The comparison of small doses of levobupivacaine in unilateral spinal anesthesia undergoing inguinal hernai operations

The interest in using small doses of long acting drugs to produce a short duration spinal block, has grown after the increasing occurance of transient neurologic symptoms with spinal lidocaine.In this study the clinical profiles of unilateral spinal anesthesia produced with either 7,5 mg of hyperbaric levobupivacaine or 10 mg of hyperbaric levobupivacaine, has been aimed to be compared in 50 patients undergoing unilateral inguinal hernia repair.Hyperbaric solutions of levobupivacaine were prepared by one of an assistant, not involved in further patient evaluation. Fifteen mg of the plain 0,75% solution was diluted with glucose and steril water to obtain a 0,5% concentration of local anesthetic with 8% glucose.The median value of maximum sensorial block was strictly higher in patients receiving 10 mg local anesthetic (p=0,032). Time to 2 segment regression of sensorial block was strictly shorter in patients receiving 7,5 mg of local anesthetic than the patients receiving 10 mg of local anesthetic (p=0,025).Clinically relevant hypotension was reported in 6 patients receiving 10 mg local anesthetic (%24) and 1 patient receiving 7,5 mg of local anesthetic (%4). In both of two groups the most frequent complication was hypotensionBradicardia was reported in 3 patients receiving 10 mg local anesthetic (%12) and 1 patient receiving 7,5 mg of local anesthetic (%4).In both of the 2 groups, demographic characteristics, time to reach the sensorial block to T10, time to reach the maximum level of the sensorial block, time to reach maximum motor block and time to reach complete regression of motor block were similar.In conclusion, results of this prospective, randomized and double-blind study demonstrate that unilateral spinal anesthesia with 7,5 mg of hyperbaric levobupivacaine was an acceptable alternative to unilateral spinal anesthesia with 10 mg of hyperbaric levobupivacaine with less adverse effects profile in patients undergoing unilateral inguinal hernia repair.Key Words: Hyperbaric levobupivacaine, small dose, unilateral spinal anesthesia