capnography ICU anesthesia waveform interpretation clinical applications 2024

https://respiratory-therapy.com/department-management/clinic…

mkdir -p /home/daytona/workspace/capnography-pptx && ls /home/daytona/workspace/…

~/capnography-pptx/build.js

const pptxgen = require("pptxgenjs");

const pres = new pptxgen();
pres.layout = "LAYOUT_16x9";
pres.author = "Orris";
pres.title = "Capnography: Principles, Waveforms & Clinical Applications";

// ─── COLOR PALETTE ───────────────────────────────────────────────────────────
// Dark teal dominates; neon lime accent; white text; slate mid-tone
const C = {
  bg:      "0D1B2A",   // deep navy  (slide backgrounds)
  bgMid:   "112233",   // slightly lighter navy
  teal:    "0B7A75",   // teal – section headers, shapes
  tealLt:  "0FA3A0",   // lighter teal – subheadings
  lime:    "C8F04D",   // neon lime accent
  white:   "FFFFFF",
  offWht:  "D6E4E4",
  slate:   "4A7896",   // muted blue-gray
  warn:    "F28B30",   // amber for alerts/warnings
  red:     "E05252",
  green:   "50C878",
};

// ─── HELPER ──────────────────────────────────────────────────────────────────
function darkSlide(slide) {
  slide.background = { color: C.bg };
}
function addTag(slide, text, x, y) {
  slide.addShape(pres.shapes.RECTANGLE, { x, y, w: 1.3, h: 0.28, fill: { color: C.lime } });
  slide.addText(text, { x, y, w: 1.3, h: 0.28, fontSize: 8, bold: true, color: C.bg, align: "center", valign: "middle", margin: 0 });
}
function addSection(slide, label) {
  slide.addShape(pres.shapes.RECTANGLE, { x: 0, y: 0, w: 10, h: 0.45, fill: { color: C.teal } });
  slide.addText(label, { x: 0.2, y: 0, w: 9.6, h: 0.45, fontSize: 11, bold: true, color: C.white, valign: "middle", margin: 0, charSpacing: 2 });
}
function addTitle(slide, title, sub) {
  slide.addText(title, { x: 0.35, y: 0.6, w: 9.3, h: 0.75, fontSize: 26, bold: true, color: C.white });
  if (sub) slide.addText(sub, { x: 0.35, y: 1.35, w: 9.3, h: 0.35, fontSize: 13, color: C.tealLt, italic: true });
}
function addFooter(slide, text) {
  slide.addText(text, { x: 0.3, y: 5.3, w: 9.4, h: 0.25, fontSize: 7.5, color: C.slate, align: "right" });
}
function bullet(text, sub) {
  const arr = [{ text, options: { bullet: true, bold: false } }];
  if (sub) arr.push({ text: "\n  " + sub, options: { fontSize: 10, color: C.offWht, breakLine: false } });
  return arr;
}

// ─── WAVEFORM DRAWING HELPER ─────────────────────────────────────────────────
// Draws a simplified capnogram shape using line objects
function drawCapnogram(slide, x, y, w, h, options = {}) {
  // options: color, label, etco2Val, phase3slope (0=flat, positive = upward slope for COPD)
  const col  = options.color  || C.lime;
  const lw   = options.lw     || 2;
  const slope = options.slope  || 0;      // extra height added across phase 3

  // Coordinate helpers (inches) from local 0,0
  const px = (fx) => x + fx * w;
  const py = (fy) => y + h - fy * h;

  // One breath: baseline → upstroke → plateau → downstroke → baseline
  // Relative x fractions: 0→0.1 baseline; 0.1→0.25 upstroke; 0.25→0.65 plateau; 0.65→0.75 downstroke; 0.75→1.0 next baseline
  const pts = [
    { x: px(0),    y: py(0) },
    { x: px(0.12), y: py(0) },
    { x: px(0.22), y: py(0.85) },
    { x: px(0.65), y: py(0.85 + slope) },
    { x: px(0.75), y: py(0) },
    { x: px(1.0),  y: py(0) },
  ];

  // Draw line segments
  for (let i = 0; i < pts.length - 1; i++) {
    slide.addShape(pres.shapes.LINE, {
      x: pts[i].x, y: pts[i].y, w: pts[i+1].x - pts[i].x, h: Math.abs(pts[i+1].y - pts[i].y),
      line: { color: col, width: lw },
      flipV: pts[i+1].y < pts[i].y,
    });
  }

  // ETCO2 label
  if (options.etco2Label) {
    slide.addText(options.etco2Label, {
      x: px(0.5), y: py(1.0) - 0.22, w: 1.5, h: 0.22,
      fontSize: 9, color: col, bold: true, align: "center",
    });
  }
  // Phase labels
  if (options.phaseLabels) {
    const labels = [
      { t: "I", fx: 0.06, fy: -0.15 },
      { t: "II", fx: 0.17, fy: 0.5 },
      { t: "III", fx: 0.45, fy: 1.0 },
    ];
    labels.forEach(l => {
      slide.addText(l.t, {
        x: px(l.fx) - 0.12, y: py(l.fy) - 0.22, w: 0.24, h: 0.22,
        fontSize: 8, color: C.offWht, align: "center",
      });
    });
  }
}

// ─── SLIDE 1: TITLE ──────────────────────────────────────────────────────────
{
  const s = pres.addSlide();
  s.background = { color: C.bg };

  // Teal accent bar left
  s.addShape(pres.shapes.RECTANGLE, { x: 0, y: 0, w: 0.18, h: 5.625, fill: { color: C.teal } });
  // Lime accent line
  s.addShape(pres.shapes.RECTANGLE, { x: 0.18, y: 0, w: 0.06, h: 5.625, fill: { color: C.lime } });

  s.addText("CAPNOGRAPHY", {
    x: 0.5, y: 0.7, w: 9.0, h: 1.1, fontSize: 52, bold: true, color: C.white,
    charSpacing: 4,
  });
  s.addText("Principles, Waveforms & Clinical Applications", {
    x: 0.5, y: 1.85, w: 9.0, h: 0.5, fontSize: 20, color: C.tealLt, italic: false,
  });
  s.addShape(pres.shapes.RECTANGLE, { x: 0.5, y: 2.45, w: 3.5, h: 0.04, fill: { color: C.lime } });
  s.addText("For ICU & Anesthesia Clinicians", {
    x: 0.5, y: 2.6, w: 6, h: 0.35, fontSize: 13, color: C.offWht,
  });
  s.addText("Comprehensive Review  |  2026", {
    x: 0.5, y: 5.15, w: 9, h: 0.3, fontSize: 10, color: C.slate,
  });
}

// ─── SLIDE 2: TABLE OF CONTENTS ──────────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "OVERVIEW");
  addTitle(s, "What We Will Cover");

  const sections = [
    ["01", "Fundamentals of CO₂ Physiology"],
    ["02", "Types of Capnographs & Technology"],
    ["03", "The Normal Capnogram (Phases I–IV)"],
    ["04", "Capnogram Waveform Interpretation"],
    ["05", "ETCO₂ vs PaCO₂ – The Gradient"],
    ["06", "Applications in Anesthesia"],
    ["07", "ICU Applications & Ventilator Management"],
    ["08", "Capnography in Resuscitation (CPR/ROSC)"],
    ["09", "Abnormal Waveform Patterns"],
    ["10", "Troubleshooting & Pitfalls"],
  ];
  const col1 = sections.slice(0, 5);
  const col2 = sections.slice(5);
  [[col1, 0.35], [col2, 5.15]].forEach(([items, xOff]) => {
    items.forEach((item, i) => {
      const yy = 1.9 + i * 0.65;
      s.addShape(pres.shapes.RECTANGLE, { x: xOff, y: yy, w: 0.48, h: 0.42, fill: { color: C.teal } });
      s.addText(item[0], { x: xOff, y: yy, w: 0.48, h: 0.42, fontSize: 12, bold: true, color: C.lime, align: "center", valign: "middle", margin: 0 });
      s.addText(item[1], { x: xOff + 0.58, y: yy + 0.05, w: 4.4, h: 0.32, fontSize: 12, color: C.offWht });
    });
  });
  addFooter(s, "Morgan & Mikhail's Clinical Anesthesiology, 7e | Barash Clinical Anesthesia, 9e | Miller's Anesthesia, 10e");
}

// ─── SLIDE 3: CO₂ PHYSIOLOGY ─────────────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 01  |  CO₂ PHYSIOLOGY");
  addTitle(s, "Why CO₂ Monitoring Matters", "CO₂ is the end-product of aerobic metabolism — its measurement reflects ventilation, perfusion, and metabolism simultaneously");

  const points = [
    ["Cellular Production", "CO₂ produced during aerobic metabolism (~200 mL/min at rest); increases with fever, malignant hyperthermia, sepsis"],
    ["Transport in Blood", "~70% as bicarbonate (HCO₃⁻), ~23% bound to Hb (carbaminohemoglobin), ~7% dissolved in plasma"],
    ["Alveolar Exchange", "Diffuses rapidly across alveolar membrane; PaCO₂ normally 35–45 mmHg"],
    ["ETCO₂ Relationship", "ETCO₂ ≈ PaCO₂ − 2 to 5 mmHg in healthy lungs; gradient widens with dead space or low cardiac output"],
    ["Clinical Equation", "ETCO₂ = f (CO₂ production, alveolar ventilation, cardiac output, V/Q matching)"],
  ];

  points.forEach((p, i) => {
    const yy = 1.85 + i * 0.66;
    s.addShape(pres.shapes.RECTANGLE, { x: 0.35, y: yy, w: 2.2, h: 0.42, fill: { color: C.teal } });
    s.addText(p[0], { x: 0.35, y: yy, w: 2.2, h: 0.42, fontSize: 10.5, bold: true, color: C.lime, align: "center", valign: "middle", margin: 0 });
    s.addText(p[1], { x: 2.7, y: yy + 0.04, w: 7.0, h: 0.38, fontSize: 11, color: C.offWht });
  });

  addFooter(s, "Morgan & Mikhail's Clinical Anesthesiology, 7e, p.226 | Barash Clinical Anesthesia 9e, Ch.26");
}

// ─── SLIDE 4: TYPES OF CAPNOGRAPHS ──────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 02  |  TECHNOLOGY");
  addTitle(s, "Types of Capnographs", "Understanding the hardware guides optimal use and troubleshooting");

  // Two columns
  const boxes = [
    {
      title: "SIDESTREAM (Diverting)",
      color: C.teal,
      items: [
        "Aspirates gas from circuit via fine tubing (50–250 mL/min)",
        "CO₂ measured in bedside sample cell",
        "Works for intubated & non-intubated patients",
        "Prone to moisture condensation → blocked tubing",
        "~20–50 ms delay (lag time)",
        "Can be used with nasal cannula or face mask",
      ],
    },
    {
      title: "MAINSTREAM (Non-diverting)",
      color: C.slate,
      items: [
        "Sensor sits directly in-line with the breathing circuit",
        "No gas aspiration — measures at airway",
        "Faster response, no lag",
        "Heavier sensor may increase dead space",
        "Risk of secretion contamination of sensor window",
        "Primarily for intubated/ventilated patients",
      ],
    },
  ];

  boxes.forEach((b, col) => {
    const xOff = 0.35 + col * 4.85;
    s.addShape(pres.shapes.RECTANGLE, { x: xOff, y: 1.75, w: 4.5, h: 0.42, fill: { color: b.color } });
    s.addText(b.title, { x: xOff, y: 1.75, w: 4.5, h: 0.42, fontSize: 12, bold: true, color: C.lime, align: "center", valign: "middle", margin: 0 });
    const textArr = b.items.map((item, i) => ({
      text: item, options: { bullet: true, breakLine: i < b.items.length - 1 },
    }));
    s.addText(textArr, { x: xOff, y: 2.25, w: 4.5, h: 3.0, fontSize: 10.5, color: C.offWht, valign: "top" });
  });

  // Bottom note
  s.addShape(pres.shapes.RECTANGLE, { x: 0.35, y: 5.1, w: 9.3, h: 0.3, fill: { color: C.bgMid } });
  s.addText("Both rely on Beer–Lambert law: infrared light absorption by CO₂ is proportional to CO₂ concentration", {
    x: 0.35, y: 5.1, w: 9.3, h: 0.3, fontSize: 9.5, color: C.lime, align: "center", valign: "middle", margin: 0,
  });
}

// ─── SLIDE 5: NORMAL CAPNOGRAM PHASES ────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 03  |  NORMAL CAPNOGRAM");
  addTitle(s, "The Four Phases of a Normal Capnogram");

  // Draw axes
  // Y-axis label
  s.addText("CO₂ (mmHg)", { x: 0.1, y: 1.7, w: 0.9, h: 2.0, fontSize: 9, color: C.slate, rotate: 270 });
  // Axis lines
  s.addShape(pres.shapes.LINE, { x: 0.85, y: 1.6, w: 0.001, h: 2.8, line: { color: C.slate, width: 1 } });
  s.addShape(pres.shapes.LINE, { x: 0.85, y: 4.4, w: 8.8,  h: 0.001, line: { color: C.slate, width: 1 } });
  s.addText("Time →", { x: 8.5, y: 4.45, w: 1.5, h: 0.25, fontSize: 9, color: C.slate });

