Background This study aimed to determine whether ultrasound-guided continuous erector spinae plane block (ESPB) had an effect on opioid consumption and postoperative rehabilitation in patients undergoing video-assisted thoracic surgery (VATS). Methods In this prospective study, 120 patients aged 20–70 years who underwent elective VATS were randomly allocated to one of three groups: group C (general anesthesia with patient-controlled intravenous analgesia [PCIA]), group T (general anesthesia with patient-controlled epidural analgesia [PCEA]), or group E (general anesthesia with continuous ESPB and PCIA). Perioperative opioid consumption, visual analog scale (VAS) scores, preoperative and postoperative Quality of Recovery-15 scores, and postoperative opioid-related adverse events were all assessed. Results Intraoperative sufentanil consumption in groups T and E was significantly lower than that in group C (both P < 0.001), and the postoperative sufentanil consumption in group E was also significantly lower than that in group C (P = 0.001). Compared with group C, the VAS scores at rest or during coughing immediately out of the post-anesthesia care unit at 6 h, 12 h, and 24 h postoperatively were significantly lower in group T (P < 0.05). However, the VAS scores at rest at 6 h and 12 h postoperatively in group E were lower than those of group C (P < 0.05), but were significantly higher than those of group T at all study times (P < 0.05). Conclusion Ultrasound-guided continuous ESPB significantly reduced perioperative opioid consumption during VATS and improved postoperative rehabilitation. However, these effects were inferior to those of thoracic epidural anesthesia. Trial registration The present study was prospectively registered at http://www.chictr.org/cn /(registration number: ChiCTR1900023050); registration date: May 82,019.

Background: The ideal fraction of nitrous oxide (N2O) in oxygen (O2) for rapid lung collapse remains unclear. Accordingly, this prospective trial aimed to determine the 50% effective concentration (EC50) and 95% effective concentration (EC95) of N2O in O2 for rapid lung collapse. Methods: This study included 38 consecutive patients undergoing video-assisted thoracoscopic surgery (VATS). The lung collapse score (LCS) of each patient during one-lung ventilation was evaluated by the same surgeon. The first patient received 30% N2O in O2, and the subsequent N2O fraction in O2 was determined by the LCS of the previous patient using the Dixon up-and-down method. The testing interval was set at 10%, and the lowest concentration was 10% (10%, 20%, 30%, 40%, or 50%). The EC50 and EC95 of N2O in O2 for rapid lung collapse were analyzed using a probit test.Results: According to the up-and-down method, the N2O fraction in O2 at which all patients exhibited successful lung collapse was 50%. The EC50 and EC95 of N2O in O2 for rapid lung collapse were 27.7% (95% confidence interval 19.9%–35.7%) and 48.7% (95% confidence interval 39.0%–96.3%), respectively.Conclusions: In patients undergoing VATS, the EC50 and EC95 of N2O in O2 for rapid lung collapse were 27.7% and 48.7%, respectively.Trial registration: http://www.chictr.org/cn/ Identifier ChiCTR19 00021474, registered on 22 February 2019

Background: The ideal fraction of nitrous oxide (N2O) in oxygen (O2) for rapid lung collapse remains unclear. Accordingly, this prospective trial aimed to determine the 50% effective concentration (EC50) and 95% effective concentration (EC95) of N2O in O2 for rapid lung collapse. Methods: This study included 38 consecutive patients undergoing video-assisted thoracoscopic surgery (VATS). The lung collapse score (LCS) of each patient during one-lung ventilation was evaluated by the same surgeon. The first patient received 30% N2O in O2, and the subsequent N2O fraction in O2 was determined by the LCS of the previous patient using the Dixon up-and-down method. The testing interval was set at 10%, and the lowest concentration was 10% (10%, 20%, 30%, 40%, or 50%). The EC50 and EC95 of N2O in O2 for rapid lung collapse were analyzed using a probit test.Results: According to the up-and-down method, the N2O fraction in O2 at which all patients exhibited successful lung collapse was 50%. The EC50 and EC95 of N2O in O2 for rapid lung collapse were 27.7% (95% confidence interval 19.9%–35.7%) and 48.7% (95% confidence interval 39.0%–96.3%), respectively.Conclusions: In patients undergoing VATS, the EC50 and EC95 of N2O in O2 for rapid lung collapse were 27.7% and 48.7%, respectively.