Spinal Anesthesia for Knee Arthroscopy Using Isobaric Bupivacaine and Levobupivacaine: Anesthetic and Neuroophthalmological Assessment

INTRODUCTION The aim of the study was to compare the sensory, motor, and neuroophthalmological effects of isobaric levobupivacaine and bupivacaine when intrathecally administered. MATERIALS AND METHODS A prospective, double-blind, randomized study with 60 ASA grade I-II patients aged 18-65 years awaiting knee arthroscopy under spinal anesthesia. Patients received 12.5 mg of isobaric bupivacaine or levobupivacaine. Several features were recorded. RESULTS No significant intergroup differences were observed for ASA classification, time to micturate, demographic data, surgery duration, and patient/surgeon satisfaction. Similar hemodynamic parameters and sensory/motor blockade duration were found for both groups. There were no neuroophthalmological effects in either group. Sensory (P = 0.018) and motor blockade onset (P = 0.003) was faster in the bupivacaine group. T6 (T2-T12) and T3 (T2-T12) were the highest sensory block levels for the levobupivacaine and bupivacaine groups, respectively (P = 0.008). It took less time to regain maximum motor blockade in the bupivacaine group (P = 0.014), and the levobupivacaine group required use of analgesia earlier (P = 0.025). CONCLUSIONS Isobaric bupivacaine and levobupivacaine are analogous and well-tolerated anesthetics for knee arthroscopy. However, for bupivacaine, sensory and motor blockade onset was faster, and greater sensory blockade with a longer postoperative painless period was achieved.