What is the immediate treatment for hyperkalemia?

Immediate Treatment for Hyperkalemia

The immediate treatment for hyperkalemia requires a three-step approach: cardiac membrane stabilization with intravenous calcium, shifting potassium into cells with insulin/glucose and albuterol, and eliminating potassium from the body through diuretics or potassium binders. 1

Assessment of Severity

• Hyperkalemia is classified as mild (5.0-5.9 mEq/L), moderate (6.0-6.4 mEq/L), or severe (≥6.5 mEq/L) 1, 2
• ECG changes (peaked T waves, flattened P waves, prolonged PR interval, widened QRS) indicate urgent treatment regardless of potassium level 1, 2
• Severe hyperkalemia (≥6.5 mEq/L) is life-threatening and requires immediate intervention 1

Step 1: Cardiac Membrane Stabilization

• Administer intravenous calcium to protect the heart from arrhythmias:
  • Calcium chloride (10%): 5-10 mL (500-1000 mg) IV over 2-5 minutes, OR
  • Calcium gluconate (10%): 15-30 mL IV over 2-5 minutes 1, 2
• Effects begin within 1-3 minutes but are temporary (30-60 minutes) 1
• Important: Calcium does not lower serum potassium but protects against arrhythmias 1
• Caution: In patients with malignant hyperthermia, calcium should only be used in extreme cases as it may contribute to calcium overload of the myoplasm 2

Step 2: Shift Potassium into Cells

• Administer insulin with glucose:
  • 10 units regular insulin IV with 25g glucose (50 mL of D50W) over 15-30 minutes 1
  • Onset within 15-30 minutes, effect lasts 4-6 hours 1, 2
• Add nebulized albuterol: 10-20 mg over 15 minutes 1
• Consider sodium bicarbonate (50 mEq IV over 5 minutes) if concurrent metabolic acidosis is present 1, 2
  • Most effective in patients with metabolic acidosis (pH < 7.35, bicarbonate < 22 mEq/L) 2

Step 3: Eliminate Potassium from Body

• For patients with adequate renal function, administer loop diuretics:
  • Furosemide: 40-80 mg IV 1, 2
• Consider cation exchange resins:
  • Sodium polystyrene sulfonate (Kayexalate): 15-50 g orally or rectally with sorbitol 1
  • Newer potassium binders (patiromer, sodium zirconium cyclosilicate) are safer alternatives 1, 2
• For severe hyperkalemia, especially in patients with renal failure, initiate hemodialysis 1, 2

Important Clinical Considerations

• Temporary measures (insulin/glucose, albuterol) provide only transient effects (1-4 hours) 1
• Rebound hyperkalemia can occur after 2 hours; monitor potassium levels closely 1
• Review and adjust medications that may contribute to hyperkalemia (ACE inhibitors, ARBs, MRAs, NSAIDs, beta-blockers) 1, 2
• The effectiveness of standard therapies is based on small studies and traditional practice patterns 3
• Chronic hyperkalemia requires a different management approach focusing on underlying causes 4

Common Pitfalls and Caveats

• Failure to recognize ECG changes may lead to delayed treatment and fatal arrhythmias 5
• Not administering calcium when ECG changes are present increases risk of cardiac complications 1, 5
• Administering insulin without glucose can cause severe hypoglycemia 6
• Rebound hyperkalemia after temporary treatments requires close monitoring 1
• Sodium polystyrene sulfonate can cause intestinal necrosis; newer binders are safer 2
• Potassium-lowering agents should be initiated early to prevent rebound 1