Chapter 1 - Complete blood count and peripheral smear examination

Abstract

A complete blood count (CBC) is one of the most common laboratory tests ordered by clinicians even during routine health check. For CBC analysis, the specimen must be collected in an EDTA (ethylenediamine tetraacetic acid) tube (lavender or purple top). CBC consists of certain numbers that are printed out from the hematology analyzer. In addition, the printout contains certain graphs and “flags.” Flags are essentially messages provided by the analyzer to the interpreting person that certain abnormalities may be present. To make a meaningful interpretation of the peripheral smear, the CBC printout should be reviewed along with patient's electronic medical records. CBC parameters that are printed from an automated hematology analyzer are red blood cell–related numbers, white blood cell–related numbers, and platelet-related numbers. Review of peripheral blood smear is also very important, and sometimes correlating abnormal findings of bone marrow biopsy with abnormalities observed during review of peripheral blood smear may be very helpful for obtaining a proper diagnosis.