ls /home/daytona/workspace/ && mkdir -p /home/daytona/workspace/pns-usg-blocks

~/pns-usg-blocks/create_ppt.js

const pptxgen = require("pptxgenjs");
const pres = new pptxgen();
pres.layout = "LAYOUT_16x9";
pres.title = "PNS vs USG-Guided Regional Blocks";
pres.author = "Anaesthesia Department";

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// ── HELPERS ─────────────────────────────────────────────────────────
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// ═══════════════════════════════════════════════════════════════════
// SLIDE 1 – Title
// ═══════════════════════════════════════════════════════════════════
{
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  s.addText("Peripheral Nerve Stimulator  |  Ultrasound Guidance  |  Landmark Technique", {
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  s.addText("Department of Anaesthesiology  ●  2026", {
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// ═══════════════════════════════════════════════════════════════════
// SLIDE 2 – Overview / Contents
// ═══════════════════════════════════════════════════════════════════
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    { num:"01", title:"Introduction to Regional Anaesthesia" },
    { num:"02", title:"Landmark Technique – Principles & Limitations" },
    { num:"03", title:"Peripheral Nerve Stimulator (PNS) – Mechanism & Practice" },
    { num:"04", title:"Indications for Regional Blocks" },
    { num:"05", title:"Advantages of PNS over Landmark" },
    { num:"06", title:"Ultrasound-Guided Regional Blocks – Principles" },
    { num:"07", title:"Advantages of USG over Landmark & PNS" },
    { num:"08", title:"Head-to-Head Comparison Tables" },
    { num:"09", title:"Clinical Applications & Evidence" },
    { num:"10", title:"Summary & Conclusions" },
  ];
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// ═══════════════════════════════════════════════════════════════════
// SLIDE 3 – Section Divider: Introduction
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  sectionDivider(s, "1", "Introduction to Regional Anaesthesia");
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 4 – What is Regional Anaesthesia?
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "What is Regional Anaesthesia?", [
    "Regional anaesthesia (RA) involves administration of local anaesthetic (LA) near a nerve or nerve plexus to produce reversible loss of sensation and motor function in a defined area of the body.",
    "Achieves surgical anaesthesia OR postoperative analgesia without requiring general anaesthesia (GA).",
    "Major categories:",
    { text:"Neuraxial: spinal, epidural, combined spinal-epidural", sub:true },
    { text:"Peripheral nerve blocks (PNB): plexus, truncal, limb", sub:true },
    { text:"Intravenous regional anaesthesia (IVRA / Bier's block)", sub:true },
    "Guidance methods have evolved from pure landmark / anatomical technique → PNS → real-time ultrasound (USG).",
    "Each generation improves accuracy, reduces LA dose required, and lowers complication rates.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 5 – Landmark Technique: Principles & Limitations
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Landmark Technique – Principles & Limitations", [
    "Based on surface anatomy, bony landmarks, paraesthesia elicitation, fascial 'clicks', or loss-of-resistance.",
    "No real-time confirmation of needle tip position relative to nerve.",
    "Success depends heavily on operator experience and patient anatomy (BMI, anatomical variants).",
    "KEY LIMITATIONS:",
    { text:"High failure / partial block rate (up to 10–20% for some blocks)", sub:true },
    { text:"Inadvertent intravascular or intraneural injection risk", sub:true },
    { text:"Relies on patient-reported paraesthesia – uncomfortable, requires cooperation", sub:true },
    { text:"Blind technique: no visualisation of adjacent vessels or fascial planes", sub:true },
    { text:"Repeated needle passes increase tissue trauma and haematoma risk", sub:true },
    { text:"Not suitable in anticoagulated or unconscious patients", sub:true },
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 6 – Section Divider: PNS
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  sectionDivider(s, "2", "Peripheral Nerve Stimulator (PNS) Technique");
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 7 – PNS: Mechanism & Setup
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "PNS Technique – Mechanism & Equipment", [
    "PNS delivers a controlled electrical stimulus (current) through an insulated needle to depolarise target nerve.",
    "Evoked motor response confirms proximity of needle tip to nerve without requiring paraesthesia.",
    "Standard setup:",
    { text:"Insulated short-bevel needle with nerve stimulator cable connection", sub:true },
