Erythrocyte parameters in the elderly: an argument against new geriatric normal values.

Erythrocyte parameters in 292 unselected geriatric patients were studied retrospectively. Statistically significant mean decreases compared to the laboratories' normal mean values were found in the red blood cell count (RBC), hemoglobin level, hematocrit, and mean corpuscular hemoglobin concentration; there also was a slight increase in mean corpuscular volume and mean corpuscular hemoglobin. However, when 17 patients with a hemoglobin level less than 10 gm/dl or a hematocrit reading less than 35 percent were excluded, all of the mean values for erythrocyte parameters fell within the normal range. In 71 percent of these 17 patients the etiology of the anemia was documented. Although one cannot definitely exclude a slight change in erythrocyte parameters with aging, it is concluded that the establishment of so-called new geriatric norms is premature, as the population studied included patients with various diseases. Good medical practice dictates continued evaluation and monitoring of patients in whom erythrocyte values are outside the established normal ranges.