RESUMEN
The purpose of this study was to compare the effectiveness and safety of etidocaine and bupivacaine for postoperative analgesia after laparoscope sterilization. The study was performed in 22 healthy patients who received either one per cent etidocaine, 2 mg.kg-1, or bupivacaine 1.5 mg.kg-1 in a double-blind, randomized fashion. The local anaesthetic was dropped onto the fallopian tubes from uterus to fimbriae before tubal occlusion. To establish safety, blood concentrations of the parent drug and its metabolites were measured before application and at 1, 3, 6, 10, 15, 30, 60 and 120 min. The mean peak concentrations were 501.8 +/- 71.3 (SEM) for etidocaine with a range of 225 to 905 ng.ml-1. For bupivacaine, the mean peak concentration was 468 +/- 73.8 SEM with a range from 191 to 1005 ng.ml-1. The mean values are one eighth of the toxic convulsive dose for humans. Etidocaine was metabolized at a faster rate than bupivacaine with a rapid appearance of 2-amino-2'-butyroxylidide (ABX). The bupivacaine metabolite 2,6-pipecoloxylidide (PPX) was detected in low concentrations in the 60-minute samples. We conclude that the topical application of either etidocaine or bupivacaine is a safe procedure in the doses and concentrations used during general anaesthesia for laparoscopic tubal banding.