  // Scale markers
  ["0", "20", "40"].forEach((v, i) => {
    const yPos = 4.4 - i * 1.3;
    s.addText(v, { x: 0.5, y: yPos - 0.12, w: 0.34, h: 0.25, fontSize: 8, color: C.slate, align: "right" });
    s.addShape(pres.shapes.LINE, { x: 0.82, y: yPos, w: 0.1, h: 0.001, line: { color: C.slate, width: 1 } });
  });

  // Draw two breath cycles
  const breathW = 3.8;
  [1.05, 5.05].forEach(startX => {
    // Phase I: baseline (0 CO2)
    s.addShape(pres.shapes.LINE, { x: startX, y: 4.15, w: 0.55, h: 0.001, line: { color: C.lime, width: 3 } });
    // Phase II: upstroke
    s.addShape(pres.shapes.LINE, { x: startX + 0.55, y: 4.15, w: 0.45, h: 1.9, line: { color: C.lime, width: 3 }, flipV: true });
    // Phase III: alveolar plateau
    s.addShape(pres.shapes.LINE, { x: startX + 1.0, y: 2.25, w: 1.7, h: 0.001, line: { color: C.lime, width: 3 } });
    // ETCO2 dot/mark
    s.addShape(pres.shapes.OVAL, { x: startX + 2.67, y: 2.17, w: 0.16, h: 0.16, fill: { color: C.warn } });
    // Phase IV: downstroke (inspiration)
    s.addShape(pres.shapes.LINE, { x: startX + 2.7, y: 2.25, w: 0.4, h: 1.9, line: { color: C.lime, width: 3 }, flipV: false });
    // Next baseline
    s.addShape(pres.shapes.LINE, { x: startX + 3.1, y: 4.15, w: 0.7, h: 0.001, line: { color: C.lime, width: 3 } });
  });

  // Phase annotations (first breath)
  const phaseData = [
    { label: "Phase I", desc: "Dead space gas\n(0 CO₂)", x: 1.05, y: 4.5 },
    { label: "Phase II", desc: "Transition — dead\nspace → alveolar", x: 1.55, y: 3.5 },
    { label: "Phase III", desc: "Alveolar plateau\n(CO₂ rich gas)", x: 2.1,  y: 1.7 },
    { label: "ETCO₂", desc: "End-tidal point\n(35–45 mmHg)", x: 2.8,  y: 1.4 },
    { label: "Phase IV", desc: "Inspiration\n(rapid ↓ to 0)", x: 3.5,  y: 3.4 },
  ];

  phaseData.forEach(p => {
    s.addShape(pres.shapes.ROUNDED_RECTANGLE, { x: p.x, y: p.y, w: 1.7, h: 0.7, fill: { color: C.bgMid }, line: { color: C.teal, width: 1 }, rectRadius: 0.05 });
    s.addText([{ text: p.label + "\n", options: { bold: true, color: C.tealLt, breakLine: true } }, { text: p.desc, options: { color: C.offWht } }], {
      x: p.x, y: p.y, w: 1.7, h: 0.7, fontSize: 9, align: "center", valign: "middle",
    });
  });

  addFooter(s, "Barash Clinical Anesthesia 9e, Fig.26-3 | Morgan & Mikhail's Clinical Anesthesiology 7e, p.228");
}

// ─── SLIDE 6: WAVEFORM INTERPRETATION ────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 04  |  WAVEFORM INTERPRETATION");
  addTitle(s, "Reading the Capnogram — Key Parameters");

  const params = [
    { name: "ETCO₂ Value", normal: "35–45 mmHg", high: "> 45 mmHg → hypoventilation, ↑ CO₂ production, rebreathing", low: "< 35 mmHg → hyperventilation, ↓ perfusion, air embolism, leak" },
    { name: "Baseline", normal: "0 mmHg", high: "Elevated baseline → rebreathing (faulty valve, exhausted CO₂ absorbent)" },
    { name: "Phase III Slope", normal: "Nearly horizontal", high: "Upsloping ('shark fin') → obstructive disease (asthma, COPD), bronchospasm" },
    { name: "Phase II Slope", normal: "Steep, rapid", low: "Gradual upstroke → uneven emptying, V/Q mismatch, partial obstruction" },
    { name: "Waveform Height", normal: "Stable breath-to-breath", high: "Sudden ↓ → disconnection, embolism, cardiac arrest" },
  ];

  const headers = ["Parameter", "Normal", "Elevated / Abnormal"];
  const colW = [2.2, 2.0, 5.4];
  const colX = [0.3, 2.6, 4.7];
  headers.forEach((h, i) => {
    s.addShape(pres.shapes.RECTANGLE, { x: colX[i], y: 1.75, w: colW[i] - 0.1, h: 0.38, fill: { color: C.teal } });
    s.addText(h, { x: colX[i], y: 1.75, w: colW[i] - 0.1, h: 0.38, fontSize: 10, bold: true, color: C.white, align: "center", valign: "middle", margin: 0 });
  });

  params.forEach((p, i) => {
    const yy = 2.22 + i * 0.58;
    const rowBg = i % 2 === 0 ? C.bgMid : C.bg;
    colX.forEach((cx, ci) => {
      s.addShape(pres.shapes.RECTANGLE, { x: cx, y: yy, w: colW[ci] - 0.1, h: 0.52, fill: { color: rowBg } });
    });
    s.addText(p.name, { x: colX[0], y: yy + 0.04, w: colW[0] - 0.1, h: 0.44, fontSize: 10, bold: true, color: C.lime, align: "center", valign: "middle" });
    s.addText(p.normal || "—", { x: colX[1], y: yy + 0.04, w: colW[1] - 0.1, h: 0.44, fontSize: 9.5, color: C.green, align: "center", valign: "middle" });
    const abnText = [p.high, p.low].filter(Boolean).join("\n");
    s.addText(abnText, { x: colX[2] + 0.05, y: yy + 0.04, w: colW[2] - 0.2, h: 0.44, fontSize: 9, color: C.offWht, valign: "middle" });
  });

  addFooter(s, "Morgan & Mikhail's Clinical Anesthesiology 7e | Barash Clinical Anesthesia 9e, Ch.26");
}

// ─── SLIDE 7: ETCO₂ vs PaCO₂ GRADIENT ───────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 05  |  ETCO₂–PaCO₂ GRADIENT");
  addTitle(s, "The (a-ET)CO₂ Gradient — Clinical Significance", "Normal gradient: 2–5 mmHg. Widening = increased alveolar dead space");

  // Gradient explanation box
  s.addShape(pres.shapes.ROUNDED_RECTANGLE, { x: 0.35, y: 1.85, w: 4.3, h: 1.35, fill: { color: C.bgMid }, line: { color: C.lime, width: 1.5 }, rectRadius: 0.08 });
  s.addText("PaCO₂ − ETCO₂ = Alveolar Dead Space Fraction", { x: 0.45, y: 1.9, w: 4.1, h: 0.38, fontSize: 12, bold: true, color: C.lime, align: "center" });
  s.addText("AVDSf = (PaCO₂ − PETCO₂) / PaCO₂\n\nNormal: 0.04–0.10  |  Concerning: > 0.20", { x: 0.45, y: 2.3, w: 4.1, h: 0.75, fontSize: 11, color: C.offWht, align: "center" });

  const causes = [
    { title: "Gradient WIDENS (↑ dead space)", color: C.warn, items: ["Pulmonary embolism", "Air/fat/venous embolism", "Cardiac arrest / ↓ CO", "Hypotension / hypovolemia", "PEEP overdistension", "Pulmonary hypertension"] },
    { title: "Gradient NARROWS", color: C.green, items: ["Improvement in cardiac output", "Successful ROSC", "Resolution of embolism", "Fluid resuscitation"] },
  ];

  causes.forEach((c, i) => {
    const xOff = 4.95 + i * 2.6;
    s.addShape(pres.shapes.RECTANGLE, { x: xOff, y: 1.85, w: 2.4, h: 0.38, fill: { color: c.color } });
    s.addText(c.title, { x: xOff, y: 1.85, w: 2.4, h: 0.38, fontSize: 9, bold: true, color: C.bg, align: "center", valign: "middle", margin: 0 });
    const textArr = c.items.map((item, idx) => ({ text: item, options: { bullet: true, breakLine: idx < c.items.length - 1 } }));
    s.addText(textArr, { x: xOff, y: 2.28, w: 2.4, h: 2.5, fontSize: 10, color: C.offWht });
  });

  // Clinical pearl
  s.addShape(pres.shapes.RECTANGLE, { x: 0.35, y: 4.85, w: 9.3, h: 0.48, fill: { color: C.teal } });
  s.addText("⚡  PEARL: A sudden drop in ETCO₂ without a change in ventilation settings should immediately prompt evaluation for embolism, circuit disconnection, or cardiac event", {
    x: 0.45, y: 4.85, w: 9.1, h: 0.48, fontSize: 10.5, color: C.white, valign: "middle",
  });
  addFooter(s, "Morgan & Mikhail's 7e, p.227-228 | Miller's Anesthesia 10e | Sabiston Textbook of Surgery");
}

// ─── SLIDE 8: APPLICATIONS IN ANESTHESIA ────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 06  |  ANESTHESIA APPLICATIONS");
  addTitle(s, "Capnography in the Operating Room", "Mandatory monitoring for all procedures requiring general anesthesia");

  const apps = [
    { icon: "✔", title: "ETT Placement Confirmation", detail: "Detects esophageal intubation within 3–5 breaths; 100% sensitivity for colorimetric and waveform methods. Does NOT reliably detect mainstem intubation." },
    { icon: "⚠", title: "Circuit Integrity", detail: "Sudden loss of waveform → disconnection. Inspired CO₂ > 0 → rebreathing (valve failure, exhausted absorbent)." },
    { icon: "🔥", title: "Malignant Hyperthermia", detail: "Marked rise in ETCO₂ is often the earliest sign — occurs before temperature spike. Prompts immediate dantrolene therapy." },
    { icon: "💉", title: "Ventilator Management", detail: "Titrate RR/TV to maintain ETCO₂ 35–45 mmHg. Hyperventilation causes cerebral vasoconstriction — critical in neurosurgery." },
    { icon: "🫁", title: "Air/Venous Embolism Detection", detail: "Acute, sudden fall in ETCO₂ (often ≥ 3 mmHg) is a sensitive early sign. Most reliable if preceded by stable tracing." },
    { icon: "😴", title: "MAC / Sedation Monitoring", detail: "Sidestream capnography via nasal cannula detects apnea 4 min before SpO₂ falls. Respiratory depression 17.6× more likely detected vs. standard monitoring alone." },
  ];

  apps.forEach((a, i) => {
    const col = i % 2;
    const row = Math.floor(i / 2);
    const xOff = 0.35 + col * 4.85;
    const yOff = 1.85 + row * 1.2;
    s.addShape(pres.shapes.ROUNDED_RECTANGLE, { x: xOff, y: yOff, w: 4.6, h: 1.08, fill: { color: C.bgMid }, line: { color: C.teal, width: 1 }, rectRadius: 0.06 });
    s.addText(a.icon + "  " + a.title, { x: xOff + 0.1, y: yOff + 0.04, w: 4.3, h: 0.3, fontSize: 11, bold: true, color: C.lime });
    s.addText(a.detail, { x: xOff + 0.1, y: yOff + 0.34, w: 4.35, h: 0.65, fontSize: 9.5, color: C.offWht });
  });

  addFooter(s, "Morgan & Mikhail's 7e, p.227 | Barash 9e (MAC monitoring) | Tintinalli's Emergency Medicine");
}

// ─── SLIDE 9: ICU & VENTILATOR MANAGEMENT ────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 07  |  ICU APPLICATIONS");
  addTitle(s, "Capnography in the ICU & Mechanical Ventilation");

  const items = [
    ["Continuous Ventilation Monitoring", "Real-time trend of ETCO₂ avoids frequent ABGs. Rising ETCO₂ trend may indicate fatigue, increasing CO₂ production, or inadequate MV."],
    ["PEEP Titration (Volumetric)", "Volumetric capnography (VCap) plots CO₂ vs. exhaled volume. Optimal PEEP = minimum alveolar dead space without overdistension."],
    ["Dead Space Assessment", "AVDSf = (PaCO₂ − PETCO₂)/PaCO₂. Values > 0.20 associated with increased mortality in ARDS (multiple pediatric/adult ICU studies)."],
    ["Bronchodilator Response", "VCap phase III slope decreases after effective bronchodilator therapy — objective assessment of airway obstruction response."],
    ["Weaning from Ventilation", "Stable ETCO₂ during SBT suggests adequate ventilatory reserve. Rapid rise or waveform irregularity → readiness in question."],
    ["Non-Invasive Scenarios", "Transcutaneous CO₂ (TcCO₂) used in HFV, neonates, and non-intubated monitoring. Sidestream adapters for NIV masks available."],
  ];

  items.forEach((item, i) => {
    const yy = 1.82 + i * 0.59;
    s.addShape(pres.shapes.RECTANGLE, { x: 0.35, y: yy, w: 2.5, h: 0.45, fill: { color: i % 2 === 0 ? C.teal : C.slate } });
    s.addText(item[0], { x: 0.35, y: yy, w: 2.5, h: 0.45, fontSize: 10, bold: true, color: C.lime, align: "center", valign: "middle", margin: 0 });
    s.addText(item[1], { x: 2.95, y: yy + 0.03, w: 6.75, h: 0.44, fontSize: 10.5, color: C.offWht });
  });

  addFooter(s, "Miller's Anesthesia 10e, p.11316 | Schwartz's Principles of Surgery 11e | Sabiston Textbook of Surgery");
}

