Hyperkalemia

Author: Michelle Lin, MD
Updated: 3/12/2010

Hyperkalemia

Potassium regulation

  • Internal K shift: modulated by insulin, catecholamines, acid-base status
  • Total body K elimination: By kidney (95%) and gut (5%)

Adverse effects of hyperkalemia

  • Cardiac: Peaked T, wide QRS, loss of P wave, sine wave; although ventricular fibrillation may be first cardiac manifestation
  • Neuromuscular: Paresthesias,weakness
  • Metabolic: Mild hyperchloremic metabolic acidosis

Treatment of hyperkalemia

Mechanism: Cardiac membrane stabilization

  • Calcium: Reduces threshold potential in myocytes; check to be sure not on digoxin
  • Hypertonic saline: Only for severe hyponatremia in setting of hyperkalemia

Mechanism: K redistribution

  • Insulin: Drives K intracellularly and drops serum K level by 0.6 mmol/L
  • Beta-agonist: Drives K intracellularly and 10 mg albuterol drops serum K level by 0.6 mmol/L (20 mg --> K drops by 1 mmol/L); effective in only 60% of patients

Mechanism: K elimination via kidney/gut

  • Bicarbonate: drives K out at distal nephron; best as infusion x 4-6 hrs
  • Loop diuretic
  • Exchange resin (sodium polystyrene sulfonate): Of minimal to no benefit.
    • Case reports of colonic necrosis
Agent Dose Onset Duration Complication
MEMBRANE STABILIZATION
Ca gluconate 10% 10 mL over 10 min Immediate 30-60 min Hypercalcemia
Hypertonic 3% NaCl 50 mL IV push Immediate Unknown Volume overload, hypertonicity
REDISTRIBUTION
Insulin 10 units IVP with D50W 20 min 4-6 hr Hypoglycemia
Albuterol nebulized 20 mg/4 cc over 10 min 30 min 2 hrs Tachycardia
ELIMINATION
Loop diuretic Furosemide 40-80 mg IV 15 min 2-3 hr Volume depletion
Sodium bicarbonate 150 mmol/L IV Hours Infusion Metabolic alkalosis, volume overload
Kayexalate 15-30 g >2 hrs 4-6 hr Variable efficacy
Hemodialysis Immediate 3 hrs Arrhythmias

References

  • Weisberg LS. Management of severe hyperkalemia. Crit Care Med. 2008; 36:3246-51. [PubMed]