What is the appropriate dose of regular insulin for a patient with a blood glucose level of hyperglycemia?

Regular Insulin Dosing for Blood Glucose of 362 mg/dL

For a hospitalized patient with blood glucose of 362 mg/dL, administer 10-15 units of regular insulin subcutaneously as a correction dose, with the specific amount depending on the patient's insulin sensitivity and whether they are already on a basal insulin regimen.

Correction Insulin Dosing Algorithm

For patients who are NPO or have poor oral intake:

• Administer supplemental regular insulin in 5-unit increments for every 50 mg/dL increase above 150 mg/dL 1
• For blood glucose of 362 mg/dL (212 mg/dL above 150 mg/dL), this calculates to approximately 20 units of regular insulin 1
• However, this maximum dose should be reduced if the patient has risk factors for hypoglycemia (age >65 years, renal failure, poor oral intake) 2

For patients with adequate oral intake on a basal-bolus regimen:

• Use the 1500 Rule for regular insulin to calculate sensitivity factor: 1500 ÷ total daily insulin dose = mg/dL drop per unit 3
• For example, if total daily dose is 50 units: 1500 ÷ 50 = 30 mg/dL drop per unit
• Target correction to 150 mg/dL: (362 - 150) ÷ 30 = approximately 7 units of correction insulin 3

Critical Considerations Before Dosing

Assess for diabetic ketoacidosis (DKA):

• If blood glucose >300 mg/dL with symptoms of hyperglycemia or catabolic features, consider immediate correction insulin 1
• If DKA is present, continuous intravenous insulin infusion is preferred over subcutaneous dosing 2

Evaluate the patient's current insulin regimen:

• If the patient is insulin-naive with blood glucose >300 mg/dL, consider starting a basal-plus regimen rather than correction insulin alone 2
• Initial total daily dose should be 0.3-0.5 units/kg for insulin-naive patients, with lower doses (0.1-0.25 units/kg) for those at high risk of hypoglycemia 2

Timing and Monitoring

Administration schedule:

• Regular insulin should be given subcutaneously every 6 hours for hyperglycemia correction in non-DKA patients 1
• Onset of action is 15 minutes to 1.2 hours, peak effect at 3-4 hours, duration 6-8 hours 4

Mandatory monitoring:

• Check blood glucose 4-6 hours after regular insulin administration to assess response 1
• If blood glucose remains >250 mg/dL at 4-6 hours, additional correction insulin may be needed 1
• Reduce or hold insulin if blood glucose falls below 100 mg/dL 2

Common Pitfalls to Avoid

Never use sliding-scale insulin alone as the sole method of treatment:

• Sliding-scale insulin is strongly discouraged and associated with poor glycemic control 2
• A basal-plus or basal-bolus regimen is required for adequate glycemic control 2

Avoid insulin stacking:

• Do not administer additional correction insulin if the previous dose is still active (within 4-6 hours for regular insulin) 1
• This creates dangerous overlap and significantly increases hypoglycemia risk 1

Account for reduced insulin requirements:

• Patients already on home insulin doses ≥0.6 units/kg/day should have a 20% reduction in total daily dose during hospitalization to prevent hypoglycemia 2
• Adjust downward for elderly patients, renal dysfunction, or poor oral intake 2

Transition to Scheduled Insulin Therapy

If this is not an isolated hyperglycemic episode:

• Calculate total daily insulin needs based on 0.4 units/kg (or 0.3 units/kg if high hypoglycemia risk) 2, 3
• Divide 50% as basal insulin and 50% as prandial insulin across three meals 2
• Continue correction insulin with meals using the sensitivity factor calculation 3