Trypsinogen is not activated during cardiac surgery with extracorporeal circulation.

Amylase, immunoreactive cationic trypsin(ogen) and complexes of cationic trypsin and alpha 1-proteinase inhibitor were analysed in plasma samples from 41 patients following cardiac surgery with extracorporeal circulation. Postoperative hyperamylasaemia was seen in seven patients (17%). In 10 patients there were elevated levels (> 100 micrograms 1(-1)) of immunoreactive cationic trypsin(ogen) on the first postoperative day. After gelfiltration, samples from these 10 patients were analysed for trypsin-alpha 1-proteinase inhibitor complexes, with a solid-phase, double-antibody enzyme-linked immunoassay. The median preoperative level of trypsin-alpha 1-proteinase inhibitor complexes was 4.5 micrograms 1(-1) (range 3.3-11.9) and the median value on the first postoperative day was 5.5 micrograms 1(-1) (range 2.6-14). The ratio between complexes and immunoreactive trypsin(ogen) decreased (p < 0.05) showing that activation of trypsinogen did not occur. This fact argues against the development of protease-mediated subclinical pancreatitis during cardiac surgery with extracorporeal circulation.