PERFORMANCE OF RETICULOCYTE COUNTS IN STORED-BLOOD SPECIMENS IN A PEDIATRIC POPULATION UTILIZING NEW METHYLENE-BLUE

Although reticulocyte counts can be reliably performed for up to 48 h after storage in EDTA, it is unclear whether this is applicable to the pediatric age group. In order to evaluate this, manual reticulocyte c ounts were performed on 20 specimens from pediatric patients stored at 4-degrees-C for up to 24 h post collection. Samples were evaluated at 1-3, 6, 12, 18, and 24 h after storage in EDTA vacutainer tubes at 4- degrees-C. The age of the subjects ranged from 1 day to 9 years with a median age of 3 years. Patients' reticulocyte counts ranged from 0 to 27% (5.89 +/- 7.21). No clinically significant changes were evident i n the reticulocyte count over 24 h after specimen collection. The mean of the 20 specimens at 1-3 h was 5.50 and at 24 h was 5.40 (P > .05). The standard deviation of the mean values ranged from 7.03 to 7.26 (P > .05). The results indicate that reticulocyte counts may be performe d on previously drawn blood held at 4-degrees-C for up to 24 h post co llection in a pediatric population without significant difference from baseline values.