['During real-time monitoring of the ultrafiltration coefficient (Kuf) in haemodiafiltration (HDF), it was noticed that the ultrafiltration performance of polysulphone membrane dialysers increased when hypertonic glucose (D50%) was administered through the venous blood return.', 'This observation was explored in six non-diabetic chronic dialysis patients during 48 HDF sessions using 1.8 m(2) polysulphone membrane dialysers. In all six patients, 24 sessions were performed with glucose supplementation (as a continuous D50% (500 g/l) infusion at 40 ml/h) and 24 sessions without supplementation.', 'Glucose supplementation led to a marked increase in Kuf from 22.8+/-2.2 (without D50%, n=24) to 32. 1+/-3.9 ml/h/mmHg (with D50%, n=24) (P<0.0001). An increase in percentage reduction ratios for urea and creatinine were also consistently observed during the sessions with glucose administration (from respective mean values of 75+/-5 and 68+/-4% to 79+/-4 and 74+/-10%). Mean double-pool Kt/V, calculated from serum urea concentrations, rose from 1.65+/-0.24 (n=24) to 1.86+/-0.24 (n=24) (P<0.005). Similar results were observed in a subgroup of 18 HDF sessions (nine with glucose and nine without) monitored with an on-line urea sensor of spent dialysate. No detrimental effects were induced at any time.'] Does intradialytic glucose infusion increase polysulphone membrane permeability and post-dilutional haemodiafiltration performances?