What is the first line treatment for Diabetic Ketoacidosis (DKA) in Type 1 Diabetes Mellitus (T1DM)?

First-Line Treatment for DKA in Type 1 Diabetes Mellitus

The first-line treatment for DKA in T1DM consists of three simultaneous interventions: aggressive intravenous fluid resuscitation with isotonic saline at 15-20 mL/kg/hour, continuous intravenous regular insulin infusion at 0.1 units/kg/hour (with or without an initial 0.1 units/kg bolus), and potassium replacement once renal function is confirmed. 1, 2

Initial Fluid Resuscitation

• Begin with isotonic saline (0.9% NaCl) at 15-20 mL/kg body weight per hour for the first hour to restore circulatory volume and tissue perfusion 1, 2
• Total fluid replacement should approximate 1.5 times the 24-hour maintenance requirements 1
• Subsequent fluid choice depends on hydration state, serum electrolytes, and urine output 3

Insulin Therapy Protocol

For moderate to severe DKA, continuous intravenous regular insulin infusion is the preferred treatment method. 1, 2

• Start with an IV bolus of regular insulin at 0.1 units/kg followed by continuous infusion at 0.1 units/kg/hour 1
• The IV route is standard of care for critically ill and mentally obtunded patients 2
• Continue insulin infusion even after glucose normalizes, as ketonemia takes longer to clear than hyperglycemia 4

Alternative for Mild-Moderate Uncomplicated DKA

• Subcutaneous rapid-acting insulin analogs may be used in the emergency department or step-down units for uncomplicated mild to moderate DKA 2
• This approach is safer and more cost-effective than IV insulin but requires adequate fluid replacement, frequent monitoring, and appropriate follow-up 2
• There is no significant difference in outcomes between IV regular insulin and subcutaneous rapid-acting analogs when combined with aggressive fluid management 2

Electrolyte Management

Potassium replacement is critical and must begin early in treatment. 1, 3

• Include 20-30 mEq/L potassium in IV fluids once renal function is assured and serum potassium is known 1, 2
• Monitor serum potassium closely as insulin therapy drives potassium intracellularly, potentially causing life-threatening hypokalemia 1, 3
• Target serum potassium between 4-5 mmol/L throughout treatment 4

Glucose Management During Treatment

• When blood glucose falls below 200-250 mg/dL, add dextrose 5% to IV fluids while continuing insulin infusion to clear ketones 4, 3
• Target glucose between 150-200 mg/dL until DKA resolution 4
• Never stop insulin infusion when glucose normalizes—this is the most common error leading to persistent or worsening ketoacidosis 4, 1

Monitoring Requirements

• Check blood glucose every 2-4 hours during treatment 1, 2
• Measure serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH every 2-4 hours 1, 3
• Venous pH (typically 0.03 units lower than arterial) and anion gap adequately monitor acidosis resolution after initial diagnosis 3, 4

Resolution Criteria

DKA is resolved when ALL of the following are met: 4, 3

• 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 (glargine or detemir) 2-4 hours BEFORE stopping IV insulin infusion to prevent rebound hyperglycemia and recurrence of ketoacidosis. 1, 2

• This timing is critical—failure to overlap basal insulin is the most common error leading to DKA recurrence 1
• Continue IV insulin for 1-2 hours after starting subcutaneous insulin to ensure adequate plasma insulin levels 4
• When the patient can eat, initiate a multiple-dose schedule combining short/rapid-acting and intermediate/long-acting insulin 4, 1

Adjunctive Therapies

• Bicarbonate therapy is generally not recommended, as it makes no difference in resolution of acidosis or time to discharge 2
• Identify and treat precipitating causes (infection, myocardial infarction, stroke, medication non-adherence) 2
• Obtain bacterial cultures of urine, blood, and throat if infection is suspected 1, 3

Critical Pitfalls to Avoid

• Never discontinue IV insulin without prior basal insulin administration—this causes DKA recurrence 1
• Never stop insulin when glucose normalizes—continue until ketoacidosis resolves 4
• Inadequate potassium monitoring and replacement can lead to fatal cardiac arrhythmias 3, 1
• Overly aggressive glucose correction without dextrose supplementation causes hypoglycemia 4
• Relying on urine ketones for monitoring—use serum β-hydroxybutyrate instead 3, 4

Special Considerations

• For euglycemic DKA (glucose <250 mg/dL with ketoacidosis, often seen with SGLT2 inhibitor use), start D5 alongside 0.9% NaCl at the beginning of insulin treatment 4
• ICU admission is indicated for cardiovascular instability, inability to protect airway, obtundation, or severe DKA (pH <7.0) 5, 3