Ma. Hauch et al., MATERNAL AND FETAL COLLOID OSMOTIC-PRESSURE FOLLOWING FLUID EXPANSIONDURING CESAREAN-SECTION, Critical care medicine, 23(3), 1995, pp. 510-514
Objectives: To characterize the changes in colloid osmotic pressure du
ring delivery and to determine the relationship between maternal and f
etal colloid osmotic pressures. Design: Clinical, prospective study. S
etting: Obstetrical operating theater in a tertiary care university ho
spital.Patients: Thirty healthy parturient patients, at term gestation
receiving spinal anesthesia for: elective cesarean section. Intervent
ions: None. Measurements and Main Results: Maternal colloid osmotic pr
essure samples were obtained at the time of intravenous insertion and
delivery, Fetal umbilical vein and umbilical artery colloid osmotic pr
essure samples were measured from the umbilical cord at delivery. The
volume of intravenous infusion and dose of ephedrine were recorded for
each patient, Maternal colloid osmotic pressure at delivery was signi
ficantly less than that value measured at the time of intravenous cath
eter insertion in each patient (15.8 +/- 0.3 vs. 23.1 +/- 0.3 mm Hg; p
< .0001). Umbilical artery colloid osmotic pressure was consistently
higher than umbilical vein colloid osmotic pressure (21.0 +/- 0.4 vs.
19.4 +/- 0.3 mm Hg; p < .0001), Both umbilical artery colloid osmotic
pressure and umbilical vein colloid osmotic pressure were significantl
y higher than maternal colloid osmotic pressure at delivery (p < .0001
). The volume of intravenous infusion and the dose of ephedrine both c
orrelated inversely with maternal colloid osmotic pressure measured at
delivery (p < .05). Conclusions: The reduction in maternal colloid os
motic pressure during delivery is, in part, related to intravenous flu
id expansion and the amount of vasopressor administered, Despite the s
ignificant fluctuations in maternal colloid osmotic pressure, the plac
enta and fetus possess the capability to alter colloid osmotic pressur
e.