Hyperkalemia: documentation that holds up
Hyperkalemia kills quietly: the ECG is an unreliable warning system, and the absolute number is only part of the picture. The defensible chart shows you treated on the whole clinical picture, ran the stabilize-shift-eliminate sequence with times, and recognized that only dialysis removes total-body potassium.
01What's at stake
The ECG is insensitive — in one series only about 55% of patients with potassium ≥6.8 had any ECG changes, and physicians miss hyperkalemia on the ECG most of the time. So a normal ECG does not exclude dangerous hyperkalemia. Treatment is driven by the clinical picture, the value, and the ECG together — and the shifting agents buy time without fixing the total-body burden.
02Can't-miss points
- The ECG is unreliable — don't let a normal tracing defer treatment in a high-risk patient.
- Shifting ≠ removal — calcium, insulin/dextrose, and albuterol stabilize/shift but don't lower total-body potassium; watch for rebound.
- Dialysis is the only proven acute removal — and the treatment of choice in the ESRD/anuric patient.
- Pseudohyperkalemia — a hemolyzed sample; but if renal failure is clinically suspected, treat and redraw rather than dismiss.
- Digoxin — in acute dig toxicity, hyperkalemia predicts mortality; give digoxin-specific Fab if K⁺ >5.
03ECG & recognition
- The classic sequence — peaked T waves → PR prolongation/loss of P → QRS widening → sine wave — but it correlates poorly with the level. → treat the patient, not the ECG
- Consider hyperkalemia in renal failure, missed dialysis, crush/rhabdo, certain medications (ACEi/ARB, K-sparing diuretics, trimethoprim), and adrenal insufficiency.
Skip the typing
Work the case in the Hyperkalemia Workup — it records the ECG, the membrane-stabilization, shift, and elimination steps, and the recheck plan, and assembles an MDM that documents the treatment sequence and disposition.
04The three-prong treatment
- Stabilize the myocardium — IV calcium (gluconate, or chloride via central line) for ECG changes or a critical level; onset minutes, lasts ~30–60 min, no effect on the level. (Reach for digoxin Fab rather than over-relying on calcium in dig toxicity.)
- Shift intracellularly — dextrose then insulin (with a glucose-monitoring protocol — hypoglycemia is common), high-dose nebulized albuterol; bicarbonate only as an adjunct if acidotic.
- Eliminate — diuresis if making urine; dialysis for refractory/anuric/ESRD patients. Note that SPS (kayexalate) and the newer binders (patiromer, ZS-9) are not proven for acute lowering.
- Treat the cause and recheck the level — anticipate rebound as shifting agents wear off.
05What to document
06Where charts fail
- Using a normal ECG to defer treatment of a high potassium.
- Relying on SPS/kayexalate (or new binders) for acute lowering instead of dialysis.
- Forgetting that calcium and shifting don't remove potassium — and not arranging definitive elimination.
- Not running a glucose-monitoring protocol after insulin/dextrose.
- Dismissing a result as "hemolyzed" when renal failure is clinically likely.
- Not rechecking the level (rebound) and not addressing the cause.
07Sources
- Ashurst J, Sergent SR, Wagner BJ. Evidence-based management of potassium disorders in the emergency department. Emergency Medicine Practice (EB Medicine). 2016;18(11).
- Wrenn KD, Slovis CM, Slovis BS. The ability of physicians to predict hyperkalemia from the ECG. Ann Emerg Med. 1991;20(11):1229-1232.
- Mahoney BA, Smith WA, Lo D, et al. Emergency interventions for hyperkalaemia. Cochrane Database Syst Rev. 2005;(2):CD003235.
- Allon M, Shanklin N. Effect of bicarbonate administration on plasma potassium in dialysis patients. Am J Kidney Dis. 1996;28(4):508-514.
© 2026 Kim Trinh, MD. All rights reserved. Educational only — synthesized from EB Medicine and primary literature. Synthetic examples. Not medical advice — apply local protocol and judgment.