Seminars in cardiothoracic and vascular anesthesia
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Semin Cardiothorac Vasc Anesth · Mar 2006
ReviewIntravenous anesthesia for the patient with left ventricular dysfunction.
Patients with heart failure have a diminished cardiac reserve capacity that may be further compromised by anesthesia. In addition to depression of sympathetic activity, most anaesthetics interfere with cardiovascular performance, either by a direct myocardial depression or by modifying cardiovascular control mechanisms. Etomidate causes the least cardiovascular depression. ⋯ For intravenous anesthesia, propofol is always combined with an opioid. Opioids have relatively few cardiovascular side effects and, in particular, do not cause myocardial depression. Indeed, they are cardioprotective, with antiarrhythmic activity, and induce pharmacologic preconditioning of the myocardium by a mechanism similar to the inhalational anesthetics.
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Semin Cardiothorac Vasc Anesth · Mar 2006
ReviewHow to reliably detect ischemia in the intensive care unit and operating room.
Detection of myocardial ischemia in the perioperative period is important because it allows for intervention that may prevent progression of ischemia to myocardial infarction. Perioperative ischemia is also an important predictor of adverse cardiovascular outcomes. Patients should first be stratified according to their risk of having cardiovascular disease by identifying major, intermediate, and minor predictors of adverse cardiovascular outcome. ⋯ Also, detection of these hemodynamic changes requires insertion of invasive monitoring devices. Transesophageal echocardiography can be used to detect myocardial ischemia by identifying changes in regional wall motion. These transesophageal echocardiography changes occur sooner and more frequently than ECG changes, but require greater knowledge and skill to properly interpret.
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Semin Cardiothorac Vasc Anesth · Mar 2006
Clinical TrialProtecting the heart with cardiac medication in patients with left ventricular dysfunction undergoing major noncardiac vascular surgery.
Patients with left ventricular dysfunction who are undergoing major noncardiac vascular surgery are at increased risk of adverse postoperative events. We sought to evaluate whether perioperative medication use, including angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, statins, and aspirin, was associated with a reduced incidence of postoperative in-hospital mortality in these high-risk patients. The study enrolled 511 patients with left ventricular dysfunction (left ventricular ejection fraction <30%) who were undergoing major noncardiac vascular surgery. ⋯ Sixty-four patients (13%) died. Perioperative use of ACE inhibitors (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.12-0.91), beta-blockers (OR, 0.03; 95% CI, 0.01-0.26), statins (OR, 0.06; 95% CI, 0.01-0.53), and aspirin (OR, 0.13; 95% CI, 0.03-0.55), was significantly associated with a reduced incidence of mortality, after adjusting for cardiac risk factors and DSE results. In conclusion, the present study showed that the perioperative use of ACE inhibitors, beta-blockers, statins, and aspirin is independently associated with a reduced incidence of in-hospital mortality in patients with left ventricular dysfunction who are undergoing major noncardiac vascular surgery.
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All volatile anesthetics have been shown to induce a dose-dependent decrease in myocardial contractility and cardiac loading conditions. These depressant effects decrease myocardial oxygen demand and may, therefore, have a beneficial role on the myocardial oxygen balance during myocardial ischemia. Recently, experimental evidence has clearly demonstrated that in addition to these indirect protective effects, volatile anesthetic agents also have direct protective properties against reversible and irreversible ischemic myocardial damage. ⋯ In the clinical practice, these effects should be associated with improved cardiac function, finally resulting in a better outcome in patients with coronary artery disease. The potential application of these protective properties of volatile anesthetic agents in clinical practice is the subject of ongoing research. This review summarizes the current knowledge on this subject.
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Semin Cardiothorac Vasc Anesth · Mar 2006
ReviewBeta-blockade in the perioperative period: where do we stand after all the trials?
Perioperative myocardial infarction following noncardiac surgery is a complex process with a variety of proposed etiologic factors. Perioperative beta-blockade has been reported to reduce perioperative myocardial infarction and cardiac death, with possible direct effects on longer-term outcome, particularly after vascular surgery. Despite two high-profile studies that have pushed this topic into the mainstream of medicine, the number of patients studied and outcomes observed remains limited, especially for a therapy recommended for widespread adoption in millions of patients globally. ⋯ Adverse effects appear to be limited to the expected primary hemodynamic side effects of bradycardia and hypotension, although a suggestion of increased mortality has been reported in one observational analysis in the lowest-risk group. beta-Blockade may be associated with reduction in length of stay and reduced analgesic requirements, although these effects remain controversial. A single mega-trial being conducted outside of the United States with a target goal of 10,000 patients is ongoing and promises to provide definitive data within the next few years. Ongoing research into various etiologies of perioperative myocardial infarction and other medications with potential efficacy in this setting, including the important antiplatelet agents, must also be considered in developing recommendations for widespread adoption of perioperative beta-blockade.