What is the treatment for severe hyperglycemia (high blood sugar) with a glucose level over 500 mg/dL?

Treatment of Severe Hyperglycemia with Glucose >500 mg/dL

For severe hyperglycemia with glucose levels over 500 mg/dL, immediate intravenous insulin infusion is the most appropriate treatment, followed by transition to a basal-bolus insulin regimen once stabilized. 1

Initial Management

Immediate Treatment

• Start continuous intravenous regular insulin infusion:
  • Adult patients: Initial IV bolus of regular insulin at 0.15 units/kg body weight, followed by continuous infusion at 0.1 unit/kg/hour (typically 5-7 units/hour) 2
  • Pediatric patients: No initial bolus; start continuous infusion at 0.1 unit/kg/hour 2
  • Monitor glucose every 30 minutes to 2 hours until stable 1

Fluid Replacement

• Initiate aggressive fluid replacement:
  • Start with isotonic saline (0.9% NaCl) at 10-20 mL/kg/hour for the first hour 2
  • In severely dehydrated patients, this may need to be repeated, but initial rehydration should not exceed 50 mL/kg over first 4 hours 2
  • After initial rehydration, switch to 0.45-0.9% NaCl (depending on serum sodium) 2

Electrolyte Management

• Monitor and replace potassium:
  • Once renal function is confirmed and serum potassium is known, add 20-40 mEq/L potassium to IV fluids 2
  • Monitor for hypokalemia, which is common during treatment of hyperglycemic crises 1

Monitoring During Treatment

• Check blood glucose every 30 minutes to 2 hours during IV insulin therapy 1
• Monitor electrolytes, especially potassium, every 2-4 hours 2
• Assess mental status regularly to identify complications 2
• Target glucose range: 140-180 mg/dL for most patients 2

Transition from IV to Subcutaneous Insulin

1. Calculate total daily dose (TDD) based on average insulin infusion rate over previous 12 hours 1
2. Administer subcutaneous insulin 1-2 hours before discontinuing IV insulin to prevent rebound hyperglycemia 1
3. Convert to basal insulin at 60-80% of the daily infusion dose 1
4. Implement basal-bolus regimen (not sliding scale alone) 1
   • 50% as basal insulin (long-acting)
   • 50% as prandial insulin (rapid-acting) divided between meals 1

Maintenance Regimen

• Basal-bolus insulin regimen:

  • Basal insulin: Once-daily long-acting insulin
  • Prandial insulin: Rapid-acting insulin before meals (starting with 4-6 units per meal) 1
  • Correction doses: Additional insulin based on pre-meal glucose readings 1

• Target glucose range:

  • 140-180 mg/dL for most hospitalized patients 2
  • More stringent goals (110-140 mg/dL) may be appropriate for selected patients if achievable without significant hypoglycemia 2

Common Pitfalls to Avoid

1. Relying solely on sliding-scale insulin - This reactive approach treats hyperglycemia after it occurs rather than preventing it 1

2. Improper transition from IV to subcutaneous insulin - Can lead to rebound hyperglycemia; always overlap subcutaneous and IV insulin by 1-2 hours 1

3. Inadequate total insulin dose - Failure to adjust both basal and bolus components leads to poor glucose control 1

4. Too rapid correction of glucose - May lead to cerebral edema, especially in pediatric patients 2

5. Neglecting potassium monitoring - Insulin therapy can cause hypokalemia 3

Special Considerations

• For patients with glucose >500 mg/dL but who are clinically stable with mild symptoms, outpatient management with subcutaneous insulin may be considered 2

• For patients with diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS), additional specific protocols should be followed 2

• Patients with severe hyperglycemia should be evaluated for precipitating factors such as infection, medication non-adherence, or new-onset diabetes 3

Remember that severe hyperglycemia (>500 mg/dL) represents a medical emergency that requires prompt treatment to prevent life-threatening complications. The cornerstone of management is insulin therapy, fluid replacement, and careful monitoring.