Abstract and Introduction
Abstract
We report on a case of a 50-year-old female patient with primary hyperaldosteronism, in whom adrenal venous sampling was required to differentiate between unilateral and bilateral disease. Because of a history of severe allergy to iodinated contrast media, premedication with glucocorticoids was indicated. Exogenous glucocorticoids, however, can affect measurements of serum cortisol. To avoid this potential confounding effects on the cortisol assay, we decided to use dexamethasone instead of prednisolone or hydrocortisone. A high-dose adrenocorticotropin (ACTH) stimulation test with the simultaneous use of dexamethasone revealed an adequate adrenal cortisol response. ACTH-stimulated adrenal venous sampling showed reliable results, which provided a solid basis for further clinical decision-making.
Introduction
Primary hyperaldosteronism (PA) is defined as autonomous overproduction of aldosterone from the adrenal gland(s). PA results in excessive water and sodium retention, kaliuresis, and inflammation-induced fibrosis in target organs such as the heart and kidney. This may lead to therapy-resistant hypertension and hypokalemia and is associated with an additionally increased risk of end-organ damage leading to cardiovascular and renal complications.[1–10] Early diagnosis and appropriate treatment is essential to prevent these deleterious outcomes.[1,3,5,7,10–16] PA is commonly caused by either an aldosterone-producing adenoma of the adrenal gland or idiopathic bilateral aldosterone hypersecretion. Other less frequent causes include unilateral hyperplasia, bilateral adenomas, and monogenetic variants. The distinction between bilateral and unilateral forms of PA is required for the selection of the most appropriate treatment. Imaging of the adrenal glands with computed tomography (CT) or magnetic resonance imaging is recommended to help delineate the subtype. The Endocrine Society Clinical Practice guidelines recommends adrenal vein sampling (AVS) as the preferred method in determining the etiology of hyperaldosteronism.[17] Unilateral disease is associated with a marked (4-fold greater than contralateral adrenal) increase in plasma aldosterone concentration (PAC) to plasma cortisol concentration (PCC) ratio on the affected side. In patients with bilateral hyperplasia there is little difference (less than 3-fold difference in PAC/PCC ratio without contralateral suppression) between the 2 sides. Correct and reliable PCC measurements are therefore paramount for a correct interpretation of AVS (see Table 1).
During the AVS procedure, intravenous iodinated contrast media (ICM) is used to confirm proper placement of the catheter. The use of ICM carries a risk of causing severe allergic reactions. Normally, premedication including glucocorticoids and antihistaminic agents are used to prevent potentially fatal reactions such as a compromised airway or anaphylactic shock.[18] However, use of a synthetic glucocorticoid could potentially interfere with the cortisol assay and may blunt the adrenocorticotropic hormone (ACTH)-driven release of adrenal hormones.[19] This would influence all AVS parameters that rely on PCC (selectivity index, lateralization index, and contralateral suppression index) (Table 1) and thereby negatively affect the reliability of AVS interpretation. Consequently, this premedication could lead to false AVS results and therefore inappropriate treatment in these patients with PA.
We here describe a case of a patient with PA and severe allergy to ICM. She underwent ACTH-stimulated AVS, with the concomitant use of dexamethasone to prevent a severe allergic reaction to the ICM. The AVS revealed accurate and reliable results.
J Endo Soc. 2021;5(10) © 2021 Endocrine Society
