What is the management of diabetic ketoacidosis (DKA)?

Management of Diabetic Ketoacidosis

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) 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, 2

Initial Assessment and Diagnosis

Diagnostic Criteria:

• Blood glucose >250 mg/dL 1
• Arterial pH <7.3 1
• Serum bicarbonate <15 mEq/L 1
• Presence of ketonemia or ketonuria 1

Essential Laboratory Tests:

• Plasma glucose, blood urea nitrogen/creatinine, serum ketones (preferably β-hydroxybutyrate), electrolytes with calculated anion gap, osmolality, urinalysis, arterial blood gases, complete blood count with differential, and electrocardiogram 3, 1, 2
• Obtain bacterial cultures (urine, blood, throat) if infection is suspected and administer appropriate antibiotics 1, 2
• Identify precipitating factors: infection, myocardial infarction, cerebrovascular accident, pancreatitis, trauma, insulin omission, or SGLT2 inhibitor use 1

Fluid Therapy Protocol

First Hour:

• Administer 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 and renal perfusion 2

Subsequent Fluid Management:

• Continue isotonic saline based on hydration status, serum electrolyte levels, and urine output 1, 2
• Critical transition point: When serum glucose reaches 250 mg/dL, change to 5% dextrose with 0.45-0.75% NaCl 1, 2
• This prevents hypoglycemia while continuing insulin therapy to clear ketosis 1, 2

Insulin Therapy

Before Starting Insulin:

• Do NOT start insulin if potassium <3.3 mEq/L - this can cause life-threatening cardiac arrhythmias and respiratory muscle weakness 1
• Aggressively replace potassium first until levels reach ≥3.3 mEq/L 1

Insulin Initiation:

• Start continuous intravenous regular insulin infusion at 0.1 units/kg/hour without an initial bolus 1, 2
• This is the standard of care for moderate to severe DKA 1

Insulin Adjustment:

• If plasma glucose does not fall by 50 mg/dL in the first hour, verify adequate hydration, then double the insulin infusion rate every hour until achieving a steady glucose decline of 50-75 mg/hour 3, 1, 2
• When glucose reaches 250 mg/dL, decrease insulin to 0.05-0.1 units/kg/hour AND add dextrose to IV fluids 3, 2

Critical Point:

• Never interrupt insulin infusion when glucose falls - this is a common cause of persistent or worsening ketoacidosis 1, 2
• Continue insulin until complete resolution of ketoacidosis, not just glucose normalization 1, 2

Electrolyte Management

Potassium Replacement:

• If K⁺ <3.3 mEq/L: Hold insulin, aggressively replace potassium until ≥3.3 mEq/L 1
• If K⁺ 3.3-5.5 mEq/L: Add 20-30 mEq potassium per liter of IV fluid (2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed 3, 1
• If K⁺ >5.5 mEq/L: Withhold potassium initially but monitor closely as levels will drop rapidly with insulin therapy 1
• Target serum potassium: 4-5 mEq/L throughout treatment 1, 2

Bicarbonate Administration:

• Generally NOT recommended for pH >6.9-7.0 1, 2
• Studies show no difference in resolution of acidosis or time to discharge with bicarbonate use 1
• Bicarbonate may worsen ketosis, hypokalemia, and increase cerebral edema risk 1

Monitoring During Treatment

Frequent Laboratory Checks:

• Blood glucose every 1-2 hours 2
• Serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH every 2-4 hours 3, 1, 2
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor acidosis resolution 3, 1, 2

Ketone Monitoring:

• Direct measurement of β-hydroxybutyrate in blood is the preferred method 3, 1
• Do NOT rely on nitroprusside method - it only measures acetoacetic acid and acetone, not β-hydroxybutyrate (the predominant ketone body), which can falsely suggest worsening ketosis during treatment 3, 1

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:

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

Subcutaneous Regimen:

• When patient can eat, start multiple-dose schedule using combination of short/rapid-acting and intermediate/long-acting insulin 3, 1, 2
• For newly diagnosed patients, consider 0.5-1.0 units/kg/day as starting dose 3

Common Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis leads to DKA recurrence 1, 2
• Stopping insulin when glucose normalizes without checking resolution criteria causes persistent ketoacidosis 1, 2
• Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin 1
• Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA 1
• Starting insulin with K⁺ <3.3 mEq/L can cause fatal arrhythmias 1
• Overly rapid correction of osmolality increases cerebral edema risk, particularly in children 1
• Using nitroprusside method alone for ketone monitoring provides misleading information about treatment response 3, 1