Effects of starting one lung ventilation and applying individualized PEEP right after patients are placed in lateral decubitus position on intraoperative oxygenation for patients undergoing thoracoscopic pulmonary lobectomy: study protocol for a randomized controlled trial

Abstract

Background: For patients receiving one lung ventilation in thoracic surgery, numerous studies have proved the superiority of lung protective ventilation of low tidal volume combined with recruitment maneuvers (RM) and individualized PEEP. However, RM may lead to overinflation which aggravates lung injury and intrapulmonary shunt. In most previous studies, RM or PEEP was not applied until atelectasis has already formed. Because atelectasis usually does not develop the moment patients are turned into lateral decubitus position, we hypothesize that applying sufficient PEEP without RM immediately after patients are turned into that position is as effective to prevent atelectasis and thus improve oxygenation as applying PEEP with RM. Methods: A total of 84 patients scheduled for elective pulmonary lobe resection necessitating one lung ventilation will be recruited and randomized to the study group and the control group. For patients in the study group , one lung ventilation will be initiated right after the position of double lumen tube in lateral decubitus position is adjusted, and then individualized PEEP titration is applied. For patients in the control group, one lung ventilation will not be initiated until pleura is opened; and after the initiation, RM will be performed followed by individualized PEEP titration. The primary endpoint will be oxygenation index. Secondary endpoints will include intrapulmonary shunt, respiratory mechanics, PPCs, and hemodynamic indicators. Discussion: Numerous previous studies compared the effects of individualized PEEP applied alone with that applied in combination with RM on oxygenation index, PPCs, intrapulmonary shunt and respiratory mechanics after atelectasis was formed in patients receiving one lung ventilation during thoracoscopic surgery. In this study, we will apply individualized PEEP before the formation of atelectasis while not performing RM in patients allocated to the study group, and then we’re going to observe its effects on the aspects mentioned above. The results of this trial will provide a ventilation strategy that not only improves intraoperative oxygenation but also avoids the detrimental effects of RM for patients receiving one lung ventilation. Trial registration: www.Chictr.org.cn ChiCTR2400080682. Registered on February 5, 2024.