Physical intradialytic patient-reported outcome measures in haemodialysis and haemodiafiltration: A cross-over study

Aim: Standard haemodialysis (sHD) is associated with a poor survival and marked adverse intradialytic patient-reported outcome measures (ID-PROMs). Whereas physical ID-PROMs (PID-PROMs) are alleviated by cool dialysate (cHD), survival is prolonged by haemodiafiltration (HDF). So far, PID-PROMs are not prospectively compared between HD and HDF. Methods: To assess whether PID-PROMs and thermal perception differ between sHD, cHD, low volume HDF (lvHDF) and high volume HDF (hvHDF), 40 patients were cross-over randomized to each modality for 2 weeks. Dialysate temperature (T _d) was 36.5°C, except in cHD (T _d 35.5°C). Target convection volumes were 15 L in lvHDF and ≥ 23 L in hvHDF. PID-PROMs were evaluated with a modified Dialysis Symptom Index (mDSI) and thermal perception with the Visual Analogue Scale Thermal Perception (VAS-TP). T _b and room temperature were measured as well. Results: Except for the item ‘feeling cold’ during cHD (p =.01), PID-PROMs did not differ between modalities, but varied markedly between patients (11/13 items, p <.05). T _b increased in sHD, lvHDF, and hvHDF (+0.30, 0.35, 0.38°C, respectively, all p <.0005), but remained stable in cHD (+0.04°C, p =.43). Thermal perception remained unaltered in sHD and both HDF modalities, but shifted towards cold in cHD (p =.007). Conclusion: (1) PID-PROMs did not differ between modalities, but varied markedly between patients. Hence, PID-PROMs are largely patient-dependent. (2) While T _b increased in sHD, lvHDF and hvHDF, thermal perception did not change. Yet, whereas T _b remained unaltered in cHD, cold perception emerged. Hence, as for bothersome cold sensations, cHD should be avoided in perceptive individuals.