// ─── SLIDE 10: RESUSCITATION ─────────────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 08  |  CPR & RESUSCITATION");
  addTitle(s, "Capnography During Cardiac Arrest", "AHA guidelines recommend continuous waveform capnography for all intubated patients during CPR");

  // Key metrics
  const metrics = [
    { val: "< 10 mmHg", label: "ETCO₂ at 20 min", desc: "Strongly predicts failure of resuscitation; consider termination of efforts (in context)" },
    { val: "> 35 mmHg", label: "Sudden spike in ETCO₂", desc: "Suggests Return of Spontaneous Circulation (ROSC) — may precede other ROSC signs" },
    { val: "≥ 10–20 mmHg", label: "Target during CPR", desc: "Adequate ETCO₂ during CPR correlates with cardiac output and chest compression quality" },
    { val: "17.6×", label: "ETCO₂ = Cardiac Output proxy", desc: "ETCO₂ correlates with cardiac output during CPR — as perfusion improves, more alveoli are perfused (↓ dead space)" },
  ];

  metrics.forEach((m, i) => {
    const xOff = 0.35 + (i % 2) * 4.85;
    const yOff = 2.05 + Math.floor(i / 2) * 1.55;
    s.addShape(pres.shapes.ROUNDED_RECTANGLE, { x: xOff, y: yOff, w: 4.5, h: 1.4, fill: { color: C.bgMid }, line: { color: C.warn, width: 1.5 }, rectRadius: 0.08 });
    s.addText(m.val, { x: xOff + 0.1, y: yOff + 0.05, w: 4.2, h: 0.55, fontSize: 22, bold: true, color: C.warn, align: "center" });
    s.addText(m.label, { x: xOff + 0.1, y: yOff + 0.55, w: 4.2, h: 0.3, fontSize: 10, bold: true, color: C.tealLt, align: "center" });
    s.addText(m.desc, { x: xOff + 0.1, y: yOff + 0.85, w: 4.2, h: 0.48, fontSize: 9.5, color: C.offWht, align: "center" });
  });

  addFooter(s, "Roberts & Hedges' Clinical Procedures, p.4051 | Rosen's Emergency Medicine | AHA ACLS 2020 Guidelines");
}

// ─── SLIDE 11: ABNORMAL PATTERNS ─────────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 09  |  ABNORMAL PATTERNS");
  addTitle(s, "Abnormal Capnogram Patterns — Quick Reference");

  const patterns = [
    { name: "Shark Fin / Upsloping Ph III", cause: "Bronchospasm, COPD, asthma, partial obstruction", etco2: "Normal–↑", color: C.warn },
    { name: "Flat Line (No Waveform)", cause: "Esophageal intubation, circuit disconnection, apnea, cardiac arrest with no output", etco2: "≈ 0", color: C.red },
    { name: "Elevated Baseline", cause: "CO₂ rebreathing: expiratory valve failure, exhausted absorbent, low fresh gas flow", etco2: "↑ baseline", color: C.warn },
    { name: "Curare Cleft (Ph III notch)", cause: "Spontaneous breathing effort during controlled ventilation — partial reversal or light anesthesia", etco2: "Normal", color: C.tealLt },
    { name: "Sudden ↓ ETCO₂ to Zero", cause: "Circuit disconnect, extubation, cardiac arrest, kinked/blocked ETT", etco2: "→ 0", color: C.red },
    { name: "Gradual ↑ ETCO₂", cause: "Hypoventilation, increasing CO₂ production (fever, MH, sepsis), rebreathing, laparoscopy CO₂ absorption", etco2: "> 45 mmHg", color: C.warn },
    { name: "Gradual ↓ ETCO₂", cause: "Hyperventilation, hypothermia, ↓ cardiac output, pulmonary embolism, blood loss", etco2: "< 35 mmHg", color: C.tealLt },
    { name: "Oscillating Baseline", cause: "Cardiogenic oscillations (cardiac movement during expiration); heartbeat visible in waveform", etco2: "Normal", color: C.slate },
  ];

  patterns.forEach((p, i) => {
    const col = i % 2;
    const row = Math.floor(i / 2);
    const xOff = 0.3 + col * 4.9;
    const yOff = 1.82 + row * 0.86;
    s.addShape(pres.shapes.RECTANGLE, { x: xOff, y: yOff, w: 0.12, h: 0.72, fill: { color: p.color } });
    s.addShape(pres.shapes.ROUNDED_RECTANGLE, { x: xOff + 0.15, y: yOff, w: 4.55, h: 0.72, fill: { color: C.bgMid }, rectRadius: 0.04 });
    s.addText(p.name, { x: xOff + 0.25, y: yOff + 0.03, w: 4.3, h: 0.27, fontSize: 10.5, bold: true, color: p.color });
    s.addText("Cause: " + p.cause + "    ETCO₂: " + p.etco2, { x: xOff + 0.25, y: yOff + 0.32, w: 4.3, h: 0.36, fontSize: 9, color: C.offWht });
  });

  addFooter(s, "Morgan & Mikhail's 7e, Fig.6-3 | Barash 9e | Tintinalli's Emergency Medicine");
}

// ─── SLIDE 12: COPD & OBSTRUCTIVE DISEASE ────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 09  |  SPECIFIC PATTERNS: OBSTRUCTIVE DISEASE");
  addTitle(s, "Capnogram in COPD & Bronchospasm", "Phase III slope is the hallmark of obstructive ventilation");

  // Left: description
  s.addShape(pres.shapes.ROUNDED_RECTANGLE, { x: 0.35, y: 1.85, w: 4.3, h: 3.2, fill: { color: C.bgMid }, line: { color: C.teal, width: 1 }, rectRadius: 0.08 });
  s.addText("Pathophysiology of the 'Shark Fin'", { x: 0.45, y: 1.95, w: 4.1, h: 0.35, fontSize: 12, bold: true, color: C.lime });
  const copdPoints = [
    "In obstructive disease, airway caliber is non-uniform",
    "Fast-emptying alveoli clear CO₂ early in expiration",
    "Slow-emptying alveoli continue releasing CO₂ late",
    "Result: progressive rise throughout Phase III (upslope)",
    "No true plateau is ever reached before next inspiration",
    "ETCO₂ actually underestimates PaCO₂ — gradient widens",
    "Severity of bronchospasm correlates with slope steepness",
    "Response to bronchodilator: slope flattens measurably",
  ];
  const copdArr = copdPoints.map((p, i) => ({ text: p, options: { bullet: true, breakLine: i < copdPoints.length - 1 } }));
  s.addText(copdArr, { x: 0.45, y: 2.35, w: 4.1, h: 2.6, fontSize: 10, color: C.offWht });

  // Right: drawn waveform comparison
  s.addText("Normal vs COPD Capnogram", { x: 4.9, y: 1.9, w: 4.8, h: 0.35, fontSize: 11, bold: true, color: C.tealLt, align: "center" });

  // Axes
  s.addShape(pres.shapes.LINE, { x: 5.0, y: 2.35, w: 0.001, h: 2.5, line: { color: C.slate, width: 1 } });
  s.addShape(pres.shapes.LINE, { x: 5.0, y: 4.85, w: 4.6, h: 0.001, line: { color: C.slate, width: 1 } });

  // Normal waveform (green)
  s.addShape(pres.shapes.LINE, { x: 5.05, y: 4.65, w: 0.4, h: 0.001, line: { color: C.green, width: 2 } });
  s.addShape(pres.shapes.LINE, { x: 5.45, y: 4.65, w: 0.3, h: 1.5, line: { color: C.green, width: 2 }, flipV: true });
  s.addShape(pres.shapes.LINE, { x: 5.75, y: 3.15, w: 1.0, h: 0.001, line: { color: C.green, width: 2 } });
  s.addShape(pres.shapes.LINE, { x: 6.75, y: 3.15, w: 0.3, h: 1.5, line: { color: C.green, width: 2 }, flipV: false });
  s.addShape(pres.shapes.LINE, { x: 7.05, y: 4.65, w: 0.5, h: 0.001, line: { color: C.green, width: 2 } });
  s.addText("Normal", { x: 5.9, y: 2.9, w: 1.2, h: 0.22, fontSize: 9, color: C.green, align: "center" });

  // COPD waveform (orange) — upsloping
  s.addShape(pres.shapes.LINE, { x: 5.05, y: 4.82, w: 0.4, h: 0.001, line: { color: C.warn, width: 2.5 } });
  s.addShape(pres.shapes.LINE, { x: 5.45, y: 4.82, w: 0.35, h: 1.7, line: { color: C.warn, width: 2.5 }, flipV: true });
  // Sloped plateau
  s.addShape(pres.shapes.LINE, { x: 5.80, y: 3.12, w: 1.0, h: 0.55, line: { color: C.warn, width: 2.5 }, flipV: true });
  s.addShape(pres.shapes.LINE, { x: 6.80, y: 2.57, w: 0.25, h: 2.25, line: { color: C.warn, width: 2.5 }, flipV: false });
  s.addShape(pres.shapes.LINE, { x: 7.05, y: 4.82, w: 0.5, h: 0.001, line: { color: C.warn, width: 2.5 } });
  s.addText("COPD / Bronchospasm", { x: 5.7, y: 2.3, w: 2.3, h: 0.22, fontSize: 9, color: C.warn, align: "center" });

  s.addText("Phase III upslope →\n'Shark fin' pattern", { x: 6.8, y: 2.75, w: 1.8, h: 0.45, fontSize: 8.5, color: C.warn, italic: true });

  addFooter(s, "Morgan & Mikhail's 7e, Fig.6-3B | Miller's Anesthesia 10e");
}

// ─── SLIDE 13: REBREATHING PATTERNS ──────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 09  |  SPECIFIC PATTERNS: REBREATHING");
  addTitle(s, "Rebreathing — Elevated Baseline on Capnogram");

  // Left: causes
  s.addShape(pres.shapes.RECTANGLE, { x: 0.35, y: 1.82, w: 4.3, h: 0.4, fill: { color: C.teal } });
  s.addText("Causes of Elevated CO₂ Baseline", { x: 0.35, y: 1.82, w: 4.3, h: 0.4, fontSize: 11, bold: true, color: C.lime, align: "center", valign: "middle", margin: 0 });

  const causes = [
    ["Exhausted CO₂ absorbent", "Soda lime / Baralyme saturated; CO₂ passes unreacted into inspiratory limb"],
    ["Expiratory valve failure", "Exhaled gas refluxes into inspiratory side; continuous CO₂ in inspiratory phase"],
    ["Inspiratory valve failure", "Partial failure — some rebreathing; not fully apparent as part of inspiration still 0 CO₂"],
    ["High rebreathing circuit", "Mapleson circuits without adequate fresh gas flow allow CO₂ accumulation"],
    ["Long breathing tubing", "Increased dead space in circuit — CO₂ remains in tubing at start of inspiration"],
  ];

  causes.forEach((c, i) => {
    const yy = 2.3 + i * 0.58;
    s.addShape(pres.shapes.RECTANGLE, { x: 0.35, y: yy, w: 0.1, h: 0.48, fill: { color: C.lime } });
    s.addText(c[0], { x: 0.55, y: yy + 0.02, w: 4.0, h: 0.22, fontSize: 10.5, bold: true, color: C.tealLt });
    s.addText(c[1], { x: 0.55, y: yy + 0.24, w: 4.0, h: 0.22, fontSize: 9.5, color: C.offWht });
  });

  // Right: waveform illustration
  s.addText("Elevated Baseline Pattern", { x: 5.0, y: 1.9, w: 4.7, h: 0.35, fontSize: 11, bold: true, color: C.tealLt, align: "center" });
  s.addShape(pres.shapes.LINE, { x: 5.1, y: 2.4, w: 0.001, h: 2.3, line: { color: C.slate, width: 1 } });
  s.addShape(pres.shapes.LINE, { x: 5.1, y: 4.7, w: 4.5, h: 0.001, line: { color: C.slate, width: 1 } });

  // Normal (green)
  s.addShape(pres.shapes.LINE, { x: 5.15, y: 4.5, w: 0.45, h: 0.001, line: { color: C.green, width: 2 } });
  s.addShape(pres.shapes.LINE, { x: 5.6,  y: 4.5, w: 0.3, h: 1.5, line: { color: C.green, width: 2 }, flipV: true });
  s.addShape(pres.shapes.LINE, { x: 5.9,  y: 3.0, w: 0.9, h: 0.001, line: { color: C.green, width: 2 } });
  s.addShape(pres.shapes.LINE, { x: 6.8,  y: 3.0, w: 0.28, h: 1.5, line: { color: C.green, width: 2 } });
  s.addShape(pres.shapes.LINE, { x: 7.08, y: 4.5, w: 0.5, h: 0.001, line: { color: C.green, width: 2 } });
  s.addText("Normal", { x: 5.95, y: 2.75, w: 1.0, h: 0.22, fontSize: 8.5, color: C.green, align: "center" });