    { text:"Surface ECG electrode as dispersive (return) electrode on patient skin", sub:true },
    { text:"Stimulator set to 1–2 Hz pulse frequency, 0.1 ms pulse width", sub:true },
    "Initial stimulating current: 1.0–1.5 mA; reduced to ≤ 0.5 mA at target location.",
    "Threshold current ≤ 0.5 mA with brisk motor response = optimal needle position.",
    "Negative response at < 0.2 mA may suggest intraneural placement – withdraw needle.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 8 – Indications for Regional Blocks
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  twoColSlide(
    s,
    "Indications for Peripheral Nerve Blocks",
    "Surgical Indications",
    [
      "Upper limb surgery: shoulder, arm, elbow, forearm, hand",
      "Lower limb: hip, knee, ankle, foot surgery",
      "Thoracic wall: rib fixation, thoracotomy (paravertebral block)",
      "Abdominal wall: hernia repair, laparotomy (TAP, QL blocks)",
      "Head & neck: ophthalmic surgery, dental procedures",
      "Breast surgery: PECS I & II, serratus anterior block",
    ],
    "Analgesic / Other Indications",
    [
      "Postoperative analgesia (opioid-sparing, ERAS protocol)",
      "Trauma: femoral nerve block, fascia iliaca block for hip fractures",
      "Chronic pain management: stellate ganglion, coeliac plexus blocks",
      "Patients unfit for GA: severe cardiorespiratory disease",
      "Anticoagulated patients (with careful site selection)",
      "Paediatrics: caudal, penile, ilioinguinal-iliohypogastric blocks",
    ],
    C.teal, C.navy
  );
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 9 – Advantages of PNS over Landmark
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Advantages of PNS over Landmark Technique", [
    "1. Objective endpoint – evoked motor response replaces subjective paraesthesia; does not rely on patient cooperation.",
    "2. Improved accuracy – stimulation confirms needle-nerve proximity, reducing failed/partial blocks.",
    "3. Repeatable and standardised – current threshold provides a quantifiable target across operators.",
    "4. Reduces intraneural injection risk – loss of motor response at < 0.2 mA signals intraneural placement.",
    "5. Applicable to sedated / anaesthetised patients – no patient cooperation required.",
    "6. Lower LA volumes – precise needle placement allows smaller, more effective LA doses.",
    "7. Enables combined stimulating catheter techniques for continuous nerve block infusions.",
    "8. Better performance in obese patients compared to pure landmark technique.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 10 – Limitations of PNS
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Limitations of PNS Technique", [
    "Still blind to surrounding structures: vessels, pleura, peritoneum cannot be seen.",
    "Motor response may be absent in neuropathic nerves (diabetic neuropathy, nerve injury).",
    "Purely sensory nerves (e.g., sural, superficial peroneal) do not produce motor response → limit applicability.",
    "Artefact from patient movement may be confused with evoked response.",
    "Special insulated equipment required; adds cost and setup time.",
    "Cannot confirm spread of LA after injection.",
    "Does not prevent intravascular injection; close surveillance and aspiration still mandatory.",
    "Stimulating catheter placement remains technically demanding.",
    "Carries residual 1–5% failure rate for major plexus blocks compared to USG.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 11 – Section Divider: USG
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  sectionDivider(s, "3", "Ultrasound-Guided (USG) Regional Blocks");
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 12 – USG Principles & Equipment
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "USG Technique – Principles & Equipment", [
    "Real-time B-mode (2D) ultrasound identifies nerve, needle, surrounding structures, and LA spread.",
    "High-frequency linear probe (6–15 MHz): superficial structures (brachial plexus, femoral, saphenous).",
    "Low-frequency curvilinear probe (2–6 MHz): deep structures (sciatic, lumbar plexus, neuraxial).",
    "Nerves appear as hyperechoic honeycomb structures (fascicular pattern) in short axis.",
    "Approaches:",
    { text:"In-plane (IP): entire needle shaft and tip visualised as bright line – preferred for accuracy", sub:true },
    { text:"Out-of-plane (OOP): needle tip seen as a bright dot – useful for superficial targets", sub:true },
    "Colour Doppler: identifies adjacent vessels prior to needle insertion.",
    "Hydro-dissection confirms perineural LA spread in real time.",
    "Sterile technique, gel, probe cover, and angling / tilting (heel-toe) to optimise nerve visibility.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 13 – Advantages of USG over Landmark
