Résumé
Sixty healthy women [ASA I and II] at term undergoing elective cesarean section were allocated randomly to receive either lactated Ringer's 20 ml/kg body weight group I [30 partiurients] or 3% hypertonic saline 6 ml/kg body weight group II [30 parturients] over 15 minutes immediately before spinal anaesthesia as a preload. After spinal anaesthesia the incidence of hypotension was greater [43% "13/30"] in group I than in group II [17% "5/30]. Also, the main dose of ephedrine required to correct arterial blood pressure was significantly greater in group I than in group II. The outcome of the newborns was uneventful in both groups and Apgar scores at 1 and 5 minutes exceeded 8 in every case. Also, the mean pH of umbilical artery did not differ between the two groups. Prehydration with hypertonic saline 3% resulted in less hypotension after spinal anaesthesia than prehydration with isotonic saline [Lactated ringer]