The effects of prophylactic infusing ephedrine combined with phenylephrine versus ephedrine alone in maternal and neonate undergoing spinal anesthesia for cesarean section: A Meta-analysis of randomized trials

Abstract

Objective Used a Meta-analysis to evaluate the effects of prophylactic infusing ephedrine alone or combined with phenylephrine on maternal hemodynamics and neonatal blood gas analysis undergoing spinal anesthesia for cesarean section. Methods Randomized controlled trial(RCT) about the effects of prophylactic infusing ephedrine alone or combined with phenylephrine on maternal and neonate undergoing spinal anesthesia for cesarean section were retrieved from Cochrane Library, PubMed, Embase, Wangfang Database, CNKI and SinoMed from the date of their establishment to September, 2017. The documents were screened and the relevant data were extracted according to the inclusion criteria. The methodological quality of the included RCT was evaluated by Jadad scale. Using RevMan 5.3 software for Meta-analysis. Continuous variables were dealt with mean differences(MD) and 95% confidence intercal(CI), and the dichotomous variables were dealt with odd ratio(OR) and 95%CI. Descriptive analysis of the RCTs which is not available for Meta-analysis. Results We identified 9 RCTs including 590 patients, including 5 RCTs in English and 4 RCTs in Chinese. Among them, 294 patients were in the ephedrine group(E group) while 296 patients were in the ephedrine combined with phenylephrine group(EP group). The results of Meta-analysis showed that the incidence of maternal hypotension [OR=0.49, 95%CI(0.3, 0.8), P<0.01], hypertension [OR=0.52, 95%CI(0.30, 0.92), P=0.02], nausea and vomiting [OR=0.32, 95%CI (0.19, 0.53), P<0.01] and the incidence of neonatal acidosis [OR=0.22, 95%CI(0.10, 0.49), P<0.01] were significantly lower in the ephedrine combined phenylephrine group than these parameters in the ephedrine alone groups. The neonatal umbilical artery pH [MD=0.1, 95%CI(0.07, 0.13), P<0.01], base excess(BE) [MD=2.24, 95%CI(0.78, 3.69), P<0.01], oxygen partial pressure(PO2) [MD=1.53, 95CI (0.08, 2.98), P<0.01] value in the ephedrine combined with phenylephrine group was significantly higher than those parameter in the ephedrine alone group. Moreover, the umbilical artery lactic acid [MD=-1.39, 95%CI (-1.73, -1.05), P<0.01], partial pressure of cardon dioxide(PCO2) [MD=-8, 95%CI(-13.2, -2.8), P<0.01] value were lower than those in the ephedrine alone group. The neonatal 1 min and 5 min Apgar score were not significant difference between the two groups. Conclusions Ephedrine combined with phenylephrine can prevent maternal hypotension undergoing spinal anesthesia for cesarean section and to maintain intraoperative hemodynamic stability. It also can reduce the incidence of maternal nausea and vomiting and neonatal acidosis. Key words: Ephedrine; Phenylephrine; Cesarean section; Hemodynamics; Heonate; Meta-analysis