Research Overview
Cardiovascular Anesthesia
Association between pulse pressure (difference between systolic and diastolic blood pressure) and perioperative fatal and non fatal ischemic outcome in coronary bypass surgery. The association between hypertension and cardiovascular or cerebrovascular ischemic complications has been attributed to the deleterious effects of diastolic hypertension (essential hypertension); however, current views suggest that such association is more pronounce in individuals having isolated systolic hypertension or increased pulse pressure. Whether pulse pressure hypertension also correlates to ischemic events in the setting of major vascular surgery such as coronary bypass surgery, has not been addressed. In a multicenter, prospective study we demonstrated that a pulse pressure of 80 mmHg or more is a strong predictor of postoperative cardiac, cerebral, and renal ischemic morbidity and mortality. Questions to be answered include: What is the mechanism? What are the effects of different anesthetic techniques on pulse pressure (do they augment or reduce pulse pressure)? Which antihypertensive agent should be used for treating pulse pressure hypertension? Is it a modifiable pre-existing condition? Should we be monitoring pulse pressure routinely perioperatively?
Inflammatory response during cardiac surgery as a marker of ischemic injury following open heart surgery requiring cardiopulmonary bypass. Ischemic complications after cardiac surgery are common and previous efforts have focused on determining predictors of outcome for individual organs to include the heart, the brain, and the kidneys. It appears however that the common pathophysiologic basis for ischemic complications involve humoral as well as cellular inflammatory response during bypass surgery. We have previously shown that platelet activation and possessing a certain genotype adds to the risk of neurologic ischemic outcome following coronary artery bypass graft (Rinder, Mathew, Fontes) Ann Thorac Surg 2001;71:663-666, Anesthesiology 2002;97:1118-22). Ongoing investigation in this area has resulted in additional manuscripts relating cellular activation to postoperative renal dysfunction (Fontes, Rinder Ann Thorac Surg, In Press).
Endotracheal Cardiac Output Monitoring (ECOM). The need for non-invasive monitors of cardiac function is important for many millions of patients who undergo surgery and or hospitalization for serious medical ailments. In order to provide appropriate therapy and cardiovascular support, it often requires use of invasive devices that can be associated with minor and major complications. In the past several years, we have been utilizing a noninvasive device which uses a technology of impedance cardiography to measure cardiac output non-invasively. We have observed very good correlation between thermodilution derived cardiac output and the ECOM system.
