Adrenal function during coronary artery bypass grafting.
OBJECTIVE
To assess adrenal function in patients undergoing coronary artery bypass grafting (CABG) by means of the low-dose (1 microg) ACTH test, and to correlate the adrenal function with clinical outcome.


METHODS
During a 5-Month period we prospectively included 45 patients undergoing elective CABG with cardiopulmonary bypass and without symptoms of endocrine disease. Low-dose (1 microg) ACTH tests were performed on the day before surgery (day -1), immediately after the operation (day 0), on the two subsequent days in the intensive care unit (day 1 and day 2), and on the day of discharge from the hospital. A number of clinical, hemodynamic and laboratory parameters were monitored throughout.


RESULTS
On day -1, 75% of the study patients had normal stimulated plasma cortisol concentrations. Eleven patients (25%) had an impaired adrenal response to 1 microg ACTH. The stimulated plasma cortisol concentrations in patients who had an inadequate adrenal response on day -1 remained significantly reduced on day 1 (756+/-205 vs 949+/-259 nmol/l, P=0.03) (mean+/-s.d.), day 2 (644 (580-793) vs 885 (713-1087), P=0.03) (median (interquartile range)), and on the day of discharge (698+/-201 vs 854+/-186, P=0.05). In patients with a normal adrenal response in the preoperative setting peak cortisol concentrations were reached on day 1, in patients with a blunted adrenal response they were reached on day 2. There were significant correlations between the stimulated plasma cortisol concentrations and the blood loss (r=-0.50, P=0.002) and Volume balance (r=0.41, P=0.015).


CONCLUSIONS
Occult (partial) adrenal insufficiency is common in patients undergoing CABG who are otherwise asymptomatic as regards endocrine disease. The adrenal function in these patients differs both in the magnitude of cortisol response to ACTH and in the time course, with significantly delayed peak cortisol concentrations. Adequate regulation of Volume balance and the amount of blood loss seem to correlate with adequacy of adrenal function.
Henzen
Christoph
C
Department of Internal Medicine, Kantonsspital, CH-6000 Luzern 16, Switzerland. Christoph.Henzen@ksl.ch
Kobza
Richard
R
Schwaller-Protzmann
Birgit
B
Stulz
Peter
P
Briner
Verena A
VA
D000309:Adrenal Insufficiency / Q000097:blood / Q000209:etiology*; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000368:Aged; D016063:Blood Loss, Surgical; D001810:Blood Volume; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D003324:Coronary Artery Disease / Q000601:surgery*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013312:Stress, Physiological / Q000097:blood / Q000209:etiology*
D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone