Blood levels of atrial natriuretic peptide, endothelin, cortisol and ACTH in patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass.

Previous studies demonstrated a biphasic time course with post-operative dissociation of blood levels of cortisol and ACTH in patients undergoing major surgery and critically ill patients. A possible role of endothelin and atrial natriuretic peptide (ANP) in the dissociation of concentrations of cortisol and ACTH in critically ill patients has been suggested. In the present study, we investigated the perioperative course of blood levels of endothelin, ANP, ACTH, and cortisol in 13 male patients undergoing cardiac surgery with cardiopulmonary bypass (CPB): group 1 consisted of 7 patients with an uneventful perioperative period and group 2 consisted of 6 patients with perioperative complications. Blood samples were taken pre-[T1], intra-[T2], post-operatively (on the day of surgery) [T3], as well as on the first [T4] and second [T5] post-operative days. Blood samples of endothelin, ANP, cortisol, and ACTH were measured using commercially available immunoassays. Perioperatively, a biphasic time course with post-operative dissociation of ACTH and cortisol concentrations was observed in all patients studied. Intraoperatively, during CPB, the highest levels of endothelin were found. Perioperatively, ANP and endothelin levels were elevated compared to pre-operative values up to the second post-operative day. On the second post-operative day, ANP concentrations were significantly higher in patients with complications in the perioperative period compared to those with an uneventful perioperative period. Our results suggest that: 1) plasma levels of ANP increased in patients with perioperative complications; 2) plasma levels of ANP may have prognostic value for patients undergoing cardiac surgery; and 3) the dissociation of ACTH and cortisol cannot solely be explained by the increase in endothelin-1 and ANP concentrations observed in patients undergoing major surgery.