Assessing adrenal status in patients before and immediately after coronary artery bypass graft surgery

Abstract

Objective: Patients with cortisol deficiency poorly tolerate any systemic inflammatory response syndrome (SIRS), and may die if not treated with sufficient exogenous glucocorticoids. Controversy surrounds what constitutes a 'normal' adrenal response in critical illness. This study uses conventional tests for adrenal insufficiency to investigate cortisol status in patients undergoing elective coronary artery bypass surgery, a condition frequently associated with SIRS. Design: A prospective, observational study. Methods: Thirty patients with impaired left ventricular function (ejection fraction O23% !50%) underwent basal ACTH measurement, and a short cosyntropin test (250 mg, i.v.) 1 week preoperatively, and at C4 h following induction of general anaesthesia. Preoperatively, a 30 min cortisol level post cosyntropin O550 nmol/l was taken as a normal response. Results: Prior to surgery, all patients had a normal response to cosyntropin. Postoperatively, eight patients (26.7%) did not achieve stimulated cortisol levels O550 nmol/l and the mean peak cortisol postoperatively was lower (1048 vs 730 nmol/l; P!0.001). There was a significant rise in ACTH after surgery (21 vs 184 ng/l; PZ0.007) and reduction in D-cortisol post cosyntropin (579 vs 229 nmol/l; P!0.001). There was no change in basal cortisol pre-and post-operatively (447 vs 501; PZ0.4). All patients underwent routine, uneventful postoperative recovery. Conclusion: Up to one quarter of patients with a normal cortisol status preoperatively demonstrated a raised ACTH and deficient cortisol response postoperatively. Despite these responses, all patients had uneventful outcomes. These data reinforce the need for caution when interpreting results of endocrine testing following major surgery or in the intensive care environment, and that prognostic value of these results may be of limited use.

Relative Adrenal Insufficiency Is Associated With Prolonged Postoperative Hemodynamic Instability

“…Our results are consistent with those of previous reports assessing postoperative adrenal function in cardiac surgery patients. Two previously published studies have reported a 25% and 27% rate of postoperative RAI in, respectively, 30 patients and 45 patients undergoing coronary artery bypass graft surgery [12,13]. In comparison, the prevalence of RAI in our study was 56% in a cohort of 135 patients.…”

“…Neither of those studies [12,13] assessed the impact of RAI on postoperative hemodynamic status. In contrast, a recently published study by Irribaren and colleagues [15] examined the impact of RAI on postoperative vasopressor requirements in 120 cardiopulmonary bypass surgery patients.…”

The central CLOCK system and the stress axis in health and disease

“…Right after, ACTH declines rapidly to normal levels, while cortisol levels decrease slowly, reaching high normal values 48 to 72 hours after the procedure. 125,127,129 This has been confirmed in coronary artery bypass graft operations, although not by all studies, 130 where basal and stimulated cortisol levels have been correlated with severity of stress, peaking shortly after extubation and being similar to levels during other major surgical procedures and critical illness. 131,132 Studies demonstrate that this principally occurs through cytokine regulation of the HPA axis primarily by direct or indirect stimulation of hypothalamic CRH, especially by IL-1, IL-6, and TNF-α, and also by directly affecting the pituitary and adrenal glands.…”

Adrenal insufficiency presenting as bilateral rigid auricles: a case report

“…Cortisol concentrations do not reflect adrenal function and are affected by hypoproteinemia [13]. The synthetic ACTH test is less reliable and at risk of showing a false positive in the postoperative phase, as exemplified by Debono et al [14,15]. Therefore, it is recommended to treat the patient with glucocorticoids when adrenal insufficiency is clinically suspected [15].…”