Determine a bleeding threshold by measuring the blood volume in ml / kg / h collected in the drainage system to define moderate bleeding postoperative cardiac surgery and define the population.~Secondary objectives:~To evaluate the kinetics of moderate SPORT and its impact on anemia and postoperative transfusion.~To evaluate the prognostic impact of the SPO moderate in terms of post-operative complications.~Determine predictors of moderate SPO.
Determine a bleeding threshold by measuring the blood volume in ml / kg / h collected in the drainage system to define moderate bleeding postoperative cardiac surgery and define the population.