Autotransfusion of whole blood in massive bleeding. An experimental study in the pig.

An experimental model for controlled massive bleeding in pigs was developed to evaluate a new method for intraoperative autotransfusion of concentrated whole blood. The animals were injured in the descending thoracic aorta, creating a massive bleeding into the left pleural cavity. By means of a new system for autotransfusion, the animals were kept alive by retransfusing the blood at the same rate as it was shed. All animals were in good condition after autotransfusion of bleeding corresponding to three blood volumes. The postoperative hematological status including hemoglobin, hematocrit, platelet counts and electrolytes was not significantly different from the values before the experiment. The coagulation assays, including platelet adhesiveness, were normal after the experiment. In one pig the urine was positive for hemoglobin using a Hemostix test although it was macroscopically clear. This new method allows autotransfusion of whole blood with a desired hematocrit, with intact platelets and coagulation factors.