Effects of Fluid Preload (crystalloid or Colloid) Compared with Crystalloid Co-load Plus Ephedrine Infusion on Hypotension and Neonatal Outcome During Spinal Anaesthesia for Caesarean Delivery

Preload with crystalloid or colloid solution is widely recommended for the prevention of maternal hypotension during spinal anaesthesia. A combination of simultaneous rapid crystalloid infusion with vasopressor has also been suggested. This study tested the hypothesis that ephedrine infusion with crystalloid loading at spinal anaesthesia would reduce hypotension and alter neonatal outcome compared with fluid preloading. One hundred and twenty women undergoing elective caesarean delivery were randomly allocated to one of three groups to receive rapid infusion of lactated Ringer's solution (20 ml.kg(-1), n=40) or 4% succinylated gelatin solution (500 ml, n =40) before spinal anaesthesia or an ephedrine infusion (1.25 mg.minute(-1)) plus lactated Ringer's solution (1000 ml, n=40) after spinal anaesthesia. The incidence of hypotension (moderate and severe) and the ephedrine dose used to treat hypotension were compared. Neonatal outcome was assessed using Apgar scores and umblical venous and arterial blood gas analysis. The frequency of moderate or severe hypotension was lower in the ephedrine group than in the crystalloid or colloid preload group (10% vs. 51% and 38%; 5% vs. 21% and 23% respectively, P < 0.05). The incidence of nausea was significantly different between the crystalloid preload and ephedrine group. Umbilical blood gas analysis and Apgar scores were similar in all groups. A combination of an ephedrine infusion at 1.25 mg.minute(-1) with a crystalloid co-load was more effective than fluid preloading with crystalloid or colloid in the prevention of moderate and severe hypotension.