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Incidence of myocardial ischemia during carotid endarterectomy
Insights
Patients undergoing carotid endarterectomy require careful monitoring for myocardial ischemia. Prophylactic nitroglycerin is crucial for those with severe angina to prevent intraoperative cardiac events.
Area of Science:
- Cardiovascular Anesthesiology
- Surgical Patient Monitoring
Background:
- Patients undergoing carotid endarterectomy frequently have coexisting coronary artery disease.
- Intraoperative myocardial ischemia can lead to serious complications like arrhythmia, left ventricular dysfunction, and myocardial infarction.
Purpose of the Study:
- To evaluate anesthetic strategies for preventing intraoperative myocardial ischemia in patients undergoing carotid endarterectomy.
- To determine the efficacy of prophylactic intravenous nitroglycerin in high-risk patients.
Main Methods:
- Anesthesia using fentanyl, flunitrazepam, pancuronium, nitrous oxide, and volatile anesthetics was employed.
- Continuous intravenous nitroglycerin at 0.7 microgram/kg/min was administered to patients with disabling angina pectoris.
Main Results:
- The standard anesthetic regimen reduced cardiovascular stimulation and myocardial ischemia incidence in patients with mild angina.
- However, patients with disabling angina still experienced a high incidence of ischemic episodes.
Conclusions:
- While standard anesthesia is beneficial for mild angina, it is insufficient for patients with disabling angina pectoris.
- Prophylactic intravenous nitroglycerin optimizes myocardial oxygenation and significantly minimizes the risk of intraoperative myocardial ischemia in high-risk patients.
Abstract:
Since patients undergoing carotid endarterectomy often suffer from coronary artery disease, the detection, adequate treatment and prevention of intra and postoperative myocardial ischemia are a major concern. Effectively, the deleterious effects of intraoperative ischemic episodes have been largely documented. They may lead to arrhythmia, left ventricular dysfunction lasting several hours or myocardial infarction. Anesthesia induced by fentanyl, flunitrazepam and pancuronium and maintained with N20 and volatile anesthetics when warranted, has the advantage of preventing cardiovascular stimulation during endotracheal intubation and surgery, and of significantly decreasing the incidence of intraoperative myocardial ischemia in patients suffering from mild angina pectoris. However, with this approach, the incidence of intraoperative ischemic episodes remains high in patients suffering from disabling angina pectoris. In such cases, prophylactic i.v. nitroglycerin, administered continuously at the dose of 0.7 microgram/kg-1/min-1, optimizes myocardial oxygenation during surgery and minimizes the risk of intraoperative myocardial ischemia.