Postoperative acute adrenal failure caused by transient corticotropin deficiency

Acute adrenal insufficiency after a surgical procedure or trauma is rarely reported. In recent years, however, we have treated seven patients with acute primary adrenal insufficiency and three patients with secondary adrenal insufficiency who presented with shock after a surgical procedure or trauma. The standard cosyntropin test was misleading for the diagnosis of corticotropin deficiency.

In this study we measured serum cortisol in patients older than 65 years who had unexplained hypotension after an abdominal surgical procedure. If the serum cortisol was less than 15 micrograms/dl, we performed 1 microgram and standard (250 micrograms) cosyntropin tests and measured thyroxine, thyrotropin, leutinizing hormone in all patients, and free testosterone in men.

We identified five (5%) of 105 patients after an operation who displayed evidence of corticotropin deficiency (i.e., serum cortisol < 15 micrograms/dl during hypotension, prompt hemodynamic improvement with glucocorticoid therapy, and normal response to standard dose cosyntropin). In these patients 1 microgram cosyntropin produced abnormal peak cortisol levels. These patients also had thyrotropin or leutinizing hormone deficiency. After recovery the low hormone levels improved or became normal.

Postoperative adrenal insufficiency, particularly that caused by transient corticotropin deficiency, is more common in patients than currently recognized. The 1 microgram cosyntropin test may be more sensitive than the standard test for identifying secondary adrenal insufficiency.