Detection of haemolysis and reporting of potassium results in samples from neonates

This version was published on 1 May 2009

Ann Clin Biochem 2009;46:222-225
© 2009 Association for Clinical Biochemistry


This Article
Right arrow
Figures Only
Right arrow
Full Text
Right arrow

Full Text (PDF)

Right arrow
All Versions of this Article:



most recent

Right arrow
Alert me when this article is cited
Right arrow
Alert me if a correction is posted
Right arrow
Email this article to a friend
Right arrow

Similar articles in this journal

Right arrow
Similar articles in PubMed
Right arrow
Alert me to new issues of the journal
Right arrow
Download to citation manager
Right arrow
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow
Articles by Jeffery, J.
Right arrow
Articles by Ayling, R. M
Right arrow Search for Related Content
Right arrow
PubMed Citation
Social Bookmarking

What’s this?

Original Articles

Jinny Jeffery,
Aabha Sharma and
Ruth M Ayling

Department of Clinical Biochemistry, Derriford Hospital, Plymouth PL6 8DH, UK

Corresponding author: Dr Ruth M Ayling. Email: ruthayling{at}

Background: In vitro haemolysis is a common occurrence in clinical laboratoriesand causes a spurious increase in potassium. In the past, haemolysiswas sought by visual inspection but is now commonly detectedby automated measurement of the haemolytic index (HI). Thisstudy compared detection of haemolysis in adult and neonatalsamples by inspection and measurement of HI and verified thata single equation is appropriate to correct for the increasein potassium in both haemolysed samples.

Methods: Laboratory staff inspected samples for haemolysis and theirobservations were compared with the measured HI. The potassiumconcentrations and haemolytic indices of 613 adult and 523 neonatalsamples were correlated to derive equations to compensate forthe increase in potassium with increase in HI. These were foundnot to differ significantly and a single equation for use inboth populations was derived.

Results: The presence of icterus was found to decrease ability to detect haemolysis on inspection. The mean (95% confidence limits) potassium increase per unit HI was 0.0094 mmol/L (0.0078–0.0103 mmol/L) for adults and 0.0108 mmol/L (0.0094–0.0121 mmol/L) for neonates. The equation developed to compensate for potassium release in haemolysed samples was: adjusted potassium = measured potassium – (HI in µmol/L x 0.01).

Conclusion: The use of HI rather than visual inspection is particularlyrecommended in neonates whose serum tends to be icteric. Itcan be used in the same correction equation as in adults tocompensate for potassium released due to haemolysis and facilitatereporting a qualitative comment to assist in immediate clinicalmanagement.

CiteULike    Complore    Connotea    Digg    Reddit    Technorati    What’s this?