Despite major advances in cardiopulmonary bypass technology, surgical techniques, and anesthesia management, central nervous system complications remain a common problem after cardiopulmonary bypass. There are several potential causes of brain damage during open-heart surgery, including prolonged or severe arterial hypotension, as well as emboli emanating from the cardiopulmonary bypass circuit or the operative field(Benedict RH, 1994, Newman 1995). In the coronary artery bypass population, advanced age (* or = 75 years) is associated with an 8.9% neurologic deficit rate. Mortality is increased ninefold in the elderly patient with a neurologic deficit.
Cerebral complications may represent the leading cause of morbidity after cardiac operations (Mills, 1995, Kuroda Y, 1993). For patients, caregivers and for funding of health-care systems, cerebral complications and cognitive dysfunction results in the cardiac patient losing ability to perform daily activities independently. The National Heart and Lung Institute in London reports that the incidence of cognitive defects is as high as 60% at 8 days postoperative with reduction to 25% to 30% incidence at 8 weeks and 12 months (Mills, 1995). A study in Germany showed that cardiac patients who have undergone coronary bypass graft (CABG) experienced deficits in orientation, word fluency, naming, arithmetic, memory, and visuoconstructive tasks.
Cognitive deficits caused by attention and short-tem memory problems impact on patients achievement in their rehabilitation programs due to the emphasis on patient education. Many times, learning is significantly impaired and in result, and affects the patients ability to integrate the information into their daily activities. As a result, it is believed that simple cognitive assessment tools may be helpful in identifying with cognitive deficits and may contribute to improve rehabilitation management aiming at better outcomes and better living lifestyles for patients.