Reticulocyte production index
Corrects the reticulocyte count for anemia and maturation time.
Inputs
0 of 2%
%
When to use
- Anemia workup.
Pearls and pitfalls
- Above 2: appropriate marrow response (blood loss or hemolysis); below 2: hypoproliferative anemia.
Why use
Separates production from destruction.
RPI = retic % × (Hct ÷ 45) ÷ maturation factor (1.0 at Hct ≥ 40, 1.5 at 30–39, 2.0 at 20–29, 2.5 below 20)