February 15-18, 2009 Washington State Convention Center Seattle ...

EVALUATION OF A POINT OF CARE BLOOD ANALYZER FOR USE IN DETERMINATION
OF SELECT HEMATOLOGICAL INDICES IN Fundulus seminolis
Matthew A. DiMaggio*, Cortney L. Ohs and B. Denise Petty
University of Florida
School of Forest Resources and Conservation
Fisheries and Aquatic Sciences Program
Indian River Research and Education Center
2199 South Rock Rd.
Fort Pierce, FL 34945 USA
mdimaggi@ufl.edu
Conventional methods of hematocrit and electrolyte determination are gradually being replaced by new technologies. Point-ofcare
blood analyzers are both efficient and user friendly. As the use of such technologies becomes more pervasive in current literature,
investigations into the accuracy and reliability of point-of-care analyzers for evaluating hematological indices of fish is
warranted. There is currently little research validating point-of-care analyzers against conventionally accepted instrumentation
for use in fish. The purpose of this study was to evaluate a point-of-care blood analyzer (i-STAT®), and chosen cartridge (E3+)
(Heska Corp., Fort Collins, CO, USA) against conventionally accepted instrumentation for use in determination of hematocrit,
sodium, potassium, and chloride values in Fundulus seminolis.
The E3+ cartridge is designed to measure sodium, potassium, chloride, hematocrit, and hemoglobin from whole blood aliquots.
Hemoglobin measurements were not examined in this study because hemoglobin is not directly measured by the i-STAT®.
The E3+ cartridge was chosen because it is one of the most basic cartridges produced by the manufacturer yet its analyzed
parameters have application across numerous disciplines. Whole blood was used to measure parameters of interest in an initial
experiment. A second experiment implemented a whole blood heparin dilution prior to analysis with the point-of-care unit.
A final experiment examined the use of undiluted plasma in the point-of-care unit to determine electrolyte concentrations of
interest. The Bland-Altman method for assessing agreement between two methods of clinical measurement was used (Bland
and Altman, 1986) as well as calculations of correlation coefficients. A two tailed paired student t-test was also used to compare
values generated by both methods of analysis.
Generally, mean values obtained from conventionally accepted instrumentation were higher when compared with the i-STAT®
using whole blood, heparin diluted blood, and plasma. Significant differences (p≤0.05) were observed between all mean parameter
values analyzed by t-tests. Bias and limits of agreement values varied considerably throughout the experiments. None
of the blood parameters analyzed by the i-STAT® in this experiment could be considered reliable. Methodological validation
must be considered paramount for the introduction of new technologies in research applications.
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