Bispectral index-guided general anaesthesia in combination with interscalene block reduces desflurane consumption in arthroscopic shoulder surgery: a clinical comparison of bupivacaine versus levobupivacaine

BACKGROUND: The goal of this study was to compare the influence of an interscalene brachial plexus block (ISB) performed with either bupivacaine or levobupivacaine in conjunction with general anaesthesia (GA) on desflurane consumption, which was titrated to maintain the recovery profiles and postoperative analgesia while also keeping the bispectral index score (BIS) between 40 and 60 in patients undergoing arthroscopic shoulder surgery. METHODS: Sixty patients undergoing arthroscopic shoulder surgery were prospectively randomized to receive GA with desflurane alone (group C) or in combination with a preoperative ISB by either bupivacaine 0.25 % (group B) 40 ml or levobupivacaine 0.25 % (group L) 40 ml. BIS scores or respiratory and hemodynamic parameters during the operation, recovery characteristics, consumed doses of desflurane and pain intensities were evaluated. RESULTS: The eye opening time was 4.0 ± 2.5 minutes for group B, 4.6 ± 2.4 minutes for group L, and 6.2 ± 2.1 minutes for group C (p < 0.05). Group B and group L saved 36 % and 25 % desflurane per unit time respectively when compared with group C (p < 0.001and p < 0.05) while the mean pain scores and analgesic requirements the first day after surgery were higher in group C (p < 0.05). CONCLUSIONS: Because of lower desflurane consumption, a superior recovery profile, and a high degree of patient acceptance, general anaesthesia in combination with interscalene block may be preferred in arthroscopic shoulder surgery. TRIAL REGISTRATION: The trial registration number is ACTRN12613000381785