1) Confirm DKA

• Glucose >250 mg/dL (can be lower in euglycemic DKA)
• Metabolic acidosis: pH <7.30 and/or HCO3 ≤18 mEq/L
• Ketosis: elevated serum beta-hydroxybutyrate or urine ketones
• Usually elevated anion gap

2) Immediate first hour

1. ABCs, monitor, IV access, cardiac monitor
2. Labs: BMP, venous/arterial blood gas, ketones, CBC, osmolality, Mg, phosphate, ECG, infection workup if indicated
3. Start fluids:
   • 0.9% saline 15 to 20 mL/kg in first hour (about 1 to 1.5 L in most adults)

3) Potassium-guided insulin start

• K <3.3 mEq/L: hold insulin, give K first (usually 20 to 30 mEq/h) until >3.3
• K 3.3 to 5.2: start insulin + add K to IV fluids (20 to 30 mEq per liter)
• K >5.2: start insulin, no K initially, recheck frequently

4) Insulin therapy

• Regular insulin IV:
  • 0.1 U/kg bolus then 0.1 U/kg/h, or
  • 0.14 U/kg/h without bolus
• Goal glucose drop: about 50 to 75 mg/dL per hour

5) Ongoing fluids and dextrose transition

• After first hour, choose fluid by corrected sodium:
  • low Na: continue 0.9% saline
  • normal/high Na: 0.45% saline
• When glucose reaches ~200 mg/dL (DKA), add D5-containing fluid and reduce insulin rate (often 0.02 to 0.05 U/kg/h) to continue clearing ketones and closing anion gap.

6) Bicarbonate and phosphate

• Bicarbonate: generally avoid unless severe acidemia (commonly pH <6.9)
• Phosphate: not routine; replace if severe hypophosphatemia, cardiac dysfunction, respiratory weakness, or other specific indications

7) Monitoring

• Hourly bedside glucose
• Electrolytes, anion gap, bicarbonate, creatinine every 2 to 4 hours
• Strict input/output, mental status, vitals
• Search and treat precipitating cause (infection, missed insulin, MI, stroke, pancreatitis, drugs). Harrison’s emphasizes identifying and treating triggers and close reassessment (p. 11347).

8) Resolution criteria (typical)

• glucose <200 mg/dL and
• two of:
  • bicarbonate ≥15 mEq/L
  • pH >7.30
  • anion gap normalized

9) Transition IV to subcutaneous insulin

• Give long-acting basal insulin
• Overlap IV insulin for 1 to 2 hours after first SC dose to prevent rebound ketosis
• Ensure patient can eat and cause is addressed

Useful reference image