7094 Post Unilateral Adrenalectomy Hyporeninemic Hypoaldosteronism: Requiring Long Term Fludrocortisone In Managing Hyperkalemia And Renal Dysfunction

Abstract Disclosure: R. Rani: None. K. Bidani: None. R. Roy: None. Adrenalectomy, seen as a potentially curative measure for unilateral aldosterone-producing adenoma (APA), targets both biochemical and clinical resolution. However, postoperative challenges may arise, including acute renal failure and hyperkalemia, due to inadequate aldosterone secretion, a consequence of prolonged suppression of the renin-angiotensin-aldosterone system (RAAS) on the contralateral side. Our case underscores the postoperative challenge of isolated aldosterone deficiency leading to renal function deterioration and hyperkalemia, necessitating fludrocortisone therapy. We are presenting case of 71-year-old male with a history of uncontrolled hypertension for over 30 years with hypokalemia (taking KCL 20mEq daily). Initial laboratory findings revealed elevated aldosterone levels 79ng/dL and an aldosterone-to-renin ratio (ARR)> 20, K- 3.2mmol/L, creatinine 1.32mg/dl, Na-145 mmol/L with normal cortisol and plasma metanephrines levels. CT abdomen disclosed a 21 x 18 mm right adrenal adenoma, with subsequent confirmation of lateralization through Adrenal vein sampling. The patient underwent right adrenalectomy. Two weeks post-surgery, he presented to the emergency department with symptoms of fatigue and weakness. Laboratory results indicated hyperkalemia (K- 6.5 mmol/L) and elevated creatinine (3.52mg/dl) with undetectable aldosterone and renin levels. Urinalysis and CT abdomen ruled out other causes of acute renal injury. Initial management included intravenous fluids and Potassium supplementation. However, due to persistent hypokalemia, the patient was initiated on fludrocortisone (0.1 mcg daily). Subsequent follow-up demonstrated improvement in renal function and potassium levels, however, his aldosterone and renin levels remain undetectable. Hyperkalemia incidence post-adrenalectomy in primary aldosteronism (PA) ranges from 6.3% to 29.1%. Notably, older age and preexisting impaired renal function, particularly in cases with prolonged hypertension are identified as potential risk factors for postoperative hyperkalemia and renal failure. Understanding the potential for a further decline in the glomerular filtration rate (GFR) post-surgery becomes crucial. This decline might manifest as a transient or permanent issue, necessitating prolonged fludrocortisone treatment. This case highlights the importance of tailored preoperative assessment and postoperative management to mitigate complications in high-risk populations. Presentation: 6/1/2024