Background <p>Arthroscopic knee surgery (AKS) is a widely performed day procedure used for both the diagnosis and treatment of various knee-related conditions. Although this surgical approach is less invasive compared to traditional methods, it still necessitates effective anesthesia management. Conventional anesthetic techniques, such as spinal anesthesia and peripheral nerve blocks, often fall short in facilitating rapid recovery after day surgery, primarily due to prolonged postanesthesia recovery times and the potential for associated complications. In contrast, general anesthesia that preserves spontaneous respiration may present a more advantageous alternative, as it avoids the complications associated with tracheal intubation. This study aims to evaluate the effects of inhalation anesthesia in comparison to total intravenous anesthesia, both with preserved spontaneous respiration, on intraoperative adverse respiratory events and postoperative recovery. To prevent leakage of volatile anesthetics, we will utilize a headgear device designed for fully enclosed inhalation anesthesia that enables patients to maintain spontaneous respiration throughout the procedure. The findings of this research are intended to provide reliable evidence to support the broader clinical application of this anesthesia technique in the context of arthroscopic knee surgery.</p> Methods <p>This study is designed as a randomized clinical trial conducted at a single center. A total of 96 participants will be randomly assigned to one of two groups: the sevoflurane group or the propofol group, with a 1:1 allocation ratio. In the sevoflurane group, sevoflurane will be utilized for the induction and maintenance of anesthesia, administered through our patented equipment. The propofol group will receive propofol via intravenous target-controlled infusion for both the induction and maintenance of anesthesia. The primary outcome measure is the incidence of intraoperative respiratory depression. Secondary outcome measures include the incidence of intraoperative hypotension, bradycardia, somatic responses, and coughing, as well as the occurrence of postoperative headache and agitation within 24&#xa0;h following surgery. Additionally, we will evaluate the severity of postoperative pain, nausea, and vomiting using a numerical rating scale (NRS) at the same postoperative interval. And the quality of recovery will be measured with the Quality of Recovery-15 score (QoR-15) at 24&#xa0;h post-surgery. The length of hospital stay and associated hospitalization costs will also be documented.</p> Discussion <p>The objective of our study is to assess the potential benefits of our fully enclosed inhalational anesthesia system in patients undergoing AKS. We will specifically examine the effects of inhalational anesthesia compared to total intravenous anesthesia on intraoperative spontaneous respiration and postoperative recovery. Our aim is also to determine which anesthesia modality offers greater safety and comfort for surgical patients.</p> Trial registration <p>China Clinical Trial Register ChiCTR2200057229. Registered on 4 March 2022.</p>