Hemodialysis with cuprophane or polysulfone: effects on uremic polyneuropathy

A longitudinal study was performed of 11 patients on hemodialysis (HD) who where changed from cuprophane (CU) to polysulfone (PSF) membranes. Delivered Kt/V was approximately 1.1 throughout the study period. Motor conduction velocities (MCV) and sensory conduction velocities (SCV) were measured predialysis and postdialysis while the patients were still on CU membranes, 1 month after changing to PSF, and 12 months after changing to PSF. There was no change in predialysis MCV or SCV. For example, predialysis MCV with CU (43.6 +/- 6.2) was still 43.6 +/- 4.8 m/s after 1 year of PSF dialysis (P = NS). Similarly, predialysis SCV with CU (45.1 +/- 4.6 m/s) was not increased after 1 year of PSF dialysis (42.0 +/- 3.6 m/s). However, the predialysis versus postdialysis comparisons did show a difference between CU and PSF for SCV. PSF dialysis increases SCV by 3.0 +/- 3.8, whereas with CU dialysis the increase in SCV (0.7 +/- 2.4) was not significant (delta SCV-CU v delta SCV-PSF, P < 0.05). Acutely, dialysis with both CU and PSF increased MCV by the same amount (CU, 1.5 +/- 2.1; PSF, 2.8 +/- 3.5; delta MCV-CU, P < 0.05; delta MCV-CU v delta MCV-PSF, P = NS). The results suggest that dialysis with PSF membranes acutely improved SCV more than dialysis with CU membranes. However, changing to PSF does not improve predialysis SCV values. Dialysis with both membranes improves MCV to the same extent.