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Advantages of USG over Landmark Technique", [
    "1. Direct nerve visualisation – nerve identified in real time; no reliance on anatomy or paraesthesia.",
    "2. Significant reduction in LA volume – UGRA allows 50–70% reduction in LA dose for equivalent block quality (e.g., ISB: 40 mL → 5–10 mL).",
    "3. Rapid onset – circumferential LA deposition around nerve accelerates block onset.",
    "4. Higher success rates – consistently superior to landmark for all major blocks (e.g., > 95% vs 80–85%).",
    "5. Avoidance of vascular puncture – Doppler identifies arteries/veins; accidental injection rate dramatically reduced.",
    "6. Prevention of pneumothorax – pleura visualised directly (interscalene, supraclavicular blocks).",
    "7. Enables novel fascial plane blocks (TAP, PECS, QL, ESP, IPACK) impossible with landmark/PNS.",
    "8. Works on challenging patients: obesity, anatomical anomalies, oedema, scarred tissue.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 14 – Advantages of USG over PNS
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Advantages of USG over PNS Technique", [
    "1. Real-time needle visualisation – operator sees exact needle-tip position; PNS only infers proximity.",
    "2. Visualises LA spread – confirms circumferential perineural deposition; detects failed spread immediately.",
    "3. Functional on purely sensory nerves – no motor response needed; applicable to sural, saphenous, cutaneous nerves.",
    "4. Applicable in neuropathy / denervated muscle – no reliance on intact motor pathway.",
    "5. No specialised equipment other than probe – avoids insulated needle and stimulator unit.",
    "6. Detects intraneural injection earlier – nerve swelling visible on ultrasound before large volumes injected.",
    "7. Lower incidence of complications – multiple meta-analyses confirm reduced pneumothorax, vascular puncture, and systemic LA toxicity.",
    "8. Continuous catheter placement – catheter threading confirmed under direct vision.",
    "9. Shorter procedure time and fewer needle passes compared to PNS-guided technique.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 15 – Head-to-Head Comparison Table
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  const headerRow = [
    { text:"Parameter",    options:{ bold:true, color:C.white, fill:{color:C.navy}, fontSize:13 } },
    { text:"Landmark",     options:{ bold:true, color:C.white, fill:{color:"C0392B"}, fontSize:13 } },
    { text:"PNS",          options:{ bold:true, color:C.white, fill:{color:C.teal}, fontSize:13 } },
    { text:"USG",          options:{ bold:true, color:C.white, fill:{color:"1A7431"}, fontSize:13 } },
  ];
  const rows = [
    ["Nerve visualisation","None","Indirect (motor response)","Direct real-time"],
    ["Vascular avoidance","Blind","Blind","Doppler-guided"],
    ["LA volume required","High","Moderate","Low (50–70% reduction)"],
    ["Success rate","~80%","~88%","~95–98%"],
    ["Applicable to sensory nerves","Yes","No","Yes"],
    ["Neuropathic patients","Difficult","Unreliable","Reliable"],
    ["LA spread confirmation","None","None","Real-time"],
    ["Intraneural injection detection","None","Partial (current)","Direct (nerve swelling)"],
    ["Equipment cost","Low","Moderate","High"],
    ["Learning curve","Low","Moderate","Moderate–High"],
    ["Pneumothorax risk (SCB)","High","Moderate","Low"],
  ];
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      text: cell,
      options: {
        color: C.navy,
        fill: { color: ri % 2 === 0 ? "DDEEFF" : C.white },
        fontSize:12,
        bold: ci === 0,
      }
    })))
  ];
  comparisonTableSlide(s, "Landmark vs PNS vs USG – Direct Comparison", tableData);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 16 – PNS + USG Combined Approach
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "PNS + USG Combined Approach", [
    "Many centres use simultaneous PNS + USG as a dual-confirmation strategy.",
    "Rationale: USG identifies nerve position; PNS confirms motor response as a safety check before injection.",
    "Benefits of combination:",
    { text:"Prevents intraneural injection: loss of motor response at < 0.2 mA prompts withdrawal", sub:true },
    { text:"Valuable when ultrasound image quality is poor (deep blocks, obese patients)", sub:true },
    { text:"Educational tool – trainees correlate motor response with real-time anatomy", sub:true },
    "Current evidence: UGRA alone is non-inferior to combined technique in experienced hands.",
    "ASRA / ESRA guidelines: USG is the preferred primary guidance method; PNS use is adjunctive.",
    "Combined approach is still recommended in resource-limited settings with suboptimal ultrasound machines.",
