What are the initial management steps for diabetic ketoacidosis (DKA)?

Management of Diabetic Ketoacidosis (DKA)

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour, followed by continuous IV 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

Initial Assessment and Diagnosis

Diagnostic Criteria:

• Blood glucose >250 mg/dL 2, 1
• Arterial pH <7.3 2, 1
• Serum bicarbonate <15 mEq/L 2, 1
• Presence of ketonemia or ketonuria 1
• Anion gap >10 mEq/L 2

Essential Laboratory Tests:

• Plasma glucose, blood urea nitrogen/creatinine, serum ketones, electrolytes with calculated anion gap, osmolality 2, 1
• Arterial blood gases, complete blood count with differential, urinalysis, urine ketones 2, 1
• Electrocardiogram 2, 1
• Direct measurement of β-hydroxybutyrate is preferred over nitroprusside method, as nitroprusside only detects acetoacetic acid and acetone, not the predominant ketone body 1, 3

Identify Precipitating Factors:

• Obtain bacterial cultures (urine, blood, throat) if infection suspected and administer appropriate antibiotics 2, 1
• Look for infection, myocardial infarction, cerebrovascular accident, pancreatitis, trauma, or insulin discontinuation/inadequacy 1
• Discontinue SGLT2 inhibitors if present, as they must be stopped 3-4 days before any planned surgery to prevent euglycemic DKA 1

Fluid Resuscitation Protocol

First Hour:

• Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adult) 2, 1, 4
• This aggressive initial fluid replacement restores tissue perfusion and improves insulin sensitivity 1

Subsequent Fluid Management:

• Use 0.45% NaCl at 4-14 mL/kg/hour if corrected serum sodium is normal or elevated 2
• Use 0.9% NaCl at similar rate if corrected serum sodium is low 2
• Correct serum sodium for hyperglycemia: add 1.6 mEq to sodium value for each 100 mg/dL glucose above 100 mg/dL 2
• When serum glucose reaches 250 mg/dL, change to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin 1, 3

Insulin Therapy

Critical Pre-Insulin Check:

• DO NOT start insulin if potassium <3.3 mEq/L 1, 4
• If K+ <3.3 mEq/L, delay insulin and aggressively replace potassium first to prevent life-threatening cardiac arrhythmias 1, 4

Insulin Initiation (once K+ ≥3.3 mEq/L):

• Start continuous IV regular insulin infusion at 0.1 units/kg/hour 1, 4
• For critically ill and mentally obtunded patients, continuous IV insulin is the standard of care 1
• For mild-to-moderate uncomplicated DKA, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective and safer 1

Insulin Adjustment:

• If glucose does not fall by 50 mg/dL in first hour, check hydration status; if acceptable, double insulin infusion rate hourly until steady decline of 50-75 mg/dL/hour achieved 1
• Target glucose between 150-200 mg/dL until DKA resolution 1
• Never interrupt insulin infusion when glucose falls below 250 mg/dL—instead add dextrose-containing fluids 1, 3

Potassium Management

Critical Thresholds:

• If K+ <3.3 mEq/L: Hold insulin, aggressively replace potassium with 20-40 mEq/L until ≥3.3 mEq/L 1, 4
• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq/L potassium to IV fluids (use 2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed 1, 4
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely, as levels will drop rapidly with insulin therapy 1
• Maintain serum potassium 4-5 mEq/L throughout treatment 1, 3

Rationale:

• Total body potassium depletion is universal in DKA despite presenting levels 1
• Insulin therapy drives potassium intracellularly, further lowering serum levels 1, 4
• Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA 1

Bicarbonate Therapy

Bicarbonate is NOT recommended for pH >6.9-7.0 1

• Studies show no difference in resolution of acidosis or time to discharge with bicarbonate use 1
• Bicarbonate may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 1
• Consider bicarbonate only if pH <6.9 or when pH <7.2 pre/post-intubation to prevent hemodynamic collapse 5

Monitoring During Treatment

Frequency:

• Check blood glucose every 1-2 hours 3
• Draw blood every 2-4 hours for serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 1, 4
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor acidosis resolution 1

Resolution Criteria

DKA is resolved when ALL of the following are met:

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

Transition to Subcutaneous Insulin

Critical Timing:

• Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion 1, 4
• This overlap prevents recurrence of ketoacidosis and rebound hyperglycemia 1, 4
• Premature termination of IV insulin without prior basal insulin is the most common error leading to DKA recurrence 4

Insulin Regimen:

• When patient can eat, start multiple-dose schedule using combination of short/rapid-acting and intermediate/long-acting insulin 1, 4
• If patient remains NPO, continue IV insulin and fluid replacement, supplement with subcutaneous regular insulin as needed 1

Common Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis (all four resolution criteria must be met) 1, 3
• Starting insulin when K+ <3.3 mEq/L, which can cause fatal cardiac arrhythmias 1, 4
• Interrupting insulin infusion when glucose falls without adding dextrose-containing fluids 1, 3
• Stopping IV insulin without prior basal insulin administration 2-4 hours earlier 1, 4
• Inadequate potassium monitoring and replacement, a leading cause of DKA mortality 1
• Using bicarbonate in patients with pH >6.9, which may worsen outcomes 1
• Overly rapid correction of osmolality, which increases cerebral edema risk, particularly in children 1, 6
• Relying solely on nitroprusside method for ketone measurement, which misses β-hydroxybutyrate 1, 3

Special Considerations for Euglycemic DKA

• Add dextrose-containing fluids earlier in treatment to maintain adequate glucose while continuing insulin to clear ketosis 3
• Continue insulin until resolution of ketoacidosis regardless of glucose levels 3
• Never interrupt insulin when glucose levels fall—inadequate carbohydrate administration alongside insulin perpetuates ketosis 3