Contamination levels in blood samples drawn from the injection intravenous line.
OBJECTIVE
Securing two intravenous lines, one for injection and one for blood sampling, can be nearly impossible in compromised patients, therefore, a need exists to quantify the potential error when simplified techniques are employed.


METHODS
Two venous catheters were placed. 2-deoxy-2-[18F]fluoro-glucose (FDG) was infused through one of the catheters. Venous blood samples were drawn from each line. Triplicate aliquots of plasma were analyzed in duplicate.


RESULTS
Concentrations from the infusion line were 2.0% higher than the concentrations from the noninfusion line. The average error was 3.3%, 2.0%, and 0.7% higher for the first, second, and third samples, respectively.


CONCLUSIONS
Blood sampling through the infusion catheter is a viable alternative to the placement of separate venous catheters. Sampling from the injection catheter, even with tubing flush and replacement, will potentially incur small (generally < 10%) over-estimations in concentration in initial samples. Subsequent sampling reduces the error to essentially zero by the third sample.
Ponto
Laura L Boles
LL
University of Iowa College of Medicine, Department of Radiology, Division of Nuclear Medicine, Positron Emission Tomography Imaging Center, Iowa City, IA 52242, USA. laura-ponto@uiowa.edu
Graham
Michael M
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Christine A
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Conklin
Amy
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Weldon
Lea
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Watkins
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Madsen
Mark T
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Hichwa
Richard D
RD