Systemic and alveolar inflammatory response in the dependent and nondependent lung in patients undergoing lung resection surgery: A prospective observational study

BACKGROUNDMeasurement of inflammatory mediators in bronchoalveolar lavage (BAL) during lung resection surgery with periods of one-lung ventilation (OLV) has revealed an intense local pulmonary response. The role of each lung in the inflammation that occurs during this procedure has never been investigated. OBJECTIVE(S)The primary objective of our study was to compare the inflammatory response in the dependent lung with that of the nondependent lung by measuring inflammatory markers in BAL. Our secondary objective was to assess the behaviour of these inflammatory mediators in patients with and without postoperative pulmonary complications (PPCs). DESIGNA prospective, observational study. SETTINGDepartment of Anaesthesiology in a university hospital. PATIENTSForty-six consecutive patients undergoing lung resection surgery. INTERVENTION(S)BAL samples were taken from dependent and nondependent lung 10 min before initiating OLV and at the end of OLV (once two-lung ventilation was established). All patients were followed up until 30 days after surgery. MAIN OUTCOME MEASURESThe concentration of cytokines [interleukin (IL)-1, IL-2, IL-6, IL-10, tumour necrosis factor-alpha (TNF-α)], nitric oxide, carbon monoxide and matrix metalloproteinase 2 (MMP-2) was analysed in both lungs before and after OLV. PPCs were recorded. RESULTSIn BAL fluid, all measured biomarkers, apart from IL-10, were significantly greater (P