    "Stimulating catheters for continuous blocks often use PNS confirmation during threading even in USG-primary practice.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 17 – Specific Block Examples
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  twoColSlide(
    s,
    "USG Advantages in Specific Blocks – Clinical Examples",
    "Supraclavicular Brachial Plexus",
    [
      "Landmark: 0.5–1% pneumothorax risk",
      "PNS: pneumothorax still possible",
      "USG: pleura and subclavian artery directly seen – pneumothorax rate < 0.1%",
      "LA volume: reduced from 40 mL → 15–20 mL",
      "Nearly 100% block success with USG",
    ],
    "Femoral / Fascia Iliaca Block",
    [
      "PNS: femoral motor response (quad twitch) as endpoint",
      "USG: direct fascial plane injection confirmed",
      "Critical in hip fracture analgesia (emergency setting)",
      "Fascia iliaca block: USG confirms spread beneath fascia covering LFCN + femoral nerve",
      "Reduces opioid requirement by 60% in hip fractures (multimodal analgesia)",
    ],
    C.teal, C.navy
  );
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 18 – Complications & Safety
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Complications – Prevention by Guidance Technique", [
    "LOCAL ANAESTHETIC SYSTEMIC TOXICITY (LAST):",
    { text:"Landmark: highest risk – inadvertent IV injection up to 0.5–1%", sub:true },
    { text:"PNS: aspiration reduces risk; no vessel visualisation", sub:true },
    { text:"USG: real-time Doppler prevents intravascular needle placement; LAST incidence < 0.01%", sub:true },
    "PNEUMOTHORAX (supraclavicular / interscalene blocks):",
    { text:"Landmark: 0.5–6%  |  PNS: 0.2–1%  |  USG: < 0.1%", sub:true },
    "NERVE INJURY (PONS data – Perioperative Nerve Injury):",
    { text:"All techniques: ~0.04% transient; < 0.005% permanent neuropathy", sub:true },
    { text:"USG allows detection of nerve swelling suggesting intraneural placement", sub:true },
    "HAEMATOMA: vascular puncture most common with landmark; lowest with USG Doppler guidance.",
    "INFECTION: standard sterile precautions apply to all techniques.",
    "PHRENIC NERVE PALSY (interscalene block): universal with all techniques unless modified low-volume USG approach used.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 19 – Evidence & Guidelines
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Evidence Base & Current Guidelines", [
    "ASRA (American Society of Regional Anesthesia) 2022 Practice Guidelines:",
    { text:"Strongly recommend USG guidance for all peripheral nerve blocks where feasible", sub:true },
    { text:"PNS remains acceptable when USG unavailable or as adjunct", sub:true },
    "ESRA (European Society of Regional Anaesthesia) Consensus:",
    { text:"USG is the gold-standard guidance technique for peripheral nerve blocks", sub:true },
    { text:"Dual guidance (PNS + USG) may be used for continuous catheter techniques", sub:true },
    "Key meta-analyses (Cochrane, BJA):",
    { text:"USG reduces block failure rate by 60% vs nerve stimulator alone", sub:true },
    { text:"USG reduces time to block performance and onset time", sub:true },
    { text:"No statistically significant difference in permanent nerve injury rates (all techniques)", sub:true },
    "Fascial plane blocks (TAP, PECS, QL, ESP) are entirely USG-dependent – PNS and landmark not applicable.",
    "ERAS (Enhanced Recovery After Surgery) protocols explicitly incorporate UGRA for opioid reduction.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 20 – Summary & Conclusions
// ═══════════════════════════════════════════════════════════════════
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  const keyPoints = [
    { icon:"▶", text:"Landmark technique: lowest cost but highest failure/complication rate – acceptable only when advanced guidance unavailable." },
    { icon:"▶", text:"PNS: significant step forward – objective endpoint, no patient cooperation needed, suitable for sedated patients." },
    { icon:"▶", text:"USG: current gold standard – real-time visualisation, lower LA volumes, superior safety, enables fascial plane blocks." },
    { icon:"▶", text:"Combined PNS + USG: valuable in difficult cases, deep blocks, training, and continuous catheter techniques." },
    { icon:"▶", text:"ASRA/ESRA guidelines endorse USG as the primary guidance method; PNS is adjunctive." },
    { icon:"▶", text:"Ongoing training, competency assessment, and quality improvement are essential regardless of technique used." },
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// ── WRITE FILE ───────────────────────────────────────────────────────
pres.writeFile({ fileName: "/home/daytona/workspace/pns-usg-blocks/PNS_vs_USG_Regional_Blocks.pptx" })
  .then(() => console.log("SUCCESS: File written."))
  .catch(e => { console.error("ERROR:", e); process.exit(1); });