  // Rebreathing (red) — elevated baseline
  const baseY = 4.0; // elevated from 4.5
  s.addShape(pres.shapes.LINE, { x: 5.15, y: baseY, w: 0.45, h: 0.001, line: { color: C.red, width: 2.5 } });
  s.addShape(pres.shapes.LINE, { x: 5.6,  y: baseY, w: 0.3, h: 1.0, line: { color: C.red, width: 2.5 }, flipV: true });
  s.addShape(pres.shapes.LINE, { x: 5.9,  y: 3.0, w: 0.9, h: 0.001, line: { color: C.red, width: 2.5 } });
  s.addShape(pres.shapes.LINE, { x: 6.8,  y: 3.0, w: 0.28, h: 1.0, line: { color: C.red, width: 2.5 } });
  s.addShape(pres.shapes.LINE, { x: 7.08, y: baseY, w: 0.5, h: 0.001, line: { color: C.red, width: 2.5 } });
  s.addText("Rebreathing", { x: 5.95, y: 3.7, w: 1.1, h: 0.22, fontSize: 8.5, color: C.red, align: "center" });

  // Annotation arrows
  s.addShape(pres.shapes.LINE, { x: 7.75, y: baseY, w: 0.5, h: 0.001, line: { color: C.red, width: 1.5 } });
  s.addShape(pres.shapes.LINE, { x: 7.75, y: 4.5, w: 0.5, h: 0.001, line: { color: C.green, width: 1.5 } });
  s.addShape(pres.shapes.LINE, { x: 8.0, y: baseY, w: 0.001, h: 0.5, line: { color: C.warn, width: 1.5 } });
  s.addText("Elevated\nbaseline\n(rebreathing)", { x: 8.1, y: baseY - 0.1, w: 1.4, h: 0.7, fontSize: 8.5, color: C.warn });

  addFooter(s, "Morgan & Mikhail's 7e, p.228 (Fig.6-3D,E) | Barash Clinical Anesthesia 9e");
}

// ─── SLIDE 14: LAPAROSCOPY & SPECIAL CASES ───────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 09  |  SPECIFIC SCENARIOS");
  addTitle(s, "Capnography in Special Clinical Scenarios");

  const cases = [
    {
      title: "Laparoscopic Surgery",
      color: C.teal,
      items: [
        "CO₂ insufflation → systemic absorption → ETCO₂ rises",
        "Increase MV by 15–25% to compensate",
        "Trendelenburg position impairs diaphragm excursion",
        "Sudden massive rise → subcutaneous emphysema or CO₂ embolism",
        "Monitor closely — surgeon should be notified of persistent ↑ ETCO₂",
      ],
    },
    {
      title: "Pregnancy & Obstetric Anesthesia",
      color: C.tealLt,
      items: [
        "Baseline PaCO₂ is lower (≈ 32 mmHg) due to progesterone-driven hyperventilation",
        "Target ETCO₂ 30–32 mmHg to reflect this physiological state",
        "Avoid hypocapnia — causes uterine vasoconstriction",
        "Useful in monitoring failed intubation situations",
      ],
    },
    {
      title: "Pediatric Patients",
      color: C.warn,
      items: [
        "High RR → insufficient time for alveolar plateau — ETCO₂ often underestimates PaCO₂",
        "Low tidal volumes → sidestream aspiration dilutes sample",
        "Mainstream sensors may increase dead space significantly",
        "Consider TcCO₂ monitoring in neonates / very small infants",
        "Low aspiration rate (<50 mL/min) may under-read ETCO₂",
      ],
    },
    {
      title: "Neurological / Neurosurgery",
      color: C.red,
      items: [
        "Cerebral vasoreactivity to CO₂: every 1 mmHg ↑ PaCO₂ → ~4% ↑ CBF",
        "ICP management: target ETCO₂ 35 mmHg; avoid >45 (↑ ICP)",
        "Deliberate hyperventilation (ETCO₂ 30–35) for acute ICP crises",
        "Sitting position: high risk of air embolism — monitor ETCO₂ + N₂",
      ],
    },
  ];

  cases.forEach((c, i) => {
    const xOff = 0.3 + (i % 2) * 4.9;
    const yOff = 1.82 + Math.floor(i / 2) * 1.85;
    s.addShape(pres.shapes.RECTANGLE, { x: xOff, y: yOff, w: 4.55, h: 0.38, fill: { color: c.color } });
    s.addText(c.title, { x: xOff, y: yOff, w: 4.55, h: 0.38, fontSize: 10.5, bold: true, color: C.bg, align: "center", valign: "middle", margin: 0 });
    const arr = c.items.map((item, idx) => ({ text: item, options: { bullet: true, breakLine: idx < c.items.length - 1 } }));
    s.addText(arr, { x: xOff + 0.05, y: yOff + 0.4, w: 4.45, h: 1.35, fontSize: 9.5, color: C.offWht });
  });

  addFooter(s, "Morgan & Mikhail's 7e | Barash Clinical Anesthesia 9e | Roberts & Hedges' Clinical Procedures");
}

// ─── SLIDE 15: TROUBLESHOOTING ────────────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 10  |  TROUBLESHOOTING");
  addTitle(s, "Troubleshooting Capnograph Problems", "Artifacts and technical failures must be distinguished from true physiological events");

  const issues = [
    { problem: "No waveform displayed", causes: ["Circuit disconnection", "Esophageal intubation", "Cardiac arrest", "Sensor or cable failure"], action: "Check circuit → confirm ETT placement → assess patient", color: C.red },
    { problem: "Sidestream: blocked sampling line", causes: ["Water condensation in tubing", "Secretions / mucus in line", "Kinked tubing"], action: "Replace sampling line; use water trap; use heated tubing", color: C.warn },
    { problem: "Readings consistently low", causes: ["Leak around ETT cuff", "Low aspiration rate diluting sample (pediatric)", "High RR with no alveolar plateau"], action: "Check cuff pressure; verify sampling rate; consider mainstream sensor", color: C.tealLt },
    { problem: "Inspired CO₂ > 0 (baseline elevated)", causes: ["Exhausted CO₂ absorbent", "Valve malfunction (inspiratory or expiratory)", "Excessive rebreathing in Mapleson circuit"], action: "Replace absorbent; test circle system valves; ↑ fresh gas flow", color: C.warn },
    { problem: "Sudden high spike then loss", causes: ["Sampling line punctured or open to air", "Patient coughed or strained during measurement"], action: "Replace sampling line; reassess", color: C.slate },
  ];

  issues.forEach((iss, i) => {
    const yy = 1.8 + i * 0.7;
    s.addShape(pres.shapes.RECTANGLE, { x: 0.3, y: yy, w: 0.1, h: 0.58, fill: { color: iss.color } });
    s.addShape(pres.shapes.ROUNDED_RECTANGLE, { x: 0.45, y: yy, w: 9.2, h: 0.58, fill: { color: C.bgMid }, rectRadius: 0.04 });
    s.addText(iss.problem, { x: 0.55, y: yy + 0.03, w: 2.3, h: 0.25, fontSize: 10.5, bold: true, color: iss.color });
    s.addText("Causes: " + iss.causes.join(" | "), { x: 0.55, y: yy + 0.28, w: 5.2, h: 0.22, fontSize: 9, color: C.offWht });
    s.addShape(pres.shapes.RECTANGLE, { x: 5.85, y: yy + 0.06, w: 3.65, h: 0.46, fill: { color: C.bg }, line: { color: iss.color, width: 0.5 } });
    s.addText("▶  " + iss.action, { x: 5.9, y: yy + 0.06, w: 3.55, h: 0.46, fontSize: 9, color: C.lime, valign: "middle" });
  });

  addFooter(s, "Morgan & Mikhail's 7e, p.228 | Barash 9e | Tintinalli's Emergency Medicine");
}

// ─── SLIDE 16: DETECTION TABLE ────────────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "SECTION 06–07  |  CRITICAL EVENTS DETECTION");
  addTitle(s, "Critical Events Detected by Capnography", "Based on Barash Clinical Anesthesia 9e, Table 26-1");

  const events = [
    ["Esophageal intubation", "CO₂ absent after 3–5 breaths", "Immediate re-intubation", C.red],
    ["Circuit disconnection", "Sudden loss of waveform", "Check all connections", C.red],
    ["Malignant hyperthermia", "Rapid ↑ ETCO₂, early sign", "Dantrolene, cooling, trigger removal", C.red],
    ["Air / venous embolism", "Acute ↓ ETCO₂ (↑ dead space)", "Position change, aspiration, notify surgeon", C.warn],
    ["Bronchospasm", "Upsloping Phase III (shark fin)", "Bronchodilator, ↑ inspiratory time", C.warn],
    ["Pulmonary embolism", "Gradual ↓ ETCO₂, ↑ gradient", "CT angiography, anticoagulation", C.warn],
    ["Rebreathing", "Elevated inspiratory CO₂ baseline", "Replace absorbent, check valves", C.tealLt],
    ["Cardiac arrest / low CO", "Very low or absent ETCO₂", "CPR quality assessment; ETCO₂ target ≥10 mmHg", C.red],
    ["ROSC", "Sudden spike in ETCO₂ > 35 mmHg", "Pulse check; post-ROSC care", C.green],
    ["Hypoventilation", "Gradual ↑ ETCO₂ > 45 mmHg", "↑ RR or TV; check sedation level", C.warn],
  ];

  const colHeaders = ["Event", "Capnographic Finding", "Clinical Action"];
  const colW2 = [2.4, 3.2, 4.0];
  const colX2 = [0.3, 2.8, 6.1];

  colHeaders.forEach((h, ci) => {
    s.addShape(pres.shapes.RECTANGLE, { x: colX2[ci], y: 1.72, w: colW2[ci] - 0.1, h: 0.35, fill: { color: C.teal } });
    s.addText(h, { x: colX2[ci], y: 1.72, w: colW2[ci] - 0.1, h: 0.35, fontSize: 10, bold: true, color: C.white, align: "center", valign: "middle", margin: 0 });
  });

  events.forEach((e, i) => {
    const yy = 2.14 + i * 0.33;
    const rowBg = i % 2 === 0 ? C.bgMid : C.bg;
    s.addShape(pres.shapes.RECTANGLE, { x: 0.3, y: yy, w: 0.08, h: 0.3, fill: { color: e[3] } });
    colX2.forEach((cx, ci) => {
      s.addShape(pres.shapes.RECTANGLE, { x: cx, y: yy, w: colW2[ci] - 0.1, h: 0.3, fill: { color: rowBg } });
    });
    s.addText(e[0], { x: colX2[0] + 0.05, y: yy + 0.02, w: colW2[0] - 0.15, h: 0.26, fontSize: 9, bold: true, color: e[3], valign: "middle" });
    s.addText(e[1], { x: colX2[1] + 0.05, y: yy + 0.02, w: colW2[1] - 0.15, h: 0.26, fontSize: 9, color: C.offWht, valign: "middle" });
    s.addText(e[2], { x: colX2[2] + 0.05, y: yy + 0.02, w: colW2[2] - 0.15, h: 0.26, fontSize: 9, color: C.offWht, valign: "middle" });
  });

  addFooter(s, "Barash Clinical Anesthesia 9e, Table 26-1 | Morgan & Mikhail's 7e | Roberts & Hedges' Clinical Procedures");
}

// ─── SLIDE 17: GUIDELINES & STANDARDS ────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "GUIDELINES & STANDARDS");
  addTitle(s, "Capnography: Guidelines & Mandatory Standards");

  const guidelines = [
    { org: "ASA", year: "2011+", text: "Continuous waveform capnography is mandatory for all patients receiving general anesthesia. Also recommended during moderate/deep sedation." },
    { org: "AHA ACLS", year: "2020", text: "Waveform capnography required to confirm and monitor ETT placement. ETCO₂ < 10 mmHg after 20 min CPR may guide termination decisions." },
    { org: "WHO", year: "2009", text: "Pulse oximetry AND capnography identified as essential monitoring for safe surgery globally — part of the Safe Surgery Saves Lives initiative." },
    { org: "AAGBI / RCoA", year: "2021", text: "Capnography is mandatory for any patient with a tracheal tube or supraglottic device under general anaesthesia." },
    { org: "80+ Societies", year: "2015–2024", text: "Over 80 clinical societies have recommended capnography in >100 guidelines — spanning anesthesia, emergency medicine, critical care, and procedural sedation." },
  ];

  guidelines.forEach((g, i) => {
    const yy = 1.85 + i * 0.7;
    s.addShape(pres.shapes.RECTANGLE, { x: 0.35, y: yy, w: 0.9, h: 0.56, fill: { color: C.teal } });
    s.addText(g.org, { x: 0.35, y: yy, w: 0.9, h: 0.35, fontSize: 11, bold: true, color: C.lime, align: "center", valign: "middle", margin: 0 });
    s.addText(g.year, { x: 0.35, y: yy + 0.33, w: 0.9, h: 0.22, fontSize: 9, color: C.white, align: "center", valign: "middle", margin: 0 });
    s.addText(g.text, { x: 1.35, y: yy + 0.05, w: 8.3, h: 0.5, fontSize: 10.5, color: C.offWht });
  });

  s.addShape(pres.shapes.RECTANGLE, { x: 0.35, y: 5.2, w: 9.3, h: 0.25, fill: { color: C.bgMid } });
  s.addText("Capnography is now considered standard of care — not optional — in any setting where a patient's airway is managed or sedation is administered", {
    x: 0.4, y: 5.2, w: 9.2, h: 0.25, fontSize: 9, color: C.lime, align: "center", valign: "middle",
  });
  addFooter(s, "ASA Standards 2011 | AHA ACLS Guidelines 2020 | WHO Safe Surgery Initiative | Respiratory Therapy 2024 review");
}

