title: Prevention of hypotension during spinal anaesthesia for caesarean section: ephedrine infusion versus fluid preload.
abstract: We compared the efficacy of prophylactic ephedrine infusion over fluid preloading in prevention of maternal hypotension during spinal anaesthesia for Caesarean section. Forty-six women undergoing elective Caesarean section at term were allocated randomly to receive either intravenous fluid preloading with Hartmann's solution 20 ml.kg-1 (fluid group) or prophylactic intravenous ephedrine 0.25 mg.kg-1 (ephedrine group). Moderate hypotension was defined as > or = 20% reduction in systolic blood pressure and severe hypotension as > or = 30% reduction in systolic blood pressure. Maternal uterine circulation was measured using Doppler ultrasound in 11 parturients before and after spinal anaesthesia. There was a lower incidence of severe hypotension in the ephedrine group compared with the fluid group (35% vs. 65%, p = 0.04), although the incidence of moderate hypotension was similar. Mean umbilical venous pH was higher in the ephedrine group than in the fluid group (7.33 vs. 7.29, p = 0.02) and the number of patients shivering was lower in the ephedrine group (2 vs. 9, p = 0.02). No difference was found between pre- and postspinal uterine artery pulsatility indices in either group. We conclude that prophylactic ephedrine infusion alone is at least as good as fluid preload alone in combating the hypotension associated with spinal anaesthesia for Caesarean section.
authors.affiliation: Department of Anaesthesiology, University of Hong Kong, Queen Mary Hospital, People's Republic of China.
authors.forename: W S
authors.initials: WS
authors.lastname: Chan
authors.forename: M G
authors.initials: MG
authors.lastname: Irwin
authors.forename: W N
authors.initials: WN
authors.lastname: Tong
authors.forename: Y H
authors.initials: YH
authors.lastname: Lam
mesh_terms: D000773:Anesthesia, Obstetrical / Q000009:adverse effects*; D000775:Anesthesia, Spinal / Q000009:adverse effects*; D002585:Cesarean Section; D000077324:Crystalloid Solutions; D004809:Ephedrine / Q000627:therapeutic use*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007022:Hypotension / Q000209:etiology / Q000517:prevention & control*; D007432:Intraoperative Period; D007552:Isotonic Solutions; D010952:Plasma Substitutes / Q000627:therapeutic use; D011247:Pregnancy; D011256:Pregnancy Outcome; D015532:Rehydration Solutions / Q000627:therapeutic use; D014599:Uterus / Q000098:blood supply; D014662:Vasoconstrictor Agents / Q000627:therapeutic use*
chemical_list: D000077324:Crystalloid Solutions; D007552:Isotonic Solutions; D010952:Plasma Substitutes; D015532:Rehydration Solutions; D014662:Vasoconstrictor Agents; D004809:Ephedrine