What is the initial treatment for a patient with diabetic ketoacidosis (DKA)?

Initial Treatment for Diabetic Ketoacidosis (DKA)

Begin immediate aggressive fluid resuscitation 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, followed by continuous intravenous regular insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L. 1, 2

Immediate Priorities: The First Hour

Fluid Resuscitation (Start First)

• Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour to restore circulatory volume and tissue perfusion 1, 2
• This aggressive initial fluid replacement is critical as it improves insulin sensitivity and helps correct the metabolic derangements 1
• After the first hour, continue fluid replacement at 4-14 mL/kg/hour based on hemodynamic status 2

Critical Laboratory Assessment

• Obtain plasma glucose, arterial blood gases (or venous pH), serum ketones (β-hydroxybutyrate preferred), electrolytes with calculated anion gap, serum bicarbonate, blood urea nitrogen, creatinine, complete blood count, urinalysis, and electrocardiogram 1, 2
• Check serum potassium immediately before starting insulin - this is a critical safety step 1

Insulin Therapy (Start After Checking Potassium)

• Do NOT start insulin if serum potassium is <3.3 mEq/L - delay insulin and aggressively replace potassium first to prevent life-threatening cardiac arrhythmias and respiratory muscle weakness 1
• Once potassium is ≥3.3 mEq/L, start continuous intravenous 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 every hour until achieving a steady decline of 50-75 mg/dL per hour 1, 2

Electrolyte Management

Potassium Replacement (Critical for Safety)

• If K+ <3.3 mEq/L: Hold insulin and aggressively replace potassium until ≥3.3 mEq/L 1
• 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 1
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely, as levels will drop rapidly with insulin therapy 1
• Target serum potassium of 4-5 mEq/L throughout treatment 1
• Common pitfall: Despite potentially normal or elevated initial potassium levels, total body potassium depletion is universal in DKA, and insulin therapy will further lower serum potassium 1

Bicarbonate (Generally NOT Recommended)

• Do not administer bicarbonate if pH >6.9-7.0 - studies show no benefit in resolution time or outcomes, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 1, 2

Ongoing Management During Treatment

Glucose Management

• When serum glucose reaches 200-250 mg/dL, add dextrose (5% dextrose with 0.45-0.75% NaCl) to IV fluids while continuing insulin infusion to prevent hypoglycemia 1, 2
• Target glucose between 150-200 mg/dL until DKA resolution parameters are met 1
• Critical pitfall: Interruption of insulin infusion when glucose levels fall is a common cause of persistent or worsening ketoacidosis 1

Monitoring Frequency

• Check blood glucose every 1-2 hours until stable 2
• Draw blood every 2-4 hours for serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 2
• Monitor for signs of cerebral edema, particularly in children (headache, altered mental status, seizures, bradycardia) 2

Resolution Criteria and Transition

DKA Resolution Parameters

• DKA is resolved when ALL of the following are met: glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L 1, 2
• Continue insulin infusion until resolution of ketoacidosis regardless of glucose levels 1

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 1, 2
• Continue IV insulin for 1-2 hours after starting subcutaneous insulin to ensure adequate plasma insulin levels 2
• When the patient can eat, start a multiple-dose schedule using a combination of short/rapid-acting and intermediate/long-acting insulin 1

Identify and Treat Precipitating Factors

• Obtain bacterial cultures (urine, blood, throat) if infection is suspected and administer appropriate antibiotics 1
• Identify potential precipitating factors: infection (most common), new diagnosis of diabetes, insulin discontinuation/inadequacy, cerebrovascular accident, myocardial infarction, pancreatitis, trauma, or drugs 1, 3, 4
• Discontinue SGLT2 inhibitors if present - these must be stopped 3-4 days before any planned surgery to prevent euglycemic DKA 1

Special Considerations

Alternative Approach for Mild-to-Moderate Uncomplicated DKA

• For mild-to-moderate uncomplicated DKA in non-critically ill patients, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective, safer, and more cost-effective than IV insulin 1, 2
• However, continuous IV insulin remains the standard of care for critically ill and mentally obtunded DKA patients 1, 2