Persistent hypoaldosteronism post-adrenalectomy for primary aldosteronism - a role for pre-operative spironolactone?

ABSTRACT

SUMMARY: Primary aldosteronism is one of the most common (affecting up to 10%) yet treatable causes of hypertension in our community, notable due to an associated elevated risk of atrial fibrillation, stroke and myocardial infarction compared to essential hypertension. Guidelines have focussed on improving case detection due to significant underdiagnosis in the community. While our case experienced significant delay in diagnosis, we highlight a state of protracted, persistent post-operative hypoaldosteronism which manifested with severe hyponatraemia and hyperkalaemia, necessitating long-term mineralocorticoid replacement. We discuss whether pre-operative mineralocorticoid receptor antagonists to stimulate aldosterone secretion from the contralateral gland may have prevented this complication. LEARNING POINTS Hypoaldosteronism is an uncommon complication of adrenalectomy for primary aldosteronism, typically manifesting with hyperkalaemia and hyponatraemia. While most cases are transient, it may be persistent, necessitating ongoing mineralocorticoid replacement. Routine electrolyte monitoring is recommended post-adrenalectomy. Risk factors for hypoaldosteronism include age >50 years, duration of hypertension >10 years, pre-existing renal impairment and adrenal adenoma size >2 cm. Mineralocorticoid receptor antagonists may assist in the management of hypokalaemia and hypertension pre-operatively. However, it is unclear whether this reduces the risk of post-operative hypoaldosteronism.