Pheochromocytoma emergencies

Patients with pheochromocytoma may have had undiagnosed symptoms for some time, but stress, abdominal palpation, parturition, general anaesthetic, or contrast media used in imaging can cause acute hypertensive crises.

Management

Take to ICU

Principle is combined α- and β-adrenoreceptor blockade, but α must be started first, as unopposed β-blockade can worsen hypertension.

1. Start with short-acting, IV α-blocker, e.g. phentolamine 2–5mg IV.
   • Repeat to maintain safe BP.
2. When BP controlled, give long-acting α-blocker, e.g. phenoxybenzamine 10mg/24h oral (increase by 10mg/d as needed, up to 30mg/12h oral)
   • Alternative is α1-selective blockers, e.g. doxazosin, are preferred in some centers, particularly if surgery is not an option, e.g. metastatic tumor.
3. A β1-blocker may also be given at this stage to control any tachycardia or myocardial ischaemia/dysrhythmias.
4. Surgery is usually done electively after 4–6wks to allow full α-blockade and volume expansion. When admitted for surgery the phenoxybenzamine dose is increased until significant postural hypotension occurs.