cd /home/daytona/workspace/pns-usg-blocks && node create_ppt.js

ls -lh /home/daytona/workspace/pns-usg-blocks/PNS_vs_USG_Regional_Blocks.pptx

~/pns-usg-blocks/create_landmark_pns.js

const pptxgen = require("pptxgenjs");
const pres = new pptxgen();
pres.layout = "LAYOUT_16x9";
pres.title = "Landmark & PNS Guided Regional Blocks";
pres.author = "Anaesthesia Department";

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// ═══════════════════════════════════════════════════════════════════
// SLIDE 1 – TITLE
// ═══════════════════════════════════════════════════════════════════
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  s.addText("Department of Anaesthesiology  ●  2026", {
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  });
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 2 – PRESENTATION OVERVIEW
// ═══════════════════════════════════════════════════════════════════
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    { num:"01", title:"Introduction to Regional Anaesthesia" },
    { num:"02", title:"Landmark Technique – Principles" },
    { num:"03", title:"Landmark Technique – Clinical Practice" },
    { num:"04", title:"Benefits of Landmark over PNS & USG" },
    { num:"05", title:"Peripheral Nerve Stimulator – Principles" },
    { num:"06", title:"PNS – Setup & Clinical Practice" },
    { num:"07", title:"Indications for PNS-Guided Blocks" },
    { num:"08", title:"Benefits of PNS over USG" },
    { num:"09", title:"Comparison Tables" },
  ];
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// ═══════════════════════════════════════════════════════════════════
// SLIDE 3 – Section Divider: Introduction
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  sectionDivider(s, "1", "Introduction to Regional\nAnaesthesia",
    "History, classification, and the evolution from landmark to advanced guidance techniques");
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 4 – Introduction to Regional Anaesthesia
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Introduction to Regional Anaesthesia", [
    "Regional anaesthesia (RA) is the targeted delivery of local anaesthetic (LA) near a nerve or plexus to produce reversible conduction block in a defined body area.",
    "Provides surgical anaesthesia OR postoperative analgesia — often eliminating the need for general anaesthesia.",
    "Classification of peripheral nerve blocks:",
    { text:"Plexus blocks: brachial plexus (ISB, SCB, infraclavicular, axillary), lumbar plexus, sacral plexus" },
    { text:"Single nerve blocks: femoral, sciatic, saphenous, ulnar, median, radial, sural" },
    { text:"Fascial plane blocks: TAP, PECS I & II, QL, ESP, IPACK, serratus anterior" },
    "Guidance techniques – historical evolution:",
    { text:"1st generation: Landmark / anatomical technique (paraesthesia, bony landmarks, fascial clicks)" },
    { text:"2nd generation: Peripheral Nerve Stimulator (PNS) – motor response as objective endpoint" },
    { text:"3rd generation: Ultrasound guidance (USG) – real-time direct visualisation" },
    "Each technique has specific advantages, indications, and a defined clinical role.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 5 – Section Divider: Landmark
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  sectionDivider(s, "2", "Landmark Technique",
    "Principles, anatomical basis, and clinical application in peripheral nerve blocks");
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 6 – Landmark Technique: Principles
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Landmark Technique – Principles & Anatomical Basis", [
    "Relies entirely on surface and deep anatomical knowledge to predict nerve location.",
    "Key endpoints used by the anaesthetist:",
    { text:"Bony landmarks: clavicle, coracoid process, inguinal ligament, greater trochanter, tibial head" },
    { text:"Paraesthesia elicitation: patient reports electric shock / tingling in nerve distribution on needle contact" },
    { text:"Fascial 'click' or 'pop': felt as needle traverses fascial layers (e.g., axillary, femoral nerve blocks)" },
    { text:"Loss-of-resistance: encountered when entering target compartment" },
    { text:"Bony contact and withdrawal: used in dental, retrobulbar, and some trunk blocks" },
    "Operator maintains a 3D mental map of anatomy: nerve → adjacent artery/vein → fascial planes.",
    "Speed of onset and quality of block depend on accuracy of LA placement around nerve.",
    "No equipment beyond needle and syringe required — highly accessible in any setting.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 7 – Landmark Technique: Clinical Applications
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  twoColSlide(
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    "Landmark Technique – Common Clinical Applications",
    "Upper Limb Blocks",
    [
      "Interscalene block: scalene triangle, lateral border of SCM",
      "Supraclavicular block: subclavian artery palpation + clavicle landmark",
      "Infraclavicular block: coracoid process landmark",
      "Axillary block: axillary artery pulsation as guide to plexus",
      "Wrist blocks: median, ulnar, radial nerve at wrist creases",
    ],
    "Lower Limb & Trunk Blocks",
    [
      "Femoral nerve block: femoral artery palpation (NAVEL)",
      "Sciatic nerve block: Labat's landmark (posterior approach)",
      "Ankle block: 5-nerve anatomical landmarks at ankle",
      "TAP block: Petit's triangle (landmark) for truncal analgesia",
      "Penile block: symphysis pubis / Buck's fascia",
      "Ilioinguinal block: anterior superior iliac spine landmark",
    ],
    C.midgreen, C.navy
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// ═══════════════════════════════════════════════════════════════════
// SLIDE 8 – Benefits of Landmark over PNS & USG
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Benefits of Landmark Technique over PNS & USG", [
