Comparative Study Between Bilateral and Unilateral Spinal Anaesthesia

The purpose of this study is to compare unilateral spinal anesthesia using hyperbaric Prilocaine with "classical bilateral spinal anesthesia" using plain Prilocaine according to block characteristics and quality of micturition, standardized to the subjects own functional bladder capacity. Our hypothesis is that unilateral spinal anesthesia will provide faster time to micturtition and discharge, lesser hypotension and lesser micturition problems.