Comparing the effect of hypotension treatment due to spinal anesthesia with ephedrine or phenylephrine on arterial blood gases and neonatal Apgar score during cesarean delivery in obese mothers: randomized clinical trial

Hypertension in obese patients is more affected by spinal anesthesia than normal people. Due to the lack of study and recommendation of articles about comparison of ephedrine and phenylephrine in obese patients during cesarean section, this study was performed with aim to compare the effect of hypotension treatment due to spinal anesthesia with ephedrine and phenylephrine on the status of arterial blood gas and Apgar score during cesarean delivery in obese mothers.

This randomized clinical trial was performed in 2016 on 100 pregnant women with BMI≥30kg/m2 (according to the formula) who were candidates for elective cesarean section in Tabriz Alzahra Hospital. Demographic characteristics and maternal and fetal status as well as analysis of arterial blood gases of umbilical artery were included in the researcher-made checklist. Data were analyzed by SPSS software (version 20) and t-test, Chi-square and Mann-Whitney U test. P< 0.05 was considered statistically significant.

There was statistically significant difference between two groups in terms of HCO3- (P=0.048), BE (P=0.035), heart rate (P=0.002), systolic (P=0.003) and diastolic (P=0.004) blood pressure during anesthesia and surgery; phenylephrine group had more stability. No significant difference was found between two groups in terms of other variables (blood pressure and arterial oxygen saturation) (P>0.06) and neonatal Apgar score (first and fifth minutes) (P>0.05).

Phenylephrine leads to better and more effective treatment of hypertension than ephedrine in pregnant women with BMI≥30kg /m2 with spinal anesthesia; also neonatal complications such as metabolic acidosis have been less observed in obese patients treated with phenylephrine.