    "1. Zero equipment dependency – only needle and syringe needed; no stimulator, no probe, no gel, no sterile covers.",
    "2. Immediately available in any setting – resource-limited environments, rural hospitals, pre-hospital/disaster medicine, military field anaesthesia.",
    "3. Lowest cost – no capital expenditure on ultrasound machines or nerve stimulators; ideal in low-income healthcare systems.",
    "4. No learning curve for equipment – avoids USG image interpretation skills and PNS current calibration; anaesthetist focuses on pure anatomy.",
    "5. Immune to equipment failure – unaffected by machine malfunction, battery failure, probe damage, or power outage.",
    "6. Builds deep anatomical knowledge – trainees who master landmark technique develop superior 3D anatomical understanding that underpins safe USG and PNS practice.",
    "7. Fast setup – no probe preparation, scanning, or equipment checks required; block can be performed immediately.",
    "8. Viable for simple, superficial, predictable blocks – wrist blocks, ankle blocks, penile block, DCIA: high success with pure anatomy.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 9 – Landmark: Specific Situational Advantages
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Landmark Technique – Situational Advantages", [
    "Emergency & Austere Environments:",
    { text:"Military combat casualty care: no time / logistics for USG; landmarks guide haematoma block, femoral nerve block for tourniquet pain" },
    { text:"Mass casualty incidents: one skilled operator can perform blocks on multiple patients without equipment queue" },
    { text:"Pre-hospital settings: rough conditions, low light, and patient movement preclude reliable USG scanning" },
    "Paediatric practice – select blocks:",
    { text:"Caudal epidural: sacral hiatus landmark; simplest, most reliable block in paediatrics worldwide" },
    { text:"Penile block, ilioinguinal block: anatomical success rates > 90% with landmark in experienced hands" },
    "Training value:",
    { text:"Landmark mastery is prerequisite before USG training in most anaesthesia curricula" },
    { text:"Forces trainees to understand anatomy before they rely on screen images" },
    "Intraoperative use:",
    { text:"Wrist block, ankle block at sterile field: rapid, no additional equipment needed" },
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 10 – Section Divider: PNS
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  sectionDivider(s, "3", "Peripheral Nerve\nStimulator (PNS)",
    "Mechanism, equipment, technique, and advantages over USG");
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 11 – PNS: Principles & Mechanism
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "PNS Technique – Principles & Mechanism of Action", [
    "Electrical stimulation at defined current threshold depolarises the motor fibres of a mixed peripheral nerve.",
    "The resultant visible muscle contraction (evoked motor response) confirms needle-nerve proximity without requiring paraesthesia.",
    "Biophysical basis:",
    { text:"Current (I), charge (Q), and distance (d) are related by: I = Q/d² (Coulomb's law analogy)" },
    { text:"Smaller current needed as needle approaches nerve → titrate down to threshold" },
    { text:"Myelinated Aα fibres (motor) depolarise at lower current than Aδ/C fibres (pain) → safe motor-only endpoint" },
    "Stimulation parameters:",
    { text:"Frequency: 1–2 Hz (1 Hz preferred – clear twitch visible)" },
    { text:"Pulse width: 0.1 ms (standard); 0.3 ms for deep / poorly responsive nerves" },
    { text:"Starting current: 1.0–1.5 mA; reduce to ≤ 0.5 mA at target, then inject if > 0.2 mA" },
    "Motor response at ≤ 0.5 mA with appropriate muscle twitch = optimal needle placement.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 12 – PNS: Equipment & Setup
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "PNS – Equipment & Procedural Setup", [
    "Equipment checklist:",
    { text:"Peripheral nerve stimulator unit: constant-current output device, displays actual delivered current" },
    { text:"Insulated short-bevel needle (Stimuplex® or equivalent): Teflon coat insulates shaft; exposed tip only conducts" },
    { text:"Dispersive (return) electrode: standard ECG electrode placed on ipsilateral limb or shoulder" },
    { text:"Extension tubing between needle hub and syringe ('immobile needle' technique)" },
    "Procedural sequence:",
    { text:"Position electrode 15–20 cm from target nerve; connect stimulator anode (+) to electrode, cathode (−) to needle" },
    { text:"Set: current 1.0–1.5 mA, frequency 1 Hz, pulse width 0.1 ms" },
    { text:"Advance needle toward nerve; observe for specific twitch (correct muscle group)" },
    { text:"Reduce current while maintaining response; target ≤ 0.5 mA, ensure > 0.2 mA before injection" },
    { text:"Aspirate; inject LA incrementally with observation for loss of twitch (Raj test)" },
    "Stimulating catheters available for continuous PNS-guided nerve block infusions.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 13 – Indications for PNS-Guided Blocks
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  twoColSlide(
    s,
    "Indications for PNS-Guided Regional Blocks",
    "Primary Indications",
    [
      "Sedated / anaesthetised patients (paraesthesia unreliable)",
      "Uncooperative or paediatric patients (no subjective reporting)",
      "Deep blocks where anatomy surface landmarks are unreliable: sciatic (parasacral, subgluteal), lumbar plexus",
      "Continuous catheter placement via stimulating catheter",
      "When USG machine is unavailable or image quality is poor",
      "Surgeon-requested intraoperative nerve mapping (awake craniotomy adjunct)",
    ],
    "Preferred PNS Blocks",
    [
      "Sciatic nerve block: all approaches (Labat, subgluteal, popliteal)",
      "Lumbar plexus / psoas compartment block",
