An atraumatic aspirator for use in autologous transfusion and cardiac bypass.

Surgical aspiration has long been seen as the weak link in surgical blood recovery. Aspiration causes a high degree of hemolysis that leads to high plasma hemoglobin levels and reduces the number of erythrocytes available for reinfusion. Aspiration also damages platelets, generates emboli, and increases bleeding time. The major source of the high hemolysis and the other blood damage that occurs during suction is the aspiration of air with the blood. To address this problem, a jet driven aspirator that immediately separates and removes air during suction was designed and tested. The aspirator suctions blood at a range of rates from 100 to at least 700 ml/min, separates and removes 80-100% of the aspirated air, operates at any orientation, and generates subatmospheric pressures on the order of only an inch of water. During in vitro hemolysis testing, the removal of air by the jet driven aspirator showed a significant reduction in hemolysis: plasma hemoglobin levels increased 19.4 mg/dl without air removal and only 1.8 mg/dl with air removal (p < 0.001). In comparative testing with a conventional vacuum operated suction tube, the jet driven aspirator showed significantly less hemolysis (p < 0.001) than did the conventional aspirator at comparable blood and air aspiration rates.