What are the step-wise treatment approaches for a patient with diabetic ketoacidosis (DKA), considering factors such as age, medical history, and severity of the condition?

Stepwise Treatment of Diabetic Ketoacidosis

Initial Assessment and Diagnosis

Begin immediate treatment once DKA is confirmed by blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria. 1

Obtain the following laboratory tests immediately: 2, 1

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

Identify precipitating factors: infection, myocardial infarction, stroke, pancreatitis, trauma, insulin omission, or SGLT2 inhibitor use. 1

Step 1: Fluid Resuscitation (First Hour)

Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adult) during the first hour to restore intravascular volume and tissue perfusion. 1, 3

This aggressive initial fluid replacement is critical for improving insulin sensitivity and restoring renal perfusion. 1

Step 2: Potassium Assessment and Replacement

Check serum potassium BEFORE starting insulin therapy. 1

Follow this algorithm: 1

• If K+ <3.3 mEq/L: DELAY insulin therapy and aggressively replace potassium until levels reach ≥3.3 mEq/L to prevent life-threatening arrhythmias
• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq potassium per liter of IV fluid (use 2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely every 2-4 hours, as levels will drop rapidly with insulin therapy

Total body potassium depletion averages 3-5 mEq/kg body weight in DKA, and insulin therapy will unmask this depletion by driving potassium intracellularly. 1

Step 3: Insulin Therapy

For moderate-to-severe DKA or critically ill/mentally obtunded patients, use continuous intravenous regular insulin at 0.1 units/kg/hour without an initial bolus in pediatric patients. 2, 1

In adults, an initial IV bolus of 0.15 units/kg may be given before starting the continuous infusion. 2

Alternative for mild-to-moderate uncomplicated DKA: For hemodynamically stable, alert patients, subcutaneous rapid-acting insulin analogs at 0.15 units/kg every 2-3 hours combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin. 1

Monitor glucose decline: 2, 1

• Target glucose decline of 50-75 mg/dL per hour
• If glucose does not fall by 50 mg/dL in the first hour, check hydration status; if acceptable, double the insulin infusion rate every hour until steady decline achieved

Step 4: Ongoing Fluid Management

After the first hour, adjust fluid therapy based on: 1

• Hydration status
• Serum electrolyte levels
• Urine output

When serum glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% NaCl while continuing insulin infusion. 1, 3

This prevents hypoglycemia while ensuring complete resolution of ketoacidosis—a critical step that prevents premature termination of insulin therapy. 1

Step 5: Monitoring During Treatment

Draw blood every 2-4 hours for: 2, 1

• Serum electrolytes (especially potassium)
• Glucose
• Blood urea nitrogen, creatinine
• Venous pH (adequate for monitoring; typically 0.03 units lower than arterial pH)
• Anion gap

Monitor β-hydroxybutyrate in blood as the preferred method for tracking ketoacidosis resolution. 2, 1

The nitroprusside method only measures acetoacetic acid and acetone, not β-hydroxybutyrate (the predominant ketone), and can falsely suggest worsening ketosis during treatment. 2

Step 6: Bicarbonate Administration (Generally NOT Recommended)

Do NOT administer bicarbonate for pH >6.9-7.0. 1

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

Step 7: Resolution Criteria

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

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

Continue insulin infusion until ALL resolution criteria are met, regardless of glucose levels. 1

Step 8: Transition to Subcutaneous Insulin

Administer basal insulin (glargine or detemir) 2-4 hours BEFORE stopping the IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia. 1, 4

This overlap period is essential—stopping IV insulin without prior basal insulin administration causes rebound hyperglycemia and ketoacidosis. 1

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

Critical Pitfalls to Avoid

• Premature insulin termination: Stopping insulin when glucose normalizes but before ketoacidosis resolves leads to DKA recurrence 1
• Inadequate potassium monitoring: Check potassium every 2-4 hours; hypokalemia is a leading cause of mortality in DKA 1
• Forgetting dextrose: Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin prevents complete ketoacidosis resolution 1
• Overly rapid osmolality correction: Increases cerebral edema risk, particularly in children 1

Special Considerations

SGLT2 inhibitors must be discontinued immediately and not restarted until 3-4 days after metabolic stability is achieved. 1

For patients with renal disease, heart failure, or pregnancy, fluid resuscitation rates require more cautious titration with nephrology or cardiology consultation. 5

Cerebral edema occurs more commonly in children and adolescents; monitor closely for altered mental status, headache, or neurological deterioration. 1