Effect of intravenous phenylephrine infusion on dose requirement of intrathecal plain levobupivacaine for cesarean section: A placebo-controlled preliminary study.

Background: Phenylephrine infusion has been shown to decrease rostral spread of plain and hyperbaric local anesthetic (LA) when compared to ephedrine infusion. However, it does not result in higher dose requirement of hyperbaric LA for cesarean section. There is no trial evaluating the effect of phenylephrine infusion on ED50 of a plain intrathecal LA.