Premium
Errors Involved in the Application of an Imperfect Peritoneal Volume Marker
Author(s) -
Weryński Andrzej,
Waniewski Jacek,
Marciniak Maria,
Baczyński Daniel,
Wańkowicz Zofia
Publication year - 2001
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1046/j.1525-1594.2001.06672.x
Subject(s) - volume (thermodynamics) , dwell time , volume fraction , peritoneal dialysis , chemistry , free fraction , absorption rate , chromatography , biomedical engineering , surgery , medicine , thermodynamics , biochemistry , plasma protein binding , physics , clinical psychology
Peritoneal volume markers have been used in numerous studies on fluid transport in peritoneal dialysis. The basic assumption used was that the macromolecular marker was stable and that the free fraction of a label (usually radiolabel) was negligibly small. In this study are presented theoretical investigations on the errors involved in application of an imperfect volume marker containing free fraction of a label. These investigations were used in assessing the errors in calculation of peritoneal volume time course, V, and fluid absorption rate (estimated by volume marker clearance, k E ) using data from 20 clinical dwell studies with 1.36% Dianeal dialysis solution and radioiodinated human serum albumin as a volume marker. It has been shown that with an in vitro measured 125 I free fraction of 2.72%, the error of k E estimation was 11%. However, the maximal error in estimation of V was only 0.2%. In conclusion, the performed analysis implies that calculation of the peritoneal volume time course during the dwell (with correction for the volume marker elimination) is very reliable, and the existence of a free fraction of a volume marker label results in a negligibly small error. However, even small free fraction of the label results in a significant overestimation of the fluid absorption rate.