// ─── SLIDE 18: CLINICAL DECISION ALGORITHM ───────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "CLINICAL DECISION SUPPORT");
  addTitle(s, "Systematic Approach to an Abnormal Capnogram");

  // Flow: Step-by-step
  const steps = [
    { n: "1", q: "Is there a waveform?", yes: "YES → proceed", no: "NO → check circuit, ETT, patient" },
    { n: "2", q: "Is the baseline (inspired CO₂) = 0?", yes: "YES → proceed", no: "NO → rebreathing (valve/absorbent)" },
    { n: "3", q: "Is ETCO₂ 35–45 mmHg?", yes: "YES → normal ventilation", no: "NO → characterize further" },
    { n: "4", q: "ETCO₂ HIGH (> 45)?", yes: "Hypoventilation / ↑ production → ↑ MV, check MH, sepsis", no: "LOW (< 35) → ↑ dead space (PE, embolism, ↓ CO, hyperventilation)" },
    { n: "5", q: "Phase III slope — flat or upsloping?", yes: "Flat = normal or hyperventilation", no: "Upsloping = obstructive disease → bronchodilator, ↑ exp time" },
  ];

  steps.forEach((step, i) => {
    const yy = 1.78 + i * 0.72;
    s.addShape(pres.shapes.OVAL, { x: 0.35, y: yy, w: 0.5, h: 0.5, fill: { color: C.teal } });
    s.addText(step.n, { x: 0.35, y: yy, w: 0.5, h: 0.5, fontSize: 14, bold: true, color: C.lime, align: "center", valign: "middle", margin: 0 });
    s.addShape(pres.shapes.ROUNDED_RECTANGLE, { x: 0.95, y: yy, w: 3.5, h: 0.5, fill: { color: C.bgMid }, line: { color: C.teal, width: 1 }, rectRadius: 0.05 });
    s.addText(step.q, { x: 1.0, y: yy + 0.05, w: 3.4, h: 0.4, fontSize: 10, bold: true, color: C.white, valign: "middle" });
    s.addShape(pres.shapes.ROUNDED_RECTANGLE, { x: 4.55, y: yy, w: 2.2, h: 0.5, fill: { color: C.bg }, line: { color: C.green, width: 1 }, rectRadius: 0.04 });
    s.addText("✔  " + step.yes, { x: 4.6, y: yy + 0.04, w: 2.1, h: 0.42, fontSize: 8.5, color: C.green, valign: "middle" });
    s.addShape(pres.shapes.ROUNDED_RECTANGLE, { x: 6.85, y: yy, w: 2.8, h: 0.5, fill: { color: C.bg }, line: { color: C.warn, width: 1 }, rectRadius: 0.04 });
    s.addText("✘  " + step.no, { x: 6.9, y: yy + 0.04, w: 2.7, h: 0.42, fontSize: 8.5, color: C.warn, valign: "middle" });
  });

  addTag(s, "ALGORITHM", 9.3, 0.5);
  addFooter(s, "Adapted from Respiratory Therapy (Farquharson & Spratt, 2024) | Morgan & Mikhail's 7e");
}

// ─── SLIDE 19: KEY NUMBERS ────────────────────────────────────────────────────
{
  const s = pres.addSlide();
  darkSlide(s);
  addSection(s, "QUICK REFERENCE");
  addTitle(s, "Key Numbers Every Clinician Should Know");

  const nums = [
    { val: "35–45", unit: "mmHg", label: "Normal ETCO₂ range" },
    { val: "2–5",   unit: "mmHg", label: "Normal PaCO₂–ETCO₂ gradient" },
    { val: "< 10",  unit: "mmHg", label: "ETCO₂ during CPR → predicts failure" },
    { val: "> 35",  unit: "mmHg", label: "Sudden ETCO₂ spike → suspect ROSC" },
    { val: "0",     unit: "mmHg", label: "Inspired CO₂ (normal baseline)" },
    { val: "≈ 4 min", unit: "", label: "Time advantage over SpO₂ in detecting apnea" },
    { val: "17.6×", unit: "more likely", label: "Resp depression detected with capnography vs. standard monitoring" },
    { val: "100%",  unit: "sensitivity", label: "Waveform capnography for ETT placement confirmation" },
    { val: "0.04–0.10", unit: "AVDSf", label: "Normal alveolar dead space fraction" },
    { val: "> 0.20",    unit: "AVDSf", label: "Concerning dead space fraction → investigate" },
  ];

  nums.forEach((n, i) => {
    const col = i % 2;
    const row = Math.floor(i / 2);
    const xOff = 0.35 + col * 4.9;
    const yOff = 1.82 + row * 0.73;
    s.addShape(pres.shapes.ROUNDED_RECTANGLE, { x: xOff, y: yOff, w: 4.6, h: 0.64, fill: { color: C.bgMid }, line: { color: C.teal, width: 0.8 }, rectRadius: 0.05 });
    s.addText(n.val, { x: xOff + 0.1, y: yOff + 0.06, w: 1.6, h: 0.52, fontSize: 20, bold: true, color: C.lime, align: "center", valign: "middle" });
    s.addText(n.unit, { x: xOff + 1.65, y: yOff + 0.06, w: 1.0, h: 0.25, fontSize: 8.5, color: C.tealLt });
    s.addText(n.label, { x: xOff + 1.65, y: yOff + 0.3, w: 2.85, h: 0.28, fontSize: 9.5, color: C.offWht });
  });

  addFooter(s, "Morgan & Mikhail's 7e | Barash 9e | Rosen's EM | Barash MAC monitoring | Respiratory Therapy 2024");
}

// ─── SLIDE 20: SUMMARY & CLOSING ─────────────────────────────────────────────
{
  const s = pres.addSlide();
  s.background = { color: C.bg };

  // Teal accent bar left
  s.addShape(pres.shapes.RECTANGLE, { x: 0, y: 0, w: 0.18, h: 5.625, fill: { color: C.teal } });
  s.addShape(pres.shapes.RECTANGLE, { x: 0.18, y: 0, w: 0.06, h: 5.625, fill: { color: C.lime } });

  s.addText("KEY TAKEAWAYS", {
    x: 0.5, y: 0.35, w: 9, h: 0.5, fontSize: 24, bold: true, color: C.lime, charSpacing: 3,
  });

  const takehomes = [
    "Capnography measures CO₂ across ventilation, perfusion, and metabolism — a single waveform reflects all three",
    "Normal ETCO₂ is 35–45 mmHg; a 2–5 mmHg gradient vs PaCO₂ reflects healthy lungs",
    "Waveform capnography is mandatory in GA, ACLS, and strongly recommended for all sedated patients",
    "Sudden loss of waveform → circuit disconnection or esophageal intubation until proven otherwise",
    "Upsloping Phase III (shark fin) = obstructive airways disease; treat the cause",
    "Elevated baseline = rebreathing; check valves and CO₂ absorbent",
    "During CPR: ETCO₂ ≥ 10 mmHg targets quality compressions; sudden spike = suspect ROSC",
    "The (a-ET)CO₂ gradient is an indirect window into alveolar dead space and cardiac output",
  ];

  const arr = takehomes.map((t, i) => ({
    text: "  " + t, options: { bullet: { code: "25CF", color: C.lime }, color: i % 2 === 0 ? C.white : C.offWht, breakLine: i < takehomes.length - 1, fontSize: 11 },
  }));
  s.addText(arr, { x: 0.5, y: 0.95, w: 9.1, h: 4.3, valign: "top" });

  s.addText("Capnography 2026  |  For ICU & Anesthesia Clinicians", {
    x: 0.5, y: 5.25, w: 9.1, h: 0.25, fontSize: 9, color: C.slate, align: "right",
  });
}

// ─── WRITE FILE ───────────────────────────────────────────────────────────────
pres.writeFile({ fileName: "/home/daytona/workspace/capnography-pptx/Capnography_ICU_Anesthesia.pptx" })
  .then(() => console.log("✅  Presentation saved successfully"))
  .catch(err => { console.error("❌  Error:", err); process.exit(1); });

cd /home/daytona/workspace/capnography-pptx && node build.js 2>&1

ls -lh /home/daytona/workspace/capnography-pptx/Capnography_ICU_Anesthesia.pptx

ls -lh /home/daytona/workspace/capnography-pptx/ && file /home/daytona/workspace…

cp /home/daytona/workspace/capnography-pptx/Capnography_ICU_Anesthesia.pptx /hom…

cd /home/daytona/workspace/capnography-pptx && libreoffice --headless --convert-…

mkdir -p /home/daytona/workspace/capnography-pptx/output && libreoffice --headle…

chmod 777 /home/daytona/workspace/capnography-pptx/output && libreoffice --headl…

cp /home/daytona/workspace/capnography-pptx/Capnography_ICU_Anesthesia.pptx /tmp…

cp /tmp/capo.pdf /home/daytona/workspace/capnography-pptx/Capnography_ICU_Anesth…

base64 /home/daytona/workspace/capnography-pptx/Capnography_ICU_Anesthesia.pdf |…

python3 -c " import base64, json with open('/home/daytona/workspace/capnography…

~/capnography-pptx/Capnography_GoogleSlides.gs

/**
 * CAPNOGRAPHY - ICU & ANESTHESIA CLINICIANS
 * Google Apps Script — paste this into script.google.com (or Tools > Script editor
 * inside any Google Slides file) and run createCapnographyPresentation().
 *
 * HOW TO USE:
 *  1. Go to https://script.google.com  → New Project
 *  2. Delete any existing code, paste this entire file
 *  3. Click Run → createCapnographyPresentation
 *  4. Grant permissions when prompted
 *  5. A new Google Slides presentation opens in your Drive
 */

// ─── PALETTE ─────────────────────────────────────────────────────────────────
var BG     = '#0D1B2A';
var TEAL   = '#0B7A75';
var TEALLT = '#0FA3A0';
var LIME   = '#C8F04D';
var WHITE  = '#FFFFFF';
var OFFWHT = '#D6E4E4';
var SLATE  = '#4A7896';
var WARN   = '#F28B30';
var RED    = '#E05252';
var GREEN  = '#50C878';
var BGMID  = '#112233';

// ─── HELPERS ─────────────────────────────────────────────────────────────────
function setSlide(slide) {
  slide.getBackground().setSolidFill(HexColor(BG));
  return slide;
}

function HexColor(hex) {
  hex = hex.replace('#','');
  return {
    red:   parseInt(hex.substring(0,2),16)/255,
    green: parseInt(hex.substring(2,4),16)/255,
    blue:  parseInt(hex.substring(4,6),16)/255
  };
}

function addRect(slide, x, y, w, h, fillHex, borderHex) {
  var shape = slide.insertShape(SlidesApp.ShapeType.RECTANGLE,
    emu(x), emu(y), emu(w), emu(h));
  shape.getFill().setSolidFill(HexColor(fillHex));
  if (borderHex) {
    shape.getBorder().getLineFill().setSolidFill(HexColor(borderHex));
    shape.getBorder().setWeight(1);
  } else {
    shape.getBorder().setTransparent();
  }
  return shape;
}

function addText(slide, text, x, y, w, h, opts) {
  opts = opts || {};
  var shape = slide.insertTextBox(text, emu(x), emu(y), emu(w), emu(h));
  shape.getBorder().setTransparent();
  shape.getFill().setTransparent();
  var tf = shape.getText();
  var style = tf.getTextStyle();
  style.setFontSize(opts.fontSize || 12);
  style.setForegroundColor(HexColor(opts.color || WHITE));
  style.setBold(opts.bold || false);
  style.setItalic(opts.italic || false);
  if (opts.fontFace) style.setFontFamily(opts.fontFace);
  var para = tf.getParagraphs()[0].getRange().getParagraphStyle();
  para.setParagraphAlignment(
    opts.align === 'center' ? SlidesApp.ParagraphAlignment.CENTER :
    opts.align === 'right'  ? SlidesApp.ParagraphAlignment.END :
    SlidesApp.ParagraphAlignment.START
  );
  return shape;
}

// Convert inches to EMUs (English Metric Units) — Google Slides API uses EMUs
function emu(inches) { return inches * 914400; }

// Section header bar
function sectionBar(slide, label) {
  addRect(slide, 0, 0, 10, 0.42, TEAL);
  addText(slide, label, 0.15, 0.02, 9.7, 0.38,
    {fontSize:10, bold:true, color:WHITE});
}

// Slide title + subtitle
function slideTitle(slide, title, sub) {
  addText(slide, title, 0.3, 0.55, 9.4, 0.75,
    {fontSize:24, bold:true, color:WHITE});
  if (sub) addText(slide, sub, 0.3, 1.32, 9.4, 0.38,
    {fontSize:12, color:TEALLT, italic:true});
}

// Footer
function footer(slide, text) {
  addText(slide, text, 0.3, 5.28, 9.4, 0.22,
    {fontSize:7, color:SLATE, align:'right'});
}

// Colored label box + body text row
function labelRow(slide, label, body, x, y, w, labelW, labelColor, rowBg) {
  if (rowBg) addRect(slide, x, y, w, 0.5, rowBg);
  addRect(slide, x, y, labelW, 0.5, labelColor || TEAL);
  addText(slide, label, x, y, labelW, 0.5,
    {fontSize:10, bold:true, color:LIME, align:'center'});
  addText(slide, body, x + labelW + 0.1, y + 0.05, w - labelW - 0.15, 0.42,
    {fontSize:10.5, color:OFFWHT});
}

