Height Adjusted Versus Standardized Dose of Bupivacaine for Spinal Anesthesia

Overview

General anesthesia during pregnancy is associated with several major risks including unanticipated difficult airway, pulmonary aspiration, and specific anesthetic effects on the newborn. Thus, intrathecal anesthesia is the technique of choice for cesarean section. Nevertheless, the main side effect of intrathecal anesthesia is arterial hypotension which depend mainly on the dose of local anesthetic administered intrathecally. To date there is no guidelines nor evidences whic help the anesthetist to precisely estimate the required dose. Most often a "standardized dose" of 8 to 10 mg of bupivacaine is administered. However, some data suggest that a lower dose may be administered resulting in less frequent arterial hypotension. Nevertheless, a well designed randomized study is lacking.

The present controlled randomized double blind trial was designed to compare 2 intrathecal dose of bupivacaine for cesarean section * a "standard" dose of 10 mg of intrathecal bupivacaine associated with morphine 100 micrograms and sufentanil 3 micrograms * a height-calculated dose of bupivacaine (0.05 mg per cm of height) on associated with morphine 100 micrograms and sufentanil 3 micrograms The main outcome is the rate of hypotension defined as a 20% or more decrease in systolic arterial pressure. Secondary outcomes focused on intrathecal anesthesia efficacy, success or failure and on interventions required to manage arterial hypotension

Conditions