What are the diagnostic criteria for inpatient admission and the discharge criteria for outpatient management of diabetic ketoacidosis (DKA)?

Criteria for Admission and Discharge in DKA

For adults, admit to inpatient care if pH <7.30, bicarbonate <15 mEq/L, or blood glucose >250 mg/dL with moderate ketonuria/ketonemia; discharge when glucose <200 mg/dL, bicarbonate ≥18 mEq/L, and venous pH ≥7.30. 1

Inpatient Admission Criteria

Adults

The diagnostic and admission thresholds are clearly defined 1:

• Blood glucose ≥250 mg/dL
• Arterial pH <7.30
• Bicarbonate <15 mEq/L
• Moderate ketonuria or ketonemia

Severe DKA requiring ICU admission includes patients needing continuous insulin infusion, particularly those with profound acidosis or altered mental status 2, 1.

Pediatric Patients (<20 years)

Similar criteria apply 1:

• Blood glucose ≥250 mg/dL
• Venous pH <7.30
• Bicarbonate <15 mEq/L
• Moderate ketonuria or ketonemia

Mild DKA Considerations

Outpatient management may be appropriate for select patients with mild DKA 3:

• pH ≥7.20 OR bicarbonate ≥10 mEq/L at presentation
• In pediatric studies, 94% of patients meeting these criteria had resolution within 3 hours of outpatient therapy
• This applies only to reliable patients with adequate follow-up and no comorbid conditions

Discharge Criteria

Resolution of DKA

All three criteria must be met before discharge 1:

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH ≥7.30

Transition to Subcutaneous Insulin

Once DKA resolves 1:

• If patient can eat, transition to subcutaneous insulin regimen
• Continue IV insulin for 1-2 hours after first subcutaneous dose to prevent rebound ketoacidosis
• If patient remains NPO, continue IV insulin and fluids

Important Discharge Considerations

Hyperglycemia at discharge is not a contraindication - Research shows that higher blood glucose at discharge (and in the 24 hours prior) is actually associated with lower readmission rates 4. This counterintuitive finding suggests that overly aggressive glucose control before discharge may not be beneficial.

Early discharge after acidosis resolution is safe - Discharging within 24 hours of acidosis resolution is not associated with higher readmission rates compared to longer observation periods 4.

Common Pitfalls to Avoid

Monitoring Ketones

• Do not use nitroprusside method (urine ketones) to assess treatment response 1
• β-hydroxybutyrate (β-OHB) is the preferred blood ketone measurement
• During treatment, β-OHB converts to acetoacetic acid, which can falsely suggest worsening ketosis on urine tests

Premature Discontinuation of IV Insulin

• Never stop IV insulin when glucose reaches 250-300 mg/dL 1
• Ketonemia takes longer to clear than hyperglycemia
• Add dextrose-containing fluids when glucose <250 mg/dL while continuing insulin infusion

Overdiagnosis

Nearly 28% of hospital admissions coded as DKA are misdiagnosed 5. Ensure strict adherence to diagnostic criteria to avoid unnecessary ICU admissions and IV insulin protocols.

Patient Education Before Discharge

Critical gaps exist in patient knowledge 6:

• Only 21% of type 1 diabetes patients possess ketone testing supplies
• Only 6% actually perform ketone testing
• 71% of type 1 diabetes patients experience recurrent DKA episodes
• Provide ketone testing supplies and education on sick-day rules before discharge

Special Populations

SGLT2 Inhibitor Users

Patients on SGLT2 inhibitors can develop euglycemic DKA (glucose may be <250 mg/dL) 6. These patients still require admission and IV insulin if they meet pH and bicarbonate criteria, even with "normal" glucose levels.