What are the initial management steps for diabetic ketoacidosis (DKA)?

Initial Management of Diabetic Ketoacidosis (DKA)

The initial management of diabetic ketoacidosis requires immediate administration of isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour, followed by continuous intravenous insulin infusion at 0.1 units/kg/hour without bolus, alongside comprehensive laboratory monitoring and identification of precipitating factors. 1, 2

Diagnosis and Assessment

• Confirm DKA diagnosis using laboratory criteria: blood glucose >250 mg/dL, arterial pH <7.3, bicarbonate <15 mEq/L, and moderate ketonuria or ketonemia 2, 1
• Obtain comprehensive laboratory evaluation including plasma glucose, blood urea nitrogen/creatinine, serum ketones, electrolytes with calculated anion gap, osmolality, urinalysis, arterial blood gases, complete blood count, and electrocardiogram 1, 3
• Direct measurement of β-hydroxybutyrate in blood is preferred over nitroprusside method for monitoring ketones 1, 4
• Identify potential precipitating factors: infection, new-onset diabetes, insulin omission, myocardial infarction, stroke, drugs affecting carbohydrate metabolism, or alcohol abuse 1, 3

Fluid Therapy

• Begin with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adult) during the first hour to restore circulatory volume and tissue perfusion 2, 1
• Subsequent fluid choice depends on hydration status, serum electrolyte levels, and urine output 1
• 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 1, 4
• Total fluid replacement should aim to correct estimated deficits (typically 6L or 100 mL/kg) within 24 hours 2, 3

Insulin Therapy

• Start continuous intravenous regular insulin infusion at 0.1 units/kg/hour (preferred method for moderate to severe DKA) 1, 4
• If plasma glucose does not fall by 50 mg/dL from initial value in the first hour, check hydration status; if acceptable, double the insulin infusion rate until a steady glucose decline of 50-75 mg/h is achieved 1
• Continue insulin infusion until resolution of ketoacidosis (pH >7.3, serum bicarbonate ≥18 mEq/L, and anion gap ≤12 mEq/L) regardless of glucose levels 1, 2
• Never interrupt insulin infusion when glucose levels fall; instead, add dextrose to prevent hypoglycemia while continuing insulin to clear ketosis 4, 5

Electrolyte Management

• Monitor potassium levels closely, as insulin administration can cause hypokalemia despite potentially normal or elevated initial serum levels due to acidosis 1, 3
• Include 20-30 mEq/L potassium (2/3 KCl and 1/3 KPO₄) in the infusion once renal function is assured and serum potassium is <5.3 mEq/L 1, 2
• Maintain serum potassium between 4-5 mmol/L throughout treatment 1, 4
• Bicarbonate administration is generally not recommended for DKA patients with pH >7.0 1, 5

Monitoring During Treatment

• Check blood glucose every 1-2 hours 4
• Draw blood every 2-4 hours to determine serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 4
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor resolution of acidosis 1

Resolution Parameters and Transition to Subcutaneous Insulin

• DKA resolution requires: glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L 1, 2
• When transitioning to subcutaneous insulin, administer basal insulin 2-4 hours before stopping the intravenous insulin to prevent recurrence of ketoacidosis 2, 1
• Administration of a low dose of basal insulin analog in addition to intravenous insulin infusion may prevent rebound hyperglycemia 2, 4

Common Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis can lead to recurrence of DKA 1, 4
• Interruption of insulin infusion when glucose levels fall is a common cause of persistent or worsening ketoacidosis 4, 5
• Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin therapy 1
• Inadequate monitoring and replacement of electrolytes, particularly potassium 1, 4
• Overzealous treatment with insulin without glucose supplementation can lead to hypoglycemia 1, 6