Biocompatible peritoneal dialysis solutions: do we have one?

Clinical experience and literature evidence suggest that peritoneal dialysis (PD) is a safe and effective treatment in short term (3 to 5 years) for stage 5 chronic kidney disease patients. A major limitation to long-term PD has been peritoneal membrane structural and functional alterations over time, resulting in significant technique failure. Much evidence implicates glucose contained in conventional PD solutions as the major cause of membrane changes. Other harmful characteristics of glucose or its degradation products are thought to cause systemic undesirable metabolic and cardiovascular effects. This led to the search for more "biocompatible" PD solutions to ameliorate complications associated with conventional glucose solutions. Studies in animals and humans show that newer biocompatible solutions may preserve membrane functions better, lead to less therapy failure, and avoid the undesirable metabolic and cardiovascular effects of systemic glucose exposure. There is evidence in specific, clinical, short-term situations of biochemical and metabolic benefits of biocompatible solutions. However, are these solutions superior to glucose in preserving peritoneal membrane long term? Are they truly more biocompatible? Clinical and experimental data suggest that newer solutions, albeit most of them glucose based, are less toxic compared with the current PD solution; however, there is currently no osmotic agent that can safely replace glucose. The future appears to be in using combinations of different osmotic agents in a more biocompatible solution, whether they are mixtures in a single bag or daily exchanges of different osmotic agents. This review discusses the current status of these biocompatible solutions in PD patients.