Autotransfusion of a restricted volume of shed mediastinal blood does not affect the haemostatic capacity in patients following cardiac surgery

The aim was to investigate the haemostatic capacity after autotransfusion of shed mediastinal blood in patients following cardiac surgery. Fifteen cardiac surgery patients with a chest tube drainage ≥ 300 mL blood within the first 6 hours postoperatively were included. The haemostatic capacity was evaluated using whole blood thromboelastometry (ROTEM(®)), impedance aggregometry (Multiplate(®)) and conventional coagulation tests. Measurements were carried out in (1) mediastinal blood, and in blood samples obtained, (2) before autotransfusion, and (3) after autotransfusion of mediastinal blood. In shed mediastinal blood, ROTEM(®) analyses showed reduced clot firmness in the EXTEM (p < 0.001), INTEM (p < 0.001), and FIBTEM assay (p = 0.002). Platelet function and conventional coagulation parameters were significantly impaired (p < 0.001). However, ROTEM(®), platelet function and conventional coagulation tests remained unchanged after autotransfusion.

Conclusion: Shed mediastinal blood has a substantially reduced haemostatic capacity, but autotransfusion of an average of 350 mL did not affect the overall haemostatic capacity.