Neonatal Polycythemia: II. Plasma, Blood, and Red Cell Volume Estimates in Relation to Hematocrit Levels and Quality of Intrauterine Growth
- 1 August 1981
- journal article
- research article
- Published by American Academy of Pediatrics (AAP) in Pediatrics
- Vol. 68 (2) , 175-182
- https://doi.org/10.1542/peds.68.2.175
Abstract
Volumes of plasma (PV), blood (BV) and red cells (RCV) were estimated within 32 h of birth in 39 neonates with normal growth, 14 neonates with intrauterine growth retardation and 20 neonates with macrosomia. Total PV, BV and RCV increased linearly with birthweight and were unaffected by deviation in the quality of fetal growth. In proportion to body weight, PV/kg, BV/kg and RCV/kg correlated neither with birthweight nor with the quality of intrauterine growth. Neonates with umbilical vein hematocrit (UV Hct) levels 51-60%, 61-65% and 66-77% had progressively lower, but not statistically different, mean PV/kg (38.1 .+-. 4.49, 37.6 .+-. 5.41 and 34.8 .+-. 5.16 ml/kg, respectively). They had progressively higher mean BV/kg (90 .+-. 10.1 vs. 101 .+-. 13.7 ml/kg, P < 0.002, and vs. 110 .+-. 19.0 ml/kg, P < 0.001). They also had progressively higher mean RCV/kg (52 .+-. 7.4, 64 .+-. 8.7 and 75 .+-. 16.4 ml/kg, P < 0.001). Although PV/kg did not correlate with UV Hct, both BV/kg and RCV/kg increased linearly with increasing UV Hct (r = 0.58 and r = 0.79, respectively). Volume estimates were repeated after partial exchange transfusion in 29 neonates. Mean UV Hct decreased from 63 .+-. 5.9% preexchange to 51 .+-. 5.2% postexchange (P < 0.001), mean PV increased from 37.7 .+-. 5.56 to 47.6 .+-. 7.99 ml/kg (P < 0.001) and mean RCV decreased from 67 .+-. 16.5 to 51 .+-. 12.3 ml/kg (P < 0.001). Despite precautions to keep the partial exchange isovolemic, mean BV decreased from 105 .+-. 18.7 to 98 .+-. 18.0 ml/kg (P = 0.001) and the mean PV increase (10 ml/kg) was less than the mean RCV decrease (16 ml/kg). Neonates with polycythemia evidently have normal PV but their RCV and Bv are elevated in direct proportion to UV Hct. Isovolemic partial exchange transfusion decreases UV Hct, RCV and BV and increases PV.This publication has 0 references indexed in Scilit: