Earlier studies showed that a low glutamine level at acute admission on the ICU is associated with a poor outcome [3,4]. Recently, we found that a low plasma glutamine is correlated with severity of illness and presence of an infection after non-elective ICU admission [5, submitted].

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].

Inclusion Criteria:

• patients undergoing elective cardiac surgery

Exclusion Criteria:

• none

All consecutive patients who undergo elective cardio-thoracic surgery during a 6 to 8 week period.

We aim to include at least 90 patients.