The complete blood cell count in a refined cohort of preterm NEC: the importance of gestational age and day of diagnosis when using the CBC to estimate mortality

Objective:the value of the white blood cell count (wbc) in necrotizing enterocolitis (nec) is controversial. one reason for this confusion may be that the various wbc lineages change substantially with increasing gestational age and thereby age of nec onset. this study postulated that if a data set was large enough and the diagnosis of nec clean enough, absolute wbc counts would facilitate prediction of nec mortality. the objective of this study was to determine whether absolute wbc counts enhance the prediction of nec mortality.study design:a de-identified data subset from the pediatrix national data set specific to the diagnoses of nec in patients who had a cbc drawn on the day of diagnosis (exclusive of the diagnoses of spontaneous intestinal perforations and congenital anomalies) was the target for analysis. values of primary interest included: gestation, day of diagnosis, absolute wbc count, platelet count, hematocrit, mortality and the day of diagnosis. stepwise regression analysis was used to predict mortality.result:a total of 4059 (79%) survivors and 1107 (21%) infants who died with a diagnosis of medical or surgical nec were included in the data set. associations with mortality were found with low gestational age, low platelet count, low hematocrit, high band/segmented neutrophil ratio, earlier day of diagnosis, high birth weight z-score, non-white race, no antenatal steroids in gestations above 24 weeks, absolute lymphocyte count adjusted for gestational age, and absolute monocyte count high and low values. a stepwise regression analysis yielded a receiver-operator curve of 0.819 with a sensitivity of 65% and specificity of 84%.conclusion:absolute wbc values enhance prediction of nec survival when used in combination with readily available data on the day of nec diagnosis.