|
|
||||||||
CASE COMMENTARIES IN PERITONEAL DIALYSIS |
Renal Unit, St James's University Hospital, Leeds, United Kingdom
Correspondence to: G. Woodrow, Renal Unit, St James's University Hospital, Beckett Street, Leeds LS9 7TF England, United Kingdom. graham.woodrow{at}leedsth.nhs.uk
Patients on peritoneal dialysis (PD) develop complex changes in body
composition. These changes reflect hydration, nutrition, and body fat, all
important elements reflecting patient well-being and efficacy of therapy that
should be assessed and monitored as guides to patient management. They are all
notoriously difficult to accurately measure in clinical practice and
simultaneous abnormalities may obscure detection, as in the malnourished
fluid-overloaded patient where body weight is misleadingly stable.
Malnutrition is a serious complication in PD that carries an adverse
prognosis. Assessment of hydration in PD is important in determining
"dry weight" to allow adjustment of dialysis prescription to
optimize fluid balance. A number of techniques have been investigated to
measure body composition in clinical practice. Of these, bioelectrical
impedance analysis (BIA) has attracted most interest and seems to be of
greatest promise. Cases illustrating different aspects of the use of BIA in PD
patients are described, and the background, possible uses, and limitations of
BIA in PD patients are discussed. To be of clinical value, BIA must be used to
distinguish between extracellular water (which reflects hydration) and body
cell mass, or intracellular water (which declines in wasting and
malnutrition). The high precision of BIA is ideally suited to detecting
changes in body composition and its main role may be in longitudinal
monitoring. However, inaccuracy of absolute measurements and variability of
normal values in the general population make precise diagnosis of the degree
of normality of body composition in an individual subject a more difficult
task for body composition analysis.
KEY WORDS: Fluid balance; bioelectrical impedance; body composition; nutrition.
Received 16 May 2007; accepted 16 July 2007.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |