Higher Symptom Frequency and Severity After the Long Interdialytic Interval in Patients on Maintenance Intermittent Hemodialysis

Abstract

Introduction: Patients on intermittent hemodialysis (HD) have a high symptom burden. Though studies report higher hospitalizations and mortality after the long interdialytic interval, whether symptoms vary based on the interdialytic interval is unclear.

Methods: This is a prospective observational study of patients over the age of 18 who received in-center HD. Patients were surveyed on the presence and severity of 20 different symptoms at the end of 12 HD sessions. Wilcoxon signed-rank test was used for comparison of severity for each symptom by the interval. Multivariable generalized estimating equation with Poisson regression by repeated measure method was used to determine the association of interdialytic interval and symptom frequency while adjusting for potential confounders.

Results: From the 97 patients enrolled, the most common symptoms were fatigue (60.8%), cramping (58.8%), and dry skin (52.6%). There was large variability in the frequency of symptoms, ranging 0% to 8% of treatments. The most severe symptoms were bone pain (mean severity score 2.2±0.9) and diarrhea (mean severity score 2.2±0.7). Eight of the 20 symptoms were significantly more common after the long interdialytic interval including fatigue (22% vs. 15%, P < 0.001) and cramping (21% vs. 16%, P = 0.003). The long interval had a 37% higher incidence rate for symptoms compared to the short interval even after adjustment. Results were similar across genders.

Conclusion: Symptoms are more common after the long interdialytic interval. Clinical assessment and research evaluating patient symptoms need to be cognizant of when patients are surveyed or include the length of interdialytic interval as a confounding variable.

Keywords: hemodialysis; interdialytic interval; symptoms.

Figure 1

Percent of patients that experienced a symptom on any of the 12 surveys during the study period. RLS, restless leg syndrome; SOB, shortness of breath.

Figure 2

Percent of surveys where the patient reported that symptom. Frequency is calculated as number of surveys where patient reported the symptom divided by 12, the total number of surveys completed. RLS, restless leg syndrome; SOB, shortness of breath.

Figure 3

Boxplot of mean severity of each symptoms per patient across all surveys only in patients who reported symptoms. RLS, restless leg syndrome; SOB, shortness of breath.

Figure 4

Percent of long and short treatments where patient reported symptoms. This percent was calculated as number of surveys after the long interdialytic interval or short interval where symptom was reported divided by 4 for the long interdialytic interval and 8 for the short interdialytic interval. RLS, restless leg syndrome; SOB, shortness of breath.