Bronchoscopy is a promising technology for lung and bronchus disease detection and therapy. However, this procedure is associated with a relatively high risk of hypoxemia, coughing, wheezing, and dyspnea. Despite the fact that propofol is the most commonly used agent in procedure sedation, the narrow therapeutic index remains challenging. Esketamine is the s-enantiomer of ketamine with potent analgesic and sedative properties. This study aims to test the hypothesis that adding subanesthetic esketamine to propofol is non-inferior to propofol alone for bronchoscopy on the recovery profile and discharge from the hospital.