Polyol concentrations in serum during hemodialysis.

Polyol concentrations were determined by selected-ion monitoring in 10 sample sets taken before dialysis and hourly for 4 h during dialysis. Predialysis concentrations (mumol/L) exceeding the upper limit of normal (mean + 2 SD; n = 33) were found for erythritol (25.4-59.0), threitol (11.5-46.7), and arabinitol (21.0-49.3) in all 10 cases; mannitol (2.7-62.0) in nine cases; and xylitol (0.7-1.3) in eight cases. Concentrations of adonitol, galactitol, and sorbitol were all within normal limits. During dialysis, the concentration of six polyols decreased by approximately 50%, but there were no significant changes for xylitol and adonitol. Erythritol, threitol, and arabinitol concentrations remained more than double the upper limit of normal in all patients after 4 h of dialysis. High residual concentrations were found for mannitol (seven cases) and xylitol (six cases). The results suggest fundamental differences in the homeostasis as well as the dialyzability of different polyols. The potential toxic significance of the high residual concentrations after a 4-h dialysis needs to be investigated.