High-voltage electrical injury for forearm fasciotomy32-year-old man, 82 kg, electrician, 3 hours after an 11,000-volt contact through the right hand

The patient

The examiner asks

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1. Consider

   What are your concerns?

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   • A 32-year-old with a high-voltage injury, myoglobinuria and forearm compartment syndrome, for urgent fasciotomy. Patient
   • As a trauma patient: a multisystem injury, so I screen his spine, chest and abdomen too.
   • Over 1000 V: bone resists the current and heats, cooking the deep muscle under small wounds. Disease
   • Dark urine and CK 38,000: rhabdomyolysis, with his kidneys at risk.
   • Pain beyond the injury in a tense forearm: compartment syndrome, so fasciotomy is urgent. Surgery

2. Prepare

   What do you check and set up before theatre?

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   • Continuous ECG: arrhythmias and heart block are common after electrical injury. Disease
   • Normal enzymes wouldn't clear his conduction system, so the monitor stays on.
   • Fluids by urine output, not skin area; a formula would underestimate his deep injury.
   • Pigmented urine: I aim for 1–2 mL/kg/h until it clears.
   • Potassium 5.6 with muscle breaking down: repeat it just before induction.
   • No suxamethonium: rhabdomyolysis already pushes his potassium up. Airway

3. Plan

   What is your anaesthetic plan?

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   • Rapid sequence with rocuronium 1.2 mg/kg in place of suxamethonium. Airway
   • Arterial line for gases and potassium; urinary catheter for hourly output. Disease
   • A plexus catheter later is fine, as long as no dense motor block hides a second compartment syndrome.
   • Dead muscle declares itself over days, so staged debridements are likely. Surgery
   • ICU after: ECG monitoring, hourly urine and CK trend. After surgery

4. Crisis

   As the fasciotomy releases the forearm, peaked T waves and multifocal ectopics appear; K+ 7.1 mmol/L, BP 108/60. What do you do?

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   • Hyperkalaemia from reperfused muscle: tell the surgeon, stop any potassium-containing fluid. (Crisis)
   • Calcium chloride 500–1000 mg IV over 3 minutes to protect his heart.
   • Insulin 10 units with 50 g glucose to drive potassium into cells.
   • Sodium bicarbonate also alkalinises his urine against myoglobin.
   • Refractory: haemofiltration or dialysis, with nephrology now.
   • Pads on; if VF or pulseless VT, standard arrest algorithm with early defibrillation.

5. Crisis

   Next morning his face and neck are swollen; still intubated, BP 132/78, HR 96, SpO2 97% on FiO2 0.4. The team wants to extubate. What do you do?

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   • Airway swelling plus a hard reintubation: I won't extubate just because it's the morning round. Airway
   • Sit him up and avoid excess fluid while the swelling settles.
   • Cuff-leak test: a leak suggests he'll keep his airway, but doesn't prove it.
   • Dexamethasone 4–8 mg IV every 8–12 hours for airway oedema.
   • When ready: daytime, over an airway exchange catheter, with a difficult airway team present. After surgery