Stethopedia | Approach

Approach to

Hyperkalemia

Get an ECG and exclude a spurious result. IV calcium if the ECG has changed; if K ≥6.0 or rising fast, shift K into cells and start removal. Then sort the cause: poor excretion, low aldosterone effect, or shift.

  1. Serum potassium above the upper limit of normal
  2. STAT 12-lead ECG and monitor; creatinine, glucose, gas, CBC; drug review1,10
  3. Hemolyzed or unexpected with normal ECG: repeat K on a blood gas before treating1,10
  4. ECG change, K ≥6.0, or rising fast?

Emergency: stabilize, shift, then remove K1,10

  • ECG: peaked T, long PR, wide QRS, brady
  • ECG change: Ca gluconate 10% 30 mL IV1
  • K ≥6.5: shift K even if ECG normal1,3
  • K 6.0–6.4: monitor, binder, recheck K1,10
  • After insulin: K in 1–2 h; glucose ≥3 h5

→ Shift: insulin 5–10 U + dextrose 25–50 g; salbutamol 10–20 mg1,4,6

Then: why is K high?

CausesCluesWorkupManagement

Low GFR or distal flow

  • AKI, especially oliguric
  • Advanced CKD; missed dialysis
  • Low distal flow: HF, hypovolemia9
  • Low urine output; rising creatinine
  • Edema, or dry and orthostatic
  • Creatinine, urea; bladder scan
  • Renal ultrasound if AKI is new
  • Dialysis if oliguric, ESKD or refractory1
  • Making urine: loop diuretic1
  • Volume-depleted: isotonic fluid first1

Low aldosterone effect

  • ACEi/ARB, MRA, K-sparing diuretic
  • NSAIDs, trimethoprim, heparin, CNIs
  • Adrenal insufficiency: low Na, low BP
  • New drug or dose, with low eGFR1,2
  • Diabetic CKD, non-gap acidosis: type 4 RTA
  • Medication and supplement review1
  • Renin, aldosterone if unclear
  • Cortisol, ACTH if adrenal suspected10
  • Hold culprit; restart RASi ± binder later11
  • Binder: SZC 10 g TID ≤48 h; SPS GI risk1,7,8
  • Adrenal crisis: IV hydrocortisone 100 mg10

Shift out of cells

  • Rhabdomyolysis, tumour lysis
  • Insulin deficiency: DKA, HHS
  • Acidosis; digoxin, β-blockers
  • Crush, found down, recent chemo
  • High glucose; anion-gap acidosis
  • CK, urate, phosphate, LDH
  • Blood gas; digoxin level if on it
  • Treat cause: DKA insulin; digoxin Fab12
  • Bicarbonate only if acidemic1
  • Serial K: lysis keeps releasing it

Pseudohyperkalemia

  • Hemolysis; fist clenching, tourniquet1
  • Very high platelets or WBC10
  • Drawn above a K-containing IV
  • Hemolysis flagged; no risk factors1
  • Implausible: no CKD, culprit drug or lysis1
  • Repeat without tourniquet; gas K1,10
  • Platelets, WBC on the CBC10
  • No treatment once repeat K is normal

Can't-miss cause Superscripts link to the references below.

References

  1. Lindner G, Burdmann EA, Clase CM, et al. Acute hyperkalemia in the emergency department: a summary from a Kidney Disease: Improving Global Outcomes conference. Eur J Emerg Med. 2020;27:329–337. PubMed 32852924
  2. Clase CM, Carrero JJ, Ellison DH, et al. Potassium homeostasis and management of dyskalemia in kidney diseases: conclusions from a KDIGO Controversies Conference. Kidney Int. 2020;97:42–61. PubMed 31706619
  3. Montague BT, Ouellette JR, Buller GK. Retrospective review of the frequency of ECG changes in hyperkalemia. Clin J Am Soc Nephrol. 2008;3:324–330. PubMed 18235147
  4. Harel Z, Kamel KS. Optimal dose and method of administration of intravenous insulin in the management of emergency hyperkalemia: a systematic review. PLoS One. 2016;11:e0154963. PubMed 27148740
  5. Apel J, Reutrakul S, Baldwin D. Hypoglycemia in the treatment of hyperkalemia with insulin in patients with end-stage renal disease. Clin Kidney J. 2014;7:248–250. PubMed 25852884
  6. Allon M, Dunlay R, Copkney C. Nebulized albuterol for acute hyperkalemia in patients on hemodialysis. Ann Intern Med. 1989;110:426–429. PubMed 2919849
  7. Noel JA, Bota SE, Petrcich W, et al. Risk of hospitalization for serious adverse gastrointestinal events associated with sodium polystyrene sulfonate use in patients of advanced age. JAMA Intern Med. 2019;179:1025–1033. PubMed 31180477
  8. Kosiborod M, Rasmussen HS, Lavin P, et al. Effect of sodium zirconium cyclosilicate on potassium lowering for 28 days among outpatients with hyperkalemia: the HARMONIZE randomized clinical trial. JAMA. 2014;312:2223–2233. PubMed 25402495
  9. Gumz ML, Rabinowitz L, Wingo CS. An integrated view of potassium homeostasis. N Engl J Med. 2015;373:60–72. PubMed 26132942
  10. Gay E, Levy N, eds. Toxicology; Acid-Base Disorders; Potassium Disorders; IV Fluids & Electrolyte Repletion; Adrenal Disorders. In: Department of Medicine Housestaff Manual, 30th ed. 2024:65, 103, 105, 107, 182.
  11. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney Int. 2024;105(4S):S117–S314. PubMed 38490803
  12. Chan BS, Buckley NA. Digoxin-specific antibody fragments in the treatment of digoxin toxicity. Clin Toxicol (Phila). 2014;52:824–836. PubMed 25089630

For education only; not a substitute for clinical judgment or local protocols. Where sources differ, the flowchart follows the current guideline.

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