The degree of oxidative stress is associated with major adverse effects after lung resection: a prospective study

This prospective randomized study was conducted in order to define the contribution of the generated oxygen and nitrogen reactive species on postlobectomy morbidity and mortality.

Between 2001 and 2003, 132 patients with non-small cell lung cancer (NSCLC) were prospectively studied. The patients were grouped according to one-lung ventilation (OLV) use or not and to the duration of lung's atelectasis. Group A included 50 patients with confirmed non-small cell lung cancer who were subjected to lobectomy without one-lung ventilation. Group B included 30 patients subjected to 60 min OLV. Group C included 30 patients subjected to 90 min OLV. Group D included 22 patients subjected to 120 min OLV. Preoperative, intraoperative and postoperative strict blood sampling protocol was followed. Malondialdehyde (MDA) plasma levels were measured. The groups were statistically compared for the occurrence of postoperative complications. OLV (groups B-D) along with other clinical parameters were entered in multivariate analysis as risk factors for complication development.

Comparison of group A with groups B-D (OLV) documented significant increase (p<0.001) of MDA levels during lung reexpansion. The magnitude of oxidative stress was related to OLV duration (group D>group C>group B, all p<0.001). Univariate analysis disclosed a higher incidence of acute respiratory failure, cardiac arrhythmias and pulmonary hypertension in group D. Multivariate analysis revealed OLV as an independent risk factor for postoperative development of cardiac arrhythmias and pulmonary hypertension.

Protracted (>1h) OLV should be considered a potential cause for cardiovascular complications through the generation of severe oxidative stress due to lung reexpansion.