ESRA19-0211 The influence of the infusion of ephedrine and phenylephrine on the stability of the circulation after subarachnoid anesthesia in senior adults

Background and aims We studied the influence of ephedrine or phenylephrine infusion given immediately after spinal anesthesia (SA) on hemodynamics in elderly orthopedic patients. Design A prospective, randomized, double-blind, placebo-controlled study. Methods After subarachnoid injection of 15 mg of levobupivacaine the participants received either an infusion of ephedrine 20 mg (E group), phenylephrine 250 mcg (P group) or saline (C group) within 30 minutes. For 15 minutes before and 30 minutes after SA we measured blood pressure, cardiac index (CI) and heart rate (HR). Results 70 patients were included in the final analysis. At the end of measurements mean arterial pressure decreased significantly after SA in comparison to baseline in the C group but was maintained in the P and E groups, with no significant differences between the groups. CI decreased after SA in the C group was maintained in the P group and increased significantly in the E group, with significant differences between the C and the E group (p=0.049) and between the P and the E (p=0.01) group at the end of measurements. HR decreased significantly after SA in the C and the P group and was maintained in the E group, with significant differences between the P and the E group (p=0.033) at the end of measurements. Conclusions Hemodynamic changes after SA in elderly orthopedic patients can be prevented by an immediate infusion of phenylephrine or ephedrine. In addition to maintaining blood pressure the ephedrine infusion also maintains HR and increases CI after spinal anesthesia.