Is 300 units of intravenous (IV) insulin safe for an insulin overdose?

Management of Insulin Overdose

300 units of IV insulin is not an appropriate treatment for insulin overdose; rather, it would constitute a massive overdose itself requiring immediate intervention.

Understanding Insulin Overdose

Insulin overdose is a medical emergency that requires prompt recognition and treatment to prevent severe hypoglycemia and its potentially life-threatening complications. The management focuses on:

1. Correcting hypoglycemia
2. Maintaining euglycemia
3. Monitoring for complications
4. Providing supportive care

First-Line Treatment

The cornerstone of insulin overdose management is intravenous glucose administration:

• Continuous IV glucose infusion (10% or 20% dextrose) should be initiated immediately 1
• Frequent blood glucose monitoring (every 15-30 minutes initially) 2
• Titrate glucose infusion to maintain blood glucose levels between 100-160 mg/dL 3

Treatment Protocol

1. Initial stabilization:

   • Establish IV access
   • Begin 10% or 20% dextrose infusion
   • Monitor vital signs continuously

2. Glucose management:

   • Target blood glucose: 100-160 mg/dL 3
   • Adjust dextrose infusion rate based on glucose levels
   • Expect prolonged treatment (median 94 hours, range 12-721 hours) 4

3. Monitoring requirements:

   • Blood glucose: Initially every 15 minutes until stable, then every 30-60 minutes 2
   • Serum potassium: Every 2-4 hours (insulin causes potassium to shift into cells) 2
   • Cardiac monitoring: Watch for arrhythmias related to electrolyte disturbances 4
   • Liver function tests: Monitor for hepatic disturbances 4

Adjunctive Therapies

If hypoglycemia is refractory to IV glucose alone, consider:

1. Glucagon:

   • Bolus: 3-10 mg IV over 3-5 minutes
   • Followed by infusion: 3-5 mg/hour (0.05-0.15 mg/kg/hour) 2
   • Note: May cause vomiting; protect airway in patients with CNS depression

2. Octreotide: Has been reported beneficial in case reports 4

3. Surgical excision: Of the injection site (if identified and if subcutaneous injection) 1

4. Oral complex carbohydrates: If patient is conscious and able to eat 4

Common Complications to Monitor

• Cerebral impairment: Present in 73% of cases 4
• Hypokalemia: Occurs in 49% of cases 4
  • Target potassium levels: 2.5-2.8 mEq/L (avoid aggressive repletion) 2
• Other electrolyte disturbances: 42% of cases 4
• Hepatic disturbances: 7% of cases 4
• Cardiac toxicity: 9% of cases 4

Duration of Treatment

• Hospitalization is typically required for 3-4 days (median 94 hours) 4
• One-third of patients require ICU admission 4
• Effects of long-acting insulin analogs may persist for 48-96 hours 1

Special Considerations

• For patients on insulin pumps: Disconnect the pump immediately
• For intentional overdoses: Psychiatric evaluation is essential once medically stable
• For accidental overdoses: Education on proper insulin administration before discharge

Prognosis

With appropriate treatment, most patients recover completely. However, complications can include:

• Hypoglycemic encephalopathy (rare)
• Death (very rare with proper treatment) 4

Remember that insulin overdose is a medical emergency requiring immediate intervention. The treatment is resource-intensive and may require several days of continuous glucose infusion and monitoring.