The aim of the study was to assess the ability a Lung Recruitment Maneuver (LRM) with a stepwise increase of PEEP to predict fluid responsiveness and right cardiac dysfunction in mechanically ventilated patients in open heart cardiac surgery. During different phases, all patients received a Passive Leg Raising (PLR) maneuver for preload status evaluation using the PICCO system, a Lung Recruitment Maneuver (LRM) and an echographic evaluation of the right cardiac function. 20 patients were analyzed. Incomplete Lung Recruitment Maneuver (LRM) can predict fluid responsiveness at phase 1, pre-operatively, with a sensitivity of 0.57 and specificity of 0.62. Performance of an incomplete Magnetic Resonance Angiography (MRA) to predict right cardiac dysfunction based on TAPSE post-operatively provides a sensitivity and specificity of respectively 0.33 and 0.17 Tolerance to a stepwise lung recruitment maneuver can not be used to evaluate reliably the preload responsiveness and guide fluid therapy except pre-operatively. The use of a lung recruitment maneuver can be a promising method for right cardiac dysfunction screening but further studies need to be done with different echographic tools for right cardiac dysfunction evaluation.

Inclusion Criteria:

• Patients receiving an elective or urgent cardiac surgery with or without extracorporeal circulation under general anesthesia, under protective mechanical ventilation, monitored by invasive arterial blood pressure and pulse contour analysis (PICCO system) for cardiac output measurement and central venous pressure

Exclusion Criteria:

• Left ventricular ejection fraction ≤ 30%
• heart arrhythmia, pulmonary hypertension (SPAP > 35 mmHg)
• right heart failure (TAPSE < 16 mm, S' at lateral tricuspid valve < 10 cm/sec)
• lower limbs obstructive arteriopathy (stage IIb, III and IV)
• severe and very severe chronic obstructive pulmonary disease (COPD)
• pneumothorax and extreme weights (BMI < 35 kg/m2).

Patients receive cardiac surgery will be included.