Fluid status in CAPD patients is related to peritoneal transport and residual renal function: evidence from a longitudinal study

• Published in: Nephrology, dialysis, transplantation dialysis, transplantation, 2003-04, Vol.18 (4), p.797-803
• Main Authors: Konings, Constantijn J. A. M., Kooman, Jeroen P., Schonck, Marc, Struijk, Dick G., Gladziwa, Ulrich, Hoorntje, Steven J., van der Wall Bake, A. Warmold, van der Sande, Frank M., Leunissen, Karel M. L.
• Format: Article
• Language: English
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Biological Transport; Body Water; Body Weight; continuous ambulatory peritoneal dialysis; Cross-Sectional Studies; Dialysis Solutions - pharmacokinetics; Emergency and intensive care: renal failure. Dialysis management; Female; fluid state; Glomerular Filtration Rate; Humans; Intensive care medicine; Kidney Failure, Chronic - diagnosis; Kidney Failure, Chronic - mortality; Kidney Failure, Chronic - therapy; Kidney Function Tests; Longitudinal Studies; Male; Medical sciences; mortality; Peritoneal Dialysis, Continuous Ambulatory - adverse effects; Peritoneal Dialysis, Continuous Ambulatory - methods; Peritoneal Dialysis, Continuous Ambulatory - mortality; peritoneal transport; Permeability; Probability; Prognosis; Reference Values; residual renal function; Risk Assessment; risk factors; Severity of Illness Index; Survival Analysis; Treatment Outcome; Water-Electrolyte Imbalance - diagnosis; Water-Electrolyte Imbalance - etiology
• ISSN: 0931-0509; 1460-2385
• DOI: 10.1093/ndt/gfg147

Background. Both peritoneal transport characteristics as well as residual renal function are related to outcome in patients treated with continuous ambulatory peritoneal dialysis (CAPD). It has been suggested that part of this relationship might be explained by an effect of both parameters on the fluid state in CAPD patients or by the relationship between inflammation and peritoneal transport. Methods. In the present study, the relationship between fluid state [extracellular water (ECW) (sodium bromide); total body water (TBW) (deuterium oxide)] with peritoneal transport characteristics (2.27% glucose dialysate/plasma creatinine [D/P (creat)] ratio), residual renal function (residual glomerular filtration rate [rGFR] by urine collection) and C‐reactive protein (CRP) was assessed in 37 CAPD patients in a cross‐sectional and longitudinal design, with 25 patients completing the study. Results. In the cross‐sectional part ECW, corrected for height (ECW:height), was inversely related to rGFR (r=−0.40, P=0.016), whereas during the longitudinal part, D/P[creat] was related to the change in ECW (r=0.40, P=0.05). Neither D/P[creat] nor rGFR were related to CRP, whereas a significant relationship was observed between ECW:height and CRP (r=0.58, P=0.0001). Patients were dichotomized according to rGFR (2 ml/min). Despite a higher daily peritoneal glucose prescription (216.3±60.0 vs 156.5±53.0 g/24 h; P=0.004) and peritoneal ultrafiltration volume (1856±644 vs 658±781 ml/24 h, respectively; P=0.0001), the patients with a rGFR 2 ml/min (12.5±3.8 vs 9.2±2.2 l/m, respectively; P=0.003). Results for TBW were comparable. Conclusion. Fluid state was significantly related to peritoneal transport characteristics and rGFR. The larger ECW:height in CAPD patients with a negligible rGFR existed despite a higher peritoneal ultrafiltration volume and higher peritoneal glucose prescription. These findings raise doubts as to whether fluid state in CAPD patients with a diminished rGFR can be adequately controlled on standard glucose solutions without an additional sodium and fluid restriction. The preliminary finding of a relationship between CRP and fluid state might suggest a relationship between overhydration and inflammation.