How to manage hyperglycemia of 380 mg/dL 2.5 hours postprandially in a patient on insulin with a 1:6 carb ratio?

Management of Postprandial Hyperglycemia with Correction Insulin

For a blood glucose of 380 mg/dL occurring 2.5 hours after a meal in a patient using a 1:6 carbohydrate ratio, you need to administer correction insulin immediately using your insulin sensitivity factor (ISF), not adjust your carbohydrate ratio. 1

Immediate Correction Dose Calculation

Calculate your correction dose using your insulin sensitivity factor (ISF):

• ISF = 1500 ÷ Total Daily Dose (TDD) of insulin 1
• Correction dose = (Current glucose - Target glucose) ÷ ISF 1
• For example, if your TDD is 50 units, your ISF = 1500 ÷ 50 = 30 mg/dL per unit 1
• Using a target of 125 mg/dL: (380 - 125) ÷ 30 = 8.5 units of rapid-acting insulin 1

Critical timing consideration: Administer rapid-acting insulin (lispro, aspart, or glulisine) immediately, as these analogs work within 15 minutes and peak at 1-2 hours 2, 1

Avoiding Insulin Stacking

Do not give correction insulin if you administered mealtime insulin within the past 3-4 hours, as the previous dose may still be active and stacking doses significantly increases hypoglycemia risk 1. Since you are 2.5 hours post-meal, some insulin activity remains, so consider reducing the calculated correction dose by 30-50% 1.

Evaluating Your Carbohydrate Ratio

Your 1:6 carbohydrate ratio may be inadequate if postprandial glucose consistently exceeds 180 mg/dL. 2, 1

• Adjust your carbohydrate ratio every 3 days based on 2-hour postprandial glucose patterns 2, 1
• If 2-hour postprandial glucose is consistently >180 mg/dL, strengthen your ratio (e.g., from 1:6 to 1:5, meaning more insulin per gram of carbohydrate) 2, 1
• The formula for carbohydrate ratio is 450 ÷ TDD for rapid-acting analogs 1

Basal Insulin Assessment

Postprandial hyperglycemia at 2.5 hours reflects inadequate mealtime insulin coverage, NOT basal insulin deficiency. 2, 1

• Basal insulin (glargine, detemir, degludec) controls fasting and between-meal glucose by restraining hepatic glucose production 2
• Do not increase basal insulin to address postprandial excursions, as this leads to "overbasalization" with increased hypoglycemia risk 2, 1
• Signs of overbasalization include: bedtime-to-morning glucose differential ≥50 mg/dL, basal dose >0.5 units/kg/day, hypoglycemia, and high glucose variability 2, 1

Monitoring Requirements

Check your blood glucose 2 hours after meals to assess adequacy of your carbohydrate coverage. 1

• Target 2-hour postprandial glucose: <180 mg/dL 2
• If consistently elevated, adjust your carbohydrate ratio by 10-15% every 3 days 2, 1
• Recheck glucose 2-3 hours after giving correction insulin to ensure it brought you into target range (80-130 mg/dL preprandial) 2, 1

When to Seek Medical Attention

Contact your healthcare provider immediately if:

• Blood glucose remains >250 mg/dL despite correction doses 1
• You experience nausea, vomiting, or abdominal pain with hyperglycemia (possible diabetic ketoacidosis) 1
• Correction doses consistently fail to bring glucose into target range, indicating your ISF needs adjustment 1
• You develop hypoglycemia after correction doses, requiring ISF recalculation 1

Common Pitfalls to Avoid

• Never blame fasting hyperglycemia on missed carbohydrate coverage - fasting glucose reflects basal insulin adequacy only 1
• Never give rapid-acting insulin at bedtime for correction unless you can monitor closely, as this significantly increases nocturnal hypoglycemia risk 1
• Never continue using the same carbohydrate ratio if postprandial glucose consistently exceeds 180 mg/dL - adjust every 3 days based on patterns 2, 1
• Never use protein-rich foods to treat hypoglycemia - use 15 grams of pure glucose or fast-acting carbohydrates instead 1