Prevention of maternal hypotension by epidural administration of ephedrine sulfate during lumbar epidural anesthesia for cesarean section.

Abstract

Our purpose was to determine whether epidural administration of ephedrine sulfate simultaneously with induction of lumbar epidural anesthesia for nonemergency cesarean section reduces the incidence of maternal hypotension. In a double-blinded, placebo-controlled trial, 50 normotensive, nonlaboring, American Society of Anesthesiologists' class I or II women with term, uncomplicated, singleton pregnancies were randomly assigned to have normal saline solution or ephedrine sulfate administered epidurally and coincidentally with induction of lumbar epidural anesthesia for nonemergency cesarean section. All subjects were prehydrated with 25 ml/kg crystalloid and placed in supine position on a 15-degree, right-sided wedge before and after induction. Serial blood pressures were compared with baseline blood pressures, chosen as the average of three preinduction blood pressures. Hypotension was defined as a decline in systolic blood pressure to < or = 90 mm Hg or < or = 70% of baseline. Differences between groups were analyzed by Fisher's Exact Test. Significance was determined at p < 0.05. The incidence of hypotension in the control group was 24%, which was not significantly different from the incidence of 32% in the treated group. Prophylactic epidural administration of ephedrine sulfate does not reduce the incidence of maternal hypotension after lumbar epidural anesthesia for nonemergency cesarean section.