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

Initial Management of Diabetic Ketoacidosis (DKA)

The initial management of diabetic ketoacidosis requires immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour, followed by continuous intravenous regular insulin at 0.1 units/kg/hour after confirming adequate renal function and potassium levels. 1, 2

Diagnosis and Initial Assessment

• DKA diagnostic criteria include: blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and moderate ketonuria or ketonemia 3, 1
• Initial laboratory evaluation should include plasma glucose, blood urea nitrogen/creatinine, serum ketones, electrolytes (with calculated anion gap), osmolality, urinalysis, urine ketones, arterial blood gases, complete blood count with differential, and electrocardiogram 1, 2
• Obtain bacterial cultures (urine, blood, throat) if infection is suspected and administer appropriate antibiotics 1
• Identify potential precipitating factors: infection, cerebrovascular accident, alcohol abuse, pancreatitis, myocardial infarction, trauma, drugs, or insulin discontinuation/inadequacy 1, 2

Fluid Therapy

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

Insulin Therapy

• Start with continuous intravenous regular insulin infusion at 0.1 units/kg/hour (preferred method for moderate to severe DKA) 1, 2
• 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
• Do not interrupt insulin infusion when glucose falls below 250 mg/dL; instead, add dextrose to the IV fluids to prevent hypoglycemia 1, 4

Electrolyte Management

• 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 <5.5 mEq/L 3, 1
• Monitor potassium levels closely, as insulin administration can cause hypokalemia; maintain serum K⁺ between 4-5 mmol/L 1, 2
• If significant hypokalemia is present initially (<3.3 mEq/L), delay insulin treatment until potassium concentration is restored to avoid arrhythmias, cardiac arrest, and respiratory muscle weakness 2
• Bicarbonate administration is generally not recommended for DKA patients with pH >7.0 3, 1
• For severe acidosis (pH <6.9), consider 100 mmol sodium bicarbonate in 400 mL sterile water at 200 mL/h 2

Monitoring During Treatment

• Draw blood every 2-4 hours to determine serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 2
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor resolution of acidosis 1
• Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA, as the nitroprusside method only measures acetoacetic acid and acetone 1, 2

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 from IV to subcutaneous insulin, administer basal insulin 2-4 hours before stopping the IV insulin to prevent recurrence of ketoacidosis and rebound hyperglycemia 3, 2
• When the patient can eat, start a multiple-dose schedule using a combination of short/rapid-acting and intermediate/long-acting insulin 1, 2

Common Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis can lead to recurrence of DKA 1
• Interruption of insulin infusion when glucose levels fall is a common cause of persistent or worsening ketoacidosis 1
• 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, 2
• Overzealous treatment with insulin without glucose supplementation can lead to hypoglycemia 1, 4
• Cerebral edema is a rare but potentially fatal complication, particularly in children, that can result from rapid correction of hyperglycemia 2, 5