What are the guidelines for managing diabetic ketoacidosis (DKA)?

Management of Diabetic Ketoacidosis

Begin immediate treatment with isotonic saline at 15-20 mL/kg/hour for the first hour, followed by continuous intravenous regular insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L, and continue insulin until complete resolution of ketoacidosis regardless of glucose levels. 1

Diagnostic Criteria

DKA is confirmed when all three criteria are present: 1, 2

• Blood glucose >250 mg/dL (though euglycemic DKA can occur, particularly with SGLT2 inhibitors)
• Arterial pH <7.3 and serum bicarbonate <15 mEq/L
• Presence of ketonemia or ketonuria with elevated anion gap

Initial Laboratory Assessment

Obtain the following tests immediately: 1

• Plasma glucose, blood urea nitrogen, creatinine, serum ketones
• Electrolytes with calculated anion gap, osmolality
• Arterial blood gases, complete blood count with differential
• Urinalysis, urine ketones, electrocardiogram
• Bacterial cultures (blood, urine, throat) if infection suspected 1

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

Fluid Resuscitation

Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L) during the first hour to restore tissue perfusion and improve insulin sensitivity. 1 This aggressive initial fluid replacement is critical for treatment success. 1

After the first hour, adjust fluid choice based on: 1

• Hydration status
• Serum electrolyte levels
• Urine output

When serum glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% NaCl while continuing insulin therapy to prevent hypoglycemia and allow complete clearance of ketones. 1 This is a critical step—failure to add dextrose is a common cause of persistent ketoacidosis. 1

Insulin Therapy

Initiation

Do NOT start insulin if potassium <3.3 mEq/L—correct hypokalemia first to prevent life-threatening arrhythmias and respiratory muscle weakness. 1 Despite potentially normal or elevated initial potassium levels, total body potassium depletion is universal in DKA. 1

Once potassium ≥3.3 mEq/L: 1

• Start continuous IV regular insulin at 0.1 units/kg/hour (no bolus needed)
• Target glucose decline of 50-75 mg/dL per hour
• If glucose doesn't fall by 50 mg/dL in the first hour, check hydration; if adequate, double the insulin infusion rate hourly until steady decline achieved

Critical Insulin Management Principle

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 Premature termination of insulin before ketosis resolves is a leading cause of DKA recurrence. 1

Alternative for Mild-Moderate DKA

For uncomplicated mild-to-moderate DKA in alert patients, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin. 1 However, continuous IV insulin remains standard for critically ill and mentally obtunded patients. 1

Electrolyte Management

Potassium Replacement

This is critical—inadequate potassium monitoring and replacement is a leading cause of DKA mortality. 1

Potassium replacement protocol: 1

• 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/L potassium to IV fluids (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
• Target serum potassium 4-5 mEq/L throughout treatment

Bicarbonate

Bicarbonate is NOT recommended for pH >6.9-7.0. 1 Studies show no benefit in resolution time or outcomes, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk. 1

Monitoring During Treatment

Draw blood every 2-4 hours to measure: 1

• Serum electrolytes, glucose, blood urea nitrogen, creatinine
• Osmolality and venous pH (typically 0.03 units lower than arterial pH)
• Anion gap to monitor acidosis resolution

Check blood glucose every 1-2 hours until stable, then every 4 hours. 3

Monitor for cerebral edema, particularly in children and with overly rapid osmolality correction (should not exceed 3 mOsm/kg/hour). 3

Resolution Criteria

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

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3
• Anion gap ≤12 mEq/L

Target glucose 150-200 mg/dL until these resolution parameters are achieved. 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 This overlap period is essential. 1

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

Treatment of Precipitating Causes

Identify and treat underlying triggers: 1

• Infection (most common—administer appropriate antibiotics)
• Myocardial infarction, cerebrovascular accident
• Insulin discontinuation or inadequacy
• Pancreatitis, trauma
• SGLT2 inhibitors must be discontinued 3-4 days before any planned surgery to prevent euglycemic DKA 1

Common Pitfalls to Avoid

Critical errors that lead to complications or treatment failure: 1

• Interrupting insulin when glucose falls while ketoacidosis persists—this is a common cause of worsening ketosis
• Failing to add dextrose when glucose <250 mg/dL while continuing insulin
• Premature termination of insulin therapy before complete ketosis resolution
• Inadequate potassium monitoring and replacement—a leading cause of mortality
• Overzealous treatment without glucose supplementation leading to hypoglycemia
• Overly rapid correction of osmolality (>3 mOsm/kg/hour) increasing cerebral edema risk

Discharge Planning

Before discharge, ensure: 1

• Identification of outpatient diabetes care providers
• Patient understanding of diabetes diagnosis and glucose monitoring
• Knowledge of home glucose goals and when to call healthcare professional
• Schedule follow-up appointments prior to discharge to increase attendance likelihood