Canadian Journal of Anesthesia, Vol 16, 37-45, Copyright © 1969 by Canadian Anesthesiologists' Society

A Comparison of Bupivacaine and Tetracaine in Epidural Analgesia for Surgery

¹ Department of Anaesthesia, McGill University, and Royal Victoria Hospital, Montreal

The new long-acting local anaesthetic, bupivacaine, has been compared with tetracaine using a 0.5 per cent solution for epidural analgesia in 103 surgical patients.

Both agents had almost identical latency of action and dose requirements. Analgesia commenced in 5.8-6.6 minutes and took about 18 minutes to spread to the first sacral segment. Dose requirements in milligrams per spinal segment at twenty years of age were the same for both agents and about one-fifth the amount needed for lignocaine or mepivacaine. The two agents differed appreciably in the qualities of their sensory and motor blockade. Tetracaine caused 66 per cent more motor paralysis of the legs than bupivacaine, whereas the duration of action of bupivacaine (196 minutes) was 20 per cent longer than that of tetracaine. There was suggestive but inconclusive evidence that the intensity of sensory blockade from bupivacaine may be superior to that of tetracaine.