Neuropsychological dysfunction following elective cardiac operation. II. A six-month reassessment

Three neuropsychological tests were administered to 245 men and women, ages 25 to 69 years, before and 6 months after coronary bypass and cardiac valve operations to provide current information regarding the incidence of long-term postoperative decrements in neuropsychological function and the factors associated with them. Biographical, psychological and medical-surgical data were studied together with changes on the Trail Making Test from the Halstead-Reitan Battery, and Visual Reproduction (VR) and Logical Memory tests, both from the Wechsler Memory Scale (WMS). Although 28% of this group showed a deterioration in one or more test scores at a 9 day postoperative examination as compared to their preoperative scores, over 80% of these patients had returned to normal range by 6 months. Similarly, the majority of the 19% of patients showing a significant decrease in one or more of four scores at 6 months had incurred their performance decrements subsequent to the 9 day examination. Hence it seems inappropriate to attribute these latter dysfunctions to the surgical epidose per se, as others have reported. Only 5% of patients showed consistent postoperative test score deterioration both at 9 days and 6 months. Decrements of function at 6 months appear to be associated with total estimated blood loss greater than 3,000 ml and administration of propranolol during the operation plus several postoperative factors including higher levels of fatigue, depression, and worries related to the operation and the recovery process. These findings underscore the need for clinicians and investigators studying neuropsychological dysfunction following cardiac operations to take concurrent emotional and physical states into account, and to make repeated measures well separated in time, before interpreting the presence or absence of residual neuropsychological problems.