Cognitive Problems After Heart Surgery

New research shows evidence of a link between cardiopulmonary bypass surgery and impaired memory and attention. The study, for the first time, shows that cognitive problems persist beyond the first couple of weeks after surgery.

Claims that people who undergo cardiopulmonary bypass surgery suffer from cognitive problems have been made for many years. Researchers at the University of North Carolina at Wilmington used statistical methods to study this relationship.

Cardiopulmonary bypass surgery is performed in the United States on more than 500,000 people each year. The procedure is like other major surgeries in that it exposes a patient’s brain to a variety of abnormal physiological conditions including inflammation, lack of oxygen, elevated blood sugar, lowered body temperature, microscopic blood clots, and exposure to amnesia-causing drugs.

The study, which reviewed data on close to 90 individuals, found the recent bypass patients and other participants from a senior wellness center showed significantly different neuropsychological performance. Researchers explain the patient’s lower scores before the surgery as likely due to anxiety or declining health. These findings, say researchers, indicate the impaired memory could be from the disease and not from the surgery.

Researchers feel these cognitive declines in bypass patients may not be unique to them, but could be associated with any major surgery. They suggest an expanded research program is needed to shed some light on this medical mystery.

SOURCE: Neuropsychology, 2002;16:411-421