On a standard reticulocyte preparation with new methylene blue,100 of 1000 cells that are counted contain blue-stained granulofilamentous material.The red blood count is 3.22 × 10¹²/L,and the hematocrit is 30%.Calculate the reticulocyte production index (RPI).

Question

Quizplus · Accepted Answer

The RPI uses the corrected reticulocyte count (calculated in Question 25).It then takes into account,based on the patient's hematocrit,the early release of RBCs from the marrow so that when the reticulocytes are counted,it is not just those released in the last 24 hours (1 day)but a piling up of those released over a longer period of time.For a hematocrit of 30%,the average length of time a reticulocyte spends in the blood is 2.0 days.Thus the corrected reticulocyte count of 6.7 is divided by 2 = 3.4.

On a Standard Reticulocyte Preparation with New Methylene Blue,100 of 1000