What is the treatment for Diabetic Ketoacidosis (DKA) in a patient?

Treatment of Diabetic Ketoacidosis (DKA) in Hospitalized Patients

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 liters in the first hour) to restore intravascular volume and renal perfusion, followed by continuous intravenous insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L. 1

Initial Assessment and Diagnosis

Before initiating treatment, confirm DKA diagnosis with the following criteria 2, 1:

• Blood glucose >250 mg/dL (though euglycemic DKA can occur, especially with SGLT2 inhibitors)
• Arterial pH <7.3
• Serum bicarbonate <15 mEq/L
• Positive serum or urine ketones
• Anion gap >10-12 mEq/L

Obtain immediate laboratory evaluation including plasma glucose, electrolytes with calculated anion gap, serum ketones (β-hydroxybutyrate preferred), arterial blood gases, complete blood count, urinalysis, and electrocardiogram 1. Identify precipitating factors such as infection, myocardial infarction, stroke, pancreatitis, or insulin omission—obtain bacterial cultures if infection is suspected 1.

Fluid Resuscitation Protocol

First Hour

Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour 2, 1. This aggressive initial fluid replacement is the most critical step, as it restores tissue perfusion and improves insulin sensitivity 1.

Subsequent Fluid Management

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

• If corrected sodium is normal or elevated: Use 0.45% NaCl at 4-14 mL/kg/hour
• If corrected sodium is low: Continue 0.9% NaCl at 4-14 mL/kg/hour
• When glucose falls to 200-250 mg/dL: Switch to 5% dextrose with 0.45-0.75% saline while continuing insulin infusion 1, 3

Note: Corrected sodium = measured sodium + 1.6 mEq/L for each 100 mg/dL glucose above 100 mg/dL 2

Insulin Therapy

Critical Pre-Insulin Check: Potassium Level

DO NOT start insulin if serum potassium <3.3 mEq/L 1. Despite potentially normal or elevated initial potassium levels, total body potassium is universally depleted in DKA, and insulin will drive potassium intracellularly, potentially causing life-threatening cardiac arrhythmias 1.

Insulin Administration

For moderate to severe DKA (pH <7.0-7.24) or critically ill patients 1:

• Start continuous IV regular insulin at 0.1 units/kg/hour (no initial bolus needed)
• If glucose does not fall by 50 mg/dL in the first hour, check hydration status and double insulin infusion rate hourly until steady decline of 50-75 mg/h is achieved 1

Alternative for Mild-Moderate Uncomplicated DKA

For stable patients with mild DKA (pH 7.25-7.30), subcutaneous rapid-acting insulin analogs combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin 1, 4. However, continuous IV insulin remains standard for critically ill and mentally obtunded patients 1.

Critical Insulin Management Rule

Continue insulin infusion until complete resolution of ketoacidosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L), regardless of glucose levels 1, 4. When glucose falls below 250 mg/dL, add dextrose to IV fluids while maintaining insulin infusion—premature discontinuation of insulin is a common cause of persistent or recurrent DKA 1.

Potassium Replacement Protocol

Monitor potassium closely and replace according to these thresholds 1:

• If K+ <3.3 mEq/L: Hold insulin, aggressively replace potassium until ≥3.3 mEq/L to prevent cardiac arrhythmias and respiratory muscle weakness
• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq/L potassium to IV fluids (use 2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed 2, 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. Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA 1.

Bicarbonate: Generally NOT Recommended

Bicarbonate administration is NOT recommended for DKA patients with pH >6.9-7.0 1, 3. Multiple studies show no difference in resolution of acidosis or time to discharge with bicarbonate use, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 1.

Monitoring During Treatment

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

• Serum electrolytes and glucose
• Blood urea nitrogen and creatinine
• Venous pH (typically 0.03 units lower than arterial pH)
• Anion gap to monitor acidosis resolution

Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA, as the nitroprusside method only detects acetoacetic acid and acetone 1, 4.

Resolution Criteria

DKA is resolved when ALL of the following are met 1, 4, 3:

• 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 1, 4, 3. This overlap period is essential—premature termination of IV insulin before complete ketosis resolution leads to DKA recurrence 1.

When the patient can eat, start a multiple-dose schedule using combination of short/rapid-acting and intermediate/long-acting insulin 1, 4.

Common Pitfalls to Avoid

• Stopping insulin when glucose normalizes: Continue insulin until acidosis resolves, add dextrose to prevent hypoglycemia 1
• Inadequate initial fluid resuscitation: This worsens insulin resistance and delays recovery 1
• Starting insulin before checking potassium: Can cause fatal arrhythmias if K+ <3.3 mEq/L 1
• Premature transition to subcutaneous insulin: Administer basal insulin 2-4 hours before stopping IV insulin 1
• Using bicarbonate routinely: Only consider if pH <6.9 in specific circumstances 1, 3
• Overly rapid correction of hyperglycemia: Increases cerebral edema risk, especially in children 1

Special Considerations

If SGLT2 inhibitors were being used, discontinue them 3-4 days before any planned surgery to prevent euglycemic DKA 1. Identify and treat underlying precipitating causes such as infection (administer appropriate antibiotics), myocardial infarction, stroke, or pancreatitis concurrently with DKA treatment 1, 4.