Abstract: Objective To analyze the impact factors for unplanned discontinuation of patient-controlled intravenous analgesia (PCIA) within 24 h after thoracic surgery so as to prevent over-use of medical resources. Methods Clinical data of patients with thoracic surgery in Peking Union Medical College Hospital from April 1, 2018 to March 31, 2019 were reviewed. Patients were divided into two groups according to the duration time from the start to the end of PCIA: group A(≤24 h) and group B(＞24 h). Univariate analysis and logistic multivariate regression were used to compare the demographic characteristics, anesthesia/surgery type, PCIA regimen and adverse effect between the two groups. Results A total of 371 patients were included in this study. Univariate analysis showed that the proportion of patients stopped PCIA in 24 hours was higher in female patients than that in male patients (16.8%/39.4%). The proportion of PCIA stop in 24 hours after thoracoscopic surgery was higher than that after thoracotomy (31.4%/19.7%). In PCIA, patients who used morphine were more likely to stop using postoperative PCIA within 24 hours than those who used oxycodone and sufentanil, and patients who used oxycodone were more likely to stop using PCIA within 24 hours than those who used sufentanil (60%/40.5%/25.3%). The proportion of patients who stopped using 5-HT3 receptor blocker in PCIA within 24 hours was lower than that of those who did not (14.9%/30.6%). Patients who were of sedation at the time of follow-up were less likely to stop using PCIA within 24 hours than those who did not have sedation (25.3%/41.8%). Patients who complained of postoperative nausea were more likely to stop using PCIA within 24 hours than those who did not(62.1%/17.3%).The proportion of patients with postoperative vomiting who stopped using PCIA within 24 hours was higher than those without postoperative vomiting (64%/22.1%). Logistic multivariate analysis showed that female, thoracoscopic surgery, intraoperative inhalation of nitrous oxide, postoperative nausea and postoperative vomiting were related with unplanned discontinuation of PCIA within 24 h after thoracic surgery. Conclusions For patients undergoing thoracic surgery,the application of postoperative PCIA should be comprehensively evaluated according to the patient's personal situation, surgery type, and the risk of postoperative nausea/vomiting.

Key words: thoracic surgery, pain management, patient-controlled intravenous analgesia, postoperative nausea and vomiting