Oxidative stress during 1-lung ventilation

ObjectivesResuming 2-lung ventilation from 1-lung ventilation might induce a re-expansion and reoxygenation effect. The oxidative stress during 1-lung ventilation/2-lung ventilation has not been studied, although severe complications, such as re-expansion pulmonary edema, were reported. Reactive oxygen species production and total antioxidant status assay levels were measured in this study during 1-lung ventilation/2-lung ventilation. The effects on extravascular lung water, cardiac output, and intrathoracic blood volume were also studied by using the Pulsion PiCCO system.MethodsTwenty patients undergoing 1-lung ventilation/2-lung ventilation (>60 minutes) for video-assisted thoracoscopic surgery with minimal lung injuries were included in this study. Reactive oxygen species production was measured by means of lucigenin (detecting superoxide mainly) and luminol (detecting H2O2 and HOCl mainly) chemiluminescence. Reactive oxygen species production, total antioxidant status assay (by using the Randox TAS kit), extravascular lung water, cardiac output, and intrathoracic blood volume values were measured before 1-lung ventilation (T1), before resuming 2-lung ventilation (T2), 5 minutes after 2-lung ventilation (T3), and 30 minutes after 2-lung ventilation (T4).ResultsOne-lung ventilation time was 118 ± 33 minutes. Lucigenin chemiluminescence (but not luminol chemiluminescence) increased significantly at T3 and T4. Total antioxidant status decreased nonsignificantly. Extravascular lung water, intrathoracic blood volume, and permeability index values changed nonsignificantly after 2-lung ventilation. Cardiac output increased significantly at T4, and there is a negative correlation between cardiac output and extravascular lung water (r = −0.431, P < .005).ConclusionsResuming 2-lung ventilation induces a massive superoxide production. Comparable extravascular lung water and intrathoracic blood volume and a nonsignificant decrease of total antioxidant status indicate adequate antioxidant capacity to counteract it. Severe oxidative injuries after 1-lung ventilation/2-lung ventilation should be considered in patients without adequate antioxidative capacity, such as those with cancer and trauma.