Combination of Continuous Positive Airway Pressure and Air Reinflation during One-Lung Ventilation Attenuates Lung Injury Following Esophagectomy: A Randomized Clinical Trial

Background: One-lung ventilation (OLV) is routinely used in esophagectomy to facilitate surgery. Lung injury may be induced by a "multiple-hit" mechanism. The aim of this study was to determine whether combined intervention using continuous positive airway pressure (CPAP) and air reinflation can reduce lung injury after OLV. Methods: Patients scheduled for esophagectomy were enrolled in this prospective study. These patients were assigned randomly to four different groups. In the control group (N=24), the collapsed lung was reinflated with 80% oxygen. In the air reinflation group (N=25), room air was used to regain two-lung ventilation. In the CPAP group (N=24), 5 cm H2O CPAP was administered to the contralateral lung during OLV. In the CPAP+AIR group (N=24), the contralateral lung received CPAP during OLV, and room air was used for reinflation of the lung. Plasma malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-8 (IL-8) levels were measured at baseline (10 minutes after two lung ventilation) and 3 hours after reinflation. Bronchoalveolar lavage fluid (BALF) was obtained 30 minutes after lung re-expansion for measurements of surfactant apoprotein A (SP-A) and surfactant apoprotein C (SP-C). Computerized tomography was used to precisely detect micro-atelectasis on the fourth postoperative day. Results: Compared with the control group, CPAP and combined intervention increased arterial oxygen pressure levels 60 minutes after OLV (164±43 vs. 217±43; 164±43 vs. 216±52, P<0.05). The plasma MDA level in the air reinflation group was lower and SOD level was higher than those in the control group 3 hours after lung reinflation (P<0.05). The CPAP group had a lower plasma IL-8 level, a less atelectasis and a higher SP-A level in BALF (P<0.05) as compared to the control group. In the CPAP+AIR group, the plasma levels of MDA, IL-6, and IL-8, and atelectatic area reduced (7.9±3.9% vs. 4.4%±3.3%, P<0.05), while levels of SOD, SP-A, and SP-C increased (P<0.05) when compared with the control group. Conclusions: CPAP combined with air reinflation increased arterial oxygen pressure levels during OLV, reduced oxidative stress and inflammation, and minimized atelectasis following esophagectomy.  Citation: Mao-Hua Wang, Guang-Xiang Chen, Ru-Rong Wang, Yun-Fei Wu, Jia-Li Wu, Xiao-Xia Duan. Combination of continuous positive airway pressure and air reinflation during one-lung ventilation attenuates lung injury following esophagectomy: a randomized clinical trial. J Anesth Perioper Med 2014; 1: 5-14. doi: 10.24015/JAPM.2014.0003 This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.