The increased analgesic efficacy of cold therapy after an unsuccessful analgesic experience is associated with inferior parietal lobule activation.

Prior experiences of successful and failed treatments are known to influence the efficacy of a newly applied treatment. However, whether that carry-over effect applies to non-pharmacological treatments is unknown. This study investigated how a failed treatment history with placebo analgesic cream affected the therapeutic outcomes of cold-pack treatment. The neural correlates underlying those effects were also explored using functional magnetic resonance imaging. The effect of the placebo analgesic cream was induced using placebo conditioning with small (44.5 °C to 43.7 °C, negative experience) and large (44.5 °C to 40.0 °C, positive experience) thermal stimuli changes. After the placebo conditioning, brain responses and self-reported evaluations of the effect of subsequent treatment with a cold-pack were contrasted between the two groups. The negative experience group reported less pain and lower anxiety scores in the cold-pack condition than the positive experience group and exhibited significantly greater activation in the right inferior parietal lobule (IPL), which is known to be involved in pain relief. These findings suggest that an unsatisfying experience with an initial pain-relief treatment could increase the expectations for the complementary treatment outcome and improve the analgesic effect of the subsequent treatment. The IPL could be associated with this expectation-induced pain relief process.

Quality of recovery in patients administered remimazolam versus those administered an inhalant agent for the maintenance of general anesthesia: a randomized control trial.

BACKGROUND: Remimazolam is a novel intravenous benzodiazepine that is appropriate for the maintenance of anesthesia. Quality of recovery is an important component of health care quality, but there is no published randomized control trial focused on the quality of recovery in patients undergoing total intravenous anesthesia with remimazolam. METHODS: This parallel-group, single-blind randomized control trial at a tertiary care medical center in South Korea was conducted to determine the difference in the quality of recovery between the patients administered remimazolam and those administered an inhalant anesthetic agent. A total of 168 patients aged 19-65 years who underwent elective laparoscopic cholecystectomy or robotic gynecologic surgery were considered for enrollment. Randomization was performed using sealed envelopes containing computer-generated random allocation sequences. Remimazolam was administered for the maintenance of anesthesia in the remimazolam group (Group R), and desflurane was administered in the desflurane group (Group D). The induction protocol and the target value of the bispectral index were identical in both groups. Patients were blinded to the drug that was administered until they finished the postoperative questionnaire. The main outcome measure was the decrement of the QoR-40 score on postoperative day 1 compared to the QoR-40 score on the day before surgery. RESULTS: A total of 165 patients were analyzed. The preoperative and postoperative global QoR-40 scores were 183 and 152 (IQR 173-192 and 136-169), respectively. The perioperative decrement of the global QoR-40 score was 29.96 ± 22.49. The decrement of the QoR-40 score was smaller in Group R than in Group D (26.99 versus 32.90, respectively; mean difference 5.91, 95% confidence interval -0.96-12.79). After adjustment for sex, the type of surgery and surgical time, the administration of remimazolam resulted in a 7.03-point (95% CI 0.35-13.72) less decrement of the QoR-40 score than desflurane. There were no severe adverse events in either group. CONCLUSION: Total intravenous anesthesia maintained with remimazolam provides a better quality of recovery than anesthesia maintained with an inhalant agent in patients undergoing laparoscopic surgery. Additionally, postoperative nausea and vomiting were largely reduced with remimazolam. TRIAL REGISTRATION: KCT0006288 , Clinical Research Information Service (CRIS), Republic of Korea Registration date: 23/06/2021.