ObjectiveTo compare the effects of flow-controlled ventilation (FCV) and conventional pressure-controlled ventilation (PCV) on postoperative pulmonary complications (PPCs) within 7 days after elective thoracic surgery. Methods Patients scheduled for elective thoracic surgery at Langzhong People's Hospital between August 2024 and June 2025 were enrolled and randomly assigned in a 1:1 ratio to either the FCV group or PCV group. The primary outcome was the incidence of PPCs within 7 days postoperatively. Secondary outcomes included systemic inflammatory factor levels at 24 hours postoperatively, numerical rating scale (NRS) pain scores at 3 days postoperatively, post-anesthesia care unit (PACU) stay duration, and length of postoperative hospitalization. Mechanical power (MP), oxygenation index, partial pressure of arterial carbon dioxide (PaCO2), peak pressure (Ppeak), positive end-expiratory pressure (PEEP), tidal volume (VT), respiratory rate (RR), and minute ventilation (MV) were compared between groups at 30 and 60 minutes after one-lung ventilation (OLV). Differences in MP between patients with and without PPCs were analyzed, and receiver operating characteristic (ROC) curves were constructed to evaluate the predictive value of MP for PPCs using area under the curve (AUC). Results A total of 60 patients were included: 30 in the FCV group [17 males, 13 females, mean age (57.4±10.0) years] and 30 in the PCV group [18 males, 12 females; mean age (58.7±11.2) years]. The FCV group demonstrated a significantly lower incidence of PPCs compared to the PCV group (16.7% vs. 40.0%, P=0.045) and reduced systemic pro-inflammatory factor levels at 24 hours postoperatively. No statistically significant difference was observed in NRS pain scores between groups at 3 days postoperatively. Additionally, the FCV group showed shorter PACU stay duration [(51.8±11.5) min vs. (66.2±24.5) min, P=0.008] and reduced postoperative hospitalization time [(7.8±1.2) d vs. (8.9±2.5) d, P=0.034]. At both 30 and 60 minutes after OLV initiation, the FCV group exhibited lower MP, MV, and RR values alongside higher oxygenation indices and VT compared to the PCV group, while PaCO2 and PEEP showed no significant differences. Although Ppeak did not differ significantly between groups at 30 minutes after OLV, it was lower in the PCV group at 60 minutes. Patients who developed PPCs consistently demonstrated higher MP values than those without PPCs at both time points. ROC curve analysis revealed excellent predictive performance of MP for PPCs occurrence within 7 days postoperatively (30-minute OLV: AUC=0.97, P<0.001; 60-minute OLV: AUC=0.93, P<0.001). Conclusion Compared with PCV, implementing FCV during OLV significantly reduces PPCs incidence. This protective effect may be attributed to reduced MP, improved oxygenation, enhanced ventilatory efficiency, and attenuated inflammatory responses. As a lung-protective ventilatory strategy, FCV effectively promotes postoperative recovery in patients undergoing elective thoracic surgery with American Society of Anesthesiologists physical status classification Ⅰ-Ⅲ.
Objective To investigate the predictive value of mechanical power (MP) in the weaning outcome of adaptive mechanical ventilation plus intelligent trigger (AMV+IntelliCycle, simply called AMV) mode for acute respiratory distress syndrome (ARDS) patients. Methods From November 2019 to March 2021, patients with mild to moderate ARDS who were treated with invasive mechanical ventilation in the intensive care unit of the First Affiliated Hospital of Jinzhou Medical University were divided into successful weaning group and failed weaning group according to the outcome of weaning. All patients were treated with AMV mode during the trial. The MP, oral closure pressure (P0.1), respiratory rate (RR) and tidal volume (VT) of the two groups were compared 30 min and 2 h after spontaneous breathing trial (SBT). The correlation between 30 min and 2 h MP and shallow rapid respiratory index (RSBI) was analyzed by Pearson correlation. Receiver operating characteristic (ROC) curve was used to analyze the predictive value of 30 min MP in ARDS patients with AMV mode weaning failure. Results Sixty-eight patients were included in the study, 49 of them were successfully removed and 19 of them failed. There was no statistical significance in age, gender, body mass index, oxygenation index, acute physiology and chronic health evaluation Ⅱ score, reasons for mechanical ventilation (respiratory failure, sepsis, intracranial lesions, and others) between the two groups (all P>0.05). The MP, P0.1 and RR at SBT 30 min and 2 h of the successful weaning group was lower than those of the failed weaning group (all P<0.05), but the VT of the successful weaning group was higher than the failed weaning group (all P<0.05). There was a significant relation between the MP at SBT 30 min and 2 h and RSBI (r value was 0.640 and 0.702 respectively, both P<0.05). The area under ROC curve of MP was 0.674, 95% confidence interval was 0.531 - 0.817, P value was 0.027, sensitivity was 71.73%, specificity was 91.49%, positive predictive value was 0.789, negative predictive value was 0.878, optimal cutoff value was 16.500. The results showed that 30 min MP had a good predictive value for the failure of weaning in AMV mode in ARDS patients. Conclusion MP can be used as an accurate index to predict the outcome of weaning in ARDS patients with AMV mode.