Icodextrin:: A major problem for glucose dehydrogenase-based glucose point of care testing systems

Recently a number of glucose dehydrogenase-based point of case (POCT) systems for glucose monitoring were successfully introduced on the market. Icodextrin, a glucose polymer is widely used as an osmotic agent in continuous ambulatory peritoneal dialysis (CAPD). Its metabolities are substrates for glucose dehydrogenase, inducing an analytical error which is gaining importance in the determination of glucose in a hospital environment. Since icodextrin is hydrolysed by amylase in the extracellular fluids, the analytical error in vivo is aggravated by the presence of the smaller oligosaccharides which originate from amylase activity. Clinicians should be warned about the spurious high glucose results which might occur in icodextrin-treated patients. In particular in conditions associated with increased amylase activities, analytical errors are to be expected in icodextrin-treated patients. Alternative glucose determination methods should be recommended in the latter group of patients.