Background: Postoperative delirium (POD) is a serious and common complication. The aim of present study is to investigate the diurnal variation of POD and the effects of esketamine in elderly patients. Methods: A randomized, double-blind, placebo-controlled clinical trial with factorial design was conducted. Patients (aged 65 to 85 years) with normal Mini-Mental State Examination (MMSE) score were stratified by age (≤70 vs. >70) and American Society of Anesthesiologists physical status classification (Ⅱ vs. Ⅲ), then randomly assigned to either morning (08:00–12:00) or afternoon (14:00–18:00) noncardiac operation under general anesthesia with or without esketamine administration (0.2 mg/kg). The primary outcome was the incidence of POD (3-Minute Diagnostic Interview for Confusion Assessment Method-defined Delirium, 3D-CAM) on postoperative days 1, 3, and 7. The secondary outcomes were the scores of MMSE and Hospital Anxiety and Depression Scale. The intention-to-treat analysis of the outcomes were performed by generalized estimating equation. Results: Six patients who did not receive an intervention because of canceled operation were excluded after randomization. The datasets containing 426 cases were analyzed following the intention-to-treat principle after handling missing data via multiple imputation method. The incidence of POD declined from about 55% on postoperative day 1 to 31 and 18% on postoperative days 3 and 7, respectively. Afternoon operation [B=−0.583, OR (95% CI) 0.558 (0.319–0.976); P=0.041], but not esketamine, significantly decreased the incidence of POD. Both esketamine and operation time failed to significantly affect MMSE, HAD, and NRS score. There was no interaction among operation time, esketamine, and follow up time. Conclusion: Elderly patients undergoing elective noncardiac surgery in the afternoon displayed lower POD incidence than those operated in the morning. A single low-dose of esketamine before general anesthesia induction failed to significantly decrease the risk of POD but decrease the risk of intraoperative hypotension and emergence agitation.

After the extubation of endotracheal tubes or removal of laryngeal masks in patients who underwent general anesthesia, complications such as hoarseness often occur, potentially leading to serious adverse effects on patients. Therefore, this study aimed to analyze the causes of hoarseness to provide improved prevention and treatment options. We conducted a retrospective analysis of patients who underwent general anesthesia at the Renmin Hospital of Wuhan University from January 2017 to December 2021, excluding patients under 18 years of age, over 80 years old, with preoperative hoarseness and undergoing multiple surgeries. The incidence, duration, influencing factors and causes of hoarseness after tracheal intubation were analyzed. The study found that the incidence of hoarseness after tracheal intubation was 11.77%. Of those patients experiencing hoarseness immediately after the operation, 79.56% could recover on the same day, 15.37% of patients could recover on the day after operation, 4.23% could recover within 3 days of the operation, and 0.83% of patients might need 5 or more days to recover. Patients aged 50 years and older, with an intubation time of more than 3 h, who underwent neck and cardiothoracic surgery, with a low BMI and with difficult airways exhibited a higher incidence of hoarseness after tracheal intubation. The main causes of hoarseness were vocal cord paralysis and arytenoid joint dislocation, with the number of patients at 8.97% (1106) and 7.32% (902) respectively. The incidences of hoarseness caused by psychological stress accounted for 4.15% of the cases. with a total of 512 patients affected. Age, intubation time, surgical site, low BMI and difficult airway were important factors affecting hoarseness after intubation. The vocal cord paralysis and arytenoid joint dislocation were major causes of hoarseness.