Restrictive Transfusion StratEgy Adjusted by SvO2 During Cardiac Surgery

Patients assigned to the SvO2 group will be transfused if Hb concentration is lower than 9 g/dL and central SvO2 ≤ 65%. Transfusion will be repeated whenever Hb concentration is lower than 9 g/dL and central SvO2 ≤ 65% during surgery and in the ICU (until day 5). Central SvO2 will be measured on a blood sample obtained from the distal lumen of the central venous catheter. Oximetry will be used for measurement with a point-of-care of gas analysis.