What is the management of 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 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

Diagnostic Criteria

Confirm DKA diagnosis with the following parameters 3, 1:

• Blood glucose >250 mg/dL (though euglycemic DKA can occur with normal glucose) 3, 4
• Arterial pH <7.3 3, 1
• Serum bicarbonate <15 mEq/L 3, 1
• Positive serum or urine ketones 3, 1
• Anion gap >10 mEq/L 3, 1

Initial Laboratory Evaluation

Obtain the following tests immediately 1, 2:

• Plasma glucose, blood urea nitrogen, creatinine
• Serum ketones (β-hydroxybutyrate preferred over nitroprusside method) 1, 2
• Electrolytes with calculated anion gap
• Arterial blood gases
• Complete blood count with differential
• Electrocardiogram
• Urinalysis with urine ketones
• Bacterial cultures (blood, urine, throat) if infection suspected 3, 1

The American Diabetes Association emphasizes that direct measurement of β-hydroxybutyrate is superior to the nitroprusside method, which only detects acetoacetic acid and acetone, not the predominant ketone body in DKA 1, 2.

Fluid Resuscitation Protocol

Initial Phase (First Hour)

Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 liters in average adults) to restore intravascular volume and renal perfusion 3, 1, 2.

Subsequent Fluid Management

After the initial hour, fluid choice depends on corrected serum sodium 3:

• If corrected sodium is normal or elevated: Use 0.45% NaCl at 4-14 mL/kg/hour 3
• If corrected sodium is low: Continue 0.9% NaCl at similar rate 3
• Correct serum sodium for hyperglycemia: Add 1.6 mEq to measured sodium for each 100 mg/dL glucose above 100 mg/dL 3

Dextrose Addition

When serum glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% saline while continuing insulin therapy 1, 2. This critical step prevents hypoglycemia while allowing continued insulin administration to clear ketosis 1.

Insulin Therapy

Initiation

Start continuous intravenous regular insulin at 0.1 units/kg/hour WITHOUT an initial bolus for moderate to severe DKA 1, 2. Do not start insulin if potassium is <3.3 mEq/L—correct hypokalemia first to prevent life-threatening arrhythmias 1.

Dose Adjustment

If plasma glucose does not fall by 50 mg/dL in the first hour, verify adequate hydration status, then double the insulin infusion rate hourly until achieving a steady glucose decline of 50-75 mg/hour 1, 2.

Maintenance Phase

When glucose reaches 250 mg/dL, decrease insulin infusion to 0.05-0.1 units/kg/hour and add dextrose-containing fluids 2. The American Diabetes Association emphasizes that insulin must never be interrupted when glucose falls—instead, add dextrose to prevent hypoglycemia while continuing insulin to clear ketosis 1.

Alternative for Mild-Moderate Uncomplicated DKA

For uncomplicated mild-to-moderate DKA in alert patients, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin 1. However, continuous IV insulin remains the standard for critically ill and mentally obtunded patients 1.

Potassium Management

Critical Safety Point

Total body potassium is universally depleted in DKA despite initial serum levels 1. Insulin therapy and acidosis correction will further lower serum potassium 1, 2.

Replacement Protocol

• If K+ <3.3 mEq/L: HOLD insulin therapy and aggressively replace potassium until ≥3.3 mEq/L to prevent cardiac arrhythmias and respiratory muscle weakness 1
• 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 3, 1, 2
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely as levels will drop rapidly with insulin 1
• Target serum potassium: 4-5 mEq/L throughout treatment 1, 2

Bicarbonate Administration

Bicarbonate is NOT recommended for DKA patients with pH >6.9-7.0 1, 2, 5. Multiple studies show no difference in resolution of acidosis or time to discharge with bicarbonate use, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 1.

The FDA label for sodium bicarbonate indicates use in "severe diabetic acidosis," but current American Diabetes Association guidelines recommend against routine use unless pH falls below 6.9 1, 5.

Monitoring Protocol

Frequent Assessments

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

Ketone Monitoring

Direct measurement of β-hydroxybutyrate is preferred over nitroprusside method, which misses the predominant ketone body 1, 2.

Resolution Criteria

DKA is resolved when ALL of the following are met 1, 2:

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

Target glucose of 150-200 mg/dL until these resolution parameters are achieved 1.

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. This overlap period is essential 1.

Recent evidence shows that adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 1.

Once the patient can eat, start a multiple-dose schedule using combination of short/rapid-acting and intermediate/long-acting insulin 1.

Identification and Treatment of Precipitating Factors

Concurrent treatment of underlying causes is crucial 1. Common precipitants include 3, 1:

• Infection (most common—obtain cultures and start appropriate antibiotics)
• Myocardial infarction
• Cerebrovascular accident
• Pancreatitis
• Trauma
• Insulin omission or inadequacy
• SGLT2 inhibitor use (discontinue 3-4 days before any planned surgery to prevent euglycemic DKA) 1

Critical Pitfalls to Avoid

• Premature termination of insulin before complete ketosis resolution leads to DKA recurrence 1, 2
• Interrupting insulin when glucose falls without adding dextrose causes persistent or worsening ketoacidosis 1
• Starting insulin with K+ <3.3 mEq/L risks life-threatening arrhythmias 1
• Inadequate potassium monitoring and replacement is a leading cause of DKA mortality 1
• Relying on nitroprusside method for ketone measurement misses β-hydroxybutyrate 1, 2
• Overly rapid correction of osmolality increases cerebral edema risk, particularly in children 1, 2
• Failure to add dextrose when glucose reaches 250 mg/dL while continuing insulin 1

Special Consideration: Euglycemic DKA

With increasing SGLT2 inhibitor use, euglycemic DKA (normal or mildly elevated glucose with ketoacidosis) is becoming more common 6, 4. In these cases, add dextrose-containing fluids earlier in treatment to maintain adequate glucose while continuing insulin to clear ketosis 6.