Initial Management of Diabetic Ketoacidosis (DKA)
Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in the first hour) to restore circulatory volume and tissue perfusion, followed by continuous intravenous regular insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L. 1, 2
Diagnostic Confirmation
Before initiating treatment, confirm DKA diagnosis when all three criteria are present: 1
- Blood glucose >250 mg/dL
- Arterial pH <7.3
- Serum bicarbonate <15-18 mEq/L with positive ketones
Critical caveat: Euglycemic DKA can occur, particularly in patients on SGLT2 inhibitors, where glucose may be normal or only mildly elevated despite severe ketoacidosis. 1, 3
Initial Laboratory Assessment
Obtain the following immediately to guide therapy and identify precipitating factors: 1, 2
- Plasma glucose, electrolytes with calculated anion gap
- Serum ketones (β-hydroxybutyrate preferred over nitroprusside method)
- Blood urea nitrogen/creatinine
- Arterial blood gases (venous pH acceptable for subsequent monitoring)
- Complete blood count with differential
- Urinalysis and urine ketones
- Electrocardiogram
- Bacterial cultures (blood, urine, throat) if infection suspected
Look specifically for precipitating factors: infection, myocardial infarction, stroke, pancreatitis, insulin omission, SGLT2 inhibitor use, or new diabetes diagnosis. 1, 2
Fluid Resuscitation (First Priority)
Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour. 1, 2 This aggressive initial fluid replacement is critical for restoring tissue perfusion and improving insulin sensitivity. 2
After the first hour, adjust fluid choice based on: 2
- Hydration status
- Serum electrolyte levels (particularly corrected sodium)
- Urine output
When serum glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy. 2 This is a common pitfall—never stop insulin when glucose falls below 250 mg/dL, as this causes persistent or worsening ketoacidosis. 2
Total fluid replacement should correct estimated deficits within 24 hours. 1, 2
Potassium Management (Critical Before Insulin)
Check serum potassium immediately and do NOT start insulin if K+ <3.3 mEq/L. 1, 2 This is life-threatening: insulin drives potassium intracellularly and can precipitate fatal cardiac arrhythmias and respiratory muscle weakness. 1, 4
Potassium replacement protocol: 1, 2
- If K+ <3.3 mEq/L: Hold insulin and aggressively replace potassium until ≥3.3 mEq/L
- If K+ 3.3-5.5 mEq/L: Add 20-30 mEq/L potassium to IV fluid (use 2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed
- If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely, as levels will drop rapidly with insulin therapy
Target serum potassium 4-5 mEq/L throughout treatment. 1 Despite normal or elevated initial potassium, total body potassium depletion is universal in DKA. 2 Hypokalemia occurs in approximately 50% of patients during treatment and is a leading cause of mortality. 1, 2
Insulin Therapy
Once potassium is ≥3.3 mEq/L, start continuous intravenous regular insulin at 0.1 units/kg/hour for moderate to severe DKA. 1, 2 This is the standard of care for critically ill and mentally obtunded patients. 2
Target glucose decline of 50-75 mg/dL per hour. 1, 2 If plasma glucose does not fall by 50 mg/dL in the first hour, check hydration status; if acceptable, double the insulin infusion rate hourly until steady glucose decline achieved. 2
Critical pitfall: Do not stop insulin when glucose falls below 250 mg/dL—this is the most common cause of persistent ketoacidosis. 1, 2 Instead, add dextrose to IV fluids and continue insulin at reduced rate. 2
Alternative 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. 2 However, IV insulin remains mandatory for critically ill or mentally obtunded patients. 2
Bicarbonate: Generally NOT Recommended
Do not administer bicarbonate for pH >6.9-7.0. 2 Studies show no difference in resolution of acidosis or time to discharge with bicarbonate use, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk. 2
Monitoring During Treatment
Draw blood every 2-4 hours for: 2
- Serum electrolytes, glucose
- Blood urea nitrogen, creatinine
- Venous pH (adequate for monitoring; repeat arterial blood gases unnecessary)
- Anion gap
Monitor fluid input/output, hemodynamic parameters, and clinical examination continuously. 2
Resolution Criteria
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
Transition to Subcutaneous Insulin
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 This overlap period is essential—premature termination of IV insulin is a common cause of DKA recurrence. 2
Special Considerations
SGLT2 inhibitors must be discontinued 3-4 days before any planned surgery to prevent euglycemic DKA. 1, 2 Monitor patients on these medications closely for euglycemic DKA, which can occur with normal or only mildly elevated glucose. 1
Identifying and treating the underlying precipitating cause (infection, myocardial infarction, medication non-adherence) is crucial for successful treatment. 1, 2 Administer appropriate antibiotics if infection suspected. 2