Comparison of phenylephrine and ephedrine in spinal anesthesia for cesarean section to correct hypotension

Objective To observe the effect of phenylephrine and ephedrine during spinal anesthesia for cesarean section to correct the effects of hypotension.Methods One hundred primipara with intraoperative use of step-up drugs were randomly divided into 2 groups(n=50):E group(ephedrine group,8 mg/ml)and P group(phenylephrine group,100 μg/ml).Before anesthesia,after anesthesia and to the end of operation,the drug dosages,maternal blood pressure,heart rate and respiratory changes were recorded.At the same time maternal nausea,vomiting situation were recorded.At the moment of the baby was delivered,the maternal blood,umbilical arterial and umbilical venous blood gas were analysed and ephedrine,phenylephrine,epinephrine and norepinephrine concentrations were measured.Newborns 1 min and 5 min Apgar scores were estimated.Results (1)The use of two drugs equivalent to correct maternal blood pressure and respiratory changes in maternal compared had no difference.(2)Neonatal 1 min and 5 min Apgar scores were not different.(3)Maternal heart rate change of P group was significantly lower than E group(P0.05),maternal nausea and vomiting,P group was significantly less than E group(P0.05).(4)Umbilical arterial and venous pH,base excess of E group were significantly lower than the P group(P0.05),while the umbilical artery PCO2 and umbilical vein PO2 of E group were significantly higher than that of P group(P0.05),umbilical artery of epinephrine and norepinephrine concentrations of E group were significantly higher than the P group(P0.05).Conclusions Phenylephrine has wore advantages to correct maternal hypotension compared with ephedrine in spinal anesthesia for cesarean section.