Link Medical Journal · Jun 2026
BIS-Guided Anesthesia and Early Cognitive Recovery in Elderly: A Controlled Trial
By Arif S, Shakeel MA, Ahmad A et al.
Background: Elderly patients undergoing general anesthesia are vulnerable to delayed cognitive recovery and postoperative delirium, partly because age-related physiological changes may increase sensitivity to excessive anesthetic depth. Objective: To compare BIS-guided anesthesia with standard anesthesia management for early postoperative cognitive recovery, delirium incidence, anesthetic consumption, and immediate recovery outcomes in elderly patients undergoing elective non-cardiac surgery. Methods: This parallel-group randomized controlled trial was conducted at a tertiary care teaching hospital in Central Punjab, Pakistan, from August 2025 to January 2026. Eighty patients aged 65–80 years undergoing elective non-cardiac surgery under general anesthesia were randomized to BIS-guided anesthesia or standard anesthesia management. In the BIS-guided group, anesthetic depth was maintained within a BIS range of 40–60. Cognitive recovery was assessed using MMSE and MoCA at baseline, 24 hours, and 72 hours postoperatively, while delirium was assessed using the Confusion Assessment Method. Final complete-case analysis included 73 participants. Results: At 72 hours, the BIS-guided group had higher MMSE scores than the standard anesthesia group (27.1 ± 1.5 vs 25.4 ± 1.9; mean difference, 1.7; 95% CI, 0.90–2.50) and higher MoCA scores (25.0 ± 1.8 vs 22.9 ± 2.1; mean difference, 2.1; 95% CI, 1.19–3.01). BIS-guided anesthesia also reduced sevoflurane consumption, extubation time, and recovery-room stay. Delirium occurred in 8.1% and 25.0% of participants, respectively, with exact testing indicating a clinically relevant but statistically non-definitive difference. Conclusion: BIS-guided anesthesia was associated with better early postoperative cognitive recovery and improved immediate recovery efficiency in elderly surgical patients.