ABSTRACT
BACKGROUND: Hyperbaric 2% prilocaine produces a faster onset and shorter duration of spinal anesthesia than a plain solution. The anesthetic profile could be improved by restricting the block to the operative side. We compared unilateral versus conventional bilateral spinal anesthesia with hyperbaric 2% prilocaine in day-case patients undergoing unilateral inguinal herniorrhaphy. METHODS: Eighty patients were randomly assigned to receive either conventional bilateral (N.=40) or unilateral (N.=40) spinal anesthesia with 50 mg hyperbaric prilocaine 2%. In the unilateral group, lateral decubitus was maintained for 10 minutes. Sensory and motor block courses, time to first micturition, and side effects were recorded. RESULTS: On the operated side, the highest sensory block was T8 (T12-T2) in the unilateral and T9 (T11-T4) in the bilateral group (P=0.0328); the time to motor (115 ± 26 min in the unilateral and 108 ± 24 min in the bilateral groups, P=0.2350) and sensory (156 ± 30 min in the unilateral and 158 ± 26 min in the bilateral groups, P=0.7550) block resolution was similar in both groups. On the non-operated side, the unilateral group had a faster motor (64 ± 48, P<0.001) and sensory (120 ± 47, P<0.001) time to block resolution than the conventional group. Restricted unilateral motor and sensory block was achieved in 30% and 12.5% of patients, respectively. Time to voiding was shorter in the unilateral than in the conventional group (220 ± 47 vs. 249 ± 51 min, respectively, P=0.0104). There were no significant differences in adequacy for surgery and side effects between the groups. CONCLUSION: In day-case inguinal herniorrhaphy, attempting unilateral spinal anesthesia with 50 mg hyperbaric 2% prilocaine produced faster time to voiding.
