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

Initial Management of Diabetic Ketoacidosis (DKA)

The initial management of DKA requires immediate administration of 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 without an initial bolus, along with comprehensive laboratory evaluation and treatment of precipitating factors. 1, 2

Diagnosis and Initial Assessment

• Diagnostic criteria for DKA include blood glucose >250 mg/dl, arterial pH <7.3, bicarbonate <15 mEq/l, and moderate ketonuria or ketonemia 1, 2
• Obtain immediate laboratory evaluation including:
  • Blood glucose, venous blood gases, electrolytes with calculated anion gap
  • Blood urea nitrogen (BUN), creatinine, calcium, phosphorous
  • Serum ketones, osmolality, complete blood count with differential
  • Urinalysis, urine ketones, and electrocardiogram 1, 2
• Obtain bacterial cultures (urine, blood, throat) if infection is suspected and administer appropriate antibiotics 3
• Direct measurement of β-hydroxybutyrate in blood is preferred over nitroprusside method, which only measures acetoacetic acid and acetone 1, 4

Fluid Therapy

• Begin with isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour during the first hour (approximately 1-1.5 liters in average adult) to restore intravascular volume and renal perfusion 1, 2
• Subsequent fluid choice depends on hydration status, serum electrolyte levels, and urine output:
  • If corrected serum sodium is normal or elevated: use 0.45% NaCl at 4-14 ml/kg/hour
  • If corrected serum sodium is low: continue with 0.9% NaCl at similar rate 1, 3
• Total fluid replacement should aim to correct estimated deficits within 24 hours, typically 1.5 times the maintenance requirements 1, 3
• When serum glucose reaches 250 mg/dl, add dextrose to IV fluids to prevent hypoglycemia while continuing insulin to clear ketosis 3

Insulin Therapy

• Start continuous intravenous regular insulin infusion at 0.1 units/kg/hour without an initial bolus for moderate to severe DKA 1, 2, 3
• If plasma glucose does not fall by 50 mg/dl in the first hour, double the insulin infusion rate hourly until a steady glucose decline between 50-75 mg/hour is achieved 1, 2
• For mild DKA only, subcutaneous or intramuscular regular insulin may be considered:
  • Give a "priming" dose of 0.4-0.6 units/kg, half as IV bolus and half as subcutaneous/intramuscular
  • Follow with 0.1 unit/kg subcutaneously or intramuscularly every hour 1
• When serum glucose reaches 250 mg/dl, decrease insulin infusion to 0.05-0.1 units/kg/hour and add dextrose to IV fluids 3

Electrolyte Management

• Monitor potassium levels closely as insulin therapy and correction of acidosis can cause hypokalemia 2, 3
• Include 20-30 mEq/L potassium (2/3 KCl and 1/3 KPO₄) in IV fluids 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 4, 3
• Bicarbonate administration is generally not recommended for patients with pH >6.9 1, 2, 5
• Phosphate replacement has not shown beneficial effects on clinical outcomes but may be indicated in patients with cardiac dysfunction, anemia, respiratory depression, or serum phosphate <1.0 mg/dl 1

Monitoring During Treatment

• Check blood glucose every 1-2 hours 2, 3
• Draw blood every 2-4 hours to determine serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 1, 2
• Follow venous pH and anion gap to monitor resolution of acidosis rather than urine or serum ketones by nitroprusside method 1, 3
• Generally, repeat arterial blood gases are unnecessary; venous pH (which is usually 0.03 units lower than arterial pH) can be followed 1

Resolution and Transition to Subcutaneous Insulin

• DKA resolution criteria: glucose <200 mg/dl, serum bicarbonate ≥18 mEq/l, venous pH >7.3, and anion gap ≤12 mEq/L 1, 3
• When DKA resolves:
  • If patient is NPO (nothing by mouth), continue IV insulin and fluid replacement
  • Administer basal insulin 2-4 hours before stopping the IV insulin infusion to prevent recurrence of ketoacidosis 1, 2
  • Recent studies suggest that administration of a low dose of basal insulin analog in addition to IV insulin may prevent rebound hyperglycemia 1, 2
• When the patient can eat, start a multiple-dose insulin regimen with combination of short/rapid-acting and intermediate/long-acting insulin 1
• Continue IV insulin infusion for 1-2 hours after starting subcutaneous regimen to ensure adequate plasma insulin levels 1

Common Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis 2, 4
• Inadequate monitoring of potassium levels during insulin therapy 2, 3
• Interruption of insulin infusion when glucose levels fall without adding dextrose 4, 3
• Relying on nitroprusside method to measure ketones, which doesn't detect β-hydroxybutyrate 1, 4
• Abrupt discontinuation of IV insulin without overlapping with subcutaneous insulin, leading to recurrence of DKA 1
• Inadequate identification and treatment of precipitating factors such as infection, myocardial infarction, or stroke 1