Perioperative Beta Blocker in High Risk Patients Undergoing Major Abdominal Surgery and its Effect on Cardiovascular Mortality and Morbidity

Abstract

Perioperative cardiac complications are an important concern for the millions of individuals who undergo surgery worldwide every year. After surgery, 2% of these patients suffer major cardiac complications. Non-cardiac surgery causes a rise in catecholamine concentrations that results in an increase in heart rate, blood pressure, and free fatty acid concentrations, which in turn increases myocardial oxygen demand. The cardiovascular effects of general anesthesia include changes in the arterial and central venous pressures, cardiac output, and varying heart rhythms. Every operation elicits a stress response. This response is initiated by tissue injury and mediated by neuroendocrine factors, and may induce tachycardia and hypertension. Fluid shifts in the perioperative period add to the surgical stress. This stress increases myocardial oxygen demand A previously stable patient may decompensate postoperatively, leading to significant postoperative morbidity and mortality. A substantial number of all deaths among patients undergoing noncardiac surgery are caused by cardiovascular complications.