What is the immediate treatment for a patient presenting with Diabetic Ketoacidosis (DKA)?

Immediate Treatment of Diabetic Ketoacidosis

Begin aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in the first hour for adults) and start continuous intravenous insulin infusion at 0.1 units/kg/hour after confirming serum potassium is ≥3.3 mEq/L. 1, 2

Initial Assessment and Diagnostic Confirmation

Before initiating treatment, confirm DKA diagnosis with the following criteria: 2

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

Obtain immediate laboratory evaluation including plasma glucose, electrolytes with calculated anion gap, arterial blood gases, serum ketones (preferably β-hydroxybutyrate), BUN/creatinine, complete blood count, urinalysis, and ECG. 2

Identify precipitating factors such as infection, myocardial infarction, stroke, insulin omission, or medications (particularly SGLT-2 inhibitors which must be discontinued). 3, 2

Fluid Resuscitation Protocol

Initial fluid therapy is critical for restoring tissue perfusion and improving insulin sensitivity. 2

• Start with 0.9% NaCl at 15-20 mL/kg/hour during the first hour 1, 2
• Subsequent fluid choice depends on hydration status, serum electrolytes, and urine output 2
• When serum glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy 1, 4, 2
• Target glucose between 150-200 mg/dL until DKA resolution parameters are met 1, 4

Insulin Therapy

Do NOT start insulin if serum potassium is <3.3 mEq/L—aggressively replace potassium first to prevent life-threatening cardiac arrhythmias. 2

Once potassium is ≥3.3 mEq/L: 2

• Begin continuous IV regular insulin infusion at 0.1 units/kg/hour 1, 2
• If glucose does not fall by 50 mg/dL in the first hour, check hydration status and double the insulin infusion rate hourly until achieving a steady decline of 50-75 mg/dL per hour 2
• Continue insulin infusion until complete resolution of ketoacidosis regardless of glucose levels—this is critical as ketonemia takes longer to clear than hyperglycemia 1, 4, 2

Common Pitfall to Avoid

Never interrupt insulin infusion when glucose levels fall below 250 mg/dL—this is a leading cause of persistent or worsening ketoacidosis. Instead, add dextrose to IV fluids while maintaining insulin therapy. 4, 2

Electrolyte Management

Potassium Replacement (Critical Priority)

Despite often presenting with normal or elevated potassium, total body potassium depletion is universal in DKA, and insulin therapy will further lower serum levels. 2

Potassium replacement protocol: 2

• If K+ <3.3 mEq/L: Delay insulin therapy and aggressively replace potassium until ≥3.3 mEq/L
• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq potassium per liter of IV fluid (use 2/3 KCl and 1/3 KPO₄) once adequate urine output is confirmed
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely as levels will drop rapidly with insulin therapy
• Target serum potassium of 4-5 mEq/L throughout treatment 1, 2

Bicarbonate Administration

Bicarbonate is NOT recommended for DKA patients with pH >6.9-7.0, as studies show no benefit in resolution time or outcomes and may worsen ketosis, cause hypokalemia, and increase cerebral edema risk. 2

Monitoring During Treatment

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

• Serum electrolytes
• Glucose
• BUN/creatinine
• Venous pH (adequate for monitoring; typically 0.03 units lower than arterial pH) 4
• Anion gap

Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA, as the nitroprusside method only measures acetoacetic acid and acetone, not the primary ketone body. 4, 2

DKA Resolution Criteria

DKA is resolved when ALL of the following parameters are met: 1, 4, 2

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

Transition to Subcutaneous Insulin

Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia. 3, 2

Once DKA is resolved and the patient can eat: 3, 1, 4

• Start a multiple-dose subcutaneous insulin regimen combining short/rapid-acting and intermediate/long-acting insulin
• Continue IV insulin infusion for 1-2 hours after starting subcutaneous insulin to ensure adequate plasma insulin levels 4

Alternative Approach for Uncomplicated Mild-to-Moderate DKA

For uncomplicated mild-to-moderate DKA in alert patients, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective, safer, and more cost-effective than IV insulin. 2 However, continuous IV insulin remains the standard of care for critically ill and mentally obtunded patients. 3, 2

Treatment of Underlying Precipitating Causes

Concurrent treatment of precipitating factors is essential: 3, 2

• Obtain bacterial cultures (blood, urine, throat) if infection is suspected and administer appropriate antibiotics
• Evaluate for myocardial infarction, stroke, pancreatitis, or trauma
• Discontinue SGLT-2 inhibitors (should be stopped 3-4 days before any planned surgery to prevent euglycemic DKA) 2