How do I manage a case of Diabetic Ketoacidosis (DKA)?

Management of Diabetic Ketoacidosis (DKA)

Begin immediate treatment with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour, followed by continuous IV regular insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L, and aggressively replace potassium to maintain levels between 4-5 mEq/L throughout treatment. 1

Initial Assessment and Diagnosis

Diagnostic Criteria:

• Blood glucose >250 mg/dL 1
• Arterial pH <7.3 1
• Serum bicarbonate <15-18 mEq/L 1, 2
• Positive serum/urine ketones 2

Essential Laboratory Evaluation:

• Plasma glucose, BUN/creatinine, serum ketones, electrolytes with calculated anion gap, osmolality 1, 2
• Arterial blood gases, complete blood count with differential, urinalysis, urine ketones 1
• Electrocardiogram with continuous cardiac monitoring in severe DKA 3
• Direct measurement of β-hydroxybutyrate (preferred over nitroprusside method which only measures acetoacetic acid/acetone) 1, 3

Identify Precipitating Factors:

• Obtain bacterial cultures (urine, blood, throat) if infection suspected and start appropriate antibiotics 1, 2
• Consider myocardial infarction, stroke, pancreatitis, trauma, insulin omission 1, 3
• Critical: Discontinue SGLT2 inhibitors immediately (should be stopped 3-4 days before any planned surgery to prevent euglycemic DKA) 1, 3

Fluid Resuscitation

Initial Hour:

• Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adult) 1, 2
• This restores intravascular volume, improves tissue perfusion, and enhances insulin sensitivity 1

Subsequent Fluid Management:

• Continue fluid replacement based on hydration status, serum electrolytes, and urine output 1, 2
• Total fluid replacement should correct estimated deficits within 24 hours 1
• When glucose reaches 250 mg/dL: Switch to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin to clear ketosis 1, 2

Critical Pitfall: Avoid overly rapid correction of osmolality (do not exceed 3 mOsm/kg/h change) to minimize cerebral edema risk, particularly in children 3, 4

Insulin Therapy

Standard Protocol for Moderate-to-Severe DKA:

• Start continuous IV regular insulin at 0.1 units/kg/hour without initial bolus 1, 2
• Do NOT start insulin if potassium <3.3 mEq/L - correct potassium first to prevent life-threatening arrhythmias and respiratory muscle weakness 1

Monitoring and Adjustment:

• If glucose does not fall by 50 mg/dL in first hour, verify adequate hydration, then double insulin infusion hourly until achieving steady decline of 50-75 mg/dL/hour 1, 2
• When glucose reaches 250 mg/dL, decrease insulin to 0.05-0.1 units/kg/hour and add dextrose to IV fluids 2
• Continue insulin infusion until complete resolution of ketoacidosis regardless of glucose levels 1, 2

Alternative for Mild-to-Moderate Uncomplicated 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 adequate fluid replacement, frequent point-of-care glucose monitoring, and treatment of concurrent infections 1

Emerging Evidence:

• Adding low-dose subcutaneous basal insulin analog (e.g., glargine) alongside IV insulin may prevent rebound hyperglycemia and shorten hospital stays 1, 3, 4

Electrolyte Management

Potassium Replacement (Critical Priority)

Potassium levels dictate insulin initiation:

• If K+ <3.3 mEq/L: Delay insulin therapy and aggressively replace potassium until ≥3.3 mEq/L 1
• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq/L potassium (2/3 KCl and 1/3 KPO₄) to each liter of IV fluid once adequate urine output confirmed 1, 2
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely as levels will drop rapidly with insulin therapy 1

Target: Maintain serum potassium 4-5 mEq/L throughout treatment 1, 2, 3

Rationale: Total body potassium depletion is universal in DKA despite potentially normal/elevated initial levels due to acidosis; insulin therapy further lowers serum potassium 1, 3

Phosphate Replacement

• Routine phosphate replacement has NOT shown clinical benefit 2, 3
• Consider careful replacement only in patients with cardiac dysfunction, anemia, respiratory depression, or serum phosphate <1.0 mg/dL 2, 3

Bicarbonate Administration

Generally NOT recommended for pH >6.9-7.0 1, 2, 3

• Studies show no difference in resolution of acidosis or time to discharge 1, 3
• May worsen ketosis, cause hypokalemia, and increase cerebral edema risk 1, 4

Exception: Consider bicarbonate only if pH <6.9 2, 3

• If pH <6.9: Give 100 mmol sodium bicarbonate in 400 mL sterile water at 200 mL/h 3
• If pH 6.9-7.0: Give 50 mmol sodium bicarbonate in 200 mL sterile water at 200 mL/h 3
• Can also consider for pH <7.2 pre/post-intubation to prevent hemodynamic collapse from apnea 4

Monitoring Protocol

Blood Glucose:

• Check every 1-2 hours 2
• Target decline of 50-75 mg/dL/hour initially 1, 2
• Target glucose 150-200 mg/dL until DKA resolution 1

Comprehensive Metabolic Panel:

• Draw blood every 2-4 hours for serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 1, 2
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor acidosis resolution 1, 2

Cardiac Monitoring:

• Continuous cardiac monitoring in severe DKA to detect arrhythmias from electrolyte imbalances 3

Resolution Criteria

DKA is resolved when ALL of the following are met:

• Glucose <200 mg/dL 1, 2
• Serum bicarbonate ≥18 mEq/L 1, 2
• Venous pH >7.3 1, 2
• Anion gap ≤12 mEq/L 1, 2

Transition to Subcutaneous Insulin

Critical Timing to Prevent Recurrence:

• Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion 1, 2, 3
• This overlap prevents recurrence of ketoacidosis and rebound hyperglycemia 1, 2

If Patient Can Eat:

• Start multiple-dose schedule using combination of short/rapid-acting and intermediate/long-acting insulin 1, 2
• For newly diagnosed patients: approximately 0.5-1.0 units/kg/day 3

If Patient Remains NPO:

• Continue IV insulin and fluid replacement, supplement with subcutaneous regular insulin as needed 1

Critical Pitfalls to Avoid

• Premature termination of insulin before complete ketosis resolution - leads to DKA recurrence 1, 2
• Interrupting insulin infusion when glucose falls without adding dextrose - causes persistent/worsening ketoacidosis 1
• Starting insulin with K+ <3.3 mEq/L - causes life-threatening arrhythmias 1
• Inadequate potassium monitoring/replacement - leading cause of mortality in DKA 1
• Stopping IV insulin without prior basal insulin administration - causes rebound hyperglycemia and ketoacidosis 1, 2
• Overly rapid osmolality correction - increases cerebral edema risk 3, 4
• Relying on nitroprusside method for ketone measurement - misses β-hydroxybutyrate 1, 3

Special Considerations

Airway Management in Critically Ill Patients:

• BiPAP is NOT recommended due to aspiration risk 4
• Use intubation and mechanical ventilation with careful acid-base and fluid status monitoring 4

Early Nutrition:

• Early initiation of oral nutrition reduces ICU and overall hospital length of stay 4

Discharge Planning:

• Identify outpatient diabetes care providers 1
• Educate on glucose monitoring, home glucose goals, recognition/prevention of DKA 1, 3
• Ensure appropriate insulin regimen and dosing 1