What is the treatment for diabetic ketoacidosis (DKA)?

Treatment of Diabetic Ketoacidosis (DKA)

Begin immediate treatment with aggressive isotonic saline resuscitation at 15-20 mL/kg/hour (approximately 1-1.5 L in the first hour), followed by continuous IV regular insulin at 0.1 units/kg/hour once serum potassium is ≥3.3 mEq/L, and continue insulin until complete resolution of ketoacidosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels. 1

Initial Assessment and Diagnosis

Before initiating treatment, confirm DKA with the following diagnostic criteria: blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria 1. Obtain laboratory evaluation including plasma glucose, electrolytes with calculated anion gap, serum ketones (preferably β-hydroxybutyrate), arterial blood gases, complete blood count, urinalysis, and electrocardiogram 1, 2. Identify precipitating factors such as infection, myocardial infarction, stroke, pancreatitis, insulin omission, or SGLT2 inhibitor use, and obtain bacterial cultures if infection is suspected 1, 2.

Fluid Resuscitation Protocol

Start with 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 for improving insulin sensitivity 1. Subsequent fluid choice depends on hydration status, serum electrolyte levels, and urine output 1. 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. Total fluid replacement should correct estimated deficits within 24 hours 1.

Critical Potassium Management

This is the most dangerous pitfall in DKA management: Despite often presenting with normal or elevated potassium, total body potassium depletion is universal in DKA, and insulin therapy will drive potassium intracellularly, causing life-threatening hypokalemia 1, 2.

Potassium-Based Treatment Algorithm:

• If K+ <3.3 mEq/L: DO NOT start insulin therapy. Delay insulin and aggressively replace potassium with 20-40 mEq/L in IV fluids until K+ ≥3.3 mEq/L to prevent cardiac arrhythmias and death 1, 2
• 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 is confirmed, then start insulin 1, 2
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely every 2 hours, as levels will drop rapidly with insulin therapy 1
• Target serum potassium of 4-5 mEq/L throughout treatment 1, 2

Insulin Therapy

For Moderate to Severe DKA (Critically Ill or Obtunded Patients):

Continuous IV regular insulin infusion at 0.1 units/kg/hour is the standard of care 1, 2. An initial IV bolus of 0.1 units/kg may be given 2. If plasma 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 glucose decline of 50-75 mg/dL per hour 1.

For Mild to Moderate Uncomplicated DKA (Alert, Stable Patients):

Subcutaneous rapid-acting insulin analogs combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin 1, 3. This approach requires adequate fluid replacement, frequent point-of-care glucose monitoring, and treatment of concurrent infections 1.

Critical Insulin Management Rules:

• 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, 2
• When glucose falls to 250 mg/dL, add dextrose to IV fluids but DO NOT stop insulin 1, 3
• Target glucose of 150-200 mg/dL until DKA resolution parameters are met 1
• Premature termination of insulin before complete ketosis resolution is the most common cause of DKA recurrence 1, 4

Bicarbonate Administration

Bicarbonate is NOT recommended for DKA patients with pH >6.9-7.0 1. 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, 3.

Monitoring During Treatment

Draw blood every 2-4 hours to measure serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 2, 3. Venous pH is typically 0.03 units lower than arterial pH and is adequate for monitoring 1, 3. Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA, as the nitroprusside method only measures acetoacetic acid and acetone 1, 3.

Transition to Subcutaneous Insulin

Once DKA is resolved (glucose <200 mg/dL, bicarbonate ≥18 mEq/L, venous pH >7.3, anion gap ≤12 mEq/L) 1, 3:

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, 3. This overlap period is essential and failure to do so is the most common error leading to DKA recurrence 2.

When the patient can eat, start a multiple-dose schedule using a combination of short/rapid-acting and intermediate/long-acting insulin 1, 2, 3. If the patient remains NPO after DKA resolution, continue IV insulin and fluid replacement, supplementing with subcutaneous regular insulin as needed 1.

Treatment of Precipitating Causes

Concurrently identify and treat underlying causes such as infection (administer appropriate antibiotics), myocardial infarction, stroke, or pancreatitis 1, 2, 3. Discontinue SGLT2 inhibitors immediately and avoid for 3-4 days before any planned surgery to prevent euglycemic DKA 1, 5, 6.

Common Pitfalls to Avoid

• Stopping IV insulin when glucose falls below 250 mg/dL without adding dextrose causes persistent or worsening ketoacidosis 1, 3
• Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA 1
• Stopping IV insulin without prior basal insulin administration (must give basal insulin 2-4 hours before stopping IV) 2
• Overly rapid correction of osmolality increases cerebral edema risk, particularly in children 1
• Starting insulin when K+ <3.3 mEq/L can cause fatal cardiac arrhythmias 1, 2

Discharge Planning

Before discharge, ensure patient education includes identification of outpatient diabetes care providers, understanding of diabetes diagnosis, glucose monitoring techniques, home glucose goals, insulin administration, sick day management, and when to call healthcare professionals 1, 2, 3.