SMALL-DOSE HYPERBARIC VERSUS PLAIN BUPIVACAINE DURING SPINAL-ANESTHESIA FOR CESAREAN-SECTION

In a double-blind, randomized trial, 98 parturients undergoing cesarea n section received either hyperbaric or plain bupivacaine 6.6 mg combi ned with sufentanil 3.3 mu g as part of a combined spinal-epidural pro cedure. To prevent hypotension, 1000 mt of lactated Ringer's solution, 500 mt of hydroxyethyl starch 6%, and ephedrine 5 mg were administere d IV. The height of the block was equal in both groups, but more patie nts in the plain group had blocks that were either too high or too low (P < 0.01). The number of patients requiring epidural supplementation was equal in both groups. Strict criteria were used to treat hypotens ion. The overall incidence of systolic blood pressure (<90 mm Hg) was 13%, whereas it was more pronounced in the plain group (21% vs 6% in t he hyperbaric group, P < 0.05), which required more ephedrine (P < 0.0 5) and in which a greater incidence of nausea was noticed (P < 0.05). We conclude that the use of a small dose of intrathecal bupivacaine co mbined with sufentanil plus our described preloading regimen resulted in a lower incidence of hypotension. Further, we conclude that the use of hyper baric bupivacaine in this manner provides a more reliable bl ock and a lower incidence of hypotension than plain bupivacaine. Impli cations: A small dose of hy perbaric bupivacaine 0.5% combined with su fentanil used intrathecally during cesarean section offered a more rel iable cephalad spread of the spinal block than the glucose-free combin ation, which was reflected in a lower incidence of hypotension and nau sea.