Effect of Time of Day of Dialysis Shift on Serum Biochemical Parameters in Patients on Chronic Hemodialysis

Abstract

It is unknown whether predialysis serum biochemical parameters may differ among chronic hemodialysis patients depending on the shift during which they are dialyzed. We studied 115 patients on chronic hemodialysis in our institution for 3 consecutive months and compared clinical and biochemical parameters based on the shift during which they were dialyzed. Predialysis serum potassium was found to be progressively higher for patients dialyzed on later as compared with earlier dialysis shifts, and phosphate was significantly higher for patients dialyzed during the evening shift as well. Regression analysis suggested that higher of potassium and phosphate levels were related to the time of day these sessions and not to patient age, amount of dialysis given or diet. By contrast, serum albumin, creatinine, sodium, and chloride levels were found to differ depending on dialysis shift, though these differences appeared to be accounted for by patient age. We concluded that the time of day of the beginning of the dialysis shift appears to mildly influence the levels of serum predialysis biochemical parameters which are important in monitoring patients on chronic hemodialysis, in particular potassium and phosphate. Further insight into the mechanism of this observed effect might improve our ability to interpret and treat derangements of these serum biochemical parameters in patients on chronic hemodialysis.