Intraoperative music significantly reduced postoperative pain (standardized mean difference, -0.84 95% confidence interval, -1.1 to -0.57 P < 0.001 I2 = 0 n = 226) and opioid requirements (SMD, -0.29 95% CI, -0.57 to -0.015 P = 0.039 I2 = 36 n = 336), while positive therapeutic suggestions did not. Mixed results were observed on postoperative behavioural and motor response after intraoperative suggestions. There was evidence of implicit memory formation in seven out of 17 studies (41%) when assessed using perceptual priming tasks. This study adhered to the PRISMA guidelines and was registered in PROSPERO (CRD42020178087).įifty-three (4,200 patients) of 5,859 identified articles were included.
We used random effects models for meta-analyses. 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 performed a systematic literature search of Embase, Ovid Medline, and Cochrane Central from inception date until 15 October 2020. 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.
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.