What is the recommended dose of insulin (regular insulin) for treating hyperkalemia?

Insulin Dose for Hyperkalemia

The recommended dose is 10 units of regular insulin IV with 25 grams of glucose (50 mL of D50W) over 15-30 minutes for adults, which effectively lowers potassium by approximately 0.8 mmol/L within 60 minutes. 1

Standard Adult Dosing Protocol

• Administer 10 units of regular insulin IV as the standard dose for hyperkalemia treatment 1
• Give with 25 grams of glucose (50 mL of D50W) over 15-30 minutes 1
• The insulin-to-glucose ratio is 1 unit of insulin for every 2.5 grams of glucose 1
• This regimen produces a mean potassium reduction of 0.78-0.79 mmol/L at 60 minutes 2

Higher Dose Regimen for Severe Cases

• For severe hyperkalemia (K+ >6.5 mEq/L) or marked ECG changes, consider 20 units of regular insulin infused over 60 minutes with 60 grams of glucose 1, 2
• This higher dose carries increased hypoglycemia risk without significant improvement in potassium reduction compared to the standard 10-unit dose 1
• The 20-unit regimen produces a mean potassium reduction of 0.79 mmol/L at 60 minutes, statistically equivalent to the 10-unit dose (P = 0.98) 2

Lower Dose Considerations

• Lower insulin doses (5 units) are not recommended as standard therapy due to reduced effectiveness in severe hyperkalemia 1
• The 5-unit dose produces 0.238 mmol/L less potassium reduction compared to 10 units in patients with K+ >6 mmol/L (P = 0.018) 3
• However, 5 units may be considered in high-risk populations for hypoglycemia, though this requires more frequent monitoring 4, 5

Pediatric Dosing

• For children, use weight-based dosing: 0.1 unit/kg of regular insulin IV with 400 mg/kg of glucose 1
• The insulin-to-glucose ratio for pediatric patients is 1 unit of insulin for every 4 grams of glucose, reflecting higher hypoglycemia risk 1
• Use D10W exclusively for pediatric patients 1

Glucose Administration Strategy

• D50W is standard for adults, but dilution to D25W is preferable when feasible 1
• For high-risk populations (low pretreatment glucose, no diabetes history, female gender, abnormal renal function, lower body weight), consider administering 50 grams of glucose instead of 25 grams with the standard 10-unit insulin dose 1, 5
• Never administer insulin without glucose, as this dramatically increases hypoglycemia risk 1

Critical Monitoring Requirements

• Monitor blood glucose hourly for at least 4-6 hours after insulin administration, as insulin's effect may exceed dextrose duration 1, 5
• Recheck potassium levels as the insulin effect wanes after 4-6 hours and rebound hyperkalemia can occur 1
• The onset of potassium-lowering effect begins at approximately 30 minutes, with peak effect at 60 minutes 6

Evidence Comparison: Bolus vs Infusion

• No statistically significant difference exists in potassium reduction between insulin administered as a bolus versus infusion 2
• Bolus administration of 10 units produces equivalent potassium reduction (0.78 mmol/L) compared to 20-unit infusion over 60 minutes (0.79 mmol/L, P = 0.98) 2
• Bolus administration is simpler and equally effective, making it the preferred method for emergency management 2

Hypoglycemia Risk Mitigation

• Almost one-fifth of patients experience hypoglycemia with insulin therapy for hyperkalemia 2
• Risk factors include low baseline glucose, no diabetes history, female sex, renal insufficiency, and lower body weight 5
• The 10-unit dose causes hypoglycemia in 19.5% of patients versus 9.2% with 5 units (P = 0.052), though this difference is not statistically significant 4
• Administer sufficient glucose: 60 grams with 20 units of insulin and 50 grams with 10 units to prevent hypoglycemia 2, 5

Common Pitfalls to Avoid

• Never administer insulin without concurrent glucose administration 1
• Do not rely on insulin alone—it is a temporizing measure that does not remove potassium from the body 1, 6
• Remember that definitive potassium removal strategies (dialysis, diuretics, potassium binders) must be implemented concurrently 1
• Avoid using lower insulin doses (5 units) in severe hyperkalemia (K+ >6 mmol/L) as they are less effective 3