Bispectral index-guided versus standard anaesthesia monitoring for intraoperative awareness prevention

Although bispectral index (BIS) monitoring provides an objective measure of hypnotic depth, its routine use to prevent awareness remains debated due to conflicting evidence and cost considerations. Therefore, it is of interest to evaluate BIS-guided versus clinically guided sevoflurane anaesthesia in 200 adults undergoing elective surgery over 60 minutes. No definite intraoperative awareness occurred in either group, confirmed by modified Brice interviews up to 30 days postoperatively. BIS monitoring reduced sevoflurane consumption by 24% (1.7 ± 0.4 vs 2.2 ± 0.5 MAC-hours; p < 0.001) and accelerated extubation (7.9 ± 2.3 vs 10.8 ± 3.1 min; p < 0.001) and PACU discharge (46.2 ± 11.8 vs 56.9 ± 14.7 min; p < 0.001). It also provided greater haemodynamic stability, with lower MAP variability (11.4 ± 3.9% vs 16.8 ± 5.6%; p < 0.001). BIS monitoring optimizes anaesthetic delivery and recovery efficiency without lowering awareness incidence compared to vigilant clinical monitoring.