Normal Reference Ranges
Adult
3.5 - 5.0 mEq/L
Pediatric
3.5 - 5.5 mEq/L
Clinical Significance
Major intracellular cation. Extremely critical for cardiac action potential. Abnormal levels can precipitate life-threatening arrhythmias (VT/VF).
Causes of High
- Acute/Chronic renal failure
- ACE inhibitors/ARBs
- Spironolactone
- Acidosis
- Cell lysis (tumor lysis, rhabdomyolysis)
Causes of Low
- Diuretics (loop, thiazide)
- Vomiting/Diarrhea
- Alkalosis
- Insulin therapy
- Hyperaldosteronism