Anesthetic management in coronary artery bypass grafting

Coronary artery bypass grafting (CABG), which is increasingly being performed worldwide, has become a common surgical procedure in recent years. Advancements in surgical, anesthetic, and percutaneous interventional techniques may have led to high risk patients being referred for CABG. OPCAB has recently been developed on an extensive scale; however, lifting, twitching, and compressing the heart to expose the posterior and lateral vessels may result in severe impairment of systemic venous return to eventuate profound hypotension. To avoid circulatory instability, a circulatory support system combined with a centrifugal pump would serve as a useful alternative for the conventional application of CABG in multiplevessel diseases. Patients with risk factors such as multivessel disease, cerebrovascular disease, chronic renal failure on hemodialysis, atheromatous and calcified ascending aorta, old age, hypertension, and ischemic heart disease were frequently encountered. The aim of anesthetic management is to preserve the myocardium and cardiac function and prevent both hypertension and hypotension during surgery. A reduction in oxygen consumption can be achieved through a decrease in the heart rate and contractility. Control of the myocardial oxygen balance is difficult to achieve using a single agent. As no ideal single agent is available as yet, we used a combination of agents to achieve the desired effect. Monitoring includes multilead ECG, pulse oximetry, urine output, core temperature, and arterial and central venous catheters. A pulmonary artery catheter is an invasive technique, in which questions have been raised regarding its risk/benefit ratio. TEE is a minimally invasive, safe, direct, and precise way for direct monitoring that provides real-time images on both the volume status and segmental myocardial contractility without interfering with the surgical field. The INVOS cerebral oximeter system affords noninvasive and continuous monitoring of regional brain blood oxygen saturation. Aggressive preoperative assessments offer reliable means for strategic planning and surgical intervention. The most important concept in anesthetic management is that special attention must be exercised to protect the heart from ischemia, since the heart then displays attenuated function and does not tolerate the disease well.