When to Stop Insulin Infusion for DKA
Discontinue the intravenous insulin infusion only after DKA has completely resolved AND basal subcutaneous insulin has been administered 2-4 hours prior to stopping the IV infusion. 1, 2
Resolution Criteria - All Must Be Met
The insulin infusion should continue until all of the following metabolic parameters are achieved: 1, 2
- Glucose <200 mg/dL
- Serum bicarbonate ≥18 mEq/L
- Venous pH ≥7.3
- Anion gap ≤12 mEq/L
- Patient able to tolerate oral intake
Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring ketoacidosis resolution, though the above criteria remain the standard for determining when to stop IV insulin. 2
Critical Timing for Subcutaneous Insulin Administration
The most common and dangerous error is stopping IV insulin without prior basal insulin administration, which leads to rebound hyperglycemia and recurrent DKA. 1, 2, 3
Mandatory Overlap Protocol:
- Administer long-acting basal insulin (glargine or detemir) subcutaneously 2-4 hours BEFORE discontinuing the IV insulin infusion 4, 1, 2
- Continue the IV insulin infusion for 1-2 hours after giving subcutaneous insulin to allow adequate absorption 2
- This overlap prevents the recurrence of ketoacidosis that occurs when there is a gap in insulin coverage 4, 1
Glucose Management During Resolution
When glucose falls below 250-300 mg/dL, do not stop the insulin infusion. Instead: 1, 5, 6
- Add dextrose (D5W or D10W) to IV fluids 1
- Continue insulin infusion at 0.05-0.1 units/kg/hour 7
- Maintain glucose above 200 mg/dL with dextrose while continuing insulin to clear ketones 5, 6
This is essential because hyperglycemia resolves faster than ketoacidosis—stopping insulin when glucose normalizes will leave the patient in persistent ketoacidosis. 5, 6
Monitoring Requirements Before Discontinuation
Check the following parameters every 2-4 hours until stable: 4, 1, 2
- Serum electrolytes (especially potassium)
- Glucose
- Venous pH
- Bicarbonate
- Anion gap
Potassium monitoring is critical as insulin drives potassium intracellularly, and hypokalemia can occur even after initial correction. 1, 2
Transition Dosing Strategy
Calculate the initial subcutaneous insulin dose based on: 2, 7
- Total daily dose = Average hourly IV insulin rate over last 12 hours × 24 2, 7
- Give 50% as basal insulin (long-acting) once daily 2, 7
- Give 50% as prandial insulin (rapid-acting) divided before meals 2
- Alternative: Start at 0.5-1.0 units/kg/day for newly diagnosed patients 1
Common Pitfalls to Avoid
Never stop IV insulin before administering subcutaneous basal insulin—this is the single most common error leading to DKA recurrence and is explicitly warned against in multiple guidelines. 1, 2, 3
Never use correction-only (sliding scale) insulin without basal coverage—this approach leads to worse outcomes and higher complication rates. 2, 7
Never stop insulin when glucose normalizes if acidosis persists—continue insulin with dextrose supplementation until all metabolic criteria are met. 5, 6
Never restart SGLT2 inhibitors during acute illness—these should remain discontinued until the patient is metabolically stable and any infection has resolved. 7