Background and goal of the study: Lung resection surgery causes an increase in pulmonary inflammatory response that has been attributed to onelung ventilation (OLV) from the dependent lung and to surgical manipulation and ischemia-reperfusion mechanisms from the non-dependent lung. The goal of the study is to compare lung inflammatory response from the dependent and non-dependent lung after OLV in lung resection surgery.
Material and methods: A prospective study was designed. Local Ethics Committee approved the study. Patients scheduled for lung resection surgery were recruited. After intubation with double-lumen tube, patients were managed with volume controlled ventilation (VCV): tidal volume (TV) 8 ml/ Kg, PEEP 3-5 cmH20, FiO2 0.4-0.5 and respiratory frequency to maintain ETCO2 30-35 mmHg. In OLV, VCV was continued: TV 6ml/kg, PEEP 5 cm-H20, permissive hipercapnia and FiO2 0.6-1 in order to maintain SatO2>90%. Fiberoptic bronchoalveolar lavage (BAL) were carried out in the dependent and non-dependent lung before and after OLV for the analysis of lung inflammatory markers. The expression of cytokines (IL-1, IL-2, IL-6, IL-10, TNFa), nitric oxide and Metalloproteinase-2 (MMP2) was analyzed with Western Blot. Carbon monoxide (CO) was analyzed by Omura and Sato test. For statistical analysis we used Mann Whitney U test and Chi2 test.
Results: 46 patients enrolled in the study. All of them completed the study successfully. The analysis showed an increase of IL-1 and MMP2 with p< 0.05 in both lungs after OLV. In addition, CO was increased in the non-dependent lung with p< 0.05, which did not occur in the dependent lung. Values of IL-1 in the dependent lung were 138.08 ± 31.93 ng/ml before OLV and 205.94 ± 39.14 ng/ml after OLV. The values in the non-dependent lung were 140.28 ± 24.56 ng/ml before OLV and 200.21 ± 50.40 ng/ml after OLV The value of MMP2 in the dependent lung was 4.32 ± 1.18 ng/ml before OLV and 8.79 ± 2.07 ng/ml after OLV whereas in the non-dependent lung was 4.67 ± 2.39 ng/ml before OLV and 8.50 ± 1.73 ng/ml after OLV The value of CO in the non-dependent lung was 6.80 ± 1.32 ng/ml before OLV and 7.20 ± 1.44 ng/ ml after OLV In all other markers analyzed, differences were not statistically significant.
Conclusions: Lung resection surgery increases pulmonary inflammatory response in a similar manner in the dependent and the non-dependent lung.