Medical and endocrine disease · Core27 / 30
Missed dialysis and hyperkalaemia for urgent hernia repair58-year-old man, 92 kg (dry weight 88 kg), for urgent repair of an incarcerated inguinal hernia
Renal failure: dialysis timing, hyperkalaemia and hyperkalaemic arrest
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Know this first
- Peaked T waves appear at potassium 5.5–6.5; suxamethonium raises it 0.5–1.0 for 10–15 minutes.
- Elective surgery is ideally about 24 hours after dialysis.
- Membrane first: calcium chloride 10 mL of 10%; then insulin 10 units with glucose to shift potassium.
- No cannula or cuff on the fistula arm.
The patient
58-year-old man, 92 kg (dry weight 88 kg), for urgent repair of an incarcerated inguinal hernia; vomiting since this morning.
Kidney failure on haemodialysis via a left forearm fistula; diabetes and hypertension; missed his last dialysis session.
Drugs: sevelamer, erythropoietin, amlodipine, insulin.
Vitals: BP 168/96, HR 92, SpO2 94% on air, RR 20. K+ 6.1 mmol/L, Hb 9.4 g/dL.
The examiner asks
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Consider
What are your concerns?
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- A 58-year-old on haemodialysis who missed his last session, for urgent repair of an incarcerated hernia. Patient
- Missed dialysis: potassium 6.1, about 4 kg above dry weight, and likely acidosis. Disease
- At 6.1 his ECG may already show peaked T waves; I look now.
- Renal anaemia, Hb 9.4, from low erythropoietin, and uraemic platelet dysfunction.
- Vomiting and uraemic gastropathy make him an aspiration risk. Airway
Prepare
How will you prepare him?
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- Dialysis first if the hernia can wait a few hours; I agree that with the surgeon now. (Disease)
- If not, his potassium is lowered medically, with continuous ECG monitoring.
- ECG changes mean calcium chloride 10 mL of 10% over 10 minutes first.
- Then insulin 10 units with 50 g glucose, and salbutamol; bicarbonate only if acidotic.
- Potassium and glucose rechecked before induction.
- Fistula arm protected: no cannula, no cuff, well padded.
Plan
How will you anaesthetise him?
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- Rapid sequence with rocuronium 1.2 mg/kg; no suxamethonium with potassium of 6.1. Airway
- Rocuronium depends less on the kidneys than vecuronium; sugammadex reverses it. Disease
- No repeated morphine: its active metabolite accumulates; fentanyl in small doses instead.
- Small volumes of balanced crystalloid; large saline volumes cause acidosis and push potassium out.
- Desmopressin 0.3 mcg/kg if uraemic bleeding is a problem.
- Dialysis booked for straight after surgery. After surgery
Crisis
Two minutes after induction the T waves peak, then a broad-complex rhythm at 30/min appears; there is no pulse. What do you do?
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- Adult arrest algorithm: pulseless broad-complex rhythm, non-shockable, with hyperkalaemia the likely cause. Crisis
- CPR now, help called, 100% oxygen through his tube.
- Give adrenaline 1 mg straight away, again each 3–5 minutes; shock only for VF.
- His cause: calcium chloride 10 mL of 10%, then insulin 10 units with 50 g glucose.
- Sodium bicarbonate 50–100 mEq, as he is likely acidotic after missed dialysis.
- No salbutamol during CPR; it adds nothing to resuscitation.
- Emergency dialysis arranged at once; ICU after return of circulation. After surgery
Fatal mistakes
- Suxamethonium without a recent potassium.
- A cannula or BP cuff on his fistula arm.
- No potassium-directed treatment or urgent dialysis plan in a hyperkalaemic arrest.
Checked against: Barash 9e · Miller 10e · AHA guidelines: special circumstances of resuscitation (2025)
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