Formula
Medical (RABBIT 2): TDD = 0.4 U/kg if glucose 140–200 mg/dL, 0.5 U/kg if 201–400 mg/dL. Surgical (RABBIT 2 Surgery): TDD = 0.5 U/kg, or 0.3 U/kg if age ≥70 y and/or creatinine ≥2.0 mg/dL. 50% basal once daily + 50% prandial divided before 3 meals.
Clinical pearls
- Evidence is for insulin-naive or low-dose (≤0.4 U/kg/day) type 2 diabetes, non-ICU, glucose 140–400 mg/dL; not for type 1 diabetes, DKA/HHS or ICU drips.
- Use lower doses (e.g. 0.3 U/kg or less) in older adults, renal impairment, poor intake or high hypoglycemia risk; hypoglycemia (<70 mg/dL) occurred in 23% with basal-bolus in RABBIT 2 Surgery.
- Hold prandial insulin if the patient is not eating, and titrate daily to a premeal target of 100–180 mg/dL.
Examples
basal bolus 80 kg glucose 180 medical patientstarting insulin dose surgical patient 75 yo 80 kg bg 220 creatinine 1.0how much insulin should I start for a 100 kg man with blood sugar 250 on medicine
FAQ
How do I calculate a starting basal-bolus insulin dose?
For a non-ICU inpatient with type 2 diabetes, start 0.4–0.5 U/kg/day (0.3 U/kg if elderly or renal impairment), half as basal and half as prandial split across 3 meals.
Why not use sliding scale insulin alone?
RABBIT 2 showed better glycemic control with basal-bolus, and RABBIT 2 Surgery showed fewer postoperative complications than sliding-scale insulin alone.
Evidence
- Umpierrez GE et al. Randomized study of basal-bolus insulin therapy in the inpatient management of patients with type 2 diabetes (RABBIT 2 trial). Diabetes Care 2007;30:2181–6.
- Umpierrez GE et al. Randomized study of basal-bolus insulin therapy in patients with type 2 diabetes undergoing general surgery (RABBIT 2 Surgery). Diabetes Care 2011;34:256–61.