The Influence of Allogeneic Red Blood Cell Transfusion Compared with 100% Oxygen Ventilation on Systemic Oxygen Transport and Skeletal Muscle Oxygen Tension After Cardiac Surgery: Retracted

In this study we investigated the effects of allogeneic red blood cell (RBC) transfusion on tissue oxygenation compared with those of 100% oxygen ventilation by using systemic oxygen transport variables and skeletal muscle oxygen tension (P ti o 2 ). Fifty-one volume-resuscitated, mechanically ventilated patients with a nadir hemoglobin concentration in the range from 7.5 to 8.5 g/dL after elective coronary artery bypass grafting were allocated randomly to receive 1 unit (transfusion 1; n = 17) or 2 units (transfusion 2; n = 17) of allogeneic RBCs and ventilation with 40% oxygen or pure oxygen ventilation (100% oxygen; n = 17) and no allogeneic blood for 3 hours. Invasive arterial and pulmonary artery pressures and calculations of oxygen delivery (oxygen delivery index) and consumption indices (oxygen consumption index) were documented at 30-min intervals. P ti o 2 was measured continuously by using implantable polarographic microprobes. Systemic oxygen transport variables and P ti o 2 were similar between groups at baseline. The oxygen delivery index increased significantly with transfusion of allogeneic RBCs and 100% oxygen ventilation, whereas the oxygen consumption index remained unchanged. Oxygen 100% ventilation increased P ti o 2 significantly (from 24.0 ± 5.1 mm Hg to 34.2 ± 6.2 mm Hg), whereas no change was found after transfusion of allogeneic RECs. Peak P ti o 2 values were 25.2 ± 5.2 mm Hg and 26.3 ± 6.5 mm Hg in the transfusion 1 and 2 groups, respectively. Transfusion of stored allogeneic RBCs was effective only in improving systemic oxygen delivery inclex, whereas 100% oxygen ventilation improved systemic oxygen transport and P ti o 2 . This improved oxygenation status was most likely due to an increase in convective oxygen transport with a large driving gradient for diffusion of plasma-dissolved oxygen into the tissue.