Inaccuracy of osmometry for measurement of plasma water in acute diabetes mellitus
Davidson, D.F.
Clinical Chemistry 39(6): 1079-1081
1993
ISSN/ISBN: 0009-9147 PMID: 8504541 Document Number: 412078
Osmometry is reportedly a relatively imprecise technique for the measurement of plasma water. However, reconsideration of the theoretical background of the test reveals that it is also likely to be inaccurate and subject to both positive errors as well as viscosity-dependent negative errors simultaneously, when applied to samples from patients admitted in acute diabetes mellitus. This was confirmed by comparison with Waugh's method of results for 59 specimens from 14 cases. Plasma water was shown to be relatively underestimated at high protein concentrations and overestimated at lower ones.