Treatment of Diabetic Ketoacidosis (DKA)
For a patient in DKA, immediately initiate aggressive fluid resuscitation with isotonic saline at 15-20 mL/kg/hour, followed by continuous intravenous regular insulin at 0.1 units/kg/hour (without bolus), while closely monitoring and replacing potassium to maintain levels between 4-5 mEq/L. 1
Initial Assessment and Stabilization
Laboratory evaluation must include: plasma glucose, electrolytes with calculated anion gap, serum ketones (preferably β-hydroxybutyrate), arterial blood gases, blood urea nitrogen/creatinine, osmolality, urinalysis, complete blood count, and electrocardiogram 1. Obtain bacterial cultures if infection is suspected as a precipitating cause 1.
Diagnostic confirmation requires: plasma glucose >250 mg/dL, arterial pH <7.30, serum bicarbonate <18 mEq/L, and positive serum/urine ketones 1. However, be aware that euglycemic DKA (glucose <250 mg/dL with ketoacidosis) can occur, particularly in patients on SGLT2 inhibitors 2, 3.
Fluid Resuscitation Protocol
First hour: Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour to restore intravascular volume and renal perfusion 1. This aggressive initial fluid management is critical for restoring circulatory volume and tissue perfusion 4.
Subsequent fluid management: Continue fluid replacement based on hydration status, serum electrolyte levels, and urine output 1. Total fluid replacement should approximate 1.5 times the 24-hour maintenance requirements 1.
When glucose reaches 250 mg/dL: Switch to 5% dextrose with 0.45-0.75% NaCl while continuing insulin therapy 5. This prevents hypoglycemia while allowing continued insulin administration to clear ketosis 1.
Insulin Therapy
For moderate to severe DKA: Start continuous intravenous regular insulin infusion at 0.1 units/kg/hour without an initial bolus 1. This is the standard of care for critically ill and mentally obtunded patients 4.
If glucose fails to fall by 50 mg/dL in the first hour: Double the insulin infusion rate hourly until achieving a steady glucose decline of 50-75 mg/hour 1.
When glucose reaches 250 mg/dL: Decrease insulin infusion to 0.05-0.1 units/kg/hour and add dextrose to IV fluids 1. Target glucose between 150-200 mg/dL until DKA resolves 5.
For mild, uncomplicated DKA in stable patients: Subcutaneous rapid-acting insulin analogs combined with aggressive fluid management can be as effective as intravenous insulin 4, 6. This approach may be safer and more cost-effective when managed in emergency departments or step-down units 4.
Potassium Management
Critical monitoring: Insulin therapy and correction of acidosis cause potassium to shift intracellularly, leading to potentially dangerous hypokalemia 1.
Once renal function is assured and serum potassium is <5.3 mEq/L: Add 20-30 mEq/L potassium to IV fluids 1. Maintain serum potassium between 4-5 mEq/L throughout treatment 1.
Monitoring During Treatment
Blood glucose: Check every 1-2 hours 1.
Laboratory monitoring: Draw blood every 2-4 hours for serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 5. Venous pH (typically 0.03 units lower than arterial pH) and anion gap should be followed to monitor resolution of acidosis 5.
Ketone monitoring: Direct measurement of β-hydroxybutyrate in blood is the preferred method 5. The nitroprusside method only measures acetoacetic acid and acetone, not β-hydroxybutyrate, and should not be used as an indicator of treatment response 5.
Bicarbonate Administration
Bicarbonate is generally not recommended for DKA patients with pH >6.9 4, 1. Multiple studies show no difference in resolution of acidosis or time to discharge with bicarbonate use 4.
Resolution Criteria
DKA is resolved when ALL of the following are met: glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L 1, 5.
Note that ketonemia typically takes longer to clear than hyperglycemia 5. Continue insulin therapy until complete resolution of ketosis, not just normalization of glucose 1.
Transition to Subcutaneous Insulin
Administer basal insulin 2-4 hours before stopping the IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia 4, 1. This timing is critical—premature termination of IV insulin is a common cause of DKA recurrence 1, 5.
Recent studies suggest that administering a low dose of basal insulin analog in addition to IV insulin infusion during treatment may prevent rebound hyperglycemia without increasing hypoglycemia risk 4.
Common Pitfalls to Avoid
Never interrupt insulin infusion when glucose falls below 250 mg/dL—this is the most common cause of persistent or worsening ketoacidosis 5. Instead, add dextrose to the hydrating solution while continuing insulin 1, 5.
Inadequate potassium monitoring and replacement can cause dangerous hypokalemia during insulin therapy 1.
Premature termination of insulin therapy before complete resolution of ketosis leads to DKA recurrence 1, 5.
Inadequate fluid resuscitation worsens DKA outcomes 6.
Treating Precipitating Causes
Identify and treat any correctable underlying cause such as sepsis, myocardial infarction, or stroke 4. Administer appropriate antibiotics if infection is suspected 1.
Special Considerations
SGLT2 inhibitors: These medications should be discontinued 3-4 days before surgery and can cause euglycemic DKA 4, 2, 3. In euglycemic DKA, start D5 alongside 0.9% NaCl at the beginning of insulin treatment 5.
Pregnancy, chronic kidney disease, heart failure, and older age require tailored management strategies, though specific guideline recommendations for these populations are limited 7, 3.