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 (Td ) was 36.5°C, except in cHD (Td 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). Tb 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). Tb 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 Tb increased in sHD, lvHDF and hvHDF, thermal perception did not change. Yet, whereas Tb remained unaltered in cHD, cold perception emerged. Hence, as for bothersome cold sensations, cHD should be avoided in perceptive individuals.