Observational Study on Plasma Glutamine Levels Before and After Cardiac Surgery

It is known that major surgery induces a stress response characterised by hormonal release and inflammatory processes [6,7]. This surgical stress response resembles the catabolic stress which is found in other forms of critical illness. We did not measure plasma glutamine before surgery so it is unknown whether the plasma glutamine level was already low before surgery in these patients or that the lowering of plasma glutamine level is a consequence of surgery. Most of the patients in the elective surgery group in our study underwent cardiac surgery with use of cardiopulmonary bypass; it is known that extracorporeal circulation induces an inflammatory response but there are no clinical data on the effects on plasma glutamine or on post-operative course in relation to plasma glutamine levels [8,9].