Hyperkalemia.
One of the few emergencies where order matters as much as the drugs: protect the heart, shift potassium into cells, then remove it from the body.
Reviewed June 2026 · verify against current guidelines
Diagnosis & Workup
Recognize. Confirm. Stage.
Confirm first
- Repeat sample if >5.5 and patient asymptomatic.
- Rule out pseudohyperK: hemolysis, fist clenching, ↑ WBC or platelets.
Severity by K and ECG
| Mild | K 5.5-6.0. Usually no ECG. Manage cause. |
|---|---|
| Moderate | K 6.0-6.5 OR peaked T waves. Treat now. |
| Severe | K >6.5 OR any ECG change (PR ↑, QRS wide, sine wave). Emergency. |
ECG progression
- Peaked T waves → PR prolongation + QRS widening → loss of P waves → sine wave → VF / asystole.
- Atypical: bradycardia, junctional rhythm, Brugada-like pattern.
ECG severity does not always track with K level. Treat the rhythm, not the number alone.
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Acute Management
First moves. First hours.
1) Stabilize the membrane
| Calcium gluconate | 1-2 g IV over 5-10 min. Repeat in 5 min if ECG unchanged. Onset 1-3 min. |
|---|---|
| Calcium chloride | 1 g IV via central line. 3× elemental Ca per gram. Reserved for arrest or peripheral failure. |
2) Shift K into cells
| Insulin + dextrose | Regular 10 U IV with D50 25-50 g. Onset 15-30 min. Recheck glucose q1h × 6 h. |
|---|---|
| Albuterol nebulized | 10-20 mg neb (4-8× standard dose). Onset 30 min. Additive to insulin. |
| Bicarbonate | Only if metabolic acidosis (pH <7.2). Limited K-shifting in isolation. |
3) Remove K from body
| Loop diuretic | Furosemide 40-80 mg IV if euvolemic / fluid-tolerant. Slow onset. |
|---|---|
| SZC | Sodium zirconium cyclosilicate 10 g PO × 3 doses in 48 h. Faster than patiromer acutely. |
| Patiromer | 8.4 g PO daily. Slower onset; favored for chronic management. |
| Hemodialysis | Definitive. Indicated if refractory, ESRD, severe acidosis, oliguric AKI. |
Pitfalls & Disposition
What gets missed.
Common errors
- Giving insulin without dextrose. Check glucose first; risk of hypoglycemia 6-12 h later.
- Relying on SPS / kayexalate alone: slow, modest K drop, risk of colonic necrosis.
- Treating the K number without addressing the cause (AKI, ACEi, K-sparing diuretic, rhabdo, TLS).
- Missing digoxin toxicity in hyperK: avoid IV calcium if dig-toxic; give DigiFab.
Disposition
| Discharge OK | Mild, no ECG change, cause reversed, K trending down, reliable follow-up. |
|---|---|
| Admit / obs | Moderate or required treatment; ECG monitoring. |
| ICU | Severe, ECG changes, arrest, or needs dialysis. |
Refractory hyperK with ECG changes or arrest: dialysis is the only definitive therapy. Call early.
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Sources
Verify against current guidelines and local protocol before acting.
- KDIGO Clinical Practice Guideline on Potassium Management (2024).
- ENERGIZE trial (SZC in ED). 2020.
- EMCrit Internet Book of Critical Care: Hyperkalemia.
Downloads
Every card for this topic — carousels and tables, print-ready for the wards or for sharing.
