Stability of heparin blood samples during transport based on defined pre-analytical quality goals.
BACKGROUND
In many countries and especially in Scandinavia, blood samples drawn in primary healthcare are sent to a hospital laboratory for analysis. The samples are exposed to various conditions regarding storage time, storage temperature and transport form. As these factors can have a severe impact on the quality of results, we wanted to study which combination of transport conditions could fulfil our pre-defined goals for maximum allowable error.


METHODS
Samples from 406 patients from nine general practitioners (GPs) in two Danish counties were sent to two hospitals for analyses, during two periods (winter and summer). Transport conditions (mail, courier pick-up, or brought to hospital by public coach), storage time, storage temperature and centrifugation requirements were different in the two counties. Results were tested for deviation from a "0-sample", the blood sample taken, centrifuged and separated at the doctor's office within 45-60 min. This sample was considered as the best estimate of a comparison value.


RESULTS
The pre-set quality goals were fulfilled for all the investigated components for samples transported to hospital by courier either as whole blood or as "on gel" after centrifugation, as long as the samples were stored at 20-25 degrees C and centrifuged/analysed within 5-6 h. A total of 4% of the samples sent by mail had mismatched identity, probably due to plasma being transferred to a new tube.


CONCLUSIONS
Samples can be sent as unprocessed anticoagulated whole blood if the above mentioned conditions are met. There is no need for centrifugation in the primary sector. Neither mailing of samples with plasma "on gel" nor public transport by coach bus fulfil our analytical goals.
Jensen
Esther A
EA
Department of Clinical Biochemistry, Odense University Hospital, Odense, Denmark. Esther.Jensen@ouh.regionsyddanmark.dk
Stahl
Marta
M
Brandslund
Ivan
I
Grinsted
Per
P
D000328:Adult; D001769:Blood; D006493:Heparin; D006801:Humans; D011786:Quality Control; D013048:Specimen Handling
D006493:Heparin