Frequency of peripheral smear review in era of automation

BACKGROUND: With the advent of automated haematology analyzer providing complete blood count with differentials, flags, cell plots and distributional histograms, the use of traditional microscopic examination of blood film has now became limited. Reviewing peripheral blood smear and performing differential counts manually when automated determinations yield identical results may undermine efficiency and lower productivity in a medical laboratory. However, relying on the findings of automated analyzer alone can result in exclusion of findings which may have significant impact on clinical decisions. OBJECTIVES: To determine the percentage of manual peripheral blood smear review in our institution in the era of automation and to identify reasons of manual review. METHODS: This was a prospective audit carried out from 1st January till 7th January 2015. Consecutive CBC samples and peripheral smear requests made up the sample size. All age groups and genders were included. Complete blood counts were performed on Sysmex XE-5000? Automated Haematology System. The variables to be analyzed included inpatient and outpatient samples, frequency of peripheral film review, identifying reasons of smear review and addition of information missed by the automated analyzer. RESULTS: During the review period, we analyzed n=1200 consecutive CBC samples. Peripheral smear was review in n=500 (42%) of the cases. Out of these n=500 samples, n=241 were inpatient and n=259 were outpatient samples. In 384/500, the findings of hematology analyzer correlated with peripheral smear review. Additional information was provided in n=243 (49%) of the cases. The main reasons for review included NRBC (n=155), immature WBC precursors (n=129) and atypical lymphocytes (n=47). CONCLUSION: Peripheral smear review was performed in 42% of the cases. The analyzer identified NRBC, immature WBC precursors and atypical lymphocytes as the most common abnormality. The information correlated in 77% of the cases. In 23%, the analyzer missed abnormal findings which were verified by peripheral smear review