Initial Management of Diabetic Ketoacidosis (DKA)
Begin with aggressive isotonic saline resuscitation at 15-20 mL/kg/hour in the first hour, followed by continuous intravenous regular insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L, while simultaneously correcting electrolyte deficits and identifying precipitating factors. 1, 2
Diagnostic Confirmation
Before initiating treatment, confirm DKA diagnosis when all three criteria are present: 1
- Blood glucose >250 mg/dL (though euglycemic DKA can occur with SGLT2 inhibitors)
- Arterial pH <7.3
- Serum bicarbonate <15-18 mEq/L with positive ketones
Obtain the following laboratory studies immediately: plasma glucose, electrolytes with calculated anion gap, serum ketones (β-hydroxybutyrate preferred), blood urea nitrogen/creatinine, arterial blood gases, complete blood count, urinalysis, and electrocardiogram. 1, 2 These tests identify precipitating factors such as infection, myocardial infarction, stroke, pancreatitis, insulin omission, or SGLT2 inhibitor use. 1
Fluid Resuscitation: The First Priority
Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adults) during the first hour to restore circulatory volume and tissue perfusion. 1, 2 This aggressive initial fluid replacement is critical as it improves insulin sensitivity and helps correct the metabolic derangements. 2
Continue fluid replacement to correct estimated deficits within 24 hours, adjusting based on hydration status, electrolyte levels, and urine output. 1, 2 When serum glucose reaches 250 mg/dL, change fluid to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy. 2
Common pitfall: Failure to add dextrose when glucose falls below 250 mg/dL is a frequent error that leads to persistent ketoacidosis or hypoglycemia. 2
Potassium Management: Critical Before Insulin
If serum potassium is <3.3 mEq/L, hold insulin therapy and aggressively replace potassium until levels reach ≥3.3 mEq/L to prevent life-threatening arrhythmias and respiratory muscle weakness. 1, 2 Despite often presenting with normal or elevated potassium, total body potassium depletion is universal in DKA, and insulin therapy will drive potassium intracellularly, potentially causing dangerous hypokalemia. 2, 3
Once potassium is ≥3.3 mEq/L and renal function is adequate (confirmed by urine output), add 20-30 mEq/L potassium to the infusion (use 2/3 KCl and 1/3 KPO₄). 2 Target serum potassium of 4-5 mEq/L throughout treatment. 1, 2
Critical warning: Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA. 2 Hypokalemia occurs in approximately 50% of patients during treatment. 1
Insulin Therapy: Start After Potassium Correction
Administer 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 a glucose decline of 50-75 mg/dL per hour. 1, 2 If plasma glucose does not fall by 50 mg/dL from the initial value in the first hour, check hydration status; if acceptable, double the insulin infusion rate every hour until steady glucose decline is achieved. 2
Do not stop insulin when glucose falls below 250 mg/dL. 1 Instead, add dextrose to IV fluids and continue insulin at a reduced rate until DKA resolves. 2 Premature termination of insulin therapy before complete resolution of ketosis is a common cause of DKA recurrence. 2
Alternative for mild-to-moderate uncomplicated DKA: Subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective and safer than IV insulin, and more cost-effective. 2 However, continuous IV insulin remains standard for critically ill patients. 2
Bicarbonate: Generally Not Recommended
Do not administer bicarbonate for DKA patients with 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 serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH. 2 Venous pH (typically 0.03 units lower than arterial pH) is adequate for monitoring; repeat arterial blood gases are generally unnecessary. 2
Monitor fluid input/output, hemodynamic parameters, and clinical examination continuously. 2 Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA resolution. 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 and failure to do so is a common cause of DKA recurrence. 2
Once the patient can eat, start a multiple-dose schedule using a combination of short/rapid-acting and intermediate/long-acting insulin. 2
Identify and Treat Precipitating Factors
Obtain bacterial cultures (urine, blood, throat) if infection is suspected and administer appropriate antibiotics. 2 Other precipitating factors include cerebrovascular accident, myocardial infarction, pancreatitis, trauma, or insulin discontinuation/inadequacy. 2
SGLT2 inhibitor consideration: Discontinue SGLT2 inhibitors 3-4 days before any planned surgery to prevent euglycemic DKA. 1, 2 Monitor patients on these medications for euglycemic DKA, which can occur with normal or only mildly elevated glucose. 1
Critical Pitfalls to Avoid
- Starting insulin before excluding hypokalemia (K+ <3.3 mEq/L) can precipitate life-threatening cardiac arrhythmias 2, 3
- Stopping insulin when glucose normalizes but before ketoacidosis resolves 2
- Failing to add dextrose when glucose falls below 250 mg/dL 2
- Overly rapid correction of osmolality increases cerebral edema risk, particularly in children 2
- Inadequate potassium monitoring and replacement 2
- Discontinuing IV insulin without prior administration of subcutaneous basal insulin 2