title: Reproducibility of Serum Potassium Values in Serum From Blood Samples Stored for Increasing Times Prior to Centrifugation and Analysis.
abstract: OBJECTIVE
  The goal of this work was to determine if immediate versus postponed centrifugation of samples affects the levels of serum potassium.
  
  
  METHODS
  Twenty participants donated normal venous blood that was collected in four serum separator tubes per donor, each of which was analyzed at 0, 1, 2, or 4 hr on the Siemens Advia 1800 autoanalyzer.
  
  
  RESULTS
  Coefficients of variation (CVs) for potassium levels ranged from 0% to 7.6% with a mean of 3 ± 2%. ANOVA testing of the means for all 20 samples showed a P-value of 0.72 (>0.05) indicating that there was no statistically significant difference between the means of the samples at the four time points. Sixteen samples were found to have CVs that were ≤5%. Two samples showed increases of potassium from the reference range to levels higher than the upper reference limit, one of which had a 4-hr value that was within the reference or normal range (3.5-5 mEq/l). Overall, most samples were found to have reproducible levels of serum potassium.
  
  
  CONCLUSIONS
  Serum potassium levels from stored whole blood collected in serum separator tubes are, for the most part, stable at room temperature for at least 4 hr prior to analysis. However, some samples can exhibit significant fluctuations of values.
authors: Department of Pathology, SUNY Downstate Medical Center, Brooklyn, New York.|Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Aaron
authors: A
authors: Harper
authors: Department of Pathology, SUNY Downstate Medical Center, Brooklyn, New York.|Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Chuanyong
authors: C
authors: Lu
authors: Department of Pathology, SUNY Downstate Medical Center, Brooklyn, New York.|Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Yi
authors: Y
authors: Sun
authors: Department of Pathology, SUNY Downstate Medical Center, Brooklyn, New York.|Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Rafael
authors: R
authors: Garcia
authors: Department of Pathology, SUNY Downstate Medical Center, Brooklyn, New York.|Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Anton
authors: A
authors: Rets
authors: Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Herol
authors: H
authors: Alexis
authors: Department of Pathology, SUNY Downstate Medical Center, Brooklyn, New York.|Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Heba
authors: H
authors: Saad
authors: Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Ikram
authors: I
authors: Eid
authors: Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Loretta
authors: L
authors: Harris
authors: Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Barbara
authors: B
authors: Marshall
authors: Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Edlira
authors: E
authors: Tafani
authors: Department of Pathology, SUNY Downstate Medical Center, Brooklyn, New York.|Department of Pathology and Laboratory Medicine, New York Harbor VA Medical Center, Brooklyn, New York.
authors: Matthew R
authors: MR
authors: Pincus
mesh_terms: D002498:Centrifugation / Q000379:methods*; D006801:Humans; D011188:Potassium / Q000097:blood*; D011309:Preservation, Biological; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D011188:Potassium
keywords: potassium; reproducibility; serum level; storage