What is the proper mixing of insulin in pediatric hyperkalemia?

Proper Mixing of Insulin in Pediatric Hyperkalemia

For pediatric hyperkalemia treatment, insulin should be administered at a dose of 0.1 unit/kg with 400 mg/kg of glucose, maintaining a ratio of 1 unit of insulin for every 4 grams of glucose. 1

Insulin and Glucose Preparation

Insulin Dosing

• Use regular insulin at 0.1 unit/kg IV with 400 mg/kg of glucose 1
• Maintain the critical ratio of 1 unit of insulin for every 4 grams of glucose to prevent hypoglycemia 1
• Do not administer an initial insulin bolus in pediatric patients, unlike in adults 1

Glucose Preparation

• For D10W: Use 4 mL/kg to deliver 400 mg/kg of glucose
• For D25W: Use 1.6 mL/kg to deliver 400 mg/kg of glucose
• For D50W: Use 0.8 mL/kg to deliver 400 mg/kg of glucose
  • Note: D50W is irritating to veins; dilution to D25W is preferable 1

Administration Protocol

1. Verify hyperkalemia with a second sample to rule out fictitious hyperkalemia from hemolysis during phlebotomy 1
2. Assess ECG and cardiac rhythm for signs of cardiac toxicity (widening QRS complex, peaked T waves)
3. Prepare insulin and glucose solution according to the 1:4 ratio (insulin:glucose in grams)
4. Administer simultaneously via IV route
5. Monitor blood glucose levels hourly for at least 4-6 hours after administration to detect hypoglycemia 2
6. Monitor serum potassium to assess treatment efficacy

Special Considerations

Severe Hyperkalemia (K+ > 7.0-7.5 mEq/L or ECG changes)

For symptomatic or severe hyperkalemia requiring more intense intervention:

• Continue with insulin/glucose as described above
• Consider additional therapies:
  • Sodium bicarbonate (1-2 mEq/kg IV push) to induce potassium shift into cells
  • Calcium gluconate (100-200 mg/kg/dose) via slow infusion with ECG monitoring for life-threatening arrhythmias 1
  • Note: Do not administer sodium bicarbonate and calcium through the same line 1

Hypoglycemia Prevention

• The risk of hypoglycemia is significant (approximately 20% of patients) 3
• Risk factors for hypoglycemia include:
  • Low pretreatment glucose
  • No history of diabetes mellitus
  • Female gender
  • Abnormal renal function
  • Lower body weight 2
• Consider using D10W infusion rather than D50W bolus to reduce hypoglycemia risk 4
• Monitor glucose levels hourly for at least 4-6 hours after insulin administration 2

Monitoring Parameters

• Blood glucose: Monitor hourly for at least 4-6 hours after insulin administration
• Serum potassium: Recheck 1-2 hours after treatment
• ECG: Monitor continuously in severe cases
• Fluid status: Ensure adequate hydration

Common Pitfalls

1. Insufficient glucose administration: Always maintain the 1:4 ratio of insulin units to glucose grams
2. Inadequate monitoring: Failure to monitor glucose levels can miss hypoglycemia
3. Improper dilution: D50W should be diluted for pediatric use to prevent vein irritation
4. Delayed treatment: Severe hyperkalemia requires immediate intervention
5. Forgetting to verify hyperkalemia: Always confirm with a second sample to rule out spurious results

By following this protocol, pediatric hyperkalemia can be effectively managed while minimizing the risk of treatment-related complications, particularly hypoglycemia.