Abstract
Although the preoperative use of alpha-receptor antagonist drugs is generally accepted for patients with phaeo-chromocytoma, evidence on the most appropriate treatment and its timing is scarce.
In this retrospective study, the effectiveness of the preoperative preparation of fourteen patients who required surgical excision of a phaeochromocytoma was examined in the light of their operative stability. A simple score was developed of blood pressure stability by scoring the need for additional antihypertensive agents intraoperatively before, and blood pressure support after, tumour removal. A higher score indicated greater instability.
Twelve patients received phenoxybenzamine and their stability was superior to the two patients treated with labetalol and with prazosin. There was no correlation between the duration of treatment with phenoxybenzamine and the operative stability (r=0.18 P=0.55 Spearman). The five patients who were treated with phenoxybenzamine for longer than 10 days did not have better perioperative blood pressure stability than the five patients who had treatment for less than a week.
Predictive factors for intra-operative blood pressure stability were also sought. The degree of postural hypotension after treatment with phenoxybenzamine did not predict operative stability (r=-0.31, P=0.33 Spearman). However, the peak total catecholamine level found during surgery correlated quite well with more operative instability (r=0.65, P=0.031, Spearman), suggesting that patients with phaeochromocytomas with high production of catecholamines are more likely to show cardiovascular instability.