How do you calculate the reticulocyte production index given the following data: Hct 15%, Normal Hct 45%, Maturation correction 2.5, Reticulocyte percentage 9%?

To calculate the reticulocyte production index (RPI), the reticulocyte percentage must first be adjusted for the patient's hematocrit (Hct) as compared to the normal Hct. The reticulocyte percentage helps assess bone marrow response to anemia.

In this case, you start with the reticulocyte percentage of 9%. Since the patient's Hct is 15% and the normal Hct is 45%, a maturation correction factor is needed to account for the degree of anemia. The maturation correction, in this scenario, is 2.5.

To find the RPI, you multiply the reticulocyte percentage by the maturation correction. This calculation effectively adjusts the observed reticulocyte count to reflect how well the bone marrow is responding to anemia, which is particularly important in patients with varying levels of Hct.

Using the maturation correction allows clinicians to understand whether the reticulocyte response is adequate given the severity of anemia. A high RPI indicates a strong response to anemia, whereas a low RPI may indicate inadequate bone marrow response.

In this question, selecting the option that states to multiply the reticulocyte percentage by the maturation correction accurately describes the correct computation for the reticulocyte production index.