Endocrine Abstracts

Introduction: Cortisol insufficiency has been reported following cardiac surgery in infants but has not been associated with postoperative complications. In our hospital serum cortisol is measured following cardiac surgery when hypotension is refractory to two inotropes at maximal dose.

Methods: Retrospective case note study to describe features of adrenal insufficiency in post-operative cardiac patients with low serum cortisol.

Results: In the period 01/09/2009–28/02/2010, 188 patients, median age 180 days (range 4 days to 19 years) underwent cardiac surgery. Serum cortisol was measured in 12 patients and was < 500 nmol/l (median 102 nmol/l, range <50–169 nmol/l) in 7 patients of whom one had biochemical features of adrenal crisis (Na 119 mmol/l, K 7.3 mmol/l) and seizures. Serum cortisol was ≥500 nmol/l (1134 nmol/l, 662–4525 nmol/l) in five patients. Patients with low cortisol levels were significantly younger than those in whom cortisol levels were ≥500 nmol/l (age 7 days, 3–30 vs 30 days, 17–910 P=0.007). All patients responded to treatment with hydrocortisone. 3/7 patients with a low serum cortisol underwent a short synacthen test 8–40 days following initial assessment (baseline cortisol 68, 192, 455, peak cortisol median 590, 836, 1335 nmol/l) including the infant with adrenal crisis (baseline cortisol 192 nmol/l, peak 836 nmol/l) and in 2 patients 09.00 cortisol and ACTH were measured (ACTH 3.0 pmol/l, cortisol 103 nmol/l and ACTH 5.5 pmol/l, cortisol 213 nmol/l). One patient died 5 days following surgery and 1 patient is currently being studied.

Conclusion: Our preliminary data reveal post-operative cortisol insufficiency can be associated with features of adrenal crisis. This study is retrospective hence we cannot comment on the relative contribution of cortisol insufficiency to postoperative hypotension. Further research is required to elucidate the cause of transient cortisol insufficiency, prevalence of associated symptoms and to define when hydrocortisone replacement therapy is beneficial.