What is the initial management for a patient presenting with Diabetic Ketoacidosis (DKA)?

Initial Management of Diabetic Ketoacidosis (DKA)

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in the first hour for average adults) while simultaneously obtaining diagnostic labs and starting continuous intravenous regular insulin at 0.1 units/kg/hour without an initial bolus. 1, 2

Diagnostic Confirmation

Confirm DKA diagnosis with the following criteria 1, 2:

• Blood glucose >250 mg/dL
• Arterial pH <7.3
• Serum bicarbonate <15-18 mEq/L
• Presence of ketonemia or ketonuria
• Elevated anion gap

Obtain comprehensive laboratory evaluation immediately 1, 2:

• Plasma glucose, blood urea nitrogen/creatinine, serum ketones (preferably β-hydroxybutyrate)
• Electrolytes with calculated anion gap, osmolality
• Arterial blood gases (or venous pH, which runs 0.03 units lower than arterial)
• Complete blood count with differential
• Urinalysis with urine ketones
• Electrocardiogram

If infection is suspected based on fever, leukocytosis, or clinical signs, obtain bacterial cultures (blood, urine, throat) and initiate appropriate antibiotics immediately 1, 2. Identify other precipitating factors including cerebrovascular accident, myocardial infarction, pancreatitis, trauma, alcohol abuse, or insulin omission 1.

Fluid Resuscitation Protocol

Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour to restore intravascular volume and tissue perfusion 1, 2. This aggressive initial fluid replacement is critical for reversing shock and improving insulin sensitivity.

After the first hour, adjust fluid choice based on 1, 2:

• Hydration status assessment
• Serum sodium levels
• Urine output

When serum glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% NaCl 1, 2. This prevents hypoglycemia while allowing continued insulin administration to clear ketosis—a critical step that is frequently missed.

Total fluid replacement should correct estimated deficits within 24 hours, typically 1.5 times the 24-hour maintenance requirements 1, 2.

Insulin Therapy

Initiate continuous intravenous regular insulin infusion at 0.1 units/kg/hour without an initial bolus for moderate to severe DKA 1, 2, 3. This is the standard of care for critically ill patients.

Monitor response closely 1, 2:

• If plasma glucose does not fall by 50 mg/dL in the first hour, verify adequate hydration status
• If hydration is acceptable, double the insulin infusion rate every hour until achieving a steady glucose decline of 50-75 mg/hour

When glucose reaches 250 mg/dL, decrease insulin to 0.05-0.1 units/kg/hour but do NOT stop insulin 2. Add dextrose to IV fluids at this point. Continue insulin infusion until complete resolution of ketoacidosis regardless of glucose levels 1, 2.

Common Insulin Management Pitfall

Interrupting insulin infusion when glucose falls is the most common cause of persistent or worsening ketoacidosis 1, 2, 4. The goal is resolution of ketosis, not just glucose control. Target glucose between 150-200 mg/dL until DKA resolves 1.

Electrolyte Management

Potassium Replacement

Once renal function is confirmed and serum potassium is <5.3 mEq/L, add 20-30 mEq/L potassium to IV fluids (2/3 KCl and 1/3 KPO₄) 1, 2. Insulin administration drives potassium intracellularly, creating life-threatening hypokalemia risk.

Maintain serum potassium between 4-5 mmol/L throughout treatment 1, 2. Check potassium levels every 2-4 hours initially.

Bicarbonate

Bicarbonate administration is NOT recommended for DKA patients with pH >6.9-7.0 1, 2, 4. Studies show no difference in resolution of acidosis or time to discharge with bicarbonate use 5, 4.

Monitoring Protocol

Check blood glucose every 1-2 hours 2.

Draw blood every 2-4 hours to measure 1, 2:

• Serum electrolytes (especially potassium)
• Glucose
• Blood urea nitrogen/creatinine
• Osmolality
• Venous pH and anion gap

Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA resolution, as the nitroprusside method only measures acetoacetic acid and acetone, missing the predominant ketone body 1, 2.

Resolution Criteria

DKA is resolved when ALL of the following are met 1, 2:

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3
• Anion gap ≤12 mEq/L

Transition to Subcutaneous Insulin

Once DKA is resolved 5, 2:

• Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia
• If patient is eating, start multiple-dose subcutaneous insulin regimen combining short/rapid-acting with intermediate/long-acting insulin
• If patient remains NPO, continue IV insulin with subcutaneous supplementation as needed

Critical Pitfalls to Avoid

Premature termination of insulin before complete ketosis resolution leads to DKA recurrence 1, 2, 4. Resolution requires normalization of pH, bicarbonate, and anion gap—not just glucose control.

Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin perpetuates treatment delays 1, 4.

Inadequate potassium monitoring and replacement during insulin therapy causes dangerous hypokalemia 1, 2.

Overzealous insulin without glucose supplementation leads to hypoglycemia 1.

Stopping IV insulin without prior basal insulin administration causes rebound hyperglycemia and ketoacidosis 5, 2.