Coronary artery bypass grafting is a current cardiac surgery. Internal thoracic artery is usually taking to restore coronary revascularization, and its dissection can lead to accidental or voluntary pleural effusions. Respiratory complications are frequent, due to the drainage required. In this study, the investigators propose one-lung ventilation to facilitate artery grafting and surgical procedure. The investigators will include all adult patients with elective coronary artery bypass surgery (CABG) by internal thoracic artery, in a prospective, controlled, randomized and monocentric study. The main objective is to demonstrate that one-lung ventilation using EZ-Blocker can reduce pleural effusion defined by presence of drainage and/or pneumothorax on X-ray chest in the ICU.