      "Interscalene & infraclavicular brachial plexus block",
      "Femoral nerve block with catheter",
      "Obturator nerve block",
      "Continuous peripheral nerve block (CPNB) infusions via stimulating catheter",
    ],
    C.midgreen, C.navy
  );
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 14 – Benefits of PNS over USG
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Benefits of PNS over USG-Guided Technique", [
    "1. No image interpretation required – motor response is a direct, unmistakable physiological endpoint; no sono-anatomy training needed.",
    "2. Consistent performance in deep blocks – lumbar plexus, sciatic nerve: PNS is as effective as USG where depth exceeds probe penetration.",
    "3. Lower capital cost than ultrasound – PNS units cost 10–20x less than a portable ultrasound machine.",
    "4. Portability and robustness – lightweight, battery-operated, undamaged by sterile field constraints or physical impact.",
    "5. Stimulating catheter for continuous blocks – PNS confirms catheter tip position during threading; USG alone cannot confirm final catheter position.",
    "6. Unaffected by calcification or scar tissue image artefacts – USG image degraded by obesity, calcification, gas; PNS response is unaffected.",
    "7. Reproducible objective threshold – 0.5 mA standard is universal and operator-independent; USG quality varies by operator skill.",
    "8. Combined PNS + USG is superior – PNS provides functional confirmation when ultrasound gives anatomical placement: dual safety net.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 15 – PNS: Deep Block Advantage
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "PNS Advantage – Deep Nerve Blocks", [
    "LUMBAR PLEXUS BLOCK (Psoas Compartment):",
    { text:"Depth 6–10 cm in adults; high-frequency USG probes cannot penetrate adequately" },
    { text:"PNS: quadriceps twitch at ≤ 0.5 mA reliably confirms needle position within psoas compartment" },
    { text:"PNS success rate for lumbar plexus comparable to USG (both ~88–92%)" },
    "SCIATIC NERVE – SUBGLUTEAL & PARASACRAL APPROACHES:",
    { text:"Depth 5–8 cm beneath gluteus maximus; curvilinear USG required but image quality variable" },
    { text:"PNS: plantar flexion / dorsiflexion / inversion at ≤ 0.5 mA confirms sciatic proximity reliably" },
    "CONTINUOUS CATHETER TECHNIQUES (CPNB):",
    { text:"Femoral, sciatic, infraclavicular continuous blocks: stimulating catheter threaded under PNS guidance" },
    { text:"Motor response confirms catheter tip within nerve sheath – not achievable by USG alone after initial placement" },
    { text:"CPNB significantly reduces postoperative opioid consumption (studies: 40–60% reduction in morphine equivalents)" },
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 16 – Head-to-Head Comparison Table
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  const hrow = [
    { text:"Parameter",        options:{ bold:true, color:C.white, fill:{color:C.deepgreen}, fontSize:12 } },
    { text:"Landmark",         options:{ bold:true, color:C.white, fill:{color:C.midgreen}, fontSize:12 } },
    { text:"PNS",              options:{ bold:true, color:C.white, fill:{color:"1A4E8A"}, fontSize:12 } },
    { text:"USG",              options:{ bold:true, color:C.white, fill:{color:"6B3FA0"}, fontSize:12 } },
  ];
  const rows = [
    ["Equipment cost","Negligible","Low–Moderate","High"],
    ["No equipment failure risk","✔ Always works","Moderate (battery)","Highest (machine/probe)"],
    ["Austere / pre-hospital use","✔ Ideal","Good","Difficult"],
    ["Deep block reliability","Operator-dependent","✔ Good","Variable (depth limit)"],
    ["Continuous catheter (CPNB)","Not applicable","✔ Stimulating catheter","Catheter tip unconfirmed"],
    ["Training for equipment","None required","Short (PNS operation)","Long (sono-anatomy)"],
    ["Anatomical education value","✔ Maximal","Moderate","Lower (screen-reliant)"],
    ["Purely sensory nerve blocks","Yes (surface)","No motor response","✔ Yes"],
    ["Image artefact problems","None","None","Obesity, scar, gas artefact"],
    ["Resource-limited settings","✔ Best option","✔ Viable","Often unavailable"],
    ["Success rate (major plexus)","~78–82%","~86–90%","~94–98%"],
  ];
  const tableData = [
    hrow,
    ...rows.map((r, ri) => r.map((cell, ci) => ({
      text: cell,
      options: {
        color: C.deepgreen,
        fill: { color: ri % 2 === 0 ? "DDF0E4" : C.white },
        fontSize: 11,
        bold: ci === 0,
      }
    })))
  ];
  compTableSlide(s, "Landmark vs PNS vs USG – Comparative Analysis", tableData);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 17 – Combined Landmark + PNS Strategy
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  contentSlide(s, "Landmark + PNS Combined Strategy", [
    "Most PNS-guided blocks begin with landmark identification of the target zone before needle insertion.",
    "Landmark provides the macro-anatomy framework; PNS provides the micro-confirmation of needle-nerve proximity.",
    "Workflow:",
    { text:"Step 1: Identify and mark anatomical landmarks (bony prominences, pulse, skin crease)" },
    { text:"Step 2: Insert insulated needle toward expected nerve position using landmark guidance" },
    { text:"Step 3: Activate PNS at 1.0–1.5 mA; adjust needle direction based on motor response" },
    { text:"Step 4: Refine needle position until response obtained at ≤ 0.5 mA, > 0.2 mA" },
    { text:"Step 5: Aspirate, inject LA in 5 mL increments; confirm loss of twitch on injection (Raj test)" },
    "This combined approach achieves success rates of 86–92% for major plexus blocks.",
    "Requires no ultrasound machine; delivers higher accuracy than landmark alone.",
    "Ideal for training environments: builds anatomical understanding while providing PNS safety.",
    "Recognised in ATLS / trauma protocols as the appropriate technique when USG unavailable.",
  ]);
}

