Endocrine Society GUIDELINES Bundle (free trial)

Primary Aldosteronism

Endocrine Society GUIDELINES Apps brought to you free of charge courtesy of Guideline Central. All of these titles are available for purchase on our website, GuidelineCentral.com. Enjoy!

Issue link: https://eguideline.guidelinecentral.com/i/1140172

Contents of this Issue

Navigation

Page 9 of 13

Diagnosis 10 Table 6. PA Confirmatory Tests Test and Procedure Interpretation Oral sodium loading test • Patients should increase their sodium intake to>200 mmol (~6 g )/d for 3 d, verified by 24-h urine sodium content. • Patients should receive adequate slow-release potassium chloride supplementation to maintain plasma potassium in the normal range. • Urinary aldosterone is measured in the 24-h urine collection from the morning of day 3 to the morning of day 4. • PA is unlikely if urinary aldosterone is <10 µg/ 24 h (28 nmol/d) in the absence of renal disease where PA may coexist with lower measured urinary aldosterone levels. • Elevated urinary aldosterone excretion (>12 µg/24 h [>33 nmol/d] at the Mayo Clinic; >14 µg/24 h [39 nmol/d] at the Cleveland Clinic) makes PA highly likely. SIT Patients stay in the recumbent position for at least 1 h before and during the infusion of 2 L of 0.9% saline IV over 4 h, starting at 8–9:30 AM. Blood samples for renin, aldosterone, cortisol, and plasma potassium are drawn at time zero and after 4 h, with BP and heart rate monitored throughout the test. In a modified approach, which appears (in preliminary studies) to have much higher sensitivity for diagnosing PA, patients remain in a seated position for ≥30 min and during the infusion. Postinfusion plasma aldosterone levels <5 ng/dL (140 pmol/L) make the diagnosis of PA unlikely, whereas levels >10 ng/dL (280 nmol/L) are a sign of very probable PA. Values between 5 and 10 ng/dL are indeterminate, although a cutoff of 6.8 ng/ dL (190 pmol/L) has been found to offer the best trade-off between sensitivity and specificity. For the seated SIT, a postinfusion plasma aldosterone of >6 ng/dL (170 pmol/L) confirms PA, provided plasma cortisol concentration is lower than the value obtained basally (to exclude a confounding ACTH effect). FST Patients receive 0.1 mg oral fludrocortisone every 6 h for 4 d, together with slow-release KCl supplements (every 6 h at doses sufficient to keep plasma K+, measured four times a day, close to 4.0 mmol/L), slow- release NaCl supplements (30 mmol three times daily with meals) and sufficient dietary salt to maintain a urinary sodium excretion rate of at least 3 mmol/kg body weight. On day 4, plasma aldosterone and PRA are measured at 10 AM with the patient in the seated posture, and plasma cortisol is measured at 7 and 10 AM. Upright plasma aldosterone >6 ng/dL (170 nmol/L) on day 4 at 10 AM confirms PA, provided PRA is <1 ng/mL/h and plasma cortisol concentration is lower than the value obtained at 7 AM (to exclude a confounding ACTH effect).

Articles in this issue

Archives of this issue

view archives of Endocrine Society GUIDELINES Bundle (free trial) - Primary Aldosteronism