Goal directed perfusion (GDP) aims to maintain an O₂ delivery above 270-300 ml/min/m², during cardiopulmonary bypass. This strategy decreases the incidence of postoperative acute kidney injury. We first developed a simple physiological hypothesis that explained why maintaining an indexed DO₂ above 280-300 ml/min/m² could optimize organ protection during bypass, then we propose to tailor the O₂ supply to patient real time VO₂ as an individualized strategy, to optimize supply to metabolism need.