Ideal volume status of patients with end-stage renal disease is one of the main goals of adequate dialysis. Volume overload has been associated with heart failure, left ventricular hypertrophy, and mortality, both in hemodialysis (HD) and peritoneal dialysis (PD) populations. The assessment of normal volume status is traditionally based on clinical parameters such as blood pressure, edema, lung auscultation, and chest X-ray. However, these parameters cannot be trustworthy to direct treatment decisions. Gold standard methods of assessing volume status are mainly isotope dilution analysis techniques. However, these methods are invasive and impractical in clinical routine. A number of handy bedside methods have been developed focusing on objective fluid status assessment, both in HD and PD patients. Bioimpedance techniques can estimate extracellular volume, intracellular volume, and total body water, whereas inferior vena cava diameter measurements, biochemical markers, and lung ultrasound provide information about the intravascular filling state and blood volume. Various studies have used the values of the above-mentioned techniques as tools for determining the overhydration of dialysis patients as well as predictors of mortality. Yet, randomized intervention studies based on these methods with hard end points (like echocardiographic parameters modification) have not been published so far in PD patients.
Part of the book: Some Special Problems in Peritoneal Dialysis