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 IV 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

Upon ICU admission, 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
• Anion gap >10-12 mEq/L

Obtain immediate laboratory evaluation including plasma glucose, arterial blood gases, complete metabolic panel with calculated anion gap, serum osmolality, serum ketones (preferably β-hydroxybutyrate), complete blood count, urinalysis with ketones, and electrocardiogram. 1, 3

Critical pitfall: Direct measurement of β-hydroxybutyrate is preferred over nitroprusside methods, which only detect acetoacetic acid and acetone, potentially underestimating ketosis severity. 2, 3

Fluid Resuscitation (First Priority)

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

After initial resuscitation 4, 1:

• If corrected serum sodium is normal or elevated: switch to 0.45% NaCl at 4-14 mL/kg/hour
• If corrected serum sodium is low: continue 0.9% NaCl at similar rate
• When glucose reaches 250 mg/dL: add 5% dextrose to IV fluids (D5-0.45% NaCl) to prevent hypoglycemia while continuing insulin to clear ketosis

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

Insulin Therapy (Second Priority—After Potassium Check)

DO NOT start insulin if serum potassium is <3.3 mEq/L—this can cause fatal cardiac arrhythmias, cardiac arrest, and respiratory muscle weakness. 2, 3

Once potassium ≥3.3 mEq/L 1, 2, 3:

• Start continuous IV regular insulin at 0.1 units/kg/hour WITHOUT an initial bolus (standard for critically ill ICU patients)
• If glucose does not fall by 50 mg/dL in the first hour, double the insulin infusion rate every hour until achieving steady decline of 50-75 mg/dL/hour
• Target glucose 150-200 mg/dL until DKA resolves (NOT normoglycemia)
• Continue insulin infusion until complete resolution of ketoacidosis, regardless of glucose levels

Critical pitfall: Stopping insulin when glucose normalizes is a common error that causes persistent or worsening ketoacidosis. The goal is clearing ketones, not just lowering glucose. 1, 3

Potassium Management (Life-Threatening Priority)

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
• 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 every 2 hours
• Target serum potassium 4-5 mEq/L throughout treatment

Critical pitfall: Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA. Check potassium every 2-4 hours during active treatment. 2, 3

Intensive Monitoring Protocol

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

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

Check blood glucose every 1-2 hours. 1

Monitor continuously for 2, 5:

• Cardiac rhythm (arrhythmias from electrolyte shifts)
• Neurological status (cerebral edema risk)
• Fluid input/output
• Hemodynamic parameters

Bicarbonate Administration (Generally NOT Recommended)

Bicarbonate is NOT recommended for DKA patients with pH >6.9-7.0, as studies show no benefit in resolution time or clinical outcomes, and may worsen ketosis, cause hypokalemia, and increase cerebral edema risk. 2, 3, 5

Consider bicarbonate only if 2:

• 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

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

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—premature termination of IV insulin is a common cause of DKA recurrence. 1, 3

Identifying and Treating Precipitating Causes

Obtain bacterial cultures (blood, urine, other sites as indicated) if infection suspected and start appropriate antibiotics. 1, 3

Search for 1, 3, 5:

• Infection (most common precipitant)
• Myocardial infarction
• Stroke
• Pancreatitis
• Medication non-compliance or insulin omission
• SGLT2 inhibitor use (can cause euglycemic DKA—discontinue immediately)

Special Considerations for ICU Patients

ICU admission is indicated for 6:

• Cardiovascular instability
• Inability to protect airway
• Obtundation or altered mental status
• Severe DKA (pH <7.0, bicarbonate <10 mEq/L)
• Acute abdominal signs suggesting gastric dilatation

For impending respiratory failure, avoid BiPAP due to aspiration risk; proceed directly to intubation and mechanical ventilation. 5

Pre-intubation consideration: IV sodium bicarbonate may be considered if pH <7.2 to prevent metabolic acidosis and hemodynamic collapse from apnea during intubation. 5

Cerebral Edema Prevention

Avoid overly rapid correction of hyperglycemia and osmolality—induced change in serum osmolality should not exceed 3 mOsm/kg/hour. 2

Risk factors for cerebral edema include 2, 3:

• Higher BUN at presentation
• Younger age (more common in children/adolescents)
• Overly aggressive fluid resuscitation with hypotonic fluids
• Rapid correction of hyperglycemia