What is the initial treatment for diabetic ketoacidosis (DKA)?

Initial Treatment of Diabetic Ketoacidosis (DKA)

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour, followed by continuous intravenous regular insulin at 0.1 units/kg/hour once adequate urine output is confirmed and serum potassium is ≥3.3 mEq/L. 1, 2, 3

Immediate Assessment and Diagnosis

• Confirm DKA diagnosis with: blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15-18 mEq/L, and presence of ketonemia or ketonuria 4, 2, 3
• Obtain STAT laboratory evaluation: plasma glucose, venous blood gases, electrolytes with calculated anion gap, blood urea nitrogen, creatinine, serum ketones (preferably β-hydroxybutyrate), urinalysis, complete blood count, and electrocardiogram 4, 2, 3
• Identify precipitating factors: infection (obtain cultures if suspected), myocardial infarction, stroke, pancreatitis, insulin omission, or SGLT2 inhibitor use 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) to restore intravascular volume and renal perfusion 1, 2, 3

Subsequent Fluid Management:

• Continue isotonic or hypotonic saline based on hydration status, serum sodium, and urine output 4, 2
• When glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% saline while continuing insulin infusion to prevent hypoglycemia and ensure complete ketoacidosis resolution 1, 2, 3
• Target total fluid replacement of approximately 1.5 times 24-hour maintenance requirements over 24-48 hours 4, 3

Insulin Therapy

Critical Timing:

• Do NOT start insulin if serum potassium <3.3 mEq/L - aggressively replace potassium first to prevent life-threatening arrhythmias and respiratory muscle weakness 2, 3

Standard Regimen:

• Start continuous IV regular insulin at 0.1 units/kg/hour without initial bolus once potassium ≥3.3 mEq/L 1, 2, 3
• If glucose does not fall by 50 mg/dL in the first hour, verify adequate hydration, then double insulin infusion rate hourly until achieving steady decline of 50-75 mg/dL/hour 2, 3
• Never interrupt insulin infusion when glucose falls - instead add dextrose to prevent hypoglycemia while continuing insulin to clear ketosis 1, 2
• Continue insulin until complete resolution: pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L (glucose level is secondary) 1, 2, 3

Alternative for Mild-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 non-critically ill patients 2, 3
• Continuous IV insulin remains standard for critically ill and mentally obtunded patients 2, 3

Potassium Management

Critical Monitoring and Replacement:

• Despite potential hyperkalemia at presentation, total body potassium is universally depleted in DKA 4, 2
• If K+ <3.3 mEq/L: Delay insulin, aggressively replace potassium until ≥3.3 mEq/L 2, 3
• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq/L potassium to each liter of IV fluid (2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed 4, 1, 2, 3
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely every 2-4 hours, as levels will drop rapidly with insulin therapy 4, 2
• Maintain serum potassium 4-5 mEq/L throughout treatment 1, 2, 3

Bicarbonate Administration

The American Diabetes Association recommends AGAINST bicarbonate use for pH >6.9-7.0 4, 2, 3

• Multiple studies show no difference in resolution time or outcomes with bicarbonate 2, 3
• Bicarbonate may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 2, 3
• Consider bicarbonate only if pH <6.9: add 100 mmol sodium bicarbonate to 400 mL sterile water, infuse at 200 mL/hour 4

Monitoring Protocol

Frequent Monitoring is Essential:

• Check blood glucose every 1-2 hours 1, 3
• Draw blood every 2-4 hours for: 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 acidosis resolution 2, 3
• Direct measurement of β-hydroxybutyrate is preferred over nitroprusside method, which only detects acetoacetic acid and acetone 1, 3

Transition to Subcutaneous Insulin

Critical Timing to Prevent Recurrence:

• DKA resolution requires: glucose <200 mg/dL, bicarbonate ≥18 mEq/L, pH >7.3, and anion gap ≤12 mEq/L 1, 2, 3
• 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
• Consider adding low-dose basal insulin analog during IV insulin infusion to prevent rebound hyperglycemia 1, 2
• Once patient can eat, initiate multiple-dose regimen combining short/rapid-acting and intermediate/long-acting insulin 4, 2

Critical Pitfalls to Avoid

• Premature termination of insulin before complete ketosis resolution - this is a leading cause of DKA recurrence 1, 2, 3
• Starting insulin with K+ <3.3 mEq/L - can cause fatal arrhythmias 2, 3
• Interrupting insulin when glucose falls without adding dextrose - perpetuates ketoacidosis 1, 2
• Inadequate potassium monitoring and replacement - hypokalemia is a leading cause of DKA mortality 2
• Overly rapid correction of osmolality - increases cerebral edema risk, particularly in children 2, 5
• Using bicarbonate routinely - worsens outcomes and increases complications 2, 3
• Relying on nitroprusside for ketone measurement - misses β-hydroxybutyrate, the predominant ketone body 1, 3

Special Considerations

• For children and adolescents, rehydrate evenly over at least 48 hours to minimize cerebral edema risk 5
• Risk factors for cerebral edema include: severity of acidosis, greater hypocapnia, higher blood urea nitrogen at presentation, and bicarbonate treatment 5
• SGLT2 inhibitors must be discontinued 3-4 days before planned surgery to prevent euglycemic DKA 2