No requirement of perioperative glucocorticoid replacement in patients with endogenous Cushing's syndrome - a pilot study.

No patient with Cushing's syndrome developed clinical or biochemical signs associated with hypocortisolism despite withholding perioperative glucocorticoids until the morning of the first postoperative day.

• 12 patients with CS (seven with central CS, five with adrenal CS) were recruited
• Patients did not receive any perioperative glucocorticoids until the morning of the first postoperative day
• No clinical or biochemical signs of hypocortisolism were observed in any patient
• Blood samplings were performed preoperatively, immediately after surgery, on the evening of surgery, and on mornings of postoperative days 1 and 3

Morning serum cortisol concentrations on the third postoperative day were significantly lower compared to preoperative measurements in patients with Cushing's syndrome.

• Third postoperative day morning cortisol: 8.5 ± 7.6 µg/dL (235 ± 210 nmol/L)
• Preoperative morning cortisol: 19.9 ± 8.9 µg/dL (549 ± 246 nmol/L)
• p = 0.023
• This decline reflects surgical remission of hypercortisolism

A subset of Cushing's syndrome patients had serum cortisol concentrations below 5.0 µg/dL on postoperative days 1 and 3.

• Serum cortisol <5.0 µg/dL (<138 nmol/L) was detected in 4 of 12 patients (33%) on the morning of postoperative day 1
• Serum cortisol <5.0 µg/dL (<138 nmol/L) was detected in 6 of 12 patients (50%) on the morning of postoperative day 3
• Despite these low cortisol values, no patient developed clinical or biochemical signs associated with hypocortisolism

During postoperative follow-up, cortisol recovery and glucocorticoid discontinuation occurred over several months in Cushing's syndrome patients.

• Serum cortisol concentrations >5.0 µg/dL (>138 nmol/L) were first observed after 129 ± 97 days
• Glucocorticoid replacement was discontinued after 402 ± 243 days
• This reflects the expected prolonged suppression of the hypothalamic-pituitary-adrenal axis following remission of CS

Patients without Cushing's syndrome who underwent pituitary surgery did not require glucocorticoid replacement at any time.

• Six control patients underwent pituitary surgery for reasons other than Cushing's syndrome
• None of the control patients required glucocorticoid replacement at any point perioperatively or during follow-up
• This control group served as a comparison for perioperative cortisol dynamics