The perennial problem with potassium.

Author(s): Trull AK, Jackson C, Walsh S, Thornton A, Culank LS, McHugh J

Publication: Ann Clin Biochem, 2004, Vol. 41, Page 47-52

PubMed ID: 14713385 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to retrospectively analyze the effects of whole blood transport time and temperature on levels of potassium in serum.

   Summary of Findings:

   Serum potassium levels increased with increasing transport time and decreased with increasing temperature of transport. The effect of temperature on potassium levels was larger than the effect of transport duration. When whole blood was transported at 20.3 degrees C or less, the probability of a high serum potassium level (>5 mmol/L) was significantly greater in specimens transported for 165 min than 10 min, but the probability of a low serum potassium level (<3.4 mmol/L) was decreased in specimens transported for 165 min than 10 min. When whole blood was transported at temperatures >20.3 degrees C, longer transport resulted in a higher probability of low potassium levels and a lower probability of high potassium levels.

   Biospecimens

   • Bodily Fluid - Blood
   • Bodily Fluid - Serum

   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)
   Storage	Between site transportation method	Courier Not transported
   Storage	Specimen transport duration/condition	10-165 min -7.6-31.4 degrees C
   Biospecimen Aliquots and Components	Centrifugation	Centrifugation delays investigated

   View more

2. Study Purpose

   The purpose of this study was to investigate the effect of centrifugation and separation of serum prior to transport on potassium levels in 40 serum specimens. Specimens were split into two equal aliquots, one of which was immediately processed to frozen serum, and the other was transported by delivery van and processed upon receipt in the laboratory. The total storage duration from venipuncture to separation includes any transport time.

   Summary of Findings:

   Neither transport duration nor transport temperature affected the difference between levels of serum potassium in specimens transported before or after separation, but the authors note small sample size and lack of temperatures below 0 degrees C. However, 5 of the 40 specimens had serum potassium levels that were more than 0.5mmol/L higher in specimens transported as whole blood than those transported after separation of serum. Of these 5, 4 were exposed to <17 degrees C during transport, and in 4 others, the total storage duration was >8 h.

   Biospecimens

   • Bodily Fluid - Blood
   • Bodily Fluid - Serum

   Preservative Types

   • None (Fresh)
   • Frozen

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Electrolyte/Metal	Clinical chemistry/auto analyzer

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Specimen transport duration/condition	0-30 degrees C
   Storage	Between site transportation method	Courier
   Storage	Storage duration	0 h 5-9 h
   Biospecimen Aliquots and Components	Blood and blood products	Serum Whole blood
   Biospecimen Preservation	Type of fixation/preservation	Frozen None (fresh)
   Biospecimen Aliquots and Components	Centrifugation	Centrifugation delays investigated

   View more