Venous collapsibility index changes in children on dialysis

Abstract

Hypervolemia is an important factor for the development of cardiac failure in end-stage renal disease. The aims of this study are to evaluate whether collapsibility index (CI) is a useful method to assess the volume status in children on haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD), and to test whether the small amounts of fluid removed after a single dialysis exchange will be reflected by a change in CI in peritoneal dialysis patients. Sixteen CAPD, nine HD patients aged from 5 to 18 years and 27 age- and sex-matched healthy children were enrolled in the study. Inferior vena cava diameters were measured from subxiphoidal long axis position in 2 cm to its junction to right atrium and CI were calculated. The collapsibility index was significantly lower in HD patients before HD and in the CAPD group before dialysate exchange when compared with the controls. No significant difference was found between the CAPD and HD groups. We observed significant increase in CI after HD, CI values reached nearly to control levels after HD. Ultrafiltrate was 1.93 +/- 0.98 kg in HD, 0.23 +/- 0.09 kg in the CAPD group. Although the change in CI values before and after dialysate exchange was significant in the CAPD group, there was still a significant difference between the CI values of the control group and the CAPD patients after dialysate exchange. We suggest that serial measurements of CI in children will be a useful guide to assess the volume changes in an individual instead of a single measurement.