These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Correction of factitious hyperkalemia in hemolyzed specimens.
    Author: Owens H, Siparsky G, Bajaj L, Hampers LC.
    Journal: Am J Emerg Med; 2005 Nov; 23(7):872-5. PubMed ID: 16291444.
    Abstract:
    BACKGROUND: Hemolysis in pediatric specimens is common due to difficult blood draws and small-bore intravenous catheters. Values of serum K+ become falsely elevated secondary to release of intracellular contents. If a reliable correction factor existed for this factitious elevation, repeat K+ measurements might be avoided. OBJECTIVE: The aim of the study was to establish a correction factor for factitiously elevated K+, using free plasma hemoglobin (p-Hgb) as a measure of in vitro hemolysis. METHODS: Twenty whole-blood specimens drawn from healthy adults via a 23-gauge needle were divided into 4 aliquots: (1) no manipulation, (2) mechanical hemolysis via a 27-gauge needle, (3) addition of potassium acetate (KAc), and (4) addition of KAc and mechanical hemolysis. KAc was added to mimic potentially significant hyperkalemia. All specimens had standard K+ and p-Hgb measurements performed. RESULTS: Nonhemolyzed and hemolyzed K+ ranged from 3.2 to 8.1 mEq/L and 3.5 to 10.0 mEq/L, respectively. A linear relationship existed between the change in K+ and p-Hgb from the nonhemolyzed to hemolyzed specimens. A correction factor for K+ of 0.00319 (95% confidence interval, 0.00290-0.00349) x p-Hgb was obtained. CONCLUSIONS: A reliable correction factor for factitious hyperkalemia in a clinically relevant range exists. By example, using the above correction factor, one can predict that the delta K+ in a specimen with 500 mg/dL of p-Hgb will be 1.6 mEq/L (range, 1.5-1.7). We suggest that when the lower bound of the predicted delta K+ results in a corrected value within the reference range, a second blood draw is unnecessary.
    [Abstract] [Full Text] [Related] [New Search]