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 once 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: 2

• Plasma glucose, electrolytes with calculated anion gap
• Arterial or venous blood gas (venous pH is sufficient and typically 0.03 units lower than arterial) 3, 2
• Serum ketones (β-hydroxybutyrate preferred over nitroprusside method) 3
• Complete metabolic panel, complete blood count
• Urinalysis with ketones
• ECG

Fluid Resuscitation Protocol

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

After the first hour, adjust fluid choice based on: 2

• Hydration status
• Serum electrolyte levels
• Urine output

When serum glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy to clear ketones. 1, 3, 2 This is crucial because ketonemia takes longer to clear than hyperglycemia. 3

Insulin Therapy

Critical potassium checkpoint: Do NOT start insulin if K+ <3.3 mEq/L. 2 Delay insulin therapy and aggressively replace potassium first to prevent life-threatening cardiac arrhythmias and respiratory muscle weakness. 2

Once K+ ≥3.3 mEq/L, initiate continuous IV regular insulin infusion at 0.1 units/kg/hour. 1, 2 This is the standard of care for moderate to severe DKA in critically ill patients. 4, 2

Continue insulin infusion until complete resolution of ketoacidosis, regardless of glucose levels. 1, 2 Target glucose between 150-200 mg/dL until DKA resolution parameters are met. 1, 3

If plasma glucose does not fall by 50 mg/dL in the first hour: 2

• Check hydration status
• If acceptable, double the insulin infusion rate hourly until achieving steady glucose decline of 50-75 mg/dL per hour

Electrolyte Management

Potassium Replacement (Critical)

Potassium replacement is essential because total body potassium depletion is universal in DKA, and insulin therapy will further lower serum potassium. 2 Target serum potassium of 4-5 mEq/L throughout treatment. 1, 2

Replacement protocol: 2

• If K+ <3.3 mEq/L: Hold insulin, 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 confirmed
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely as levels will drop rapidly with insulin therapy

Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA. 2

Bicarbonate (Generally NOT Recommended)

Bicarbonate administration is NOT recommended for DKA patients with pH >6.9-7.0. 2 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. 4, 2

Monitoring During Treatment

Draw blood every 2-4 hours to determine: 1, 3, 2

• Serum electrolytes
• Glucose
• Blood urea nitrogen, creatinine
• Venous pH (adequate for tracking acidosis resolution)
• Anion gap (provides confirmation of ketoacid clearance)

Use direct measurement of β-hydroxybutyrate in blood as the preferred method for monitoring DKA, as the nitroprusside method only measures acetoacetic acid and acetone, not β-hydroxybutyrate. 3, 2

Resolution Criteria

DKA is resolved when ALL of the following parameters are met: 1, 3, 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. 4, 2 This overlap period is essential. 2

Once DKA is resolved and the patient can eat, start a multiple-dose subcutaneous insulin regimen combining short/rapid-acting and intermediate/long-acting insulin. 1, 3

Treatment of Underlying Precipitating Cause

Identify and treat any correctable underlying cause: 4, 2

• Infection (obtain cultures if suspected, administer appropriate antibiotics)
• Myocardial infarction
• Stroke
• Insulin omission or inadequacy
• Medications (discontinue SGLT2 inhibitors 3-4 days before any planned surgery to prevent euglycemic DKA) 2

Alternative Approach for Mild-to-Moderate Uncomplicated DKA

For uncomplicated mild-to-moderate DKA, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective, safer, and more cost-effective than IV insulin. 4, 2 This approach requires: 4

• Adequate fluid replacement
• Frequent point-of-care blood glucose monitoring
• Treatment of concurrent infections
• Appropriate follow-up

However, continuous IV insulin remains the standard of care for critically ill and mentally obtunded patients. 4, 2

Common Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis leads to recurrence of DKA 2
• Interrupting insulin infusion when glucose falls is a common cause of persistent or worsening ketoacidosis 3, 2
• Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin therapy 3, 2
• Inadequate potassium monitoring and replacement is a leading cause of mortality 2
• Overzealous insulin treatment without glucose supplementation can lead to hypoglycemia 3
• Overly rapid correction of osmolality increases risk of cerebral edema, particularly in children 2