Granulocyte Elastase Release during Extracorporeal Oxygenation: Effects of Bubble, Membrane, and Hollow Fiber Oxygenators

Abstract

Activation or lesions of PMN-granulocytes among other effects result in release of proteases i.e., elastase (E). Plasma E is mainly inactivated by alpha 1-proteinase inhibitor (alpha 1-PI) by formation of E-alpha 1-PI complexes. However, E may be able to destroy plasma proteins (i.e., clotting factors, immunoglobulins, etc.) before complex formation occurs. The effects of extracorporeal oxygenators on blood cells were investigated in samples of 26 patients before, during and up to three days after extracorporeal circulation (ECC) and oxygenation in open heart surgery. Three types of oxygenators were compared in clinical use: bubble (A), membrane (B), and hollow fiber (C). A significant increase of E alpha 1-PI concentrations is observed during ECC. The extent of E release depends on time of ECC and on the type of extracorporeal oxygenator (E alpha 1-PI levels at the end of ECC: 1514 +/- 557 ng/ml −A, 842 +/ 480 ng/ml − B, 506 +/ 128 ng/ml −C). Complex levels increase further on and reach maxima 2h after the end of ECC. The increase of E in plasma is more pronounced than other hemolytic parameters. E-alphal-PI complex levels thus seem to be a sensitive indicator for leukocyte lesions and/or activation during extracorporeal oxygenation.