What is the recommended initial rate of insulin infusion for the management of diabetic ketoacidosis (DKA)?

DKA Insulin Infusion Rate

For moderate to severe DKA in adults, start continuous intravenous insulin at 0.1 units/kg/hour after giving an initial bolus of 0.15 units/kg, provided serum potassium is ≥3.3 mEq/L. 1

Initial Insulin Dosing Strategy

Moderate to Severe DKA (Standard Approach)

• Administer an IV bolus of 0.15 units/kg regular insulin before starting the continuous infusion 1, 2
• Follow immediately with continuous IV infusion at 0.1 units/kg/hour (typically 5-7 units/hour in adults) 1
• This bolus-then-infusion approach rapidly achieves therapeutic insulin levels and produces a steady glucose decline of 50-75 mg/dL per hour 1, 2

Mild DKA (Alternative Approach)

• Consider subcutaneous rapid-acting insulin analog at 0.1 units/kg as initial bolus 1
• Follow with 0.1 units/kg every 1 hour OR 0.2 units/kg every 2 hours subcutaneously 1
• This approach is as effective as IV insulin for uncomplicated mild DKA 3

Critical Safety Checkpoint: Potassium

Do not start insulin if serum potassium is <3.3 mEq/L 1, 2

• Insulin drives potassium intracellularly and can precipitate life-threatening hypokalemia 1, 2
• If K+ <3.3 mEq/L: hold insulin, give potassium replacement, and recheck every 2 hours 1
• Once K+ is 3.5-5.0 mEq/L: start insulin and add 20-30 mEq potassium to each liter of IV fluid 1, 2

Adjusting the Infusion Rate

If Glucose Isn't Falling Adequately

• If plasma glucose doesn't drop by 50 mg/dL in the first hour: verify adequate hydration, then double the insulin infusion rate every hour until achieving steady decline of 50-75 mg/dL per hour 1

When Glucose Reaches Target

• When glucose reaches 250 mg/dL: decrease insulin infusion to 0.05 units/kg/hour 1
• Add 5-10% dextrose to IV fluids while continuing insulin 1
• The 2022 Joint British Diabetes Society guidelines recommend de-escalating from 0.1 to 0.05 units/kg/hour when glucose drops below 14 mmol/L (252 mg/dL) to reduce hypoglycemia risk 4

Duration of Insulin Therapy

Continue insulin infusion until DKA resolves, NOT just until glucose normalizes 1, 2, 5

• Resolution criteria: pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L, AND glucose <200 mg/dL 1, 2
• Ketone clearance takes longer than glucose normalization—this is a common pitfall 1, 2
• Maintain glucose between 150-200 mg/dL with dextrose-containing fluids until acidosis resolves 1

Special Populations and Situations

Pediatric Patients

• Do NOT give an initial insulin bolus in children 2
• Start directly with continuous infusion at 0.1 units/kg/hour 2

HHS (Hyperosmolar Hyperglycemic State)

• Start at lower rate: 0.05 units/kg/hour 1
• Some experts recommend withholding insulin until glucose stops falling with fluids alone 1

Monitoring Requirements

Check glucose hourly and comprehensive metabolic panel every 2-4 hours 1, 2

• Monitor: glucose, electrolytes, BUN, creatinine, venous pH, anion gap 1, 2
• Venous pH is adequate for monitoring (typically 0.03 units lower than arterial pH) 1
• Direct measurement of β-hydroxybutyrate is preferred over urine ketones 2, 5

Common Pitfalls to Avoid

• Never stop insulin when glucose normalizes if acidosis persists—this causes rebound ketoacidosis 2, 5
• Don't rely on urine ketones to assess response—β-hydroxybutyrate converts to acetoacetate during treatment, making urine ketones appear worse even as DKA improves 1
• Ensure adequate potassium replacement throughout—hypokalemia is a leading cause of complications 1, 2, 4
• When transitioning to subcutaneous insulin, give basal insulin 2-4 hours before stopping IV insulin to prevent rebound hyperglycemia 2

Evidence Quality Note

The most recent American Diabetes Association 2025 guidelines provide the current standard of care 1, building on the foundational 2001 protocols 1. While research shows lower insulin doses (0.025 units/kg/hour) may be safe 6, the 0.1 units/kg/hour rate remains the evidence-based standard with the most robust safety and efficacy data 1, 2.