Abstract: SA-PO266
Resistant Hypertension in Dialysis Patients: Pitfalls of Biochemical Testing
Session Information
- Trainee Case Reports - VI
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Reports
- 1403 Hypertension and CVD: Mechanisms
Authors
- Chamarthi, Gajapathiraju, University of Flroida, Gainesville, Florida, United States
- Lee Loy, Justin, University of Florida Gainesville, Gainesville, Florida, United States
- Ejaz, A. Ahsan, University of Florida Gainesville, Gainesville, Florida, United States
- Mohandas, Rajesh, University of Florida Gainesville, Gainesville, Florida, United States
Introduction
Hypertension is common in patents with End Stage Renal Disease (ESRD). Fluid retention and excess sympathetic activity are thought to be responsible for high blood pressures in majority of these patients. Rarely, pheochromocytomas have been reported in patients with ESRD. Non-specific elevation of catecholamine levels in renal failure, inability to check urinary catecholamine levels and interference from medications can make diagnosis challenging. We present a patient with ESRD with severely elevated catecholamine levels.
Case Description
68-year-old female with ESRD on hemodialysis presented with a BP of 260/80 mm Hg and pulmonary edema. She was started on a Nicardipine infusion and underwent dialysis with aggressive ultrafiltration. She was restarted on her usual antihypertensive medications (Amlodipine 10 mg daily, Clonidine 0.3mg TID, Hydralazine 100mg TID, Labetalol 300mg TID, Losartan 100 mg daily and Prazosin 2mg bid). A work up for secondary causes of hypertension revealed markedly elevated norepinephrine levels of 7332 pg/ml (ref range 80- 520) and plasma normetanephrine at 3.26 nmol/L (ref range 0-0.89). Epinephrine and metanephrine levels were within normal limits. Patient underwent an extensive imaging for occult pheochromocytoma including CT scan of abdomen and pelvis, 123 MIBG scan, Octreotide scan and whole body PET scan, all of which failed to reveal any evidence of a catecholamine secreting tumor.
Discussion
Catecholamine levels are often elevated in patients with ESRD and normal levels in chronic kidney disease or ESRD have not been established. Our patient had levels of norepinephrine that were 14 fold higher than upper limit of the reference range. She was on Mirtazapine, Prazosin and Labetalol, all of which can specifically increase norepinephrine levels. Normal metanephrine levels, absence of tumors on imaging, improvement in blood pressures with ultrafiltration and a downward trend in norepinephrine levels suggested the elevated norepinephrine levels were due to a combination of medications and ESRD. We conclude that one should be cautious in interpreting biochemical tests for pheochromocytoma in patients with kidney disease, particularly those on dialysis. Elevations in metanephrines might be more specific for pheochromocytoma. More studies are necessary to establish cut offs for catecholamine levels in dialysis patients.