How does the management of diabetic ketoacidosis (DKA) vary by severity, from mild to moderate to severe?

Management of Diabetic Ketoacidosis by Severity

The management of diabetic ketoacidosis (DKA) must be tailored according to its severity, with mild cases potentially managed with subcutaneous insulin while moderate to severe cases require intravenous insulin therapy and more aggressive fluid resuscitation. 1, 2

Diagnostic Criteria for DKA Severity

Parameter	Mild	Moderate	Severe
Arterial pH	7.25-7.30	7.00-7.24	<7.00
Serum bicarbonate (mEq/L)	15-18	10-<15	<10
Anion gap	>10	>12	>12
Mental status	Alert	Alert/drowsy	Stupor/coma
Blood glucose	>250 mg/dL	>250 mg/dL	>250 mg/dL
Urine/serum ketones	Positive	Positive	Positive

1, 2

Initial Assessment and Monitoring

• Obtain arterial blood gases, complete blood count with differential, urinalysis, plasma glucose, blood urea nitrogen (BUN), electrolytes, chemistry profile, and creatinine levels STAT 1
• Perform electrocardiogram and obtain chest X-ray and cultures as needed 1
• Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA 2, 3
• Blood should be drawn every 2-4 hours to determine serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 3

Fluid Therapy by Severity

Mild DKA

• Begin with isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour for the first hour 2
• Continue with 0.45-0.9% NaCl at 4-14 ml/kg/hour based on corrected serum sodium 1

Moderate to Severe DKA

• More aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour for the first hour 1
• Continue with 0.45-0.9% NaCl at 4-14 ml/kg/hour based on corrected serum sodium and hemodynamic monitoring 1
• Fluid replacement should correct estimated deficits within the first 24 hours 1

Insulin Therapy by Severity

Mild DKA

• Subcutaneous rapid-acting insulin analogs combined with aggressive fluid management can be as effective as intravenous insulin 2, 4
• Give subcutaneous regular insulin as needed every 4 hours in 5-unit increments for every 50 mg/dL increase in blood glucose above 150 mg/dL (up to 20 units for blood glucose of 300 mg/dL) 1

Moderate to Severe DKA

• Intravenous regular insulin is the treatment of choice 1
• Begin with an intravenous bolus of regular insulin at 0.15 units/kg body weight, followed by a continuous infusion at 0.1 unit/kg/hour (5-7 units/hour in adults) 1
• If plasma glucose does not fall by 50 mg/dL from initial value in the first hour, check hydration status; if acceptable, double the insulin infusion every hour until a steady glucose decline between 50-75 mg/hour is achieved 1

Electrolyte Management (All Severities)

• Monitor potassium levels closely, as insulin administration can cause hypokalemia 2, 5
• Once renal function is assured, include 20-30 mEq/L potassium (2/3 KCl and 1/3 KPO₄) in the infusion until the patient is stable 1
• Ensure adequate potassium replacement to maintain serum K⁺ between 4-5 mmol/L 2

Transitioning from IV to Subcutaneous Insulin

• When DKA is resolved (glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3), transition to subcutaneous insulin 3
• Administer basal insulin 2-4 hours before stopping the intravenous insulin to prevent recurrence of ketoacidosis 2
• Start a multiple-dose schedule using a combination of short/rapid-acting and intermediate/long-acting insulin when the patient is able to eat 3

Special Considerations

Glucose Management During Treatment

• When glucose falls below 200-250 mg/dL, add dextrose to the hydrating solution while continuing insulin infusion to resolve ketosis 3
• Target glucose between 150-200 mg/dL until DKA resolution parameters are met 3

Monitoring for Resolution

• DKA resolution requires glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L 3
• Ketonemia typically takes longer to clear than hyperglycemia 3

Common Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis can lead to recurrence of DKA 2
• Inadequate fluid resuscitation can worsen DKA 2
• Interruption of insulin infusion when glucose levels fall is a common cause of persistent or worsening ketoacidosis 2, 3
• Relying on nitroprusside method to measure ketones, which only measures acetoacetic acid and acetone, not β-hydroxybutyrate 1, 3
• Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin therapy 3
• Inadequate monitoring of electrolytes, particularly potassium, during treatment 3, 5