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

Initial Treatment of Diabetic Ketoacidosis (DKA)

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour, followed by continuous IV regular insulin infusion at 0.1 units/kg/hour once serum potassium is ≥3.3 mEq/L. 1, 2

Immediate Initial Assessment

Obtain stat laboratory evaluation including: 1, 2, 3

• Plasma glucose, arterial or venous blood gases
• Complete metabolic panel with calculated anion gap
• Serum ketones (β-hydroxybutyrate preferred) and osmolality
• Complete blood count with differential
• Electrocardiogram
• Urinalysis with urine ketones

Critical diagnostic criteria for DKA: blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria. 3, 4

Identify precipitating factors immediately: infection (obtain cultures of urine, blood, throat if suspected), myocardial infarction, stroke, pancreatitis, insulin omission, or SGLT2 inhibitor use. 1, 3

Fluid Resuscitation Protocol

Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adult) during the first hour. 1, 2, 3

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

• Hydration status
• Serum sodium levels
• Urine output
• Total fluid replacement should approximate 1.5 times the 24-hour maintenance requirements

When serum glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% saline while continuing insulin therapy. 3 This prevents hypoglycemia and ensures complete ketoacidosis resolution.

Potassium Management: The Critical First Step Before Insulin

DO NOT start insulin if serum potassium is <3.3 mEq/L—this is an absolute contraindication. 1, 2, 3 Insulin will drive potassium intracellularly and can precipitate life-threatening cardiac arrhythmias, respiratory muscle weakness, and death. 1, 2

Potassium Replacement Algorithm:

If K+ <3.3 mEq/L: 1, 2, 3

• Hold all insulin therapy
• Aggressively replace potassium at 20-40 mEq/L in IV fluids
• Confirm adequate urine output before potassium administration
• Recheck potassium levels frequently
• Do not start insulin until K+ ≥3.3 mEq/L

If K+ 3.3-5.5 mEq/L: 1, 2, 3

• Add 20-30 mEq potassium per liter of IV fluid
• Use combination: 2/3 KCl (or potassium-acetate) and 1/3 KPO₄
• Proceed with insulin therapy

If K+ >5.5 mEq/L: 2, 3

• Withhold potassium initially
• Monitor closely—levels will drop rapidly with insulin therapy
• Prepare to add potassium once levels decline

Target serum potassium of 4-5 mEq/L throughout treatment. 2, 3 Despite potential hyperkalemia at presentation, total body potassium depletion is universal in DKA. 3

Insulin Therapy Protocol

Once potassium is ≥3.3 mEq/L, start continuous IV regular insulin infusion at 0.1 units/kg/hour. 1, 2, 3 For moderate to severe DKA, an initial IV bolus of 0.1 units/kg may be given, though this is optional for intubated or critically ill patients. 1, 2

Insulin Adjustment Algorithm:

Target glucose decline: 50-75 mg/dL per hour. 1

If glucose does not fall by 50 mg/dL in the first hour: 1, 3

• Verify adequate hydration status
• If hydration is acceptable, double the insulin infusion rate every hour
• Continue doubling until steady glucose decline of 50-75 mg/dL/hour is achieved

Critical pitfall to avoid: Do not stop insulin when glucose normalizes. 1, 3 Continue insulin infusion until complete resolution of ketoacidosis, regardless of glucose levels. 1, 3

When glucose reaches 250 mg/dL: 1, 3

• Add dextrose to IV fluids (5% dextrose with 0.45-0.75% saline)
• Continue insulin infusion at same or reduced rate
• Target glucose 150-200 mg/dL until DKA resolves

Alternative Approach for Mild-Moderate Uncomplicated DKA

For hemodynamically stable, alert patients with mild-moderate DKA, 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: 1

• Hemodynamic stability
• Alert mental status
• Adequate fluid replacement
• Frequent point-of-care glucose monitoring

However, continuous IV insulin remains the standard of care for critically ill, mentally obtunded, or intubated patients. 2, 3

Monitoring Protocol

Draw blood every 2-4 hours for: 1, 2, 3

• Serum electrolytes (especially potassium)
• Glucose
• Blood urea nitrogen and creatinine
• Osmolality
• Venous pH (typically 0.03 units lower than arterial pH)
• Anion gap

Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring ketoacidosis, as the nitroprusside method only measures acetoacetic acid and acetone. 1, 3

Check blood glucose every 2-4 hours while patient is fasting. 1

DKA Resolution Criteria

DKA is resolved when ALL of the following are met: 1, 2, 3

• 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 AND the patient can tolerate oral intake, administer basal insulin (glargine or detemir) 2-4 hours BEFORE stopping the IV insulin infusion. 1, 2, 3 This overlap period is essential to prevent recurrence of ketoacidosis and rebound hyperglycemia.

This is the most common error leading to DKA recurrence—never stop IV insulin without prior basal insulin administration. 1

For patients who remain NPO (intubated): 2, 3

• Continue IV insulin and fluid replacement
• Supplement with subcutaneous regular insulin every 4 hours as needed

When patient can eat, start multiple-dose insulin schedule: 1, 3

• Combination of short/rapid-acting and intermediate/long-acting insulin
• Continue IV insulin for 1-2 hours after first subcutaneous dose

Bicarbonate: Generally NOT Recommended

Bicarbonate 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. 1, 3 Bicarbonate may: 1, 3

• Worsen ketosis
• Cause hypokalemia
• Increase cerebral edema risk

Special Considerations for Intubated Patients

For intubated patients with DKA: 2

• Start continuous IV regular insulin at 0.1 units/kg/hour WITHOUT a bolus
• Check for precipitating factors requiring immediate intervention: sepsis, myocardial infarction, stroke, aspiration pneumonia, pancreatitis
• Obtain electrocardiogram to assess cardiac effects of electrolyte abnormalities
• Monitor for respiratory muscle weakness from hypokalemia

Common Pitfalls to Avoid

Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA. 3 Monitor potassium closely throughout treatment as insulin therapy continuously lowers serum potassium. 1, 2

Premature termination of insulin therapy before complete resolution of ketosis leads to DKA recurrence. 3

Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin therapy. 3

Overly rapid correction of osmolality increases risk of cerebral edema, particularly in children. 3