Postoperative anaesthesia care

In an attempt to reduce perioperative cardiac morbidity, intense study and research has been centred, practically exclusively, on the anaesthetic management during the preoperative and intraoperative periods. The postoperative period has been virtually ignored. However, recent data strongly suggest that we should be directing the same intense interest to management of the immediate postoperative period. In 1990 Mangano et al.~ reported on their study of 474 male patients with either known coronary artery disease (CAD) (243) or at high risk for it (231) undergoing elective non-cardiac surgery. In this study 41% of patients had postoperative myocardial ischaemia compared with only 20% preoperatively and 25% intraoperatively. Of more importance, these ischaemic episodes were silent in 97% of patients. Furthermore, they found a threefold increase in the likelihood of having an adverse cardiac outcome associated with the occurrence of postoperative ischaemia, similar to that shown with patients having cardiac surgery. These findings are not so surprising when we remember that the postoperative period is associated with major changes in adrenergic activity, plasma catecholamine concentrations, body temperature, pulmonary function, fluid balance and perception of pain. 2 Fluctuations of these factors can lead to an imbalance between the relationship of myocardial oxygen supply and demand, thus promoting the likelihood of the development of myocardial ischaemia. It may be that by blunting the activation of the sympathetic nervous system in the postoperative period, thus preventing the resultant endocrine, metabolic and haemodynamic changes, this imbalance might be shifted away from ischaemia. Since the introduction of regional anaesthesia techniques, it has been suggested that their use may reduce postoperative morbidity and even mortality in high risk surgical patients. Whether or not this is true has been the subject of much debate, research and controversy ! It is well established that patients undergoing major