Dialysis symptoms and stabilization in long-term dialysis. Practical application of the CUSUM plot.

Six symptoms that occur during hemodialysis were investigated to determine their frequency and to define when a patient's condition becomes "stable." Three symptoms--nausea, hypotension, and muscle cramps--stabilized after 13 dialysis treatments (approximately one month). Two symptoms, hypertension and vomiting, stabilized after 17 and 20 dialyses, respectively. Headache showed little variation per dialysis. The changes in the frequency of these symptoms were detected through the use of the cumulative sum technique (CUSUM). This technique was found to be much more discriminating than the original data. Hemodialysis patients should not be considered "stable" for investigation of changes in techniques or therapy until after 1 1/2 months of dialysis. Even then, symptoms will be found during each dialysis.