Norepinephrine versus phenylephrine for postspinal hypotension in parturients undergoing cesarean section: a systematic review and meta-analysis

INTRODUCTION: Multiple studies have compared varying prophylactic and therapeutic doses of norepinephrine and phenylephrine given as either intermittent bolus or fixed-rate infusion to combat postspinal hypotension in patients un-dergoing cesarean section (CS). We conducted a systematic review to figure out the best alternative to treat postspinal hypotension.EVIDENCE ACQUISITION: PubMed and Cochrane databases were extensively searched for eligible RCTs. A total of 15 studies were found eligible and analyzed for the incidence of maternal bradycardia as the primary outcome and other maternal adverse effects, fetal acidosis and Apgar scores at 1 and 5 min as the secondary outcome. Data was analyzed using Review Manager Version 5.3. software.EVIDENCE SYNTHESIS: There was no significant difference in the efficacy of norepinephrine and phenylephrine for managing postspinal hypotension (OR=1.15 [95% CI: 0.91-1.45], P=0.24, I2=0%,moderate quality) in parturients under-going CS. Odds of incidence of maternal bradycardia decrease significantly by 61% with norepinephrine versus phenyl-ephrine (OR=0.39 [95% CI: 0.31-0.49], P<0.00001, I2=27%, high quality evidence). Significant higher umbilical artery mean pH values were observed with NE versus PE (MD=0.0 [95% CI: 0.00 to 0.01], P=0.03), although not clinical rel-evant. However, no significant difference was found in the incidence of other maternal adverse effects and fetal outcomes. CONCLUSIONS: Comparable efficacy for management of postspinal hypotension, though, norepinephrine was found to cause less incidence of maternal bradycardia as compared to phenylephrine.

Automated summary

Norepinephrine and phenylephrine showed comparable efficacy in managing postspinal hypotension, but norepinephrine had a lower incidence of maternal bradycardia.