Objective To study the effects of ephedrine and phenylepbedrine for maintenance of arterial pressure during combined spinai/epidural anesthesia (CSEA) for caesarean section. Methods Forty patients, ASA grade Ⅰ - Ⅱ, who were scheduled for caesarean section by CSEA were randomly divided into two groups, when patients were hypotension, phenylephedrine 100 μg (group P, 20 cases ) or ephedrine 10 mg (group E, 20 cases). The variety of blood pressure (Bp), heart rate (HR) and oxyhemoglobin saturation (SpO2) were monitored; recorded before anesthesia (T0), at 15 min after anesthesia (T1), fetuses were taken out of uterus (T2) and at the end of operation (T3); umbilical arterial blood gas analysis was monitored; neonatal Apgar score was investigated. Results Umbilical arterial blood gas analysis of pH,PaO2, PaCO2, HCO3-, SaO2 were normal in two groups, there were no significant difference in PaO2, PaCO2 and SaO2 between two groups, but pH and HCO3- in group P were higher than those in group E [7.38±0.07 vs7.30±0.02 and (21.5±3.4) mmol/L vs (19.3±3.3) mmol/L] (P <0.05). There were no significant difference in Apgar score and Bp between two groups. Compared with group P, the HR in group E was increased obviously at T1 and T2 (P < 0.05). Conclusion Phenylephedrine is the vasopresser that most closely meets the criteria for the best vasopressor to use in obstetric patients.

0.05).Traction reactions,the use of sedative and centrally acting anesthesia drugs during the operation were significantly less in group AEA than those in group EA(P