Neuraxial techniques are the anesthetic techniques of choice in contemporary obstetric anesthesia practice, with a definitive superiority as compared to general anesthesia, since, by their use, serious complications involving the airway can be avoided.Spinal anesthesia has become the favorable technique for both elective and emergency cesarean section due to a quick and predictable onset of action, however, it can be frequently complicated by hypotension, with incidence exceeding 80% occasionally.

The aim of the current randomized controlled double-blinded trial was to compare the effect of a fixed-rate norepinephrine infusion versus a fixed-rate phenylephrine infusion versus placebo in parturients subjected to elective cesarean section under combined spinal-epidural anesthesia. All parturients will also receive colloid co-hydration.