title: A revised rule of thumb for predicting haematocrit rise in premature infants following packed red blood cell transfusion.
abstract: The purpose of this study is to compare a revised rule of thumb with the Harriet Lane and Behrman's formulas for predicting haematocrit rise following packed red blood cell (PRBC) transfusion in premature neonates. Pre- and post-transfusion, equilibrated central haematocrits were obtained within 24 h of transfusion in 12 premature neonates undergoing 18 transfusions. Iatrogenic blood loss between pre- and post-transfusion haematocrit determinations was measured for each transfusion event, and infants with detectable, non-iatrogenic blood loss were excluded. Expected haematocrit rise was calculated three different ways using the Behrman, Harriet Lane, and proposed formulas (see text). The Harriet Lane formula predicted haematocrit rise with a correlation, r = 0.66 and slope m = 0.43. The Behrman's formula predicted haematocrit rise with a correlation r = 0.81 and slope m = 0.60. The proposed formula predicted haematocrit rise with a correlation r = 0.79 and slope m = 0.56. On the basis of these findings, we propose the following formula: Quantity PRBC transfused (ml) = 4/3 X desired haematocrit rise X weight (Kg) This formula takes into account the higher blood volume per kilogram body weight seen in premature infants while estimating PRBC unit haematocrit as 0.75 to obviate the need of measurement before each transfusion and, therefore, is an accurate, practical, and simple replacement for the Harriet Lane and Behrman's formulas.
mesh_terms: D000740:Anemia / Q000628:therapy; D001699:Biometry; D001803:Blood Transfusion; D017707:Erythrocyte Transfusion; D006400:Hematocrit; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature