{'fraction_non_alphanumeric': 0.015493581230633024, 'fraction_numerical': 0.006640106241699867, 'mean_word_length': 5.4756446991404015, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Management of anaesthesia for phaeochromocytoma

The management of patients undergoing surgical removal of phaeochromocytoma continues to present to the anaesthetist complex problems of cardiovascular control. Much of the pre-operative preparation and anaesthetic management is directed towards the prevention, modification or suppression of the occasionally violent and potentially dangerous alterations in heart rate and rhythm, arterial blood pressure and relative blood volume which may occur during surgery. Since these manifestations are directly related to the raised plasma adrenaline and nor-adrenaline levels, it is not surprising that most recently reported regimes of management have made use of specific aand Dadrenergic blocking agents, both in the pre-operative and operative periods to modify the intensity of the responses. Their effectiveness is beyond doubt. Ross et al. 1 in a series of 30 operations on 27 patients, and Black et al. 2 in a child, have reported the use of phenoxybenzamine and propranolol for this purpose. Crout & Brown3 in a series of 16 operations on 14 patients also recommended pre-treatment with phenoxybenzamine and claimed pre-operative expansion of blood volume, control of arterial pressure, alleviation of symptoms and modification of the cardiovascular responses during subsequent surgery. Cooperman et al. 4 reporting 14 cases, found propranolol effective in abolishing arrhythmias during halothane anaesthesia and this agent has also been used to abolish tachyphylaxis to phentolamine 5. However, suppression of sympatho-adrenal activity by these very potent drugs deprives the cardiovascular system of an important homeostatic mechanism designed to meet fluctuating demands upon it. The sudden transition from an abnormal state of intense and varying sympathetic stimulation during dissection of the tumour, to partial or complete withdrawal of such stimulus when the tumour is removed (table l), creates a situation in which the need for suppression of the abnormal state is suddenly replaced by a need for re-establishment of normal mechanisms of cardiovascular control. For this reason we have attempted to achieve in a number of patients some basal modification of this highly labile state, some element