Severe Hyperkalemia After a Missed Session With Hidden Potassium Sources
A 67-year-old woman with type 2 diabetes and end-stage kidney disease misses her Friday hemodialysis session because of transport problems and arrives Monday morning. She takes lisinopril 20 mg daily, spironolactone 25 mg daily, and calcium carbonate 1,250 mg with meals. She admits using a 'NoSalt' salt substitute and eating two oranges daily. Pre-dialysis potassium is 6.8 mEq/L, ECG shows peaked T waves but no widened QRS. BP is 168/92 mmHg, weight 64.2 kg, dry weight 62.5 kg, and glucose 210 mg/dL. She has no muscle weakness or palpitations. The dialysis machine is ready and the nephrologist is rounding on another floor. Her last potassium was 5.9 mEq/L two weeks ago; she reports constipation and has missed one session before.
1. What are the immediate treatment priorities for this hyperkalemia before and during dialysis?
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Because potassium is 6.8 mEq/L with peaked T waves, treat this as an emergency while preparing dialysis. Place the patient on continuous ECG monitoring; if the QRS widens or an arrhythmia occurs, give IV calcium gluconate per protocol for cardiac membrane stabilization. Give insulin with glucose and a beta-2 agonist to shift potassium intracellularly, monitoring glucose closely.
Dialysis is definitive; start as soon as possible with a low-potassium dialysate, usually 2 mEq/L rather than 0–1 mEq/L, and ensure adequate blood flow and treatment time. Avoid oral potassium binders as sole acute therapy in this situation. Recheck potassium and ECG after treatment.
2. Which medications and dietary practices contributed to the hyperkalemia, and what specific changes should be recommended?
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Spironolactone and lisinopril both raise potassium; spironolactone should be stopped acutely and lisinopril reviewed with the prescriber. 'NoSalt' is potassium chloride and must be stopped. Oranges and orange juice are high-potassium foods; the dietitian should quantify intake and substitute lower-potassium choices. Calcium carbonate is a phosphate binder and should be taken with meals, not as a potassium treatment, and constipation can worsen potassium retention, so bowel management matters.
Check for missed-session and transport barriers, glucose control, and other medications that impair potassium excretion. Do not simply tell her to 'avoid potassium' without a practical plan.
3. What education and follow-up should be arranged to prevent recurrence?
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Provide written education on hidden potassium sources such as salt substitutes, citrus, potatoes, tomatoes, and dairy; missed-session prevention; and when to call. Confirm the transport plan and consider a backup. Schedule dietitian review, medication reconciliation, and repeat potassium before the next session.
Document the event, ECG, treatments, and response. At handover, flag the medication changes and need for follow-up. Audit missed sessions and hyperkalemia episodes to improve unit processes.