DURHAM, N.C. -- While physicians have long noticed and written off the fact that many patients develop fever shortly after coronary bypass surgery, a new Duke University Medical Center study shows that these fevers are associated with measurable cognitive decline six weeks following surgery.
Specifically, the researchers found a relationship between the maximum postoperative temperature experienced by the patient during the first 24 hours in the intensive care unit and significant cognitive decline, as measured by a standard battery of cognitive and psychological tests administered before and after surgery. Thirty-nine percent of the patients in their study were found to have cognitive deficits six weeks after bypass surgery.
Such elevated temperatures, a condition known as hyperthermia, are common after bypass surgery and have traditionally been seen more as a nuisance than a pressing medical issue, said the Duke researchers. For that reason, early post-operative hyperthermia has not received serious scientific study, they said.
The study was published today (Feb. 1, 2002) in the journal Stroke. The research was supported by grants from the National Institutes of Health. "This is the first study to look at early post-operative hyperthermia, and it shows a clear association between this hyperthermia and cognitive decline," said Dr. Hilary Grocott, associate professor of anesthesiology and lead investigator of the Duke study.
"While this study does not answer the question of whether the cognitive decline develops as a result of the hyperthermia, or whether the cognitive decline and the hyperthermia are caused by the same underlying process, the association is definitely there," he continued. "Clearly, this is a common phenomenon, and one in which we could potentially intervene to improve the cerebral outcome of heart surgery patients."