Immediate Management of Ketonuria in Uncontrolled Diabetes
Patients with ketonuria and suspected diabetic ketoacidosis (DKA) require immediate risk stratification: those who are hemodynamically unstable, unable to tolerate oral fluids, have altered mental status, or show signs of worsening illness must be sent to the emergency department immediately for intravenous fluid resuscitation and insulin therapy. 1
Initial Assessment and Risk Stratification
When a patient presents with ketonuria, immediately assess whether they meet criteria for DKA: blood glucose >250 mg/dL, venous pH <7.3, bicarbonate <15 mEq/L, and moderate ketonuria or ketonemia 2, 3. However, be vigilant for euglycemic DKA (glucose <200 mg/dL), which can occur in pregnant patients and those on SGLT2 inhibitors—these patients still require aggressive treatment despite normal glucose levels 1, 3, 4.
Absolute Indications for Emergency Department Referral
Send the patient to the ER immediately if ANY of the following are present:
- Inability to tolerate oral hydration or persistent vomiting 1
- Altered mental status or confusion 1
- Blood glucose not responding to insulin (failure to decrease by 50-75 mg/dL per hour) 1
- Signs of worsening illness: increasing lethargy, worsening abdominal pain, or respiratory distress 1
- Pregnancy (any concern for DKA due to significant feto-maternal harm risk) 1
- Pediatric patients (higher risk of cerebral edema during treatment) 1
Home Management Protocol (Only for Select Patients)
Home management may be attempted ONLY if the patient meets ALL of the following criteria:
- Hemodynamically stable (normal blood pressure and heart rate) 1
- Cognitively intact (alert and oriented) 1
- Able to tolerate oral fluids without vomiting 1
- Able to self-administer subcutaneous insulin 1
Home Management Steps
Aggressive oral hydration: 8-12 ounces of sugar-free fluids every hour 1
Supplemental rapid-acting insulin: Administer additional subcutaneous insulin every 2-4 hours based on glucose levels 2
Continue basal insulin: Never discontinue insulin during illness, even if not eating—this is a critical pitfall that can worsen ketoacidosis 1
Monitor response: Blood glucose should decrease by 50-75 mg/dL per hour 1
Recheck ketones every 2-4 hours: Use blood ketone testing (preferred over urine) for more accurate real-time assessment 1
Hospital Management Protocol
For patients requiring ER evaluation, the American Diabetes Association guidelines provide clear treatment priorities 2:
Fluid Resuscitation (First Priority)
- Initial bolus: 15-20 mL/kg/hour of 0.9% normal saline in the first hour (1-1.5 liters in average adult) 2
- Subsequent fluids: Switch to 0.45% saline at 4-14 mL/kg/hour if corrected sodium is normal or elevated; continue 0.9% saline if corrected sodium is low 2
Insulin Therapy
- Continuous IV insulin infusion is preferred for moderate to severe DKA 2
- For mild DKA, subcutaneous regular insulin every 4 hours may be used (5-unit increments for every 50 mg/dL increase above 150 mg/dL, up to 20 units for glucose of 300 mg/dL) 2
- Add dextrose to IV fluids when glucose falls to 200-250 mg/dL, but continue insulin until ketoacidosis resolves 2, 3, 5
Electrolyte Replacement
- Potassium supplementation is critical: Add 20-30 mEq/L to IV fluids (2/3 KCl and 1/3 KPO4) once renal function is assured 2
- Insulin therapy lowers serum potassium, making supplementation mandatory to prevent fatal cardiac arrhythmias 2, 5
Monitoring During Treatment
- Draw labs every 2-4 hours: Serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 2
- Monitor venous pH (usually 0.03 units lower than arterial pH) and anion gap to track acidosis resolution 2
- Do NOT rely on urine ketones to assess treatment response—the nitroprusside method doesn't measure β-hydroxybutyrate (the predominant ketone), which converts to acetoacetate during treatment, falsely suggesting worsening ketosis 2, 3
Resolution Criteria
DKA is resolved when ALL three criteria are met:
Critical transition point: Continue IV insulin for 1-2 hours after starting subcutaneous insulin to ensure adequate plasma insulin levels and prevent rebound hyperglycemia 2, 6. Premature discontinuation of IV insulin is a common pitfall that leads to poor glycemic control 6.
Special Considerations
Euglycemic DKA Management
For patients with ketoacidosis but glucose <200 mg/dL (pregnant patients, SGLT2 inhibitor users):
- Continue insulin therapy despite normal glucose 3
- Add dextrose to hydrating solution while continuing insulin 3
- Monitor for resolution based on pH >7.3, bicarbonate ≥18 mEq/L, and anion gap ≤12 mEq/L—not glucose levels 3