Phaeochromocytoma crisis (PCC) is an acute catecholamine-induced state of haemodynamic instability which can lead to end-organ dysfunction associated with significant mortality. Catecholamine-induced ileus is a feature of PCC that is rarely described.
We report a case of PCC with ileus in a 46-year-old male with a newly diagnosed 10 cm phaeochromocytoma, triggered by high dose oral dexamethasone. This manifested as inverted Takotsubo cardiomyopathy, type one respiratory failure and acute pulmonary oedema, further complicated by concurrent ileus which responded poorly to conventional measures. After initial intensive care management, there was interval clinical improvement. However, despite escalating doses of oral phenoxybenzamine exceeding 1 mg / kg over six days, paroxysmal diaphoresis and hypertension requiring glyceryl trinitrate persisted. Inadequate phenoxybenzamine absorption was suspected in the context of ileus. IV phentolamine was used with concurrent phenoxybenzamine up-titration, which ultimately resulted in resolution of ileus and improvement of cardiac function and allowed use of oral alpha blockade in the pre-operative period.
In PCC ileus, it is proposed that excess catecholamines cause decrease in intestinal peristalsis, motility and tone via activation of alpha and beta adrenergic receptors in intestinal smooth muscle (1). Reported cases of ileus are often refractory to conventional therapies including decompression with nasogastric and rectal tubes, laxatives and enemas. Alpha blockade can attenuate catecholamine stimulus and is helpful in catecholamine-induced ileus (1). To our knowledge, the challenges in adequate systemic absorption of oral alpha blockers in ileus are not highlighted in the literature. This case demonstrates PCC with ileus resulting in reduced oral absorption of phenoxybenzamine, requiring IV phentolamine for resolution of ileus and cardiac function.