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

Immediate Management of Diabetic Ketoacidosis (DKA)

Begin with aggressive fluid resuscitation using isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour, followed by continuous IV regular insulin at 0.1 units/kg/hour without an initial bolus, while closely monitoring and replacing potassium to prevent life-threatening hypokalemia. 1, 2

Initial Assessment and Diagnosis

Obtain the following laboratory studies immediately 1:

• Plasma glucose, serum ketones (β-hydroxybutyrate preferred), arterial blood gases
• Electrolytes with calculated anion gap, serum osmolality
• Blood urea nitrogen, creatinine (to assess renal function and cerebral edema risk)
• Complete blood count, urinalysis with urine ketones
• Electrocardiogram (to monitor for arrhythmias from electrolyte shifts)

Diagnostic criteria: Plasma glucose >250 mg/dL, arterial pH <7.30, serum bicarbonate <18 mEq/L, and positive serum/urine ketones 1

Fluid Therapy: The Foundation of Treatment

Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour to restore intravascular volume and renal perfusion 1, 2. This initial aggressive resuscitation is critical—some evidence suggests balanced electrolyte solutions may achieve faster DKA resolution, though isotonic saline remains the standard 2, 3.

After the first hour 1:

• Continue fluid replacement to correct estimated deficits over 24 hours
• Target 1.5-2 times the 24-hour maintenance requirements
• Critical pitfall: Do not allow serum osmolality to change by more than 3 mOsm/kg/h to prevent cerebral edema 2

Insulin Therapy: Timing and Dosing

Start continuous IV regular insulin at 0.1 units/kg/hour WITHOUT an initial bolus 1, 2. The American Diabetes Association recommends this as standard care for critically ill patients 2. Some guidelines suggest an initial bolus of 0.15 U/kg, but the no-bolus approach is equally effective and simpler 2.

Goal: Reduce plasma glucose by 50-75 mg/hour 1

If glucose does not fall by 50 mg/dL in the first hour, double the insulin infusion rate hourly until steady decline is achieved 1, 2.

Emerging evidence: Adding low-dose subcutaneous basal insulin (e.g., glargine) alongside IV insulin may prevent rebound hyperglycemia and shorten hospital stays, though this is not yet universal standard practice 2, 3.

Electrolyte Management: Preventing Fatal Complications

Potassium Replacement (Most Critical)

Total body potassium is always depleted in DKA despite potentially normal or elevated initial levels due to acidosis-induced extracellular shift 1, 2. As insulin therapy and acidosis correction drive potassium intracellularly, life-threatening hypokalemia can develop rapidly 1.

Protocol 1, 2:

• Once renal function is confirmed and serum potassium <5.3-5.5 mEq/L, add 20-40 mEq/L potassium to IV fluids
• Use 2/3 KCl and 1/3 KPO4 to maintain serum potassium 4-5 mEq/L 2
• Critical safety point: If initial potassium is <3.3 mEq/L, DELAY insulin therapy until potassium is restored to prevent arrhythmias, cardiac arrest, and respiratory muscle weakness 2

Bicarbonate: Generally NOT Recommended

Do not administer bicarbonate for pH >7.0 as studies show no benefit on clinical outcomes and potential harm (worsening ketosis, hypokalemia, increased cerebral edema risk) 2, 3.

Exception: For pH <6.9, consider 100 mmol sodium bicarbonate in 400 mL sterile water at 200 mL/h; for pH 6.9-7.0, give 50 mmol in 200 mL at 200 mL/h 2. Also consider bicarbonate pre/post-intubation when pH <7.2 to prevent hemodynamic collapse from apnea 3.

Phosphate: Rarely Needed

Routine phosphate replacement has not shown clinical benefit 2. Consider only if serum phosphate <1.0 mg/dL or patient has cardiac dysfunction, anemia, or respiratory depression 2.

Monitoring During Treatment

Blood glucose: Every 1-2 hours 1

Comprehensive metabolic panel: Every 2-4 hours to assess electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 1, 2

Follow venous pH and anion gap to monitor acidosis resolution—venous pH is typically 0.03 units lower than arterial pH and is adequate for monitoring 2

Continuous cardiac monitoring is essential to detect arrhythmias from electrolyte shifts 2

Transition to Subcutaneous Insulin: Preventing Rebound

DKA resolution criteria: Glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, AND anion gap ≤12 mEq/L 1, 2

Critical timing: Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin to prevent recurrence of ketoacidosis and rebound hyperglycemia 1, 2. This overlap period is essential—stopping IV insulin without prior subcutaneous coverage is a common and dangerous error.

For newly diagnosed patients, initiate 0.5-1.0 units/kg/day using a combination of short/rapid-acting and intermediate/long-acting insulin 2.

Identifying and Treating Precipitating Causes

Search for 1, 2:

• Infections: Obtain cultures (urine, blood) and start appropriate antibiotics if suspected
• Medication issues: Insulin omission/nonadherence, SGLT2 inhibitors (can cause euglycemic DKA—discontinue 3-4 days before surgery)
• Acute stressors: Myocardial infarction, stroke, new diabetes diagnosis

Cerebral Edema: The Most Feared Complication

Occurs in 0.7-1.0% of children with DKA but can be fatal 2. Risk factors include 2, 4:

• Higher BUN at presentation
• Severe acidosis with greater hypocapnia
• Treatment with bicarbonate
• Rapid overcorrection of hyperglycemia and osmolality

Prevention strategies 2, 3, 4:

• Gradual correction of glucose and osmolality (osmolality change <3 mOsm/kg/h)
• Avoid excessive fluid administration rates after initial resuscitation
• Use isotonic fluids initially, then at least 0.45% saline for maintenance

Special Considerations for Mild DKA

For uncomplicated mild DKA, subcutaneous rapid-acting insulin analogs may be used in emergency departments or step-down units with aggressive fluid management, which may be safer and more cost-effective than IV insulin 2. Alternatively, subcutaneous regular insulin every 4 hours (5-20 units based on glucose level) can be effective 2.

Airway Management in Critically Ill Patients

BiPAP is NOT recommended due to aspiration risk 3. For impending respiratory failure, proceed with intubation and mechanical ventilation 3. Consider bicarbonate administration pre/post-intubation if pH <7.2 to prevent metabolic acidosis and hemodynamic collapse during the apneic period 3.

Early Nutritional Support

Initiate oral nutrition early once the patient can tolerate it—this has been shown to reduce ICU and overall hospital length of stay 3.