What is the approach to managing Diabetic Ketoacidosis (DKA) in adults?

Comprehensive Management of Diabetic Ketoacidosis (DKA) in Adults

The management of DKA in adults requires immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour for the first hour, followed by insulin therapy, electrolyte replacement, and identification of precipitating factors to reduce mortality. 1

Diagnosis and Initial Assessment

• DKA diagnostic criteria: blood glucose >250 mg/dl, arterial pH <7.3, bicarbonate <15 mEq/l, and moderate ketonuria or ketonemia 1
• Obtain arterial blood gases, complete blood count with differential, urinalysis, blood glucose, blood urea nitrogen, electrolytes with calculated anion gap, serum ketones, osmolality, chemistry profile, creatinine levels, and electrocardiogram 1
• Obtain chest X-ray and bacterial cultures (urine, blood, throat) if infection is suspected 1
• Differentiate from other causes of high anion gap metabolic acidosis including alcoholic ketoacidosis, lactic acidosis, salicylate ingestion, methanol, ethylene glycol, paraldehyde ingestion, and chronic renal failure 1

Fluid Therapy

• Begin with isotonic saline (0.9% NaCl) at 15-20 ml/kg/h during the first hour (approximately 1-1.5 liters in average adult) to restore intravascular volume and renal perfusion 1
• After initial resuscitation:
  • Use 0.45% NaCl at 4-14 ml/kg/h if corrected serum sodium is normal or elevated 1
  • Continue 0.9% NaCl if corrected serum sodium is low 1
• Correct serum sodium for hyperglycemia (add 1.6 mEq to sodium value for each 100 mg/dl glucose >100 mg/dl) 1
• Target fluid replacement to correct estimated deficits within 24 hours 1
• Monitor fluid input/output, blood pressure, and clinical examination to assess progress 1

Insulin Therapy

• Start continuous intravenous regular insulin without an initial bolus at 0.1 units/kg/hour 2
• Continue insulin therapy until resolution of ketoacidosis, regardless of glucose levels 2
• Add dextrose 5% to intravenous fluids when serum glucose reaches 250 mg/dL while continuing insulin infusion 2
• Target glucose between 150-200 mg/dL until DKA resolution parameters are met 2
• Transition to subcutaneous insulin when DKA resolves and patient can eat 2
• Administer basal insulin 2-4 hours before stopping IV insulin to prevent recurrence of ketoacidosis 2

Electrolyte Management

• Monitor potassium closely as total body potassium is depleted despite potentially normal or elevated initial serum levels due to acidosis 1
• Once renal function is assured and serum potassium is known, add 20-30 mEq/L potassium (2/3 KCl and 1/3 KPO₄) to IV fluids when serum levels fall below 5.5 mEq/L 1
• Typical electrolyte deficits in DKA include: potassium (3-5 mEq/kg), phosphate (5-7 mEq/kg), magnesium (1-2 mEq/kg), and calcium (1-2 mEq/kg) 1
• Bicarbonate administration is generally not recommended as it does not improve outcomes 3

Monitoring During Treatment

• Check blood glucose hourly 2
• Check electrolytes, blood urea nitrogen, creatinine, and osmolality every 2-4 hours until stable 1, 2
• Monitor venous pH and anion gap to assess resolution of acidosis 2
• Assess for signs of volume overload, particularly in patients with renal or cardiac compromise 1, 2
• Ensure the induced change in serum osmolality does not exceed 3 mOsm/kg/h to prevent cerebral edema 1
• Continue monitoring for at least 24 hours after resolution of DKA 2

Resolution Criteria

• Blood glucose <200 mg/dL 1
• Serum bicarbonate ≥15 mEq/L 1
• Venous pH >7.3 1
• Anion gap normalized 1

Special Considerations

• In hemodialysis patients, monitor cardiac and respiratory status closely during fluid administration 2
• Recent evidence suggests balanced crystalloids (Ringer's lactate or Plasma-Lyte) may lead to faster DKA resolution than saline (median 13.0 vs 16.9 hours) 4
• Cerebral edema is a rare but serious complication, more common in pediatric patients than adults 5

Prevention Strategies

• Develop a structured discharge plan tailored to the individual patient 2
• Schedule follow-up appointments prior to discharge 2
• Provide patient education on:
  • Early recognition of DKA symptoms (thirst, polyuria, abdominal pain, nausea, vomiting, fruity breath odor) 6
  • Sick day management including never omitting insulin 6
  • When to contact healthcare providers 5
  • Blood glucose monitoring during illness 6

Common Pitfalls to Avoid

• Failing to identify and treat the precipitating cause (infection is most common at 30-50%) 7
• Discontinuing insulin too early before ketosis resolves 2
• Inadequate potassium replacement leading to arrhythmias 1
• Overly rapid correction of hyperglycemia and hyperosmolality 1
• Insufficient monitoring of electrolytes and acid-base status 2
• Not overlapping IV insulin with subcutaneous insulin during transition 2