The Protective Effects of a New Type of Leukocyte-depletion Filter-1 on Red Blood Cells During Cardiopulmonary Bypass

Objective To assess the protective effects of a new type of leukocyte-depletion filter-1 (LD-1) on red blood cells during cardiopulmonary bypass(CPB). Methods Twelve Mongolian dogs, weight range 25-30kg, were divided into control group and leukocyte depletion group (LD group) with random number table, LD group (n=6) had our new type of leukocyte depletion filter-1 placed in venous line which was used within the first 5 minutes after onset of CPB. The control group (n=6) had no leukocyte depletion filter installed in the circuit. CPB was set up by cannulated with a venous cannula through the right atrium and with an aortic cannula after median sternotomy. Aorta was clamped at 10 minutes of CPB and released at 70 minutes of CPB. Dogs were observed for 2 hours after weaning from CPB. Blood samples were collected prior to, at 10, 40, 75 minutes, end of and 2 hours after CPB to determine circulating leukocytes, erythrocyte fragility and plasma levels of malondialdehyde(MDA), superoxide dismutase(SOD) and free hemoglobin(FHB). Results Leukocyte numbers were significantly reduced in LD group during CPB(P0.01), and lower than those in control group (P0.05). Plasma levels of SOD dropped after 75 minutes of CPB in control group, but those kept normal in LD group, and higher than those in control group at 2 hours after CPB (P0.05, 0.01). Serum MDA and FHB levels increased sharply in two groups (P0.01), but were lower in LD group than those in control group. The concentrations of NaCl when starting and complete hemolysis were also lower in LD group than those in control group at end of and 2 hours after CPB. Conclusion The new type of LD-1 used in venous line only 5 minutes after onset of CPB can decrease leukocyte counts, and reduce erythrocyte injury effectively.