A healthy volunteer study to investigate trace element contamination of blood samples by stainless steel venepuncture needles.
BACKGROUND
The trace elements cobalt (Co), chromium (Cr), manganese (Mn) and nickel (Ni) are normally present at low concentrations in blood. There has been a concern that stainless steel venepuncture needles typically used for collection of blood samples may contaminate these samples, leading to the masking of deficiency states or causing potential clinical confusion as to whether an individual has a "toxic" concentration.


OBJECTIVE
To determine whether there is any difference between the concentrations of the trace elements obtained by different methods of blood sampling.


METHODS
We took blood samples using a standard venepuncture needle, a "butterfly" winged infusion needle (three consecutive samples) and a plastic intravenous cannula (three consecutive samples) from 10 healthy volunteers. We measured the concentrations of Co, Cr, Mn and Ni in the samples using Inductively Coupled Plasma Mass Spectrometry, and used analysis of variance (ANOVA) to investigate if there was any difference between the methods of blood sampling.


RESULTS
The mean ± standard deviation blood metal concentrations were: Co 0.33 ± 0.2 μg/l, Cr 2.43 ± 1.55 μg/l, Mn 8.07 ± 7.74 μg/l and Ni 10.4 ± 4.69 μg/l. There was considerable variation between blood metal concentrations of individual subjects and a few sporadic high values. By ANOVA, there was no significant difference between the metal concentrations measured using different methods of blood collection.


CONCLUSIONS
It is not necessary to routinely use a plastic cannula for blood sampling for trace element analysis. However, it is possible that sporadic contamination due to stainless steel needles may occur, so we would recommend that unexpected high concentrations are verified by taking a second sample taken through a plastic cannula.
King's College London, UK.
Darragh
D
Hodnett
David M
DM
Wood
Kishor
K
Raja
Paul I
PI
Dargan
Anoop D
AD
Shah
D000328:Adult; D001800:Blood Specimen Collection / Q000295:instrumentation*; D002857:Chromium / Q000097:blood; D003035:Cobalt / Q000097:blood; D006801:Humans; D008345:Manganese / Q000097:blood; D008670:Metals / Q000097:blood*; D009339:Needles; D009532:Nickel / Q000097:blood; D013193:Stainless Steel; D014131:Trace Elements / Q000097:blood*; D055815:Young Adult
D008670:Metals; D014131:Trace Elements; D002857:Chromium; D013193:Stainless Steel; D003035:Cobalt; D008345:Manganese; D009532:Nickel