A survey of some pre-analytical errors identified from the Biochemistry Department of a Scottish hospital

Abstract

Background: It is estimated that 70% of all health care decisions affecting diagnosis or treatment involve laboratory testing. The pre-analytical phase of the testing process shows the highest prevalence of errors accounting for 70% of all mistakes in laboratory diagnostics. It is recommended that laboratories collect statistics on pre-analytical error rates. This survey examined some mistakes in blood collection, i.e. specimen haemolysis, and EDTA contamination.

Methods: Survey was from June 2011 to May 2012. Haemolysis was detected by analysers' automated haemolysis index function. Plasma EDTA was measured by an automated system. Data were captured from our laboratory information management system.

Results: For a total workload of 763,577 blood specimens, the overall haemolysis rate was 3.2%. Much higher rates of both specimen haemolysis and EDTA contamination were observed when blood was not collected by trained phlebotomists.

Conclusions: Better training in blood collection, achieving the standard of professional phlebotomists, will improve validity of diagnostic information; reduce risks of dangerous misinterpretation of results, unwanted anaemia and needlestick injury and decrease laboratory supplies costs. This type of audit could be replicated in other Scottish Health Boards with some benefit and thereby better target future training needs.

Keywords: EDTA contamination; Phlebotomy; in vitro haemolysis; training.