What is the appropriate dose of short-acting insulin (e.g. aspart or lispro) for a patient with hyperglycemia (blood sugar level of 479 mg/dL)?

Management of Severe Hyperglycemia with Blood Sugar of 479 mg/dL

For a blood sugar of 479 mg/dL, an appropriate initial dose of short-acting insulin (aspart or lispro) would be 0.1 units/kg or approximately 7-10 units administered subcutaneously. 1

Initial Assessment and Management

• Evaluate for symptoms of hyperglycemic crisis (polyuria, polydipsia, nausea, vomiting, abdominal pain, altered mental status) as severe hyperglycemia may indicate diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state 1
• Check for signs of dehydration, electrolyte abnormalities, and acidosis in patients with severe hyperglycemia 1
• Consider checking venous pH, electrolytes, and anion gap if DKA is suspected with this level of hyperglycemia 1

Insulin Dosing Approach

• For insulin-naive patients with severe hyperglycemia (479 mg/dL), start with 0.3-0.5 units/kg total daily insulin dose, with half as basal insulin and half as prandial/correctional insulin 1
• For patients already on insulin, use 10-20% of total daily dose or 0.1 units/kg as correction dose for this level of hyperglycemia 1
• Rapid-acting insulin (lispro, aspart, or glulisine) should be administered subcutaneously every 4 hours for correctional coverage of severe hyperglycemia 2

Follow-up Management

• After initial correction dose, implement a basal-bolus insulin regimen with basal insulin (glargine or detemir) once or twice daily and prandial insulin before meals 1
• Monitor blood glucose every 2-4 hours until stable with this level of hyperglycemia 1
• If blood glucose remains >180 mg/dL after initial dose, consider additional correction dose 1

Special Considerations

• For hospitalized patients with this level of hyperglycemia, target blood glucose range should be 140-180 mg/dL 2
• If subcutaneous insulin is ineffective at controlling this severe hyperglycemia, consider intravenous insulin infusion, particularly in critically ill patients 2
• Evaluate hydration status and provide IV fluids if needed, as severe hyperglycemia can cause significant dehydration 1
• For patients receiving enteral nutrition, approximately 1 unit of rapid-acting insulin per 10-15g carbohydrate should be given subcutaneously before each feeding, in addition to correctional insulin 2

Pitfalls and Caveats

• Avoid rapid correction that might lead to hypoglycemia; hyperglycemia itself can reduce glucose uptake and contribute to insulin resistance 1, 3
• Prolonged hyperglycemia increases infection risk through impairment of host defenses, including decreased polymorphonuclear leukocyte mobilization, chemotaxis, and phagocytic activity 4
• When using insulin lispro for correction, remember it has a faster onset (peak serum concentration is three times higher than regular insulin) and shorter duration of action (half as long as regular insulin) 5, 6
• For patients on glucocorticoid therapy with severe hyperglycemia, higher doses of prandial and correctional insulin may be needed in addition to basal insulin 2