Pudendal Nerve Block in Male Goats: Comparison of Ischiorectal Fossa and Ischial Arch Approaches Using Low Volume 1% Lignocaine Hydrochloride

Abstract

Abstract Thirty (30) adult male goats were injected xylazine (0.05 mg/kg, IM) and randomly divided into three equal groups. Internal pudendal nerve block was tried using 3.5 ml (on each side) of 1% lignocaine hydrochloride byischiorectal fossa or ischial arch approaches in goats from Group 1 and Group 2 respectively, 15 minutes after giving xylazine. Inadvertent puncture of the rectal wall and prick to the finger placed in the rectum was experienced once in Group 1 animal. None of the animals showed protrusion of the penis without manual manipulation. Prolapse of the prepucial ring was noticed in three animals from Group 1 and two each from Group 2 and 3. The application of mild manual push percutaneously resulted in the exposure of the penis in eight and six animals belonging to Group 1 and Group 2 respectively, 15 minutes after injection of the local anaesthetic. Statistically significant (P>0.05) difference between Group 1 and 2 values was detected only once at 90 minutes following injection of the local anaesthetic. The block lasted longer in animals of Group 1. The exposed organ was flaccid and insensitive. The organ retracted into the prepucial cover within five minutes of its release in all the animals. The penile exposure could not be achieved by similar manipulation in any of the Group 3 animals. From this study it was concluded that the ischiorectal fossa approach is cumbersome and may lead to inadvertent punctures, but the block develops in more number of animals for a longer period than with the ischial arch approach. The outcome of the two techniques did not show statistically significant (P>0.05) difference for most of the assessment period. Reducing the concentration of lignocaine hydrochloride may reduce the chances of continued relaxation of the penis beyond the required period and also the drug toxicity. However, studies using larger volume of 1% lignocaine hydrochloride may be undertaken for short term exposure of the penis without manual manipulation.