// ─── MAIN FUNCTION ────────────────────────────────────────────────────────────
function createCapnographyPresentation() {
  var pres = SlidesApp.create('Capnography — ICU & Anesthesia Clinicians');
  // Remove default blank slide
  var slides = pres.getSlides();

  // ── SLIDE 1: TITLE ──────────────────────────────────────────────────────────
  var s = slides[0];
  s.getBackground().setSolidFill(HexColor(BG));
  addRect(s, 0, 0, 0.18, 5.625, TEAL);
  addRect(s, 0.18, 0, 0.06, 5.625, LIME);
  addText(s, 'CAPNOGRAPHY', 0.5, 0.6, 9.0, 1.1,
    {fontSize:48, bold:true, color:WHITE});
  addText(s, 'Principles, Waveforms & Clinical Applications',
    0.5, 1.8, 9.0, 0.5, {fontSize:20, color:TEALLT});
  addRect(s, 0.5, 2.42, 3.5, 0.05, LIME);
  addText(s, 'For ICU & Anesthesia Clinicians | 2026',
    0.5, 2.6, 7.0, 0.38, {fontSize:14, color:OFFWHT});
  addText(s, 'Sources: Morgan & Mikhail 7e · Barash Clinical Anesthesia 9e · Miller\'s Anesthesia 10e',
    0.5, 5.15, 9.0, 0.28, {fontSize:8.5, color:SLATE});

  // ── SLIDE 2: TABLE OF CONTENTS ───────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'OVERVIEW');
  slideTitle(s, 'What We Will Cover');
  var toc = [
    ['01','CO₂ Physiology'],['02','Types of Capnographs'],
    ['03','Normal Capnogram Phases'],['04','Waveform Interpretation'],
    ['05','ETCO₂ vs PaCO₂ Gradient'],['06','Applications in Anesthesia'],
    ['07','ICU & Ventilator Management'],['08','Capnography in Resuscitation'],
    ['09','Abnormal Waveform Patterns'],['10','Troubleshooting & Pitfalls'],
  ];
  toc.forEach(function(item, i) {
    var col = i < 5 ? 0 : 1;
    var row = i < 5 ? i : i - 5;
    var xo = 0.35 + col * 4.85;
    var yo = 1.85 + row * 0.64;
    addRect(s, xo, yo, 0.46, 0.42, TEAL);
    addText(s, item[0], xo, yo, 0.46, 0.42,
      {fontSize:12, bold:true, color:LIME, align:'center'});
    addText(s, item[1], xo + 0.56, yo + 0.06, 4.1, 0.32,
      {fontSize:12, color:OFFWHT});
  });
  footer(s, 'Morgan & Mikhail 7e | Barash 9e | Miller\'s 10e');

  // ── SLIDE 3: CO₂ PHYSIOLOGY ─────────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 01  |  CO₂ PHYSIOLOGY');
  slideTitle(s, 'Why CO₂ Monitoring Matters',
    'CO₂ is the end-product of aerobic metabolism — reflects ventilation, perfusion & metabolism simultaneously');
  var phys = [
    ['Cellular Production','CO₂ produced during aerobic metabolism (~200 mL/min at rest); increases with fever, MH, sepsis'],
    ['Blood Transport','~70% as HCO₃⁻ (bicarbonate), ~23% bound to Hb (carbaminoHb), ~7% dissolved in plasma'],
    ['Alveolar Exchange','Diffuses rapidly across alveolar membrane; normal PaCO₂ = 35–45 mmHg'],
    ['ETCO₂ Relationship','ETCO₂ ≈ PaCO₂ − 2 to 5 mmHg in healthy lungs; gradient widens with dead space or low cardiac output'],
    ['Clinical Equation','ETCO₂ = f(CO₂ production, alveolar ventilation, cardiac output, V/Q matching)'],
  ];
  phys.forEach(function(p, i) {
    labelRow(s, p[0], p[1], 0.35, 1.82 + i*0.64, 9.3, 2.2, TEAL, i%2===0?BGMID:BG);
  });
  footer(s, 'Morgan & Mikhail\'s Clinical Anesthesiology 7e, p.226 | Barash Clinical Anesthesia 9e, Ch.26');

  // ── SLIDE 4: TYPES OF CAPNOGRAPHS ───────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 02  |  TECHNOLOGY');
  slideTitle(s, 'Types of Capnographs',
    'Understanding the hardware guides optimal use and troubleshooting');
  var types = [
    {title:'SIDESTREAM (Diverting)', color:TEAL, items:[
      '• Aspirates gas from circuit via fine tubing (50–250 mL/min)',
      '• CO₂ measured in bedside sample cell',
      '• Works for intubated AND non-intubated patients',
      '• Prone to moisture condensation → blocked tubing',
      '• ~20–50 ms lag time',
      '• Usable with nasal cannula or face mask',
    ]},
    {title:'MAINSTREAM (Non-diverting)', color:SLATE, items:[
      '• Sensor sits in-line with breathing circuit',
      '• No gas aspiration — measures at the airway',
      '• Faster response, virtually no lag',
      '• Heavier sensor may increase dead space',
      '• Risk of secretion contamination of sensor window',
      '• Primarily for intubated / ventilated patients',
    ]},
  ];
  types.forEach(function(t, col) {
    var xo = 0.35 + col * 4.85;
    addRect(s, xo, 1.75, 4.5, 0.42, t.color);
    addText(s, t.title, xo, 1.75, 4.5, 0.42,
      {fontSize:12, bold:true, color:LIME, align:'center'});
    addText(s, t.items.join('\n'), xo + 0.05, 2.25, 4.4, 3.0,
      {fontSize:10.5, color:OFFWHT});
  });
  addRect(s, 0.35, 5.08, 9.3, 0.32, BGMID);
  addText(s, 'Both rely on Beer–Lambert law: infrared light absorption by CO₂ ∝ CO₂ concentration',
    0.35, 5.08, 9.3, 0.32, {fontSize:9.5, color:LIME, align:'center'});
  footer(s, 'Morgan & Mikhail\'s 7e, p.226');

  // ── SLIDE 5: NORMAL CAPNOGRAM PHASES ────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 03  |  NORMAL CAPNOGRAM');
  slideTitle(s, 'The Four Phases of a Normal Capnogram');
  var phases = [
    {name:'Phase I',   desc:'Dead space gas — no CO₂ (baseline = 0 mmHg)'},
    {name:'Phase II',  desc:'Transition zone — dead space mixes with alveolar gas; rapid upstroke'},
    {name:'Phase III', desc:'Alveolar plateau — CO₂-rich alveolar gas; nearly horizontal in healthy lungs'},
    {name:'ETCO₂',     desc:'End-tidal point = highest CO₂ value per breath (normal 35–45 mmHg)'},
    {name:'Phase IV',  desc:'Inspiration — rapid fall to 0 as fresh gas enters'},
  ];
  phases.forEach(function(p, i) {
    addRect(s, 0.35, 1.82 + i*0.65, 2.1, 0.55, TEAL);
    addText(s, p.name, 0.35, 1.82 + i*0.65, 2.1, 0.55,
      {fontSize:12, bold:true, color:LIME, align:'center'});
    addText(s, p.desc, 2.55, 1.87 + i*0.65, 7.1, 0.45,
      {fontSize:11, color:OFFWHT});
  });
  // Capnogram ASCII art as a text element
  var wave = [
    '         ETCO₂ (35-45 mmHg)',
    '          ___________↑',
    '         /            \\',
    '        /              \\',
    '  ______/                \\______',
    '  Ph I    Ph II  Ph III   Ph IV',
  ].join('\n');
  addRect(s, 5.5, 1.82, 4.1, 2.3, BGMID, TEALLT);
  addText(s, wave, 5.6, 1.9, 3.9, 2.1,
    {fontSize:11, color:LIME, fontFace:'Courier New'});
  addText(s, '↑ Y-axis: CO₂ concentration    → X-axis: Time',
    5.5, 4.15, 4.1, 0.3, {fontSize:9, color:SLATE, align:'center'});
  footer(s, 'Barash Clinical Anesthesia 9e, Fig.26-3 | Morgan & Mikhail\'s 7e, p.228');

  // ── SLIDE 6: WAVEFORM INTERPRETATION ────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 04  |  WAVEFORM INTERPRETATION');
  slideTitle(s, 'Reading the Capnogram — Key Parameters');
  var params = [
    ['ETCO₂ Value','35–45 mmHg','HIGH >45: hypoventilation, ↑CO₂ production, rebreathing\nLOW <35: hyperventilation, ↓perfusion, air embolism, leak'],
    ['Baseline','0 mmHg','Elevated baseline → rebreathing (faulty valve, exhausted CO₂ absorbent)'],
    ['Phase III Slope','Nearly horizontal','Upsloping ("shark fin") → obstructive disease (asthma, COPD, bronchospasm)'],
    ['Phase II Slope','Steep & rapid','Gradual upstroke → uneven emptying, V/Q mismatch, partial obstruction'],
    ['Waveform Height','Stable breath-to-breath','Sudden ↓ → disconnection, embolism, cardiac arrest'],
  ];
  var colHdrs = ['Parameter','Normal','Elevated / Abnormal'];
  var cw = [2.1, 1.9, 5.5]; var cx = [0.3, 2.5, 4.5];
  colHdrs.forEach(function(h, ci) {
    addRect(s, cx[ci], 1.72, cw[ci]-0.1, 0.38, TEAL);
    addText(s, h, cx[ci], 1.72, cw[ci]-0.1, 0.38,
      {fontSize:10, bold:true, color:WHITE, align:'center'});
  });
  params.forEach(function(p, i) {
    var yy = 2.18 + i*0.6;
    var bg = i%2===0 ? BGMID : BG;
    cx.forEach(function(x, ci) {
      addRect(s, x, yy, cw[ci]-0.1, 0.54, bg);
    });
    addText(s, p[0], cx[0]+0.05, yy+0.05, cw[0]-0.2, 0.44,
      {fontSize:10, bold:true, color:LIME});
    addText(s, p[1], cx[1]+0.05, yy+0.05, cw[1]-0.2, 0.44,
      {fontSize:9.5, color:GREEN});
    addText(s, p[2], cx[2]+0.05, yy+0.05, cw[2]-0.2, 0.44,
      {fontSize:9, color:OFFWHT});
  });
  footer(s, 'Morgan & Mikhail\'s 7e | Barash Clinical Anesthesia 9e, Ch.26');

  // ── SLIDE 7: ETCO₂ – PaCO₂ GRADIENT ────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 05  |  ETCO₂–PaCO₂ GRADIENT');
  slideTitle(s, 'The (a-ET)CO₂ Gradient — Clinical Significance',
    'Normal gradient: 2–5 mmHg. Widening = increased alveolar dead space');
  addRect(s, 0.35, 1.82, 4.3, 1.4, BGMID, LIME);
  addText(s, 'PaCO₂ − ETCO₂ = Alveolar Dead Space', 0.45, 1.88, 4.1, 0.4,
    {fontSize:13, bold:true, color:LIME, align:'center'});
  addText(s, 'AVDSf = (PaCO₂ − PETCO₂) / PaCO₂\n\nNormal: 0.04–0.10  |  Concerning: > 0.20',
    0.45, 2.32, 4.1, 0.78, {fontSize:11, color:OFFWHT, align:'center'});
  var gradCauses = [
    {title:'Gradient WIDENS (↑ dead space)', color:WARN,
     items:'• Pulmonary embolism\n• Air/fat/venous embolism\n• Cardiac arrest / ↓CO\n• Hypotension / hypovolemia\n• PEEP overdistension\n• Pulmonary hypertension'},
    {title:'Gradient NARROWS', color:GREEN,
     items:'• Improvement in cardiac output\n• Successful ROSC\n• Resolution of embolism\n• Fluid resuscitation'},
  ];
  gradCauses.forEach(function(c, i) {
    var xo = 4.95 + i*2.7;
    addRect(s, xo, 1.82, 2.55, 0.4, c.color);
    addText(s, c.title, xo, 1.82, 2.55, 0.4,
      {fontSize:9.5, bold:true, color:BG, align:'center'});
    addText(s, c.items, xo+0.05, 2.28, 2.45, 2.5,
      {fontSize:10, color:OFFWHT});
  });
  addRect(s, 0.35, 4.85, 9.3, 0.48, TEAL);
  addText(s, '⚡ PEARL: A sudden drop in ETCO₂ without ventilation change → evaluate immediately for embolism, disconnection, or cardiac event',
    0.45, 4.85, 9.1, 0.48, {fontSize:10.5, color:WHITE});
  footer(s, 'Morgan & Mikhail\'s 7e, p.227-228 | Miller\'s Anesthesia 10e | Sabiston Textbook of Surgery');

