[Catheter peridural anesthesia with bupivacaine HCI and bupivacaine CO2. A comparison and the effects of premedication].

A controlled prospective randomized study was carried out to compare the action of 0.5% bupivacaine-CO2 and 0.5% bupivacaine-HCI both with and without diazepam premedication. Those patients given an epidural with 0.5% bupivacaine-CO2 and diazepam premedication showed both the briefest time to onset of action and the greatest degree of motor block. In contrast to the other three groups, none of these patients had missed segments. Despite the fact that no significant differences could be calculated, the difference in intensity of action observed in this investigation may well be of clinical relevance.