if N₂O-free"],
    ["SpO₂ ↓ / BP ↓", "Late / large VAE only"],
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    bullet("N₂O should be discontinued at first sign of VAE", 0),
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  footerSlide(s);
}

// ─── SLIDE 15: SUMMARY ──────────────────────────────────────────────────────
{
  const s = addSlide(C.navy);
  slideHeader(s, "Summary & Key Take-Home Points", "Monitoring During Neurosurgery — MD Anesthesia");

  const pts = [
    { num: "01", text: "MULTIMODAL MONITORING: No single monitor is sufficient. Combine standard + neurophysiological + cerebral perfusion monitors for optimal patient safety.", c: C.teal },
    { num: "02", text: "ANESTHETIC CHOICE MATTERS: TIVA (propofol + remifentanil) is the gold standard when IONM (SSEP/MEP) is required. Volatile agents should be ≤0.5 MAC.", c: C.tealLt },
    { num: "03", text: "ALERT CRITERIA: SSEP/MEP — 50% amplitude decrease or 10% latency increase demands immediate response (surgical pause, correct hypotension/anemia, adjust anesthesia).", c: C.gold },
    { num: "04", text: "ICP MANAGEMENT: Maintain CPP ≥ 60 mmHg. Target MAP to preserve autoregulation. Ventriculostomy is gold standard for ICP monitoring and CSF drainage.", c: "#C77DFF },
    { num: "05", text: "SITTING POSITION: Always use precordial Doppler + NIRS + continuous IBP. Prepare for VAE. Discontinue N₂O if VAE occurs.", c: C.red },
    { num: "06", text: "NMBs: Avoid completely if EMG or MEP monitoring is used. Use only for intubation if required, then allow full reversal before monitoring begins.", c: C.mdGray },
  ];

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  });
  footerSlide(s);
}

// ─── WRITE FILE ──────────────────────────────────────────────────────────────
pres.writeFile({ fileName: "/home/daytona/workspace/neuro-monitoring-ppt/Monitoring_During_Neurosurgery.pptx" })
  .then(() => console.log("SUCCESS: File written."))
  .catch(e => console.error("ERROR:", e));

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/neuro-monitoring-ppt/build.js'