“…However, the BIS algorithm is known to exhibit a flat dose-response curve, particularly in the elderly, and may not be an ideal device to guide general anesthesia. 4 The trial by Wang et al 5 in this issue of the Journal is the first large trial to investigate pEEG-guided general anesthesia and its influence on POD using the Patient State Index (PSI) and Spectral Edge Frequency (SEF) (SEDline, Masimo Corporation, CA) to titrate intravenous general anesthesia. The trial recruited 1545 patients aged 50 years and older with American Society of Anesthesiologists physical status classification 1-3, scheduled for laparoscopic surgery with an expected minimum hospital stay of 3 days.…”