Purpose Interest in implicit memory formation and unconscious auditory stimulus perception during general anesthesia has resurfaced as perioperative music has been reported to produce beneficial effects. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating explicit and implicit memory formation during general anesthesia and its effects on postoperative patient outcomes and recovery.Source We performed a systematic literature search of Embase, Ovid Medline, and Cochrane Central from inception date until 15 October 2020. Eligible for inclusion were RCTs investigating intraoperative auditory stimulation in adult surgical patients under general anesthesia in which patients, healthcare staff, and outcome assessors were all blinded. We used random effects models for meta-analyses. This study adhered to the PRISMA guidelines and was registered in PROSPERO (CRD42020178087). Principal findings Fifty-three of 5,859 identified articles (4,200 patients) were included. There was evidence of implicit memory formation in seven out of 17 studies (41%) when assessed using perceptual priming tasks. Mixed results were observed on postoperative behavioural and motor response after intraoperative suggestions. Intraoperative music significantly reduced postoperative pain (standardized mean difference [SMD], -0.84; 95% confidence interval [CI], -1.1 to -0.57; P \ 0.001; I 2 = 0; n = 226) and opioid requirements (SMD, -0.29; 95% CI, -0.57 to -0.015; P = 0.039; I 2 = 36; n = 336), while positive therapeutic suggestions did not. Conclusion The results of this systematic review and meta-analysis show that intraoperative auditory stimuli can be perceived and processed during clinically adequate, general anesthesia irrespective of surgical procedure severity, leading to implicit memory formation without explicit awareness. Intraoperative music can exert significant beneficial effects on postoperative pain and opioid requirements. Whether the employed intraoperative anesthesia regimen is of influence is not yet clear.

Purpose Current studies have demonstrated conflicting results regarding surgical care for acute appendicitis during the COVID-19 pandemic. This study aimed to assess trends in diagnosis as well as treatment of acute appendicitis in the Netherlands during the first and second COVID-19 infection wave. Methods All consecutive patients that had an appendectomy for acute appendicitis in nine hospitals from January 2019 to December 2020 were included. The primary outcome was the number of appendectomies for acute appendicitis. Secondary outcomes included time between onset of symptoms and hospital admission, proportion of complex appendicitis, postoperative length of stay and postoperative infectious complications. Outcomes were compared between the pre-COVID group and COVID group. Results A total of 4401 patients were included. The mean weekly rate of appendectomies during the COVID period was 44.0, compared to 40.9 in the pre-COVID period. The proportion of patients with complex appendicitis and mean postoperative length of stay in days were similar in the pre-COVID and COVID group (respectively 35.5% vs 36.8%, p = 0.36 and 2.0 ± 2.2 vs 2.0 ± 2.6, p = 0.93). There were no differences in postoperative infectious complications. A computed tomography scan was used more frequently as a diagnostic tool after the onset of COVID-19 compared to pre-COVID (13.8% vs 9.8%, p < 0.001, respectively). Conclusion No differences were observed in number of appendectomies, proportion of complex appendicitis, postoperative length of stay or postoperative infectious complications before and during the COVID-19 pandemic. A CT scan was used more frequently during the COVID-19 pandemic.