The purpose of this study is to investigate the feasibility of using balanced propofol sedation for bronchoscopy. And screen out the optimal balanced propofol sedation compatibility plan.

Balanced propofol sedation (BPS) is a technique proposed and developed by gastroenterologists. In recent years, multiple studies have confirmed that the use of BPS in gastrointestinal endoscopy can not only ensure patient comfort, but also reduce the incidence of respiratory and circulatory suppression. Moreover, the postoperative recovery time is short. Even for non-anesthesiologists applying BPS in gastrointestinal endoscopy , it has high safety.

Compared with gastrointestinal endoscopy, bronchoscopy occupies the respiratory tract and most patients have respiratory system diseases. Therefore, it is more necessary for strict respiratory management and control of patient sedation depth. Traditional midazolam combined with opioid drugs or propofol monosedation cannot effectively meet clinical needs. The excellent sedative and analgesic effects of BPS, as well as its maintenance of respiratory and circulatory functions, make it theoretically very suitable for application in bronchoscopy. However, there is currently a lack of evidence to support the application of BPS in bronchoscopy.

Inclusion Criteria:

1. American Society of Anesthesiologists classes I-IV ;
2. Patients undergo painless bronchoscopy, including bronchoscopic biopsy (bronchoscopic lesion biopsy, bronchial mucosal biopsy, bronchoscopic transmural lung biopsy, bronchoscopic needle aspiration biopsy) ,bronchoalveolar lavage and bronchoscopic treatment;
3. Normal communication skills and able to cooperate in completing this study;
4. Patients who voluntarily accept this experimental study and sign the "Trial Informed Consent Form".

Exclusion Criteria:

1. Patients with contraindications or allergies to anesthesia;
2. Individuals with a history of alcoholism or drug abuse;
3. Patients with contraindications for puncture of the cricoid membrane;
4. Patients with mental or neurological disorders, taking anti anxiety/depression drugs, or primary diseases with laboratory evidence indicating possible changes in hormone levels;
5. Patients with difficulty in language communication, poor understanding ability, and inability to cooperate in completing experimental studies;
6. Patients who require laryngeal mask or tracheal intubation for assisted ventilation during the examination process;
7. Patients undergoing rigid bronchoscopy treatment;
8. Patients who refuse to receive sedation or have not signed the "Trial Informed Consent Form".

Population undergoing bronchoscopy examination at Qingdao University Affiliated Hospital from December 2023 to January 2014.