A Single, Post-ACTH Cortisol Measurement to Screen for Adrenal Insufficiency in the Hospitalized Patient.

BACKGROUND: Cosyntropin stimulation testing (CST) is used to screen patients for adrenal insufficiency (AI). Traditionally, CST includes baseline cortisol concentration, the administration of cosyntropin, and cortisol concentration at 30 and 60 minutes poststimulation. There is debate surrounding the utility of testing and cut-off points for concentrations at each time point. OBJECTIVE: To determine if a single cortisol measurement at 30 or 60 minutes could replace the traditional approach. DESIGN: looked retrospectively at inpatients who underwent standard, high-dose CST (n = 702) and evaluated the number of patients who would screen positive for AI by using a single time point (30 or 60 minutes) compared with the traditional CST. SETTING: A tertiary-care, academic medical center. PATIENTS: Hospital inpatients present between January 2012 and September 2013. RESULTS: Of tests, 84.3% were normal, which was defined as at least 1 cortisol concentration of 18 mcg/dL or higher at any time after stimulation. The average 60-minute concentration was higher than the average 30-minute concentration (P < .001). A single 60-minute concentration is 100% concordant with the full CST in the intensive care unit (ICU) subgroup and 99.6% concordant in floor patients. A single 30-minute concentration is significantly less concordant, 91.9% and 86.9%, in the ICU and floor subgroups, respectively. CONCLUSIONS: Overall, a single 60-minute cortisol concentration to screen for AI was 99.7% concordant with the traditional CST, and the positive percent agreement was 98%. Fewer false-positive screens would occur with a single 60-minute cortisol concentration compared with a single 30-minute concentration (P < .001). High-dose CST screening may safely be interpreted with single 60-minute poststimulation cortisol serum concentrations.

Screening for Cushing's syndrome in an era of epidemic obesity.

Cushing's syndrome is a rare cause of several very common conditions, including obesity, diabetes mellitus and hypertension. Screening tests for Cushing's syndrome have generally high sensitivity and specificity, but if applied to unselected obese patients they have unacceptably high false positive rates. Only obese patients with more specific signs of the disorder should be screened for Cushing's syndrome.

Preparation of patients with thyroid cancer for 131I scintigraphy or therapy by 1-3 weeks of thyroxine discontinuation.

UNLABELLED: To assess whether the patient preparation procedure for (131)I scintigraphy could be streamlined, we evaluated the time course of thyroid-stimulating hormone (TSH) elevation after total thyroidectomy or after discontinuation of thyroxine (T(4)) in patients with thyroid cancer. METHODS: The clinical records of 284 patients with well-differentiated thyroid cancer were reviewed. All patients had undergone total thyroidectomy. Two groups of patients were evaluated. The immediate postoperative group consisted of 176 patients who were not given thyroid hormone replacement after surgery because of planned postoperative (131)I therapy. The surveillance group consisted of 108 patients in whom T(4) replacement was stopped (without triiodothyronine [T(3)] replacement) in preparation for surveillance whole-body (131)I scintigraphy. We recorded the first TSH measurement and number of days after surgery or without thyroid hormone for each patient. RESULTS: In the immediate postoperative group, TSH levels obtained 6-65 d (median, 17 d) after surgery ranged from 18.2 to 194.8 micro IU/mL (median, 46.6 micro IU/mL). The TSH values exceeded 30 micro IU/mL in 89% of patients evaluated at 1-2 wk, in 88% of those evaluated at 2-3 wk, and in 90% of those evaluated after 3 wk. In patients discontinuing T(4) (without T(3) replacement), TSH levels obtained from 6 to 35 d (median, 20 d) later ranged from 23.4 to 214.5 micro IU/mL (median, 61.1 micro IU/mL). The TSH levels exceeded 30 micro IU/mL in 100% of patients evaluated at 1-2 wk, in 89% of those evaluated at 2-3 wk, and in 96% of those evaluated after 3 wk. CONCLUSION: In most patients with thyroid cancer being prepared for (131)I imaging or therapy, a TSH level exceeding 30 micro IU/mL can be achieved by withdrawal of thyroid hormone therapy for 1-3 wk.