Effects of Modified ultrafiltration at cardiopulmonary bypass animal experiment

Han, Jae Jin; Won, Tae Hee; Park, Sung Soo

Abstract

BACKGROUND: Modified ultrafiltration performed in a short time after ceasing the cardio pulmonary bypass has been known to lessen the adverse effects of extracorporeal circulation, e.g. tissue edema and inflammatory reaction. Considering the pulmonary injury caused by activated leukocyte after CPB, we tried to evaluate the modified ultrafiltration effects, especially to the lung tissues in animal experiments using CPB. MATERIAL AND METHOD: In the orthotopic heart transplantation experiments using 16 pairs of mongrel dogs weighing 15 to 22 Kg(mean 16.5+/-0.5), we divided them into the conventional CPB group and the modified ultrafiltration group, which was performed for 10 to 15 minutes immediately after the CPB- off through the circuit composed by arterial cannula-> Roller pump with Amicon Diafilter-> right atrial cannula. Blood sampling and lung biopsy were performed before starting the CPB, after ceasing the CPB and after modified ultrafiltration(for the control group, 10-15 minutes after CPB-off). We monitored the systemic arterial, right atrial and left atrial pressure and measured the gas analysis, hemoglobin concentration, hematocrit, leukocyte counts, platelet counts, serum protein and albumin concentration, water content of the biopsied lung(freeze drying method). The light and electronic microscopic findings were compared for the effects of CPB and modified ultrafiltration. RESULT: The changes in the hemoglobin level during pre-CPB, CPB-off, and modified ultrafiltration were 10.3+/-1.7, 6.3+/-1.7, 8.3+/-2.8 mg/dl, respectively.(P=0.0078, 0.0117) The serum concentrations of proteins were 4.3+/-0.9, 3.1+/-1.5, 4.1+/-1.6 mg/dl, and of albumin were 1.9+/-0.5, 1.4+/-0.7, 1.8+/-0.8 mg/dl, showing significant increases after the modified ultrafiltration respectively.(P=0.0280, 0.0277) Water content changes of the lung were 75.1+/-8.6%, 82.8+/-6.0%, 77.88% in the ultrafiltration group and 74.7+/-4.9%, 82.1+/-5.9%, 82.3+/-5.1% in the control group. Ultrastructural studies showed drastic decrease of CPB-caused edematous change at the endothelial fused basement membranes and mitochondria after the modified ultrafiltration. However, the destructive findings of mitochondrial christae and membrane seemed to be intensified. The endoplasmic reticular expansion and vacuolar change in its cytoplasm also seemed to be aggrevated. The leukocyte count increased after CPB, and its degenerative change and degranulation increased after CPB and after the modified ultrafiltration.
CONCLUSION
Modified ultrafiltration showed effective recovery of blood hemoglobin and serum protein level after CPB and a drastic decrease of edema in the ultrastructural pulmonary tissue.