Adrenal function during coronary artery bypass grafting

Abstract

Objective: To assess adrenal function in patients undergoing coronary artery bypass grafting (CABG) by means of the low-dose (1 mg) 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 mg) ACTH tests were performed on the day before surgery (day 21), 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 2 1, 75% of the study patients had normal stimulated plasma cortisol concentrations. Eleven patients (25%) had an impaired adrenal response to 1 mg ACTH. The stimulated plasma cortisol concentrations in patients who had an inadequate adrenal response on day 2 1 remained significantly reduced on day 1 (756^205 vs 949^259 nmol/l, P ¼ 0.03) (mean^S.D.), day 2 (644 (580 -793) vs 885 (713-1087), P ¼ 0.03) (median (interquartile range)), and on the day of discharge (698^201 vs 854^186, P ¼ 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 ¼ 2 0.50, P ¼ 0.002) and volume balance (r ¼ 0.41, P ¼ 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.

Genetic variation of TLR4 influences immunoendocrine stress response: an observational study in cardiac surgical patients

“…Therefore, one could speculate that in TLR4 SNP carriers, cortisol release might be rather locally triggered, while adrenal glands of non-carriers are mainly controlled by systemic ACTH. In an ACTH stimulation study in 45 cardiac surgery patients, 11 (25%) had an impaired cortisol response [48]. These effects could be explained by our findings in that TLR4 SNP carriers were part of the patient population.…”

Relative adrenal insufficiency and hemodynamic status in cardiopulmonary bypass surgery patients. A prospective cohort study

“…Henzen et al studied adrenal function in patients who underwent CABG[15]. After administration of 1 μg of ACTH, the incidence of RAI was 25% and there were no increasing dose requirements of vasoactive drugs, but in that study no patients received etomidate, which could have influenced the results.…”

Differential Effects of a Perioperative Hyperinsulinemic Normoglycemic Clamp on the Neurohumoral Stress Response during Coronary Artery Surgery

“…Future studies will aim at the association between clamping induced dampening of the HPA axis response to CABG and clinical outcome. Because a certain degree of stress response by the body is absolutely crucial to survive, this approach carries the risk of inducing relative adrenal insufficiency (19), which may negatively affect outcome, especially in high-risk patients.…”