Participants

According to the global initiative for chronic obstructive lung diseases (GOLDs), patients with a previous history of dyspnea, chronic cough, or sputum, post-bronchodilator forced expiratory volume in the first second/forced vital capacity (FEV₁/FVC) < 0.7 and airflow restriction after inhalation of bronchodilators, and indications for bronchoscopy were selected as the research object. A total of 93 patients with COPD who underwent painless bronchoscopy from April 2019 to December 2019 in our hospital were included. SPSS software was used to generate a random assignment sequence, and 93 patients were randomly divided into two groups: the lidocaine group (group L, n = 48) and the control group (group C, n = 45). The randomly assigned sequences are placed in sequentially coded opaque sealed envelopes. After confirming that the patients met the inclusion criteria, the envelopes were distributed and opened according to the chronological order of patients' inclusion, then the patients were assigned to the corresponding groups and recorded. All the patients after screening were enrolled in the study (Figure 1).

Consort flowchart.

After the patient entered the operating room, the anesthesiologist opened the sealed envelope and she was responsible for preparing the study drug. Another anesthesiologist was responsible for the intraoperative medication of all patients and did not know the grouping. Bronchoscopy doctors and nursing staff responsible for data collection did not know the grouping of patients as well.