Leukocyte depletion results in improved lung function and reduced inflammatory response after cardiac surgery

Abstract

Leukocyte depletion during cardiopulmonary bypass has been demonstrated in animal experiments to improve pulmonary function. Conflicting results have been reported, however, with clinical depletion by arterial line filter of leukocytes at the beginning of cardiopulmonary bypass. In this study, we examined whether leukocyte depletion from the residual heart-lung machine blood at the end of cardiopulmonary bypass would improve lung function and reduce the postoperative inflammatory response. Thirty patients undergoing elective heart operations were randomly allocated to a leukocyte-depletion group or a control group. In the leukocyte-depletion group (n = 20), all residual blood (1.2 to 2.1 L) was filtered by leukocyte-removal filters and reinfused after cardiopulmonary bypass, whereas in the control group an identical amount of residual blood after cardiopulmonary bypass was reinfused without filtration (n = 10). Leukocyte depletion removed more than 97% of leukocytes from the retransfused blood (p < 0.01) and significantly reduced circulating leukocytes (p < 0.05) and granulocytes (p < 0.05) compared with the control group. Levels of the inflammatory mediator thromboxane B2 determined at the end of operation (p < 0.05) were significantly lower in the depletion group than in the control group, whereas no statistical differences in interleukin-6 levels were found between the two groups. After operation, pulmonary gas exchange function (arterial oxygen tension at a fraction of inspired oxygen of 0.4) was significantly higher in the leukocyte-depletion group 1 hour after arrival to the intensive care unit (p < 0.05) and after extubation (p < 0.05). There were no statistical differences between the two groups with respect to postoperative circulating platelet levels and blood loss, and no infections were observed during the whole period of hospitalization. These results suggest that leukocyte depletion of the residual heart-lung machine blood improves postoperative lung gas exchange function and is safe for patients who are expected to have a severe inflammatory response after heart operations.

Effects of Leukoreduction and Storage on Erythrocyte Phosphatidylserine Expression and Eicosanoid Concentrations in Units of Canine Packed Red Blood Cells

“…The mechanism of increased PGF 2α after leukoreduction in our study is unclear, but PGFS may have been released from lymphocytes activated during the filtration process. Some studies have described leukocyte activation with the use of leukocyte depletion filters,37, 38, 39 but these findings were not consistently replicated in other leukoreduction studies 40, 41, 42, 43. Furthermore, leukocyte rupture is possible with prolonged filtration, resulting in free enzymes and other cellular components 44.…”

Transfusion Reduction in Orthopedic Surgery

“…The leucocytes activated in the study of Innerhofer, however, were activated by contact with foreign surfaces, not by the wound itself for he used pre-donated autologous blood and compared that to allogeneic blood. Others believe thus activated leucocytes induce a generalized activation of the immune system which reduces lung function and increases the inflammatory response of the body (Gu et al, 1996). Especially in cardiac surgery the effects of extracorporeal circulation have been extensively investigated.…”

Effects of Cell-Saving Devices and Filters on Transfusion in Cardiac Surgery: A Multicenter Randomized Study

“…Although this is recommended by several authors and manufacturers [6][7][8] cardiotomy suction blood to the cardiopulmonary bypass (CPB) circuit is usually the first step in blood conservation during cardiac surgery. Cardiotomy blood is highly inflammatory and associated with increased transfusion requirements and organ injury [9,10].…”

“…We previously demonstrated that retransfusion of residual blood from the CPB circuit through an LD filter resulted in improved postoperative lung function [7]. Thus, transfusion of both cardiotomy suction blood and residual blood from the CPB circuit through an LD filter could have a similar clinical effect as processing this blood with a CS.…”