Cognitive status in hemodialysis as a function of fluid adherence.

Previous work has shown that dialysis improves cognitive functioning in hemodialysis patients, perhaps due to improvements in anemia among these patients. Such improvements in cognitive performance may lead to better levels of self-care and adherence with treatment. This study examined the relationship between fluid adherence and cognitive functioning in patients receiving hemodialysis. One hundred forty-seven patients were assessed with a brief screening instrument, the Cognistat, to determine their current level of functioning during the first hour of hemodialysis. Fluid nonadherence was operationalized as interdialytic weight gain above 1 kg/day. Rates of impairment on the Cognistat subscale ranged from 2.7% (orientation) to 54% (memory) in this sample. Roughly 68% of the sample was nonadherent during the course of treatment. Results found no differences in mean levels of cognitive performance between those who were adherent and those who were not and only modest relationships of measures of anemia to certain aspects of cognitive performance. For the hemodialysis patient to benefit from self-care education, the patient must be able to understand, remember, reason, and use cognitive processes to modify behavior. These results suggest that more in-depth assessment of cognitive performance may be needed. In addition, this assessment may need to be conducted on a day when treatment is not received.