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Intra-operative crises · Core01 / 21

Ventricular tachycardia in the beach-chair position74-year-old man, 82 kg, for elective total shoulder replacement in the beach-chair position

Broad-complex tachycardia with a pulse, then shockable arrest: two algorithms

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Know this first

  • Unstable broad-complex tachycardia (systolic under 80 or altered mentation): synchronised shock, 100 J for monomorphic VT.
  • Stable VT with a pulse: amiodarone 150 mg IV over 10 min, then 1 mg/min.
  • Verapamil and diltiazem are harmful in broad-complex tachycardia.
  • Arrest: adrenaline 1 mg every 3–5 min; amiodarone 300 mg, then 150 mg, for shock-refractory VT.
  • Sitting up, the pressure that matters is at the circle of Willis, read at the ear.

The patient

74-year-old man, 82 kg, for elective total shoulder replacement in the beach-chair position. Ischaemic cardiomyopathy after an old inferior infarct, EF 35%; no angina; climbs two flights of stairs without stopping. Drugs: bisoprolol, furosemide, atorvastatin. Morning K+ 3.2 mmol/L. Vitals: BP 132/78, HR 64 sinus, SpO2 96% on air, RR 14.

The examiner asks

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  1. Consider

    What are your concerns before his shoulder replacement?

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    • A 74-year-old with ischaemic cardiomyopathy, EF 35%, for an elective shoulder replacement sitting up. Patient
    • At 74 with EF 35%, he has little reserve for the pressure fall when he's sat up.
    • ACC/AHA, applied to him: elective surgery, so there is time to assess. Stem trigger
    • No active cardiac condition: his angina is stable, his failure compensated, no sustained arrhythmia. Disease
    • RCRI 2, his old infarct and heart failure, so his risk is elevated.
    • Two flights of stairs is over 4 METs, so he proceeds without stress testing.
    • K+ 3.2 is mild: he can proceed, but gets 20–40 mEq IV over 30 minutes and a magnesium check.

  2. Prepare

    How do you set up for him?

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    • Defibrillator pads on his chest and connected before he is sat up and draped. Crisis
    • Arterial line zeroed at his ear, because the circle of Willis is the pressure that counts. Surgery
    • Cerebral oximetry if we have it; most beach-chair patients show brain desaturation, lateral ones don't.
    • Phenylephrine 50–100 mcg boluses drawn up before he is raised, to protect his brain and coronaries.
    • He keeps bisoprolol today; stopping it suddenly risks rebound, and his statin continues too. Disease

  3. Crisis

    Forty minutes in, the monitor shows a regular broad-complex tachycardia at 180. BP 78/46, and he still has a palpable pulse. Talk me through it.

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    • Adult tachycardia algorithm: broad-complex tachycardia at 180 with a pulse, in a man with an infarct scar. (Crisis)
    • Unstable, systolic under 80: synchronised shock at 100 J now, escalating if it fails.
    • He's already anaesthetised; I deepen only if it costs no time, then shock synchronised.
    • Table back to flat while the pads charge, to restore his brain and coronary perfusion.
    • Had he been stable: 12-lead first, then amiodarone 150 mg IV over 10 minutes, then 1 mg/min.
    • No verapamil: it won't stop VT and can drop him into shock and arrest.
    • His reversible causes: low potassium, low magnesium and ischaemia on the 12-lead.

  4. Crisis

    After the shock he goes pulseless in VT; ETCO2 falls to 10 mmHg. What now?

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    • Adult arrest algorithm, shockable branch: pulseless VT; flat on the table and compressions now. Crisis
    • Unsynchronised shock at the defibrillator's recommended energy, or maximum, then straight back to compressions.
    • Once early shocks have failed, adrenaline 1 mg IV, and again each 3–5 minutes.
    • Still in VT after shocks: amiodarone 300 mg IV, then 150 mg.
    • Gas for potassium now; if still low, 20–40 mEq over 3–10 minutes.
    • A sudden rise in his ETCO2 during compressions will tell me circulation is back.
    • After ROSC: stop surgery, 12-lead and troponin, ICU, and cardiology today for his VT. After surgery

Fatal mistakes

  • Verapamil for his broad-complex tachycardia.
  • Delaying the synchronised shock while he is hypotensive in VT.
  • Ignoring his K 3.2 and magnesium with no check or plan in a scarred ventricle.

Checked against: AHA guidelines: adult advanced life support (2025) · Barash 9e · Stoelting 8e · Miller 10e · AHA/ACC 2024

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