  // ── SLIDE 8: ANESTHESIA APPLICATIONS ────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 06  |  ANESTHESIA APPLICATIONS');
  slideTitle(s, 'Capnography in the Operating Room',
    'Mandatory monitoring for all general anesthesia procedures');
  var apps = [
    ['✔ ETT Placement Confirmation','Detects esophageal intubation within 3–5 breaths; 100% sensitivity. Does NOT reliably detect mainstem intubation.'],
    ['⚠ Circuit Integrity','Sudden loss of waveform → disconnection. Inspired CO₂ > 0 → rebreathing (valve failure, exhausted absorbent).'],
    ['🔥 Malignant Hyperthermia','Marked rise in ETCO₂ is often the earliest sign — occurs before temperature spike. Prompt dantrolene therapy.'],
    ['💉 Ventilator Management','Titrate RR/TV to maintain ETCO₂ 35–45 mmHg. Hyperventilation causes cerebral vasoconstriction — critical in neurosurgery.'],
    ['🫁 Air/Venous Embolism','Acute sudden fall in ETCO₂ (≥3 mmHg) is a sensitive early sign. Most reliable if preceded by stable tracing.'],
    ['😴 MAC / Sedation Monitoring','Sidestream via nasal cannula detects apnea 4 min before SpO₂ falls. Respiratory depression 17.6× more likely detected vs standard monitoring.'],
  ];
  apps.forEach(function(a, i) {
    var col = i%2; var row = Math.floor(i/2);
    var xo = 0.35 + col*4.85; var yo = 1.82 + row*1.22;
    addRect(s, xo, yo, 4.6, 1.1, BGMID, TEAL);
    addText(s, a[0], xo+0.1, yo+0.04, 4.35, 0.32,
      {fontSize:11, bold:true, color:LIME});
    addText(s, a[1], xo+0.1, yo+0.38, 4.35, 0.65,
      {fontSize:9.5, color:OFFWHT});
  });
  footer(s, 'Morgan & Mikhail\'s 7e, p.227 | Barash 9e (MAC) | Tintinalli\'s Emergency Medicine');

  // ── SLIDE 9: ICU APPLICATIONS ────────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 07  |  ICU APPLICATIONS');
  slideTitle(s, 'Capnography in the ICU & Mechanical Ventilation');
  var icu = [
    ['Continuous Monitoring','Real-time ETCO₂ trend avoids frequent ABGs. Rising trend may indicate fatigue, ↑CO₂ production, or inadequate MV.'],
    ['PEEP Titration (VCap)','Volumetric capnography plots CO₂ vs exhaled volume. Optimal PEEP = minimum alveolar dead space without overdistension.'],
    ['Dead Space Assessment','AVDSf = (PaCO₂ − PETCO₂)/PaCO₂. Values >0.20 associated with increased ICU mortality in ARDS.'],
    ['Bronchodilator Response','VCap Phase III slope decreases after effective bronchodilator — objective measure of airway obstruction response.'],
    ['Weaning Assessment','Stable ETCO₂ during SBT suggests adequate ventilatory reserve. Rapid rise or waveform irregularity → reassess readiness.'],
    ['Non-invasive Scenarios','TcCO₂ used in HFV and neonates. Sidestream adapters available for NIV masks and standard nasal cannulae.'],
  ];
  icu.forEach(function(item, i) {
    labelRow(s, item[0], item[1], 0.35, 1.82+i*0.59, 9.3, 2.5,
      i%2===0 ? TEAL : SLATE, i%2===0 ? BGMID : BG);
  });
  footer(s, 'Miller\'s Anesthesia 10e, p.11316 | Schwartz\'s Principles of Surgery 11e | Sabiston Textbook of Surgery');

  // ── SLIDE 10: CPR & RESUSCITATION ────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 08  |  CPR & RESUSCITATION');
  slideTitle(s, 'Capnography During Cardiac Arrest',
    'AHA 2020: continuous waveform capnography required for all intubated patients during CPR');
  var cpr = [
    ['< 10 mmHg','ETCO₂ at 20 min CPR','Strongly predicts resuscitation failure; consider termination in context'],
    ['> 35 mmHg','Sudden spike in ETCO₂','Suggests ROSC — may precede pulse detection and other clinical signs'],
    ['≥ 10–20 mmHg','Target during CPR','Adequate ETCO₂ correlates with cardiac output and compression quality'],
    ['ETCO₂ = CO proxy','During CPR','As perfusion ↑, more alveoli are perfused → ↓ dead space → ↑ ETCO₂'],
  ];
  cpr.forEach(function(m, i) {
    var xo = 0.35 + (i%2)*4.85; var yo = 2.05 + Math.floor(i/2)*1.6;
    addRect(s, xo, yo, 4.6, 1.45, BGMID, WARN);
    addText(s, m[0], xo+0.1, yo+0.04, 4.4, 0.58,
      {fontSize:22, bold:true, color:WARN, align:'center'});
    addText(s, m[1], xo+0.1, yo+0.62, 4.4, 0.3,
      {fontSize:10, bold:true, color:TEALLT, align:'center'});
    addText(s, m[2], xo+0.1, yo+0.94, 4.4, 0.44,
      {fontSize:9.5, color:OFFWHT, align:'center'});
  });
  footer(s, 'Roberts & Hedges\' Clinical Procedures, p.4051 | Rosen\'s Emergency Medicine | AHA ACLS 2020');

  // ── SLIDE 11: ABNORMAL PATTERNS ──────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 09  |  ABNORMAL PATTERNS');
  slideTitle(s, 'Abnormal Capnogram Patterns — Quick Reference');
  var pats = [
    [RED,   '"Shark Fin" / Upsloping Ph III','Bronchospasm, COPD, asthma, partial obstruction','Normal–↑'],
    [RED,   'Flat Line (No Waveform)','Esophageal intubation, circuit disconnection, apnea, cardiac arrest','≈ 0'],
    [WARN,  'Elevated Baseline','CO₂ rebreathing: expiratory valve failure, exhausted absorbent','↑ baseline'],
    [TEALLT,'Curare Cleft (Ph III notch)','Spontaneous breathing during controlled ventilation — light anesthesia','Normal'],
    [RED,   'Sudden ↓ ETCO₂ to Zero','Circuit disconnect, extubation, cardiac arrest, blocked/kinked ETT','→ 0'],
    [WARN,  'Gradual ↑ ETCO₂','Hypoventilation, ↑CO₂ production (fever, MH, sepsis), laparoscopy','> 45 mmHg'],
    [TEALLT,'Gradual ↓ ETCO₂','Hyperventilation, hypothermia, ↓CO, pulmonary embolism, blood loss','< 35 mmHg'],
    [SLATE, 'Oscillating Baseline','Cardiogenic oscillations — heartbeat artifact visible in waveform','Normal'],
  ];
  pats.forEach(function(p, i) {
    var col = i%2; var row = Math.floor(i/2);
    var xo = 0.3 + col*4.9; var yo = 1.82 + row*0.88;
    addRect(s, xo,      yo, 0.12, 0.74, p[0]);
    addRect(s, xo+0.15, yo, 4.55, 0.74, BGMID);
    addText(s, p[1], xo+0.25, yo+0.03, 4.3, 0.3,
      {fontSize:10.5, bold:true, color:p[0]});
    addText(s, 'Cause: '+p[2]+'   |   ETCO₂: '+p[3], xo+0.25, yo+0.36, 4.3, 0.34,
      {fontSize:9, color:OFFWHT});
  });
  footer(s, 'Morgan & Mikhail\'s 7e, Fig.6-3 | Barash 9e | Tintinalli\'s Emergency Medicine');

  // ── SLIDE 12: COPD / BRONCHOSPASM ────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 09  |  OBSTRUCTIVE DISEASE');
  slideTitle(s, 'The "Shark Fin" — COPD & Bronchospasm',
    'Phase III upslope is the hallmark of obstructive ventilation');
  addRect(s, 0.35, 1.82, 4.3, 3.2, BGMID, TEAL);
  addText(s, 'Pathophysiology', 0.45, 1.9, 4.1, 0.32,
    {fontSize:12, bold:true, color:LIME});
  var copdTxt = [
    '• Non-uniform airway caliber in obstructive disease',
    '• Fast-emptying alveoli clear CO₂ early in expiration',
    '• Slow-emptying alveoli release CO₂ late',
    '• Result: progressive rise throughout Phase III',
    '• No true plateau reached before next inspiration',
    '• ETCO₂ UNDERESTIMATES PaCO₂ — gradient widens',
    '• Slope steepness correlates with severity',
    '• Response to bronchodilator: slope flattens measurably',
  ].join('\n');
  addText(s, copdTxt, 0.45, 2.28, 4.1, 2.6, {fontSize:10, color:OFFWHT});
  // Waveform comparison
  addRect(s, 4.8, 1.82, 4.8, 3.2, BGMID, SLATE);
  addText(s, 'Normal vs COPD Capnogram', 4.9, 1.88, 4.6, 0.32,
    {fontSize:11, bold:true, color:TEALLT, align:'center'});
  var normalWave = '         __________\n        /          \\\n_______/            \\______\n\n← Normal (flat plateau)';
  var copdWave  = '             _____/\n           /\n__________/\n\n← COPD (upsloping Phase III)';
  addRect(s, 4.9, 2.25, 2.1, 1.3, BG, GREEN);
  addText(s, normalWave, 4.95, 2.3, 2.0, 1.2,
    {fontSize:9, color:GREEN, fontFace:'Courier New'});
  addRect(s, 7.15, 2.25, 2.1, 1.3, BG, WARN);
  addText(s, copdWave, 7.2, 2.3, 2.0, 1.2,
    {fontSize:9, color:WARN, fontFace:'Courier New'});
  addText(s, 'Clinical response: administer bronchodilator → upslope should flatten\nIncrease expiratory time (↓ I:E ratio) to allow full exhalation',
    4.9, 3.65, 4.6, 0.9, {fontSize:10, color:OFFWHT});
  footer(s, 'Morgan & Mikhail\'s 7e, Fig.6-3B | Miller\'s Anesthesia 10e');

  // ── SLIDE 13: REBREATHING ────────────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 09  |  REBREATHING PATTERNS');
  slideTitle(s, 'Rebreathing — Elevated Baseline on Capnogram');
  var rbCauses = [
    ['Exhausted CO₂ Absorbent','Soda lime / Baralyme saturated; CO₂ passes unreacted into inspiratory limb → hypercapnia'],
    ['Expiratory Valve Failure','Exhaled gas refluxes into inspiratory side; CO₂ present throughout inspiratory phase'],
    ['Inspiratory Valve Failure','Partial failure — some rebreathing; not fully apparent as part of inspiration still reads 0'],
    ['Mapleson Circuits','Inadequate fresh gas flow in Mapleson circuits allows CO₂ accumulation in rebreathing limb'],
    ['Excessive Tubing Dead Space','Long breathing tubing → CO₂ remains in tubing at start of next inspiration'],
  ];
  rbCauses.forEach(function(c, i) {
    var yy = 1.82 + i*0.6;
    addRect(s, 0.35, yy, 0.1, 0.5, LIME);
    addText(s, c[0], 0.55, yy+0.02, 3.5, 0.24, {fontSize:10.5, bold:true, color:TEALLT});
    addText(s, c[1], 0.55, yy+0.26, 7.5, 0.24, {fontSize:9.5, color:OFFWHT});
  });
  addRect(s, 0.35, 5.0, 9.3, 0.38, BGMID, RED);
  addText(s, '🔧 Fix: replace CO₂ absorbent → test circle system valves → increase fresh gas flow → check for Mapleson circuit misuse',
    0.45, 5.0, 9.1, 0.38, {fontSize:10, color:WHITE});
  footer(s, 'Morgan & Mikhail\'s 7e, p.228 (Fig.6-3D,E) | Barash Clinical Anesthesia 9e');

  // ── SLIDE 14: SPECIAL SCENARIOS ──────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 09  |  SPECIAL SCENARIOS');
  slideTitle(s, 'Capnography in Special Clinical Scenarios');
  var specials = [
    {title:'Laparoscopic Surgery', color:TEAL,
     text:'CO₂ insufflation → systemic absorption → ETCO₂ rises\n↑ MV by 15–25% to compensate\nTrendelenburg impairs diaphragm\nSudden massive ↑ → subcutaneous emphysema or CO₂ embolism'},
    {title:'Pregnancy / Obstetrics', color:TEALLT,
     text:'Baseline PaCO₂ lower (≈32 mmHg) — progesterone-driven hyperventilation\nTarget ETCO₂ 30–32 mmHg\nAvoid hypocapnia → uterine vasoconstriction\nUseful in failed intubation scenarios'},
    {title:'Pediatric Patients', color:WARN,
     text:'High RR → no alveolar plateau — ETCO₂ underestimates PaCO₂\nLow TV → sidestream aspiration dilutes sample\nMainstream sensor may increase dead space significantly\nConsider TcCO₂ monitoring in neonates'},
    {title:'Neurosurgery / ↑ICP', color:RED,
     text:'Each 1 mmHg ↑ PaCO₂ → ~4% ↑ CBF\nTarget ETCO₂ 35 mmHg; avoid >45 (↑ICP)\nDeliberate hyperventilation (ETCO₂ 30–35) for acute ICP crisis\nSitting position: high air embolism risk — monitor ETCO₂ + N₂'},
  ];
  specials.forEach(function(sp, i) {
    var xo = 0.3 + (i%2)*4.9; var yo = 1.82 + Math.floor(i/2)*1.88;
    addRect(s, xo, yo, 4.55, 0.4, sp.color);
    addText(s, sp.title, xo, yo, 4.55, 0.4,
      {fontSize:11, bold:true, color:BG, align:'center'});
    addText(s, sp.text, xo+0.05, yo+0.44, 4.45, 1.35, {fontSize:10, color:OFFWHT});
  });
  footer(s, 'Morgan & Mikhail\'s 7e | Barash Clinical Anesthesia 9e | Roberts & Hedges\'');

