Treatment Plan for Acute Diabetic Ketoacidosis (DKA)
Initial Assessment and Laboratory Evaluation
Immediately obtain the following laboratory tests upon presentation: plasma glucose, serum ketones (preferably direct β-hydroxybutyrate measurement), electrolytes with calculated anion gap, venous blood gas (venous pH is sufficient), blood urea nitrogen, creatinine, serum osmolality, complete blood count, urinalysis with urine ketones, and electrocardiogram 1, 2. If infection is suspected based on fever, leukocytosis, or clinical signs, obtain bacterial cultures of urine, blood, and throat, and initiate appropriate antibiotics 2. Chest X-ray should be obtained if respiratory symptoms are present 2.
Fluid Resuscitation Protocol
Begin immediate fluid resuscitation with isotonic saline at 15-20 mL/kg/hour for the first hour 1, 2. This aggressive initial fluid replacement is critical for restoring circulating volume and improving tissue perfusion 1. After the first hour, adjust the rate based on hemodynamic status, typically continuing isotonic saline but at reduced rates 1. Total fluid replacement should approximate 1.5 times the 24-hour maintenance requirements 2.
Critical Potassium Management
Before initiating insulin therapy, verify that serum potassium is ≥3.3 mEq/L 2. This is an absolute threshold—do not start insulin if potassium is below this level, as insulin will drive potassium intracellularly and can precipitate life-threatening cardiac arrhythmias and death 2. If potassium is <3.3 mEq/L, continue isotonic saline and aggressively replace potassium with 20-40 mEq/L added to IV fluids (using 2/3 KCl or potassium-acetate and 1/3 KPO4) until the level reaches ≥3.3 mEq/L 2, 3. Obtain an electrocardiogram to assess for cardiac effects of hypokalemia 2.
Once insulin is started and serum potassium falls below 5.5 mEq/L (assuming adequate urine output), add 20-30 mEq potassium to each liter of IV fluid to maintain serum potassium in the target range of 4-5 mEq/L throughout treatment 1, 3. Both insulin therapy and acidosis correction will decrease serum potassium, creating ongoing risk for life-threatening complications 3.
Insulin Therapy Initiation and Management
Once serum potassium is confirmed ≥3.3 mEq/L, administer an IV bolus of 0.1 units/kg regular insulin, followed immediately by continuous IV infusion at 0.1 units/kg/hour 1, 2. This continuous intravenous regular insulin infusion is the preferred treatment method for moderate to severe DKA 2. The target glucose decline is 50-75 mg/dL per hour 1, 2.
If glucose does not fall by at least 50 mg/dL in the first hour, verify adequate hydration status and double the insulin infusion rate every hour until achieving a steady decline of 50-75 mg/dL/hour 2. Continue the insulin infusion at 0.1 units/kg/hour as the standard rate 3.
Alternative Approach for Mild-Moderate Uncomplicated DKA
For hemodynamically stable, alert patients with mild to moderate DKA who can tolerate oral intake, subcutaneous rapid-acting insulin analogs at 0.15 U/kg every 2-3 hours combined with aggressive fluid management can be as effective and more cost-effective than IV insulin 2, 4, 5. However, this approach requires the patient to be hemodynamically stable with frequent monitoring of capillary glucose levels 2.
Bicarbonate Therapy Decision
No bicarbonate is necessary when pH ≥7.0, as insulin therapy alone is sufficient to resolve ketoacidosis 3. Bicarbonate may only be considered in adult patients with severe acidemia (pH <6.9), and even for pH 6.9-7.0, prospective randomized studies have failed to show beneficial or deleterious changes in morbidity or mortality 3. The critical point: do not administer bicarbonate based solely on low bicarbonate levels—the pH is the determining factor 3.
Monitoring Requirements
Check blood glucose every 2-4 hours and measure serum electrolytes (particularly potassium), venous pH, blood urea nitrogen, creatinine, and anion gap every 2-4 hours until stable 1, 2, 3. Direct measurement of β-hydroxybutyrate in blood is preferred for ketone monitoring 2.
DKA Resolution Criteria
DKA is considered resolved when ALL of the following criteria are met simultaneously: glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L 2, 3. All four criteria must be present before transitioning to subcutaneous insulin 2.
Transition to Subcutaneous Insulin
When DKA has completely resolved and the patient can tolerate oral intake, administer long-acting basal insulin (glargine or detemir) subcutaneously 2-4 hours BEFORE discontinuing the IV insulin infusion 1, 2. This timing is critical to allow for absorption and prevent DKA recurrence 2. Continue the IV insulin infusion for 1-2 hours after administering subcutaneous insulin 1, 2.
Initiate a multiple-dose insulin regimen using a combination of short-acting/rapid-acting and intermediate-acting/long-acting insulin 2. Continue monitoring glucose levels every 2-4 hours during the transition period 2.
Critical Pitfall to Avoid
Do not discontinue IV insulin without prior administration of subcutaneous basal insulin—this is the most common error leading to DKA recurrence 2. Do not initiate subcutaneous insulin before complete resolution of metabolic acidosis or when the patient is still unable to tolerate oral intake 2.
Precipitating Event Management
Identify and treat the underlying precipitating event, which commonly includes infections, newly discovered diabetes, insulin omission, or other significant stressors 2, 6. Address these triggers to prevent DKA recurrence 6.
Discharge Planning
Structured discharge planning should include patient education on insulin administration, glucose monitoring, sick day management, and actions to prevent DKA recurrence 2. Ensure proper selection and administration of insulin regimens before discharge 6.