The effects of peritoneal dialysis on blood glutamate levels: implementation for neuroprotection.

BACKGROUND Previous study has demonstrated the efficacy of hemodialysis in reducing blood glutamate levels. The purpose of the present study is to investigate whether peritoneal dialysis (PD) may be effective in lowering blood glutamate levels, which may serve as a potential tool for improving neurological function after brain injury. METHODS Two liters of dialysis solution were infused over 10 minutes into 18 patients with stage V chronic kidney disease. Blood samples were collected immediately before initiation of PD, and hourly for a total of 5 blood samples. Blood samples were sent for determination of glutamate, creatinine, urea, glucose, glutamate oxaloacetate transaminase, and glutamate pyruvate transaminase. PD samples were collected and analyzed for glutamate, creatinine, urea, and glucose at the same time points as the blood samples. RESULTS Blood glutamate concentrations were significantly reduced by 60 minutes after the infusion of dialysis solution (P<0.0001), whereas levels of glutamate in the dialysis solution were increased significantly by 60 minutes (P<0.0001). CONCLUSIONS We demonstrated that PD is an effective modality in reducing blood glutamate concentrations. This method may be potentially utilized for the treatment of acute and chronic brain disorders that are accompanied by elevated glutamate in the brain's extracellular fluid. Considering the rapid saturation of the PD solution with glutamate, we recommend frequent dwelling of the PD solution in order to maintain low concentrations of blood glutamate.