The effect of one-lung ventilation upon pulmonary inflammatory responses during lung resection

One-lung ventilation (OLV) is commonly used during thoracic surgery. Clinical studies using bronchoalveolar lavage fluid analysis have demonstrated that OLV induces pulmonary inflammatory reactions in the ventilated dependent lung. However, few clinical studies have investigated such inflammatory reactions in the dependent lung compared with the collapsed nondependent lung. Here we used a bronchoscopic microsampling method to obtain epithelial lining fluid (ELF) from each lung, and then compared the inflammatory reactions in the dependent lung and the nondependent lung during thoracic surgery. Twenty adult patients were studied. All patients underwent thoracic surgery using OLV. Propofol and remifentanil were used for total intravenous anesthesia. A double-lumen endotracheal tube was used to perform OLV. ELF was obtained from each lung using the bronchoscopic microsampling method. ELF levels of inflammatory mediators, tumor necrosis factor alpha, interleukin (IL)-1 beta, IL-6, IL-8, IL-10, and IL-12p70 were measured using ELISA before and after OLV. ELF levels of IL-1 beta, IL-6, and IL-8 were significantly increased in the dependent lung and the nondependent lung at the end of surgery compared with their baseline levels (p < 0.05). ELF level of IL-6 was significantly higher in the dependent lung than in the nondependent lung at the end of surgery (p = 0.019). One-lung ventilation induced inflammatory responses of the bronchial epithelia in the dependent lung and the nondependent lung during thoracic surgery. In addition, these inflammatory responses were more augmented in the dependent lung than in the nondependent lung.