Material and Methods Patient selection Consecutive patients who require elective lung resection for cancer at the University Hospital of Geneva will be screened for the presence of risk factors for postoperative ALI or hydrostatic lung edema: age > 60 yrs, history of chronic alcohol consumption (>60g/day), prior radiation or chemotherapy, cardiac insufficiency (left ventricular ejection fraction < 40%, or a history of past acute heart failure), coronary artery disease (history of myocardial infarct, Q wave on the ECG, positive stress test or coronary angiogram), recent pneumonia (within 6 weeks of hospital admission), reduced diffusion capacity for carbon monoxide (DLCO < 60% of predicted values) and predicted postoperative lung perfusion of < 55% of total lung perfusion. Patients with at least 3 risk factors for postoperative lung edema will be considered eligible for the study. Patients undergoing pneumonectomy or presenting with intracardiac shunts, valvular diseases or aortic abdominal aneurysm will all be excluded as these conditions preclude valid measurements of extravascular lung water volumes. In addition, chronic treatment with inhaled bronchodilators, a history of any adverse reaction to bronchodilators and liver or kidney insufficiencies will be considered exclusion criteria.