Management of Basal Insulin During NPO Status in Type 2 Diabetes

Introduction to Basal Insulin Management

The American Diabetes Association recommends continuing the full 15 units of Lantus (insulin glargine) daily when NPO, as basal insulin provides essential background insulin coverage independent of nutritional intake 1
Basal insulin like Lantus provides continuous background insulin coverage that is required 24 hours daily regardless of eating status, mimicking the body's baseline insulin secretion that occurs even during fasting states 1

The 2017 Diabetes Care guidelines for hospitalized older adults explicitly state that when patients have reduced oral intake or become NPO, the basal insulin should be maintained while adding dextrose infusion (10% dextrose) to prevent hypoglycemia rather than reducing the basal dose 1
Start 10% dextrose infusion (typically 75-100 mL/hour) when the patient becomes NPO to provide glucose substrate while maintaining basal insulin coverage 1

Monitor blood glucose every 4-6 hours during NPO status, with more frequent checks if any value falls below a certain threshold 1
Hold all prandial (mealtime) insulin completely during NPO periods, as these are specifically designed to cover carbohydrate intake 1

If blood glucose drops below a certain threshold during NPO status despite dextrose infusion, reduce the Lantus dose by 10-20% (to 12-13.5 units) 1
For older adults (age 65) with any degree of renal impairment, frailty, or recurrent hypoglycemia, consider reducing to 80% of the usual dose (12 units) prophylactically when NPO 2, 1
The 15-unit daily dose is already conservative for a 65-year-old, suggesting either good glycemic control or intentional conservative dosing, which supports maintaining the full dose during brief NPO periods 2

Reduce to 50-80% of usual dose (7.5-12 units) if the patient has acute kidney injury or chronic kidney disease stage 4-5, severe liver dysfunction, history of severe hypoglycemia, prolonged NPO status expected (>48 hours), or sepsis or critical illness with unpredictable insulin sensitivity 2, 1, 3
For same-day procedures with brief NPO periods (<12 hours), continue the full 15 units without modification 1