What is the initial management of Diabetic Ketoacidosis (DKA) in the Intensive Care Unit (ICU)?

Initial Management of Diabetic Ketoacidosis (DKA) in the ICU

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour, followed by continuous intravenous regular insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L, while aggressively monitoring and replacing electrolytes—particularly potassium—to prevent life-threatening complications. 1, 2, 3

Diagnostic Confirmation and Initial Assessment

Before initiating treatment, confirm DKA diagnosis with the following criteria 4, 1:

• Plasma glucose >250 mg/dL
• Arterial pH <7.30
• Serum bicarbonate <18 mEq/L
• Positive serum and urine ketones

Obtain comprehensive laboratory evaluation immediately 1, 2, 3:

• Plasma glucose, arterial blood gases, complete blood count with differential
• Serum electrolytes with calculated anion gap, BUN/creatinine, osmolality
• Serum and urine ketones (direct β-hydroxybutyrate measurement preferred over nitroprusside method) 1, 3
• Electrocardiogram with continuous cardiac monitoring 2
• Bacterial cultures (blood, urine, throat) if infection suspected 1, 3

Fluid Resuscitation: The Critical First Step

Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 liters in average adults) during the first hour to restore intravascular volume and renal perfusion. 4, 1, 2, 3 This aggressive initial fluid replacement is paramount as it improves insulin sensitivity and tissue perfusion 3.

After the first hour, adjust fluid choice based on corrected serum sodium 4, 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 similar rate
• When glucose reaches 250 mg/dL: Switch to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin 3

Note: Some evidence suggests balanced electrolyte solutions may achieve faster DKA resolution than normal saline, though isotonic saline remains the standard 2, 5.

Insulin Therapy: Timing and Dosing

Do NOT start insulin if serum potassium is <3.3 mEq/L—this is a critical safety checkpoint to prevent fatal cardiac arrhythmias. 3 Aggressively replace potassium first until levels reach ≥3.3 mEq/L 3.

Once potassium is safe and fluid resuscitation has begun 1, 2:

• Administer continuous IV regular insulin at 0.1 units/kg/hour (no initial bolus for moderate to severe DKA) 1, 3
• If glucose does not fall by 50 mg/dL in the first hour, double the insulin infusion rate hourly until achieving steady decline of 50-75 mg/hour 1, 2, 3
• Continue insulin infusion until complete resolution of ketoacidosis, regardless of glucose levels 3

Common pitfall: Interrupting insulin when glucose falls below 250 mg/dL is a frequent cause of persistent ketoacidosis—instead, add dextrose to IV fluids and continue insulin at reduced rate (0.05-0.1 units/kg/hour) until acidosis resolves 1, 3.

Electrolyte Management: Potassium is Life-or-Death

Despite potentially normal or elevated initial levels, total body potassium depletion is universal in DKA, and insulin therapy will drive potassium intracellularly, causing dangerous hypokalemia. 2, 3

Potassium replacement protocol 1, 2, 3:

• If K+ <3.3 mEq/L: HOLD insulin, aggressively replace potassium until ≥3.3 mEq/L to prevent arrhythmias, cardiac arrest, and respiratory muscle weakness
• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq/L potassium to each 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
• Target: Maintain serum potassium 4-5 mEq/L throughout treatment

Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA. 3

Bicarbonate: Generally Avoid

Bicarbonate administration is NOT recommended for DKA patients with pH >6.9-7.0. 1, 2, 3 Studies show no benefit in resolution time or clinical outcomes, and bicarbonate may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 2, 3.

Consider bicarbonate only if 2, 3:

• pH <6.9: Give 100 mmol sodium bicarbonate in 400 mL sterile water at 200 mL/hour
• pH 6.9-7.0: Give 50 mmol sodium bicarbonate in 200 mL sterile water at 200 mL/hour
• Pre/post-intubation with pH <7.2 to prevent hemodynamic collapse 5

Intensive Monitoring Protocol

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

• Serum electrolytes, glucose, BUN, creatinine, osmolality, venous pH
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor acidosis resolution 1, 3
• Check blood glucose every 1-2 hours 1

Monitor for cerebral edema risk factors (particularly in children but can occur in adults) 3:

• Higher BUN at presentation
• Overly rapid correction of osmolality (should not exceed 3 mOsm/kg/hour) 2
• Avoid excessive hypotonic fluids 3

Resolution Criteria

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

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

Transition to Subcutaneous Insulin: Critical Timing

Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion—this overlap is essential to prevent recurrence of ketoacidosis and rebound hyperglycemia. 2, 3 Premature termination of IV insulin is a common cause of DKA recurrence 1, 3.

When patient can eat, transition to multiple-dose regimen using combination of short/rapid-acting and intermediate/long-acting insulin 3. For newly diagnosed patients, start at approximately 0.5-1.0 units/kg/day 2.

Identify and Treat Precipitating Causes

Search for and treat underlying triggers 1, 3:

• Infection (most common)—obtain cultures and start appropriate antibiotics
• Myocardial infarction or stroke—obtain ECG, cardiac biomarkers
• Insulin omission or inadequacy
• SGLT2 inhibitors—discontinue 3-4 days before surgery to prevent euglycemic DKA 2, 3
• Pancreatitis, trauma, alcohol abuse

Special Consideration: Mild DKA

For uncomplicated mild DKA in hemodynamically stable patients, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective, safer, and more cost-effective than IV insulin. 2, 3 However, continuous IV insulin remains standard of care for critically ill and mentally obtunded ICU patients 2, 3.

ICU Admission Criteria

ICU admission is indicated for 6:

• Cardiovascular instability
• Inability to protect airway
• Obtundation or altered mental status
• Acute abdominal signs suggesting gastric dilatation
• Need for frequent monitoring that cannot be provided on general floor