Transport and temperature effects on measurement of serum and plasma potassium.
Author(s): Seamark D, Backhouse S, Barber P, Hichens J, Salzmann M, Powell R
Publication: J R Soc Med, 1999, Vol. 92, Page 339-41
PubMed ID: 10615270 PubMed Review Paper? No
Purpose of Paper
Conclusion of Paper
Studies
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Study Purpose
The purpose of this study was to determine the effects of transport of whole blood prior to centrifugation or transport of separated plasma or serum at ambient temperatures for up to 12 h on potassium concentrations.
Summary of Findings:
Potassium concentrations were highest in serum specimens that had been centrifuged prior to transport, within 30 minutes of venipuncture (4.2 mmol/L). Serum and plasma which were transported by courier service prior to centrifugation had lower concentrations of potassium (4.1 and 4.0 mmol/L, respectively), but this decrease was only significant for plasma (p<0.001). However, 4.3% of serum specimens were considered hypokalaemic after transport prior to centrifugation. The maximum temperature and duration prior to centrifugation were not significant predictor variables for potassium levels in serum, but for plasma, both maximum temperature and time prior to centrifugation had a significant effect on potassium levels (p<0.0001). In conclusion, when possible, specimens should be centrifuged within 30 minutes and serum specimens are preferable to plasma for measuring potassium concentration.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Not specified
Platform:
Analyte Technology Platform Electrolyte/Metal Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Blood and blood products Serum
Plasma
Storage Storage temperature Room temperature
15-30 degrees C
Storage Storage duration 2 h 47 min- 12 h 18 min
30 min
Storage Within hospital transportation method Hand-delivered
Not transported
Biospecimen Aliquots and Components Centrifugation Centrifugation delays investigated