Cosyntropin stimulation testing on postoperative day 1 allows for selective glucocorticoid replacement therapy after adrenalectomy for hypercortisolism: Results of a novel, multidisciplinary institutional protocol.

Background: Secondary adrenal insufficiency (AI) can occur after unilateral adrenalectomy for adrenal-dependent hypercortisolism. Postoperative glucocorticoid replacement (GR), although given routinely, may not be necessary. We sought to identify factors that, in combination with postoperative day 1 cosyntropin stimulation testing (POD1-CST), would predict the need for GR.

Methods: We reviewed 31 consecutive patients who underwent unilateral adrenalectomy for hypercortisolism (study patients) or hyperaldosteronism (control patients). A standard POD1-CST protocol was used. Hydrocortisone was started for clinical evidence of AI, basal plasma cortisol ≤ 5 (μg/dL), or a stimulated plasma cortisol <18.

Results: A normal POD1-CST was found in all nine control patients and 11 of 22 patients (50%) with Cushing's syndrome; the other 11 study patients (50%) received GR based on the POD1-CST. These patients were younger (51 vs 62 years; P = .017), had a higher body mass index (BMI; 31 vs 29 kg/m(2)), and smaller adrenal neoplasms (16.9 vs 33.0 g; P = .009) than non-GR study patients.

Conclusion: After unilateral adrenalectomy for hypercortisolism, only 50% of patients received GR. No preoperative biochemical characteristics were associated with postoperative AI, although patients who received GR were younger, and tended to have a higher BMI and smaller adrenal nodules. Use of this novel protocol for postoperative dynamic adrenal function testing prevented unnecessary GR in 50% of patients and allowed for individualized patient care.