the decrease in thoracopulmonary compliance after cardiac surgery is well known . The investigators hypothesize that the major factor determining pulmonary outcome after cardiac surgery is the alteration of pulmonary compliance during cardiopulmonary bypass(CBP) and that this alteration is due to CBP itself through pulmonary blood emptying.

compliance is the compliance calculate when thorax is closed, the pulmonary compliance is the compliance calculated when thorax is opened After operation chest X-ray are daily done and blood samples as needed. Were recorded death, time of extubation,duration of non invasive ventilation,of Intensive Care Unit stay and of total hospital stay, troponin peak, lactates, blood gases, ionogram and count.Variations of compliance is analyzed through one factor paired Anova or Wilcoxon paired test. Decrease of compliance and respiratory complications are analyzed through binomial logistic regression.

Inclusion Criteria:

• scheduled for standard aortic
• mitral or coronary surgery

Exclusion Criteria:

• emergency operation
• no complete preoperative echocardiography
• surgery needing multiple table position changes
• unstable cardiac or respiratory condition
• difficult patient needing multiple care and/or special attention

Every ASA 2 or 3 patient eligible for non-complex and non-urgent cardiac surgery