Sunil V. Badve
Centre for Kidney Disease Research, Translational Research Institute, University of Queensland, Brisbane Australia
David W. Johnson
Princess Alexandra Hospital, Brisbane, Australia
Series: Nephrology Research and Clinical Developments
The peritoneal membrane is the lifeline for peritoneal dialysis (PD) patients. Our understanding of mechanisms of injury and functional responses continues to expand and will hopefully lead to therapies that improve clinical outcomes. A key characteristic of the peritoneal membrane is its permeability or transport status. This can be measured by a variety of methods, but most commonly involves measurement of the ratio of dialysate to plasma concentration of creatinine following a 4 hour dwell of 2 L of 2.5% glucose dialysate (D:P Cr) using a Peritoneal Equilibration Test. Standardisation of the PET is critically important as the D:P Cr result can be appreciably influenced by a number of variables, including dialysate composition and volume, the presence or absence of a dialysate exchange preceding the PET and the proximity of the PET to dialysis commencement.
Transport status is typically categorised into 4 groups according to the mean Â¡Ã€ 1 standard deviation of D:P Cr: High (D:P Cr Â¡Ã0.81, 16%), High-average (D:P Cr 0.65-0.80, 51%), Low-average (D:P Cr 0.50-0.64, 28%), and Low (D:P Cr <0.50, 5%). Higher peritoneal transport status at the commencement of PD is independently associated with racial origin, older age and lower body mass index and predicts higher risks of both technique failure and death. We have also demonstrated that transport status can change significantly over time in an appreciable minority of patients and is associated with increased risks of encapsulating peritoneal sclerosis, membrane failure and death. High transporters on chronic PD are challenged by increased protein losses, high glucose absorption, and poor ultrafiltration. Treatment with automated PD has been associated with improved survival in high transporters and reduced survival in low transporters. Icodextrin may also provide ultrafiltration benefits in high transporters.
This chapter reviews in detail the assessment, diagnosis, predictors, prognostic implications and therapeutic management of peritoneal transport status in PD patients. Suggestions for future research directions are also discussed. (Imprint: Nova Biomedical )