MO124: Intradialytic Symptomatology is Largely Patient-Specific in both Haemodialysis and Haemodiafiltration: A Randomized Cross-Over Trial between Four Intermittent Dialysis Modalities

Abstract

Abstract BACKGROUND AND AIMS Standard haemodialysis is associated with a considerable burden of intradialytic symptoms. Although haemodialysis with cool dialysate is associated with less intradialytic discomfort in general, the incidence of cold sensations increases significantly. Whether treatment with online post-dilution high-volume haemodiafiltration [target convection volume (CV) ≥23 L/session] reduces adverse intradialytic symptoms and provokes cold sensations is unknown. METHOD We performed a randomized controlled cross-over trial in 40 prevalent dialysis patients, who were subjected to two haemodialysis modalities: standard haemodialysis [sHD; dialysate temperature (Td) of 36.5°C] and cool haemodialysis (cHD; Td 35.5°C) and two haemodiafiltration modalities: low-volume haemodiafiltration (lvHDF, CV 15 L/1.73 m2/session, Td 36.5°C) and high-volume haemodiafiltration (hvHDF, CV ≥23 L/1.73 m2/session, Td 36.5°C). Every dialysis modality lasted 2 weeks. Intradialytic symptoms were evaluated after the last session of each dialysis modality, with a slightly modified Dialysis Symptom Index (mDSI). Intradialytic thermal sensations were scored on the Visual Analogue Scale Thermal Perception (VAS-TP) before and after 1 and 3 h of each treatment session. Patients were trained to use the mDSI and VAS-TP, in order to reduce incidental stress and unwanted learning responses due to the trial environment. Repeated measures analysis of variance (ANOVA) and one-way ANOVA were used to measure potential differences in intradialytic symptoms between the dialysis modalities (intraindividual differences) and to assess potential interindividual differences in intradialytic symptoms. Linear mixed models with an interaction term between time and modality were used to determine differences in rate of change of VAS-TP between the four modalities. When appropriate, stratified models were fitted subsequently. RESULTS With the exception of cold sensations during cHD (P = .01), intradialytic symptoms did not differ between modalities, but varied markedly between patients (P < .05 in 11/13 items, Table 1). While the VAS-TP score remained unaltered in sHD, lvHDF and hvHDF, patients felt significantly more cold sensations during cHD (P = .007)(Figure 1). Stratified models showed a decrease of 0.43 points/h on the VAS-TP scale (P = .007) in the first hour of cHD and remained unaltered thereafter [+0.10 points/h (P = .20)]; thermal perception remained unaltered [0.04 points/h (P = .77)] in the other modalities. CONCLUSION Intradialytic symptomatology was, except for the symptom feeling cold, by and large similar in all modalities, but it varied markedly between patients. Hence, adverse intradialytic symptoms seem largely patient-specific. Patients experienced more cold sensations during cool HD, but not during haemodiafiltration.