Overcoming glucose delivery by on-line hemodiafiltration: a feasible chimera for diabetics on dialysis

The increasing number of patients with diabetes undergoing renal replacement therapy has raised interest in the issue of glucose delivery with the substitution fluid—over 20 g per session. The ideal situation would be to have a glucose-containing bath to avoid glycemic disarrays and a glucose-free substitution fluid. But this seems a chimera because the substitution fluid is nothing else than an ultrapure dialysis bath. In this technical note, we present a cheap solution to realize the desired mix, using a commercially available glucose-free dialysate and adding glucose in the inlet dialysate compartment of the dialyzer by means of a common pump and a unique handmade T-tube. Our in vitro experiments showed glucose levels in the dialysate (mean ± SD, mg/dl): 99.7 ± 4.6 at baseline, 100.7 ± 7.3 at mid-session and 100.7 ± 2.1 at the end of dialysis, whereas measurements in the substitution fluid always gave a “low” output (p < 0.0001). Similar results were obtained in single 1- and 4-h in vivo experiments carried out in a non-diabetic overweight hemodialysis patient. Our simple, yet unequivocal, results lay the foundation for assembling a hemodialysis machine equipped with an infusion pump to modify the on-line substitution fluid without affecting the dialysate. This would overcome the ethical issue of delivering glucose intravenously in certain groups of patients.