Cardiac risk reduction in non-cardiac surgery: the role of anaesthesia and monitoring techniques.
ABSTRACT Cardiac complications are the major cause of perioperative morbidity and mortality of patients undergoing non-cardiac surgery. This is related to the frequent presence of underlying coronary artery disease. In the last few decades, attention has focused on preoperative cardiac risk assessment that may help to identify patients at increased cardiac risk for whom cardioprotective medication and, when indicated, coronary revascularization may improve perioperative outcome. On the other hand, less attention was given to the role of anaesthesia and monitoring techniques in the cardiac risk management of high-risk patients undergoing non-cardiac surgery. The aim of this review was to summarize the current evidence from published studies on the effect of the type of anaesthesia and monitoring techniques on perioperative cardiac outcome in non-cardiac surgery.
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ABSTRACT: The direct manipulation of coronary blood flow to induce regional myocardial ischemia has been almost entirely limited to experimental animal models. Thus, the detection of ischemia-induced left ventricular dysfunction in human subjects has been generally limited to observations made under conditions of diagnostic loading or during spontaneous clinical events. Percutaneous coronary angioplasty requires repeated interruptions of coronary blood flow for periods as long as 1 minute. The resulting appearance of or increase in ischemia-produced changes in myocardial function were detected by two-dimensional echocardiography in 18 patients undergoing angioplasty of 22 coronary stenoses. Accordingly, left ventricular contraction was studied during 52 episodes of regional coronary blood flow interruption and reperfusion in the process of inflating and deflating the angioplasty balloon. Before angioplasty, left ventricular wall motion was normal in 14 patients. There was mild anteroapical hypokinesia in two patients, anteroapical akinesia in one and mild inferior hypokinesia in one. Balloon inflations repeatedly produced new or increased wall motion abnormalities in the distribution of the instrumented coronary artery in 19 (86.4%) of the 22 procedures, but did not alter wall motion during angioplasty of one left circumflex artery lesion, one highly collateralized left anterior descending artery stenosis and one left anterior descending stenosis that had already caused severe anteroapical dyssynergy. Hypokinesia, usually rapidly progressing to dyskinesia, began 19 +/- 8 seconds (mean +/- SD) after coronary occlusion. Wall motion began to normalize 17 +/- 8 seconds after reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)Journal of the American College of Cardiology 03/1985; 5(2 Pt 1):193-7. · 14.09 Impact Factor
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ABSTRACT: Because acute segmental wall motion abnormalities (SWMAs) of the left ventricle are highly sensitive and specific indicators of myocardial ischemia, this study compared the incidence and significance of ischemia, as detected by two-dimensional transesophageal echocardiography and surface electrocardiography, during anesthesia and surgery in patients at high risk of myocardial ischemia. During surgery, 24 of the 50 patients studied had new SWMAs, whereas only six had ST segment changes. All patients with ST segment changes also had new SWMAs: in three instances, SWMAs occurred before the ST segment change, and in three instances, they occurred simultaneously. All three patients who had intraoperative myocardial infarctions also had persistent intraoperative SWMAs, whereas only one patient had ST segment changes. Ten healthy patients requiring noncardiovascular surgery were monitored similarly; none of these had SWMAs, ST segment changes, or myocardial infarction. This study demonstrates the superiority of two-dimensional transesophageal echocardiography over electrocardiography for the intraoperative detection of myocardial ischemia. Furthermore, when new SWMAs persist to the conclusion of surgery, myocardial infarction is likely to have occurred.Circulation 12/1985; 72(5):1015-21. · 15.20 Impact Factor
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ABSTRACT: To obtain reliable estimates of the effects of neuraxial blockade with epidural or spinal anaesthesia on postoperative morbidity and mortality. Systematic review of all trials with randomisation to intraoperative neuraxial blockade or not. 141 trials including 9559 patients for which data were available before 1 January 1997. Trials were eligible irrespective of their primary aims, concomitant use of general anaesthesia, publication status, or language. Trials were identified by extensive search methods, and substantial amounts of data were obtained or confirmed by correspondence with trialists. All cause mortality, deep vein thrombosis, pulmonary embolism, myocardial infarction, transfusion requirements, pneumonia, other infections, respiratory depression, and renal failure. Overall mortality was reduced by about a third in patients allocated to neuraxial blockade (103 deaths/4871 patients versus 144/4688 patients, odds ratio=0.70, 95% confidence interval 0.54 to 0.90, P=0. 006). Neuraxial blockade reduced the odds of deep vein thrombosis by 44%, pulmonary embolism by 55%, transfusion requirements by 50%, pneumonia by 39%, and respiratory depression by 59% (all P<0.001). There were also reductions in myocardial infarction and renal failure. Although there was limited power to assess subgroup effects, the proportional reductions in mortality did not clearly differ by surgical group, type of blockade (epidural or spinal), or in those trials in which neuraxial blockade was combined with general anaesthesia compared with trials in which neuraxial blockade was used alone. Neuraxial blockade reduces postoperative mortality and other serious complications. The size of some of these benefits remains uncertain, and further research is required to determine whether these effects are due solely to benefits of neuraxial blockade or partly to avoidance of general anaesthesia. Nevertheless, these findings support more widespread use of neuraxial blockade.BMJ 12/2000; 321(7275):1493. · 14.09 Impact Factor