Hyperkalemia Treatment: Insulin Dosing
For acute hyperkalemia treatment, administer 10 units of regular insulin IV with 25 grams of glucose (50 mL of D50W) over 15-30 minutes, which lowers potassium by approximately 0.8 mmol/L within 60 minutes. 1, 2
Standard Adult Protocol
The insulin-to-glucose ratio is critical: 1 unit of insulin for every 2.5 grams of glucose 1. This translates to:
- Insulin dose: 10 units regular insulin IV 1, 2
- Glucose dose: 25 grams (50 mL of D50W) 1, 2
- Administration time: Over 15-30 minutes 1, 2
- Expected effect: Potassium reduction of ~0.8 mmol/L at 60 minutes 1, 2
Alternative Dosing for Severe Hyperkalemia
For patients with severe hyperkalemia (K+ >6.5 mmol/L) or marked ECG changes (prolonged PR interval, wide QRS complex), consider 20 units of regular insulin infused over 60 minutes with 60 grams of glucose 3. However, this higher dose carries substantially increased hypoglycemia risk without statistically significant improvement in potassium reduction compared to the standard 10-unit dose 3.
Reduced Dose Considerations
Lower insulin doses (5 units) are NOT recommended as standard therapy despite theoretical hypoglycemia reduction 4, 5. The evidence shows:
- 5 units produces similar potassium reduction in mild-moderate hyperkalemia 5, 6
- However, 5 units is significantly less effective when baseline K+ >6.0 mmol/L (difference of -0.238 mmol/L compared to 10 units, p=0.018) 6
- The hypoglycemia reduction with 5 units was not statistically significant (9.2% vs 19.5%, p=0.052) 5
Given the life-threatening nature of severe hyperkalemia, the standard 10-unit dose should be used unless the patient has specific high-risk features for hypoglycemia 1, 2.
Pediatric Dosing
For children, use weight-based dosing: 0.1 unit/kg of regular insulin IV with 400 mg/kg of glucose 1, 2. The insulin-to-glucose ratio for pediatrics is 1 unit per 4 grams of glucose, reflecting higher hypoglycemia risk in this population 1.
Use D10W exclusively for pediatric patients 1.
Glucose Solution Selection
- D50W is standard for adults 1, 2
- Dilution to D25W is preferable when feasible to reduce vein irritation 1, 2
- D10W infusion (250 mL over 1 hour) is an acceptable alternative to D50 bolus, with equivalent hypoglycemia rates (22% vs 26%, p=0.77) and may be preferred during D50 shortages 7
Critical Monitoring Requirements
Monitor glucose levels at these specific intervals 2:
- 1-2 hours after administration 2
- Every hour for 4-6 hours after insulin administration 1, 2
- Recheck potassium when insulin effect wanes at 4-6 hours to detect rebound hyperkalemia 1, 2
High-Risk Populations for Hypoglycemia
Patients at increased hypoglycemia risk include those with 4:
- Low pretreatment glucose
- No history of diabetes mellitus
- Female gender
- Abnormal renal function
- Lower body weight
For these patients, consider administering 50 grams of glucose instead of 25 grams with the standard 10-unit insulin dose 3, 4.
Critical Errors to Avoid
- NEVER administer insulin without glucose in hyperkalemia treatment—this dramatically increases hypoglycemia risk 1
- NEVER use 50 units of insulin—this is 5 times the standard dose and causes severe, potentially fatal hypoglycemia 2
- NEVER add potassium to insulin infusions—keep insulin and potassium on separate lines to allow independent titration 8
- Remember insulin's effect is temporary—definitive potassium removal strategies (dialysis, diuretics, potassium binders) must be implemented concurrently 1, 2
Special Clinical Scenario: Malignant Hyperthermia
In malignant hyperthermia specifically, use glucose 50 mL of 50% solution with 10 units of insulin for hyperkalaemia treatment 9. Intravenous calcium should only be used in extremis in this context, as calcium influx may worsen myoplasmic calcium overload 9.