// ═══════════════════════════════════════════════════════════════════
// SLIDE 18 – Summary & Conclusions
// ═══════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s, C.deepgreen);
  leftBar(s, C.accent);
  s.addShape(pres.ShapeType.rect, { x:0.15, y:0, w:9.85, h:0.88, fill:{color:"0A2B20"} });
  s.addText("Summary & Conclusions", {
    x:0.3, y:0, w:9.4, h:0.88,
    fontSize:24, bold:true, color:C.white, fontFace:"Calibri", valign:"middle", margin:0,
  });

  const keyPoints = [
    { col:C.accent,       text:"Landmark technique: zero-equipment, always-available, anatomy-educating — essential foundation for every regional anaesthetist." },
    { col:C.gold,         text:"PNS: objective physiological endpoint, ideal for deep blocks and continuous catheter techniques, works without USG." },
    { col:C.accent,       text:"Landmark + PNS combined: practical, cost-effective, achieves 86–92% success — standard practice in resource-limited settings." },
    { col:C.gold,         text:"PNS excels for lumbar plexus and sciatic blocks where USG depth penetration is insufficient." },
    { col:C.accent,       text:"Stimulating catheters (CPNB) rely on PNS for catheter tip confirmation — a role USG alone cannot fulfil." },
    { col:C.gold,         text:"Deep anatomical knowledge from landmark training underpins safe USG practice — the two are complementary, not competitive." },
  ];
  keyPoints.forEach((p, i) => {
    const y = 1.02 + i * 0.73;
    s.addShape(pres.ShapeType.rect, { x:0.3, y, w:9.3, h:0.62, fill:{color:"0C3026"}, line:{color:p.col, pt:0.8} });
    s.addShape(pres.ShapeType.rect, { x:0.3, y, w:0.12, h:0.62, fill:{color:p.col} });
    s.addText(p.text, { x:0.5, y: y+0.02, w:9.0, h:0.58, fontSize:13, color:C.offwhite, fontFace:"Calibri", valign:"middle" });
  });
  s.addText('"Landmark builds the surgeon's eye, PNS builds the surgeon's hand — together they build the complete regional anaesthetist."', {
    x:0.5, y:5.26, w:9, h:0.28,
    fontSize:10, color:C.gold, fontFace:"Calibri", italic:true, align:"center",
  });
}

// ── WRITE FILE ───────────────────────────────────────────────────────
pres.writeFile({ fileName: "/home/daytona/workspace/pns-usg-blocks/Landmark_PNS_Regional_Blocks.pptx" })
  .then(() => console.log("SUCCESS: File written."))
  .catch(e => { console.error("ERROR:", e); process.exit(1); });

cd /home/daytona/workspace/pns-usg-blocks && node create_landmark_pns.js

~/pns-usg-blocks/create_landmark_pns.js

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/pns-usg-blocks/create_landmark_pns.js'

cd /home/daytona/workspace/pns-usg-blocks && node create_landmark_pns.js

ls -lh /home/daytona/workspace/pns-usg-blocks/Landmark_PNS_Regional_Blocks.pptx