Significant reduction of air microbubbles with the dynamic bubble trap during cardiopulmonary bypass

Air microbubbles mostly occur unnoticed during cardiopulmonary bypass and a re predominantly responsible for serious postoperative psycho-neurological dysfunction. A dynamic bubble trap (DBT), which removes air microbubbles fr om the arterial blood, was tested in a clinical study. The aim was to evalu ate the efficiency of microbubble removal under clinical conditions. As blood passes through the DBT, which is placed in the arterial line betwe en the arterial filter and arterial cannula, it is converted into a rotatin g stream. The bubbles are directed to the centre of the blood flow and are collected in the distal end of the DBT, from where they are returned to the cardiotomy reservoir. Doppler ultrasonography was used to detect the micro bubbles before and after the DBT, and also the number of high-intensity tra nsient signals (HITS) in the right and left middle cerebral artery during e xtracorporeal circulation. A significant reduction of microbubbles in the a rterial line (3990 before DBT, 537 after, p < 0.001) and HITS in the brain (51 in the DBT group, 77 in the placebo group, p = 0.04) was measured.