What are the criteria for resolving diabetic ketoacidosis (DKA) in a patient?

DKA Resolution Criteria

DKA is considered resolved when ALL of the following three criteria are met: glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, and venous pH >7.3. 1, 2

Core Resolution Parameters

The American Diabetes Association defines resolution with these specific thresholds that must ALL be achieved simultaneously:

• Glucose <200 mg/dL - indicates resolution of hyperglycemia 1, 2
• Serum bicarbonate ≥18 mEq/L - indicates resolution of metabolic acidosis 1, 2
• Venous pH >7.3 - indicates resolution of acidemia 1, 2
• Anion gap ≤12 mEq/L - provides additional confirmation of ketoacid clearance 1, 2

Critical Monitoring Strategy During Treatment

Monitor every 2-4 hours by drawing blood for electrolytes, glucose, BUN, creatinine, osmolality, and venous pH until resolution criteria are met. 1, 2

Use Venous pH, Not Arterial

• Venous pH is sufficient for monitoring acidosis resolution after initial diagnosis 1, 2
• Venous pH typically runs 0.03 units lower than arterial pH 1, 2
• Repeated arterial blood gases are unnecessary and cause patient discomfort 1

Track Anion Gap in Parallel

• The anion gap provides additional confirmation that ketoacids are clearing from circulation 1, 2
• Follow both venous pH and anion gap together to monitor resolution 1, 2

Ketone Monitoring Considerations

Ketonemia takes longer to clear than hyperglycemia - this is why you cannot stop insulin when glucose normalizes. 1, 2

Preferred Method: Direct β-Hydroxybutyrate Measurement

• Direct blood measurement of β-hydroxybutyrate (β-OHB) is the gold standard for monitoring DKA 1, 2, 3
• β-OHB is the predominant and strongest ketoacid in DKA 1

Critical Pitfall to Avoid

• Never use nitroprusside-based urine or serum ketone tests to monitor treatment response 1, 2
• These tests only measure acetoacetate and acetone, completely missing β-OHB 1, 2
• During treatment, β-OHB converts to acetoacetate, making nitroprusside tests paradoxically appear worse even as the patient improves 1

Management During Resolution Phase

When Glucose Falls to 200-250 mg/dL

• Add dextrose 5% to IV fluids while continuing insulin infusion 1, 2
• Target glucose between 150-200 mg/dL until full DKA resolution 2
• This prevents hypoglycemia while allowing insulin to continue clearing ketones 1, 2

Common Pitfall: Premature Insulin Discontinuation

• Never discontinue IV insulin when glucose normalizes - ketoacidosis takes longer to resolve than hyperglycemia 1
• Premature insulin cessation causes recurrent ketoacidosis 1
• Continue insulin infusion until ALL resolution criteria are met 1, 2

Transition to Subcutaneous Insulin After Resolution

Once ALL resolution criteria are met and the patient can eat:

1. Administer basal subcutaneous insulin (NPH, detemir, glargine, or degludec) 2-4 hours BEFORE stopping IV insulin 1, 2
2. Start a multiple-dose regimen combining short/rapid-acting and intermediate/long-acting insulin 2
3. Continue IV insulin infusion for 1-2 hours after starting subcutaneous insulin to ensure adequate plasma insulin levels 2

If Patient Remains NPO After Resolution

• Continue IV insulin and fluid replacement 2
• Supplement with subcutaneous regular insulin every 4 hours as needed 2
• For adults: give 5-unit increments for every 50 mg/dL increase in blood glucose above 150 mg/dL (up to 20 units for glucose of 300 mg/dL) 2

Special Consideration: Euglycemic DKA

In euglycemic DKA (glucose <250 mg/dL at presentation), the same resolution criteria apply for pH and bicarbonate, but glucose management differs:

• Start dextrose 5% alongside 0.9% saline from the beginning of insulin treatment 2, 4, 5, 6
• This scenario can occur with SGLT2 inhibitor use, pregnancy, starvation, or recent insulin administration 4, 5, 6
• Never overlook ketoacidosis just because glucose is normal - check pH and ketones in all ill diabetic patients regardless of glucose level 6