What is the initial management for a diabetic patient in diabetic ketoacidosis (DKA)?

Initial Management of Diabetic Ketoacidosis in the Inpatient Setting

Begin immediate treatment 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 adequate hydration and potassium levels are confirmed. 1, 2

Diagnostic Confirmation

Before initiating treatment, confirm DKA with the following criteria 1:

• Blood glucose >250 mg/dL (though euglycemic DKA can occur, particularly with SGLT-2 inhibitor use) 3, 4
• Arterial pH <7.3 1
• Serum bicarbonate <15-18 mEq/L 1, 2
• Presence of ketonemia or ketonuria 1
• Anion gap >10-12 mEq/L 1, 4

Obtain the following labs immediately 1, 2:

• Plasma glucose, electrolytes with calculated anion gap, serum ketones (β-hydroxybutyrate preferred over nitroprusside method)
• Blood urea nitrogen, creatinine, osmolality
• Arterial or venous blood gas
• Complete blood count with differential
• Urinalysis with urine ketones
• Electrocardiogram
• If infection suspected: blood cultures, urine cultures, throat cultures, and chest X-ray 1

Step-by-Step Treatment Algorithm

1. Fluid Resuscitation (FIRST PRIORITY)

Hour 1: 1, 2

• Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adult)
• This restores intravascular volume and improves renal perfusion before insulin administration

After Hour 1: 1

• Continue IV fluids based on hydration status, electrolyte levels, and urine output
• Aim to correct estimated fluid deficits within 24 hours
• When glucose reaches 250 mg/dL: Switch to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin 1, 2

2. Insulin Therapy (Start AFTER initial fluid resuscitation)

Initial Dosing: 1, 2

• Start continuous IV regular insulin at 0.1 units/kg/hour without an initial bolus
• Do NOT start insulin until adequate hydration is achieved

Titration: 1, 2

• If glucose does not fall by 50 mg/dL in the first hour, check hydration status
• If hydration is adequate, double the insulin infusion rate hourly until steady glucose decline of 50-75 mg/hour is achieved
• When glucose reaches 250 mg/dL, decrease insulin to 0.05-0.1 units/kg/hour but never stop insulin 2

Critical Point: Continue insulin infusion until complete resolution of ketoacidosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels 1, 3, 2. This is the most common pitfall—stopping insulin when glucose normalizes before ketosis resolves.

3. Potassium Replacement (ESSENTIAL)

Before starting insulin, check potassium level: 1, 2

• If K+ <3.3 mEq/L: Hold insulin and give potassium replacement first
• If K+ 3.3-5.3 mEq/L: Add 20-30 mEq/L potassium to IV fluids (2/3 KCl and 1/3 KPO₄)
• If K+ >5.3 mEq/L: Hold potassium replacement but recheck frequently

Target: Maintain serum potassium between 4-5 mmol/L throughout treatment 1, 2. Insulin drives potassium intracellularly, causing potentially life-threatening hypokalemia.

4. Monitoring Protocol

Every 1-2 hours: 3, 2

• Blood glucose

Every 2-4 hours: 1, 2

• Serum electrolytes (especially potassium)
• Venous pH (typically 0.03 units lower than arterial pH)
• Anion gap
• Blood urea nitrogen, creatinine, osmolality

Preferred ketone monitoring: Direct measurement of β-hydroxybutyrate rather than nitroprusside method, which only detects acetoacetic acid and acetone 1, 3

5. Bicarbonate Administration

Generally NOT recommended for pH >6.9-7.0 1, 2. Bicarbonate can worsen hypokalemia, increase risk of cerebral edema, and paradoxically worsen ketosis 5, 6.

Exception: Consider if pH <6.9 or in peri-intubation period to prevent hemodynamic collapse 5

Resolution Criteria and Transition

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

Transition to subcutaneous insulin: 3, 2

• Administer basal insulin (long-acting) 2-4 hours before stopping IV insulin infusion
• This overlap prevents rebound ketoacidosis
• Patient must be able to eat before transitioning

Critical Pitfalls to Avoid

1. Stopping IV insulin when glucose normalizes before ketoacidosis resolves—this causes recurrent or worsening DKA 1, 3, 2

2. Failing to add dextrose when glucose falls below 250 mg/dL while continuing insulin therapy 1, 3

3. Inadequate potassium monitoring and replacement—insulin therapy causes rapid intracellular potassium shift leading to life-threatening hypokalemia 1, 2

4. Premature termination of insulin therapy before complete resolution of all metabolic parameters 1, 3, 2

5. Using nitroprusside method alone to measure ketones, which misses β-hydroxybutyrate, the predominant ketone body 1, 3

6. Overly rapid correction in younger patients increases cerebral edema risk 5, 7