What is the initial management of Diabetic Ketoacidosis (DKA)?

Initial Management of Diabetic Ketoacidosis (DKA)

Begin with aggressive isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour, followed by continuous intravenous regular insulin infusion at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L, while adding dextrose-containing fluids when glucose reaches 250 mg/dL to prevent hypoglycemia while continuing insulin until complete resolution of ketoacidosis. 1, 2

Diagnostic Confirmation and Initial Assessment

Before initiating treatment, confirm DKA with the following criteria:

• Blood glucose >250 mg/dL (though euglycemic DKA can occur, especially with SGLT2 inhibitors) 2
• Arterial pH <7.3 1, 2
• Serum bicarbonate <15 mEq/L 1, 2
• Presence of ketonemia or ketonuria (direct measurement of β-hydroxybutyrate is preferred over nitroprusside method) 1, 2

Obtain the following laboratory studies immediately: plasma glucose, blood urea nitrogen/creatinine, serum ketones (β-hydroxybutyrate preferred), electrolytes with calculated anion gap, osmolality, urinalysis, arterial blood gases, complete blood count, and electrocardiogram 1, 2, 3. If infection is suspected, obtain bacterial cultures from urine, blood, and throat, and administer appropriate antibiotics 2, 3.

Fluid Resuscitation Protocol

First Hour:

• Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adults) 1, 2, 3
• This aggressive initial fluid replacement restores tissue perfusion and improves insulin sensitivity 2

Subsequent Fluid Management:

• Continue fluid replacement based on hydration status, serum electrolyte levels, and urine output 2
• Critical transition point: When serum glucose reaches 250 mg/dL, change to 5% dextrose with 0.45-0.75% NaCl 1, 2
• Total fluid replacement should correct estimated deficits within 24 hours 2

Insulin Therapy

Timing of Insulin Initiation:

• DO NOT start insulin if potassium <3.3 mEq/L - this is an absolute contraindication to prevent life-threatening cardiac arrhythmias and death 2, 3
• Aggressively replace potassium first until levels reach ≥3.3 mEq/L 2, 3

Insulin Dosing:

• Start continuous intravenous regular insulin infusion at 0.1 units/kg/hour without an initial bolus 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 every hour until achieving a steady decline of 50-75 mg/dL per hour 2, 3

Critical Principle - Never Interrupt Insulin:

• Continue insulin infusion until complete resolution of ketoacidosis (pH >7.3, serum bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels 1, 2
• When glucose falls below 250 mg/dL, add dextrose to IV fluids rather than stopping insulin 1, 2
• Premature termination of insulin before complete ketosis resolution is a common cause of treatment failure and DKA recurrence 1, 2

Electrolyte Management

Potassium Replacement Algorithm:

• If K+ <3.3 mEq/L: Hold insulin, aggressively replace potassium until ≥3.3 mEq/L 2, 3
• If K+ 3.3-5.3 mEq/L: Add 20-30 mEq/L potassium to IV fluids (use 2/3 KCl and 1/3 KPO₄) once adequate urine output is confirmed 1, 2, 3
• If K+ >5.3 mEq/L: Withhold potassium initially but monitor closely, as levels will drop rapidly with insulin therapy 2
• Target: Maintain serum potassium between 4-5 mEq/L throughout treatment 1, 2

Bicarbonate Administration:

• Generally NOT recommended for pH >6.9-7.0 2
• Studies show no difference in resolution of acidosis or time to discharge with bicarbonate use 2
• Bicarbonate may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 2

Monitoring Protocol

Frequent Laboratory Monitoring:

• Check blood glucose every 1-2 hours 1
• Draw blood every 2-4 hours to measure serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 2, 3
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor resolution of acidosis 2
• Monitor potassium levels closely, as insulin therapy and correction of acidosis cause hypokalemia 1, 2

Resolution Criteria and Transition to Subcutaneous Insulin

DKA Resolution Requires ALL of the Following:

• Glucose <200 mg/dL 2
• Serum bicarbonate ≥18 mEq/L 1, 2
• Venous pH >7.3 1, 2
• Anion gap ≤12 mEq/L 1, 2

Transition Protocol:

• 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, 3
• This overlap period is essential - stopping IV insulin without prior basal insulin administration is the most common error leading to DKA recurrence 3
• Once the patient can eat, start a multiple-dose schedule using a combination of short/rapid-acting and intermediate/long-acting insulin 2, 3

Common Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) 1, 2
• Interrupting insulin infusion when glucose falls without adding dextrose - this perpetuates ketoacidosis 1, 2
• Starting insulin with potassium <3.3 mEq/L - this can cause life-threatening arrhythmias 2, 3
• Inadequate potassium monitoring and replacement - a leading cause of mortality in DKA 2
• Stopping IV insulin without prior basal insulin administration - leads to DKA recurrence 3
• Relying solely on nitroprusside method to measure ketones, which doesn't detect β-hydroxybutyrate, the predominant ketone body in DKA 1, 2
• Overly rapid correction of osmolality - increases risk of cerebral edema, particularly in children 2, 4

Special Considerations

Alternative Approach for Mild-to-Moderate Uncomplicated DKA:

• Subcutaneous rapid-acting insulin analogs combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin for mild-to-moderate uncomplicated DKA 2
• However, continuous IV insulin remains the standard of care for critically ill and mentally obtunded DKA patients 2

British Guidelines Approach:

• Using subcutaneous insulin glargine along with continuous regular IV insulin has shown faster DKA resolution and shorter hospital stays compared to continuous IV insulin alone 4

Identify and Treat Precipitating Factors:

• Common triggers include infection, myocardial infarction, cerebrovascular accident, pancreatitis, trauma, insulin discontinuation/inadequacy, and SGLT2 inhibitor use 2, 5
• SGLT2 inhibitors must be discontinued 3-4 days before any planned surgery to prevent euglycemic DKA 2