Abstract

Background: Pre-analytical errors account for up to 70% of all mistakes made in
laboratory diagnostics, most of which arise from problems in patient preparation,
sample collection, transportation, and preparation for analysis and storage. Preanalytical
errors influence the total error thus hindering TQM in laboratory,
consequently decreasing the accuracy and reliability of the results generated. The
frequencies of PAE and sample rejection rates in pediatric clinics are not yet fully
understood compared to PAE in adult departments. Such pre-analytical errors (PAE)
can affect children’s safety due to delayed clinical decision-making support or
discomfort related to repeat blood sampling. This study was conducted with the aim to
determine nature and frequency of the occurrence of pre-analytical errorsin pediatric
patients.
Material and Methods: This prospective analytical study was designed to evaluate the
pre-analytical errors observed in a total of 2971 out-patient and inpatient samples
received from pediatric patients. Samples received for routine clinical chemistry
analysis were screened for pre-analytical errors. Samples received for other
investigations were excluded. We recorded all nonconformities and errors occurring
over a 3-month period and corrective measures were suggested to minimize them.
Laboratory personnel were asked to register rejections, and pre-analytical causes for
rejection of ward as well as out-patient samples collected in the laboratory. Types of
inappropriateness were evaluated as follows: hemolysed, blood collection in wrong
tubes, clotted blood, inappropriate timing of collection, improperly labeled samples,
insufficient volume of specimen and old samples.
Results: A total of 2971 samples from the outpatient pediatric department and in-house
pediatric patients were received by our clinical biochemistry laboratory during the
period from March 2022 to May 2022. Out of these 95 samples were found unsuitable
for further processing. This accounted for 3.2% of all samples collected in the
laboratory and pre-analytical errors were responsible for these samples to be rejected
over a period of 3 months. Rejections arose as a result of the following reasons: 1.02%
were rejected due to hemolysis; 0.67% were blood collected in wrong tubes; 0.61% were
clotted blood; 0.29% had inappropriate timing of collection; 0.26%were mislabeled
samples; 0.21% had insufficient sample quantity and 0.14% were old samples.