[Immunological changes following heart surgery under extracorporeal circulation (author's transl)].

Post-operative immunological changes were studied in 40 patients undergoing heart surgery. Tty-five patients were operated upon under extracorporeal circulation (ECC), and 15 without ECC. Immunological investigations were performed before, immediately after the operation and again 7 days later. The post-operative changes recorded were early decrease in IgG and IgM followed by a rise in IgM, transient lymphocytopenia affecting mainly T lymphocytes and delayed increase in complement (CH50, C2, C3). These changes were comparable in both groups of patients and therefore seemed to relate to the operation itself rather than to the ECC. It may be concluded that ECC does not appear to increase the risk of post-operative infection by depressing immune defence mechanisms.