  // ── SLIDE 15: TROUBLESHOOTING ─────────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'SECTION 10  |  TROUBLESHOOTING');
  slideTitle(s, 'Troubleshooting Capnograph Problems',
    'Artifacts and technical failures must be distinguished from true physiological events');
  var trbl = [
    [RED,   'No waveform displayed',       'Circuit disconnection | Esophageal intubation | Cardiac arrest | Sensor failure',   'Check circuit → confirm ETT → assess patient'],
    [WARN,  'Blocked sidestream line',      'Water condensation | Mucus / secretions | Kinked tubing',                           'Replace sampling line; use water trap; use heated tubing'],
    [TEALLT,'Readings consistently low',   'ETT cuff leak | Low aspiration rate (pediatric) | High RR / no plateau',            'Check cuff pressure; verify sampling rate; consider mainstream'],
    [WARN,  'Inspired CO₂ > 0',            'Exhausted CO₂ absorbent | Valve malfunction | Mapleson rebreathing',                'Replace absorbent; test valves; ↑ fresh gas flow'],
    [SLATE, 'Sudden spike then loss',       'Sampling line open to air | Patient coughed / strained',                            'Replace sampling line; reassess'],
  ];
  trbl.forEach(function(t, i) {
    var yy = 1.8 + i*0.71;
    addRect(s, 0.3, yy, 0.1, 0.6, t[0]);
    addRect(s, 0.45, yy, 9.2, 0.6, BGMID);
    addText(s, t[1], 0.55, yy+0.03, 2.5, 0.26, {fontSize:10.5, bold:true, color:t[0]});
    addText(s, 'Causes: '+t[2], 0.55, yy+0.32, 5.2, 0.22, {fontSize:9, color:OFFWHT});
    addRect(s, 5.85, yy+0.06, 3.65, 0.48, BG);
    addText(s, '▶ '+t[3], 5.9, yy+0.06, 3.55, 0.48, {fontSize:9, color:LIME});
  });
  footer(s, 'Morgan & Mikhail\'s 7e, p.228 | Barash 9e | Tintinalli\'s Emergency Medicine');

  // ── SLIDE 16: CRITICAL EVENTS TABLE ──────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'CRITICAL EVENTS DETECTION');
  slideTitle(s, 'Critical Events Detected by Capnography',
    'Based on Barash Clinical Anesthesia 9e, Table 26-1');
  var events = [
    [RED,   'Esophageal intubation',    'CO₂ absent after 3–5 breaths',             'Immediate re-intubation'],
    [RED,   'Circuit disconnection',    'Sudden loss of waveform',                  'Check all connections'],
    [RED,   'Malignant hyperthermia',   'Rapid ↑ ETCO₂, earliest sign',            'Dantrolene, cooling, remove trigger'],
    [WARN,  'Air/venous embolism',      'Acute ↓ ETCO₂ (↑ dead space)',            'Position, aspiration, notify surgeon'],
    [WARN,  'Bronchospasm',             'Upsloping Phase III (shark fin)',           'Bronchodilator, ↑ expiratory time'],
    [WARN,  'Pulmonary embolism',       'Gradual ↓ ETCO₂, ↑ gradient',            'CT-PA, anticoagulation'],
    [TEALLT,'Rebreathing',             'Elevated inspiratory CO₂ baseline',         'Replace absorbent, check valves'],
    [RED,   'Cardiac arrest',           'Very low or absent ETCO₂',                 'CPR quality; target ETCO₂ ≥10 mmHg'],
    [GREEN, 'ROSC',                     'Sudden spike in ETCO₂ >35 mmHg',          'Pulse check; post-ROSC care'],
    [WARN,  'Hypoventilation',          'Gradual ↑ ETCO₂ >45 mmHg',               '↑ RR or TV; check sedation depth'],
  ];
  var ch2 = ['Event','Capnographic Finding','Clinical Action'];
  var cw2 = [2.4,3.2,3.9]; var cx2 = [0.3,2.8,6.1];
  ch2.forEach(function(h, ci) {
    addRect(s, cx2[ci], 1.72, cw2[ci]-0.1, 0.36, TEAL);
    addText(s, h, cx2[ci], 1.72, cw2[ci]-0.1, 0.36,
      {fontSize:10, bold:true, color:WHITE, align:'center'});
  });
  events.forEach(function(e, i) {
    var yy = 2.15 + i*0.33;
    var bg = i%2===0 ? BGMID : BG;
    addRect(s, 0.3, yy, 0.08, 0.3, e[0]);
    cx2.forEach(function(x, ci) {
      addRect(s, x, yy, cw2[ci]-0.1, 0.3, bg);
    });
    addText(s, e[1], cx2[0]+0.05, yy+0.02, cw2[0]-0.15, 0.26,
      {fontSize:9, bold:true, color:e[0]});
    addText(s, e[2], cx2[1]+0.05, yy+0.02, cw2[1]-0.15, 0.26,
      {fontSize:9, color:OFFWHT});
    addText(s, e[3], cx2[2]+0.05, yy+0.02, cw2[2]-0.15, 0.26,
      {fontSize:9, color:OFFWHT});
  });
  footer(s, 'Barash Clinical Anesthesia 9e, Table 26-1 | Morgan & Mikhail\'s 7e | Roberts & Hedges\'');

  // ── SLIDE 17: GUIDELINES ──────────────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'GUIDELINES & STANDARDS');
  slideTitle(s, 'Capnography: Mandatory Standards & Guidelines');
  var gls = [
    ['ASA','2011+','Continuous waveform capnography mandatory for all patients receiving general anesthesia. Also recommended for moderate/deep sedation.'],
    ['AHA ACLS','2020','Waveform capnography required to confirm and monitor ETT placement. ETCO₂ <10 mmHg at 20 min CPR may guide termination decisions.'],
    ['WHO','2009','Pulse oximetry AND capnography identified as essential monitoring for safe surgery globally — Safe Surgery Saves Lives initiative.'],
    ['AAGBI/RCoA','2021','Capnography is mandatory for any patient with a tracheal tube or supraglottic device under general anaesthesia.'],
    ['80+ Societies','2015–2024','Over 80 clinical societies have recommended capnography in >100 guidelines spanning anesthesia, emergency medicine, critical care, and procedural sedation.'],
  ];
  gls.forEach(function(g, i) {
    var yy = 1.82 + i*0.7;
    addRect(s, 0.35, yy, 1.1, 0.58, TEAL);
    addText(s, g[0], 0.35, yy, 1.1, 0.36, {fontSize:11, bold:true, color:LIME, align:'center'});
    addText(s, g[1], 0.35, yy+0.34, 1.1, 0.24, {fontSize:9, color:WHITE, align:'center'});
    addText(s, g[2], 1.55, yy+0.06, 8.1, 0.5, {fontSize:10.5, color:OFFWHT});
  });
  addRect(s, 0.35, 5.2, 9.3, 0.25, BGMID);
  addText(s, 'Capnography is standard of care — not optional — wherever airway management or sedation is administered',
    0.4, 5.2, 9.2, 0.25, {fontSize:9, color:LIME, align:'center'});
  footer(s, 'ASA Standards 2011 | AHA ACLS 2020 | WHO Safe Surgery | Respiratory Therapy 2024');

  // ── SLIDE 18: DECISION ALGORITHM ─────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'CLINICAL DECISION SUPPORT');
  slideTitle(s, 'Systematic Approach to an Abnormal Capnogram');
  var algo = [
    ['1','Is there a waveform?','YES → proceed to step 2','NO → check circuit, ETT position, patient status'],
    ['2','Is baseline (inspired CO₂) = 0?','YES → proceed to step 3','NO → rebreathing (check valve / absorbent)'],
    ['3','Is ETCO₂ 35–45 mmHg?','YES → normal ventilation ✓','NO → characterize further (steps 4–5)'],
    ['4','ETCO₂ HIGH (>45 mmHg)?','YES → hypoventilation / ↑CO₂ production → ↑MV, check MH, sepsis','LOW (<35) → ↑dead space (PE, embolism, ↓CO, hyperventilation)'],
    ['5','Phase III slope — flat or upsloping?','Flat → normal or hyperventilation','Upsloping → obstructive disease → bronchodilator, ↑expiratory time'],
  ];
  algo.forEach(function(step, i) {
    var yy = 1.78 + i*0.73;
    addRect(s, 0.35, yy, 0.48, 0.52, TEAL);
    addText(s, step[0], 0.35, yy, 0.48, 0.52,
      {fontSize:14, bold:true, color:LIME, align:'center'});
    addRect(s, 0.93, yy, 3.4, 0.52, BGMID);
    addText(s, step[1], 0.98, yy+0.06, 3.3, 0.42,
      {fontSize:10, bold:true, color:WHITE});
    addRect(s, 4.43, yy, 2.5, 0.52, BG);
    addText(s, '✔ '+step[2], 4.48, yy+0.04, 2.4, 0.44,
      {fontSize:8.5, color:GREEN});
    addRect(s, 7.03, yy, 2.65, 0.52, BG);
    addText(s, '✘ '+step[3], 7.08, yy+0.04, 2.55, 0.44,
      {fontSize:8.5, color:WARN});
  });
  footer(s, 'Adapted from Respiratory Therapy (Farquharson & Spratt, 2024) | Morgan & Mikhail\'s 7e');

  // ── SLIDE 19: KEY NUMBERS ─────────────────────────────────────────────────
  s = pres.appendSlide();
  s.getBackground().setSolidFill(HexColor(BG));
  sectionBar(s, 'QUICK REFERENCE');
  slideTitle(s, 'Key Numbers Every Clinician Should Know');
  var nums = [
    ['35–45 mmHg', 'Normal ETCO₂ range'],
    ['2–5 mmHg',   'Normal PaCO₂–ETCO₂ gradient (healthy lungs)'],
    ['< 10 mmHg',  'ETCO₂ during CPR → predicts resuscitation failure'],
    ['> 35 mmHg',  'Sudden ETCO₂ spike → suspect ROSC'],
    ['0 mmHg',     'Normal inspired CO₂ baseline'],
    ['≈ 4 min',    'Time advantage vs SpO₂ in detecting apnea/hypoventilation'],
    ['17.6×',      'More likely to detect respiratory depression vs standard monitoring'],
    ['100%',       'Sensitivity of waveform capnography for ETT placement confirmation'],
    ['0.04–0.10',  'Normal alveolar dead space fraction (AVDSf)'],
    ['> 0.20',     'Concerning AVDSf — investigate dead space cause'],
  ];
  nums.forEach(function(n, i) {
    var col = i%2; var row = Math.floor(i/2);
    var xo = 0.35 + col*4.9; var yo = 1.82 + row*0.72;
    addRect(s, xo, yo, 4.6, 0.64, BGMID, TEAL);
    addText(s, n[0], xo+0.08, yo+0.06, 1.6, 0.52,
      {fontSize:20, bold:true, color:LIME, align:'center'});
    addText(s, n[1], xo+1.75, yo+0.18, 2.75, 0.3,
      {fontSize:10, color:OFFWHT});
  });
  footer(s, 'Morgan & Mikhail\'s 7e | Barash 9e | Rosen\'s EM | Respiratory Therapy 2024');

  // ── SLIDE 20: TAKEAWAYS ───────────────────────────────────────────────────
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  s.getBackground().setSolidFill(HexColor(BG));
  addRect(s, 0, 0, 0.18, 5.625, TEAL);
  addRect(s, 0.18, 0, 0.06, 5.625, LIME);
  addText(s, 'KEY TAKEAWAYS', 0.5, 0.3, 9.0, 0.5,
    {fontSize:22, bold:true, color:LIME});
  var tks = [
    'Capnography measures CO₂ across ventilation, perfusion & metabolism — one waveform reflects all three.',
    'Normal ETCO₂ is 35–45 mmHg; a 2–5 mmHg gradient vs PaCO₂ reflects healthy lungs.',
    'Waveform capnography is mandatory in GA, ACLS, and strongly recommended for all sedated patients.',
    'Sudden loss of waveform = circuit disconnection or esophageal intubation until proven otherwise.',
    'Upsloping Phase III ("shark fin") = obstructive airways disease — treat the underlying cause.',
    'Elevated baseline = rebreathing — check valves and CO₂ absorbent immediately.',
    'During CPR: ETCO₂ ≥10 mmHg targets quality compressions; sudden spike = suspect ROSC.',
    'The (a-ET)CO₂ gradient is an indirect window into alveolar dead space and cardiac output.',
  ];
  addText(s, tks.map(function(t){ return '● ' + t; }).join('\n\n'),
    0.5, 0.95, 9.1, 4.4, {fontSize:11, color:OFFWHT});
  addText(s, 'Capnography 2026  |  ICU & Anesthesia Clinicians', 0.5, 5.25, 9.1, 0.25,
    {fontSize:9, color:SLATE, align:'right'});

  // ── DONE ──────────────────────────────────────────────────────────────────
  Logger.log('✅ Presentation created: ' + pres.getUrl());
  SlidesApp.getUi().alert(
    '✅ Done! Your Capnography presentation has been created.\n\nURL: ' + pres.getUrl()
  );
}