What is the recommended insulin regimen for a hospital patient who is nothing by mouth (NPO)?

Insulin Management for NPO Hospital Patients

For hospitalized patients who are nothing by mouth (NPO), basal insulin or a basal-plus-correction insulin regimen is the preferred treatment, while sliding scale insulin alone is strongly discouraged. 1

Recommended Insulin Regimen

Basal-Plus-Correction Approach (Preferred)

• Administer basal insulin at a reduced dose (typically 0.1-0.25 units/kg/day for insulin-naive patients or those on low doses at home) 1
• Add correction doses of rapid-acting insulin every 4-6 hours or before scheduled glucose checks 1
• For patients already on home insulin at doses ≥0.6 units/kg/day, reduce the total daily dose by 20% to prevent hypoglycemia 1
• Administer basal insulin at 60-80% of the usual home dose (or half the NPH dose if applicable) to prevent both ketosis and hypoglycemia 2

Critical Monitoring Requirements

• Check blood glucose every 4-6 hours minimum while NPO 1, 2
• Increase monitoring frequency to every 1-2 hours if hypoglycemia has occurred or if the patient is on insulin infusion 2
• Target glucose range of 140-180 mg/dL for most noncritically ill patients 1

What NOT to Do

Sliding Scale Insulin Alone is Strongly Discouraged

• Using only correction/supplemental insulin without basal insulin is explicitly contraindicated for NPO patients 1
• This reactive approach leads to both hyperglycemia and hypoglycemia 2
• Sliding scale alone does not account for basal insulin requirements, particularly dangerous in type 1 diabetes 1

Special Considerations by Patient Type

Type 1 Diabetes Patients

• Must continue receiving basal insulin even when NPO to prevent diabetic ketoacidosis 2
• Intravenous insulin infusion is preferred over subcutaneous administration for NPO type 1 diabetics 2
• Never use sliding scale insulin alone in type 1 diabetes 1

Critically Ill Patients

• Continuous intravenous insulin infusion is the most effective method for achieving glycemic targets 1
• Use validated written or computerized protocols that allow predefined adjustments based on glycemic fluctuations 1
• Target glucose range of 140-180 mg/dL (7.8-10.0 mmol/L) for most critically ill patients 1

Common Pitfalls to Avoid

Hypoglycemia Prevention

• Inappropriate timing of short-acting insulin in relation to NPO status is a common precipitating factor for hypoglycemia 2
• Failure to reduce insulin doses when patients become NPO leads to preventable hypoglycemia 2
• Unexpected interruption of enteral feedings or parenteral nutrition without insulin adjustment causes hypoglycemia 1, 2
• Reduced infusion rate of intravenous dextrose and sudden reduction of corticosteroid dose can trigger hypoglycemia 2

Treatment Protocol Requirements

• Implement a standardized hospital-wide, nurse-initiated hypoglycemia treatment protocol to ensure timely treatment 1, 2
• Document all hypoglycemic episodes in the medical record to track patterns 2
• Any blood glucose <70 mg/dL requires review of the treatment regimen 2

Transitioning from IV to Subcutaneous Insulin

When discontinuing intravenous insulin infusion:

• Administer subcutaneous basal insulin 1-2 hours before stopping the IV infusion 1
• Convert to basal insulin at 60-80% of the 24-hour IV insulin dose 1
• This transition protocol is associated with lower morbidity and costs of care 1