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.