Abstract

The effects of the Trendelenberg position, 10° for 60 seconds versus horizontal position, on the anesthetic spread of 0.5% tetracaine or 0.5% bupivacaine in 5% glucose 4 ml each, were investigated in 80 male patients undergoing urological surgery. The local anesthetic solutions were randomly injected into the patients, who were divided into four groups of 20, and the anesthetic profile of each solution was then evaluated in a double-blind fashion for the two positions by an independent observer. The maximum cephalad spread of analgesia was greater for tetracaine at horizontal position, compared with the three other groups ( p < 0.05). However, the time for maximum spread of analgesia was shorter for bupivacaine/10° and tetracaine/10° ( p < 0.05), compared with the horizontal control group. Regression of sensory anesthesia was longer in both tetracaine groups than in the bupivacaine groups ( p < 0.05). The onset of 2+ and 3+ motor blockade was significantly faster in the bupivacaine/10° group ( p < 0.05) when compared with the horizontal group. However, motor blockade of the lower limbs persisted for significantly longer in the tetracaine-treated patients than in the bupivacaine groups ( p < 0.05). Results of this study suggest that 4 ml of 0.5% bupivacaine injected at 10° Trendelenberg provides a rapid and controllable spread of analgesia for transurethral resection of the prostate, of optimal duration and moderately rapid regression of motor block.