Capillary venous differences in neonatal neutrophil values

Sixty paired venous and capillary total neutrophil counts (TNCs) were obtained from 30 healthy, term neonates on days 1 and 2 of life. Day 1 venous TNC (8,200 +/-- 3,800/cu mm) and capillary TNC (10,400 +/- 4,400/cu mm) were significantly different when examined by the paired t test as were day 2 venous TNC (8,700 +/- 3,300/cu mm) and capillary TNC (9,800 +/- 3,400/cu mm). Application of published reference ranges for capillary TNC to paired samples revealed a 35% incidence of differing clinical interpretations between paired TNCs. The application of capillary reference ranges to venous TNC may result in frequent misdiagnoses and inappropriate management. Venous reference ranges should be established.