Obesity increases the risk of prolonged emergence from general anesthesia due to the delayed release of anesthetic agents from body fat. This trial aimed to evaluate the effects of sevoflurane and desflurane along with anesthetic depth monitoring on emergence time from anesthesia in obese patients. Adults with a body mass index ≥ 30 kg·m-2 undergoing laparoscopic sleeve gastrectomy at a medical center were randomized into four groups: sevoflurane or desflurane anesthesia with or without M-Entropy guidance on anesthetic depth in a ratio of 1:1:1:1. In the M-Entropy guidance groups, the dosage of sevoflurane and desflurane was adjusted to achieve response and state entropy values between 40 and 60 during surgery. In the non-M-Entropy guidance groups, the dosage of anesthetics was titrated according to clinical signs. Primary outcome was time to spontaneous eye opening. A total of 80 participants were randomized. Compared to sevoflurane, desflurane anesthesia significantly reduced the time to spontaneous eye opening [mean difference (MD): -129 s; 95% confidence interval (CI): -211, -46], obeying commands (-160; -243, -77), tracheal extubation (-172; -266, -78), and leaving operating room (-148; -243, -54). M-Entropy guidance further reduced time to eye opening (MD: -142 s; 99.2% CI: -276, -8), tracheal extubation (-199; -379, -19), and leaving operating room (-190; -358, -23) in the desflurane but not the sevoflurane group. M-Entropy guidance significantly reduced the risk of agitation during emergence, i.e., risk difference: -0.275 (95% CI: -0.464, -0.086); and number needed to treat: 4. Compared to sevoflurane, using desflurane to maintain general anesthesia accelerated the return of consciousness in obese patients. M-Entropy guidance further hastened awakening in patients using desflurane and prevented emergence agitation.
Keywords: bariatric surgery; depth of anesthesia; electroencephalographic monitoring; emergence agitation; morbid obesity.