Canadian Journal of Anesthesia/Journal canadien d anesthésie

Sebel, Peter S.

doi: 10.1007/bf03022271pmid: 9196846

Moudgil, Girish C.

doi: 10.1007/bf03022267pmid: 9196842

Eltringham, Roger

doi: 10.1007/bf03022272pmid: 9196847

Park, G. R.

doi: 10.1007/bf03022264pmid: 9196839

Young, J. D.

doi: 10.1007/bf03022262pmid: 9196837

Foëx, Pierre; Howell, S. J.

doi: 10.1007/bf03022266pmid: 9196841

ConclusionsThe effects of anaesthesia on the compromised heart are complex. They depend exquisitely upon the type of any ischaemic threat, the level of autonomic nervous system activity, and the quality of the endothelium. In the face of acute coronary occlusion, most anaesthetic agents minimize the extent of ischaemia and limit infarct size. In the face of critical or supracritical coronary stenosis, anaesthetic agents which decrease pressure cause selectively exaggerated depression of compromised myocardium. The possibility of exaggerated myocardial depression also exists when agents cause coronary vasodilatation. However, inhalational anaesthetics appear to protect the stunned myocardium. The overall effect of anaesthetic agents on the myocardium will be the result of the balance struck between several complex effects. It is probably because of the complexity of the regulation of the coronary circulation in patients with ischaemic heart disease and the varied effects of anaesthetic agents on the compromised heart that outcome appears to be little influenced by the choice of the anaesthetic agent. The quality of the control of the circulation (blood pressure, heart rate) throughout the perioperative period is likely to play a more important role that the choice of the anaesthetic agent.

Mutch, W. A. C.

doi: 10.1007/bf03022268pmid: 9196843

ConclusionsAnaesthesia for carotid artery surgery is exacting and good results demand a strong team approach. I believe that the recent multicentre trials have given both surgeon and anaesthetist a touchstone with which they can compare their results. For instance, if your centre’s results are as good or better than the NASCET criteria (mortality of 0.6% and a stroke rate of 2.1%) then your team is performing at an acceptable level. If not, improvements in technique are desirable. Better results at one or more centres may point the way to optimal anaesthetic and surgical management. Regardless, the NASCET, ECST and ACAS studies should cause us to rethink our management of these cases to improve patient outcome. This is especially important because there has already been a dramatic increase in the frequency of this procedure. These studies should prompt those of us involved in the management of these difficult cases to conduct well conceived clinical trials to answer some of the controversies raised above. Only then will the risks of anaesthesia and surgery for this procedure be reduced to an absolute minimum based on sound scientific judgement.

Doak, Greg J.

doi: 10.1007/bf03022270pmid: 9196845

ConclusionsIn the majority of cases, patients should continue their usual medications preoperatively. Exceptions to this have been alluded to. Of greater importance is the recognition of potential adverse interactions with anaesthesia and the modification of the anaesthetic technique to reflect this. When it is necessary to withhold a drug preoperatively, knowledge of the T1/2β and the behaviour of any metabolites is required to ensure the expected decline in drug activity. Whenever drug levels are allowed to decrease preoperatively, a resurgence of symptoms of the underlying pathology must be anticipated. Communication with the prescribing physician and surgeon may be appropriate.