Volume preloading is not essential to prevent spinal-induced hypotension at caesarean section.

We have compared the protective effect of 1000 ml preload with 200 ml preload of crystalloid solution, administered during the 10 min before spinal anaesthesia was induced, in 60 healthy women with no fetal compromise undergoing elective Caesarean section. The spinal anaesthetic was managed identically in both groups by an anaesthetist who was unaware of the volume of fluid administered. A prophylactic infusion of ephedrine 60 mg in Hartmann's solution 500 ml was given according to maternal arterial pressure. Hypotension was defined as > or = 30% reduction from baseline or < 90 mm Hg, and was treated by i.v. ephedrine bolus doses. There was no significant difference in ephedrine requirements between the two groups or in the incidence, severity or duration of hypotension: 10 women in the 1000-ml group, five episodes lasting > or = 3 min compared with nine women in the 200-ml group, four lasting > or = 3 min. There was no difference between neonates in each group. We have now abandoned the routine of preloading before regional anaesthesia.