摘要:Background: Ultrasound-guided axillary brachial plexus block (ABPB) is a technique of choice for regional anesthesia during hand and forearm surgery. Intravenous sedation may facilitate this procedure, particularly for those suffering from anxiety; however, it can also be associated with respiratory, cardiovascular, and neurological side effects. The objective of this study was to evaluate the effect of intravenous sedation on perioperative respiratory depression for patients undergoing day-case hand surgery under ABPB. Methods: A prospective, observational, single-center study was conducted between 1 May and 1 November 2016. Results: A total of 2318 patients were included, with 501 patients in the group with IV sedation and 1817 in the group without. A multivariable propensity-score matched analysis showed that the variables associated with the number of desaturation were: (i) sedation (aRR 1.534 [95% CI: 1.283 to 1.836]), (ii) age and sex, (iii) type of surgery, and iv) Body Mass Index (BMI). Conclusions: Supplementing ABPB with IV sedation was associated with an increased rate of respiratory depression (episodes of desaturation) compared to fully awakened patients. The rate of oxygen administration was also higher in sedated patients even though they had fewer cases of chronic respiratory diseases and fewer were active smokers than non-sedated patients. Future research should consider precisely evaluating patient satisfaction, as well as the differences between sedation and drug-free approaches.