Case of the Month #20 - hypertension

Published 01/02/2022

Given a suspected diagnosis of phaeochromocytoma, what is the appropriate immediate management in this case?

  • Intravenous anti-hypertensives with continuous haemodynamic monitoring (often necessitates central venous access).
  • Ideally use an intravenous α-antagonist – such as phentoalmine (however often limited availability)
  • Aim to reduce MAP by 20-25% over several hours1. Too rapid reduction in MAP risks multi-organ ischaemia caused by hypo-perfusion secondary to failure of autoregulation3.
  • Magnesium sulphate can be a useful adjunct to anti-hypertensive therapy. Magnesium inhibits adrenal catecholamine release and reduces α-adrenergic receptor sensitivity to catecholamines4. It has additional beneficial effects of arteriolar vasodilation.
  • Despite the pulmonary oedema in this case, intravenous fluid resuscitation is often required on commencement of anti-hypertensive therapy. Patients often have chronic dehydration due to chronic RAAS activation by circulating catacheolamies4.

An adrenal mass is identified on the renal ultrasound and subsequent abdominal CT scan. Plasma metanephrines are reported as follows:
– Plasma normetadrenaline: 20900pmol/L (<2500)
– Plasma metadreanline 16200pmol/L (<900)

The diagnosis of phaeochromocytoma is confirmed.