Management of DKA When Blood Glucose Reaches 140 mg/dL
When blood glucose falls to 140 mg/dL during DKA treatment, immediately add dextrose 5% to your IV fluids (switching to D5 with 0.45-0.75% NaCl) while continuing the insulin infusion at the current rate—never stop or reduce insulin until DKA is fully resolved. 1
Critical Action Steps at Glucose 140 mg/dL
Fluid Management
- Switch from normal saline to 5% dextrose with 0.45-0.75% normal saline 1
- The American Diabetes Association recommends adding dextrose when glucose falls below 200-250 mg/dL, so at 140 mg/dL you should already have dextrose running 1, 2
- Continue potassium supplementation (20-30 mEq/L) in the dextrose solution to maintain serum K+ between 4-5 mmol/L 1, 3
Insulin Management
- Continue IV regular insulin infusion at 0.1 units/kg/hour without reduction 1, 2
- Target glucose between 150-200 mg/dL until complete DKA resolution 1, 3
- The most common error causing persistent or worsening ketoacidosis is stopping or reducing insulin when glucose normalizes 1, 3
Why Continue Full-Dose Insulin Despite Low Glucose
- Ketonemia takes substantially longer to clear than hyperglycemia 1, 3
- DKA resolution requires ALL of the following: glucose <200 mg/dL **AND** serum bicarbonate ≥18 mEq/L **AND** venous pH >7.3 AND anion gap ≤12 mEq/L 1, 2, 3
- Glucose normalization is only ONE criterion—you must continue insulin to clear ketones even with normal or low glucose 1, 3
Monitoring Requirements
- Check blood glucose every 1-2 hours at this critical phase 2, 4
- Measure serum electrolytes, venous pH, bicarbonate, and anion gap every 2-4 hours 1, 2, 3
- Monitor serum potassium closely as insulin drives potassium intracellularly 2, 3
- Follow β-hydroxybutyrate levels if available (preferred over urine ketones) 2, 4
Adjusting Dextrose Concentration
- If glucose continues to fall below 150 mg/dL despite D5, consider increasing to 10% dextrose while maintaining insulin infusion 5, 6
- In severe DKA cases, insulin rates of 4-6 U/hour or higher with 10-20% dextrose may be necessary to clear ketones while preventing hypoglycemia 5
When to Stop IV Insulin
- Do NOT stop IV insulin until DKA is completely resolved: pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L, and glucose <200 mg/dL 1, 2, 3
- Administer basal subcutaneous insulin (glargine or detemir) 2-4 hours BEFORE stopping IV insulin 2, 3
- Continue IV insulin for 1-2 hours after giving subcutaneous insulin to ensure adequate plasma levels and prevent DKA recurrence 1, 2, 3
Critical Pitfalls to Avoid
- Never discontinue or reduce insulin infusion when glucose normalizes—this is the leading cause of persistent ketoacidosis 1, 3
- Never stop IV insulin without prior basal insulin administration—this causes immediate DKA recurrence 2, 3
- Failure to add dextrose when glucose falls below 250 mg/dL leads to hypoglycemia while trying to clear ketones 1, 3
- Inadequate potassium monitoring during this phase can cause life-threatening hypokalemia as insulin drives K+ intracellularly 2, 3