Key Points
- Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
- Use system-specific risk tools to guide testing and disposition.
- Order high-yield tests first; escalate imaging when indicated.
- Start evidence-based initial therapy and reassess frequently.
Algorithm
- Primary survey and vitals; IV access and monitors.
- Focused history/physical; identify red flags and likely etiologies.
- Order system-appropriate labs and imaging (see Investigations).
- Initiate guideline-based empiric therapy (see Pharmacology).
- Reassess response; arrange consultation and definitive management.
Clinical Synopsis & Reasoning
Hyperkalemia threatens membrane excitability and cardiac conduction; verify with repeat lab and evaluate for hemolysis. Assess ECG for peaked T waves, QRS widening, and sine‑wave morphology; identify precipitants such as renal failure, tissue breakdown, and RAAS‑inhibiting drugs.
Treatment Strategy & Disposition
Stabilize myocardium with IV calcium for ECG changes, shift K⁺ intracellularly with insulin–dextrose and β‑agonists, and enhance elimination via loop diuretics, potassium binders, or dialysis when appropriate. Address causative agents and correct metabolic acidosis. Admit for ECG changes, ongoing tissue breakdown, or need for continuous monitoring; otherwise arrange timely outpatient follow‑up and medication reconciliation.
Epidemiology / Risk Factors
- Varies by presentation; age/comorbidities matter
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|---|---|---|
| CBC/BMP | Baseline labs | Abnormalities | |
| CXR/targeted imaging | Common ED complaints | Findings vary | |
| Troponin/EKG (chest pain) | ACS rule-out | MI changes | Use risk tools |
ECG Progression (Typical)
| K level (mEq/L) | ECG Finding |
|---|---|
| 5.5–6.5 | Peaked T waves |
| 6.5–7.5 | PR prolongation, QRS widening |
| >7.5 | Sine-wave, VF/asystole risk |
Pharmacology
| Medication | Mechanism | Onset | Role in Therapy | Limitations |
|---|---|---|---|---|
| Insulin + dextrose | Cellular K⁺ shift | Minutes | Temporizing | Hypoglycemia; ED use |
| Calcium gluconate (IV) | Myocardial membrane stabilization | Minutes | ECG changes or K ≥6.5 | Extravasation risk; ED use |
| Albuterol (neb) | β2-agonist | Minutes | Adjunct shift | Tachycardia; ED use |
| Sodium bicarbonate (IV) | Buffers acidosis | Minutes | If severe acidemia | Volume/Na load; ED use |
| Loop diuretic / dialysis | K⁺ removal | Hours | Definitive removal | Volume depletion / access; ED use |
Prognosis / Complications
- Outcomes tied to emergency and timeliness of care
Patient Education / Counseling
- Explain red flags and when to seek emergent care.
- Reinforce medication adherence and follow-up plan.
Notes
Calcium chloride provides more elemental calcium but requires central line; gluconate is safer peripherally. Watch for rebound hyperkalemia after shifts.
References
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