Immediate Management of Diabetic Ketoacidosis
Begin aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour, followed by continuous intravenous regular insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L, while closely monitoring and replacing electrolytes—particularly potassium—to prevent life-threatening complications. 1, 2
Initial Assessment and Diagnosis
Perform immediate laboratory evaluation including: 1
- Plasma glucose, arterial blood gases (or venous pH)
- Serum ketones (β-hydroxybutyrate preferred), electrolytes with calculated anion gap
- Blood urea nitrogen/creatinine, osmolality
- Complete blood count, urinalysis with urine ketones
- Electrocardiogram
Diagnostic criteria: glucose >250 mg/dL, arterial pH <7.30, serum bicarbonate <18 mEq/L (some sources <15 mEq/L), and positive serum/urine ketones 1, 2
Identify precipitating factors immediately: infection (obtain cultures if suspected), myocardial infarction, stroke, pancreatitis, trauma, insulin omission, or SGLT2 inhibitor use 2
Fluid Resuscitation (First Priority)
Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adult) during the first hour to restore intravascular volume and renal perfusion 1, 2
Continue fluid replacement to correct estimated deficits within 24 hours, targeting 1.5-2 times the 24-hour maintenance requirements 1
When glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy 2
Insulin Therapy (Second Priority—After Addressing Potassium)
CRITICAL: Do NOT start insulin if potassium <3.3 mEq/L—aggressively replace potassium first to prevent life-threatening cardiac arrhythmias and respiratory muscle weakness 2
Once potassium ≥3.3 mEq/L, start continuous IV regular insulin at 0.1 units/kg/hour without an initial bolus 1, 2
If glucose does not fall by 50 mg/dL in the first hour, check hydration status; if adequate, double the insulin infusion rate hourly until achieving steady decline of 50-75 mg/hour 1, 2
Continue insulin infusion until complete resolution of ketoacidosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels—premature termination is a common cause of recurrent DKA 2
Target glucose between 150-200 mg/dL until DKA resolution parameters are met 2
Electrolyte Management (Critical Throughout)
Potassium Replacement Protocol:
If K+ <3.3 mEq/L: Delay insulin therapy and aggressively replace potassium until ≥3.3 mEq/L 2
If K+ 3.3-5.5 mEq/L: Add 20-30 mEq/L potassium to IV fluids (use 2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed 1, 2
If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely, as levels will drop rapidly with insulin therapy 2
Target serum potassium 4-5 mEq/L throughout treatment—inadequate monitoring and replacement is a leading cause of mortality in DKA 2
Bicarbonate:
Bicarbonate is NOT recommended for pH >6.9-7.0—studies show no benefit in resolution time, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 1, 2
Consider bicarbonate only if pH <6.9 or in peri-intubation period when pH <7.2 to prevent hemodynamic collapse 3
Monitoring Protocol
Draw blood every 2-4 hours to assess: serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 2
Check blood glucose every 1-2 hours 1
Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor acidosis resolution 2
Direct measurement of β-hydroxybutyrate is preferred over nitroprusside method for monitoring ketosis 2
Resolution Criteria and Transition
DKA is resolved when ALL of the following are met: 1, 2
- Glucose <200 mg/dL
- Serum bicarbonate ≥18 mEq/L
- Venous pH >7.3
- Anion gap ≤12 mEq/L
Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia 1, 2
Once patient can eat, transition to multiple-dose insulin schedule using combination of short/rapid-acting and intermediate/long-acting insulin 1, 2
Special Considerations and Pitfalls
For mild-to-moderate uncomplicated DKA: Subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective, safer, and more cost-effective than IV insulin, though continuous IV insulin remains standard for critically ill and mentally obtunded patients 1, 2
SGLT2 inhibitors must be discontinued 3-4 days before any planned surgery to prevent euglycemic DKA, which can occur with normal or only mildly elevated glucose levels 1
Common pitfalls to avoid: 2
- Premature termination of insulin before complete ketosis resolution
- Failure to add dextrose when glucose falls below 250 mg/dL
- Starting insulin with potassium <3.3 mEq/L
- Inadequate potassium monitoring and replacement
- Overly rapid correction of osmolality (increases cerebral edema risk, especially in children)
Thromboprophylaxis with enoxaparin can be initiated upon admission after initial fluid resuscitation, as DKA creates a hypercoagulable state 4