| Criteria for peripheral blood smear review Initial analysis of the peripheral blood picture is made in most clinical laboratories with an automated instrument. Samples are selected for further analysis when quantitative or qualitative abnormalities beyond a defined standard are found. The following are examples of quantitative RBC abnormalities that may prompt a blood smear review. Each laboratory, however, should develop its own guidelines: Hgb: < 8 or >18 g/dL (<10 or > 21g/dL in a newborn)Hct: <20% or > 60% in adults (<40% or >65% in a newborn)MCHC: <29 g/dLMCV: <69 femtoliters (fl) or >110flFlags generated by the hematology analyzer that indicate possible red cell abnormalities or spurious resultsAny of these findings should be followed up with a peripheral blood smear review. | View Page |
| Guidelines for standard reports In a study on the reporting of red blood cell morphology abnormalities conducted in Ontario, Canada (Hookey L, Dexter D, Lee DH, Laboratory Hematology 7:83-88, 2001), fewer than 50% of 33 participants used the same term to describe the quantitative frequency of peripheral blood abnormalities. Seven blood smears, each containing one of several abnormal erythrocytes-- schistocytes, teardrop cells, acanthocytes, and Howell-Jolly bodies--were evaluated by 32 participants. The participants were asked to document their evaluations from a list of quantitative terms. There was a heterogeneity in the use of terms "rare," "slight," "occasional," "few," "mild", "present," "moderate," "many," and "marked." Choices of terms were subjective without points of reference. Guidelines for establishing standardized qualitative estimations of abnormal erythrocytes in the peripheral smear are presented as follows: 1+ = 2 - 4/Oil Immersion Field (OIF) 2+ = 5 - 7/OIF 3+ = 8 - 10/OIF 4+ = >10/OIF. The terms "few," "moderate," "many," and "marked" may be substituted for the 1+ - 4+ grading system, but only when their specific points of reference are universally understood in tandem with the above guidelines. A comment should be triggered if any erythrocyte abnormalities are seen in numbers >3/OIF including, but not limited to, polychromasia, basophilic stippling, nucleated RBC's, and Howell-Jolly bodies. Rouleaux or RBC agglutination are important findings and must be documented. | View Page |
| Qualitative reports: Follow-up Any review of a peripheral smear is highly subjective; therefore, each laboratory must establish its own guidelines for quantitating observations and issuing reports in a consistent format. The key question for the laboratory is "How will the clinician use the terms of qualitative results in the reports issued to decide on the next course of action with this patient?" Formats for reporting have been geared more toward the needs of instrumentation facilitation and computer management than toward needs of access and understanding by clinicians working to improve patient care outcomes. Evidence based medicine (EBM) is the formal term used for the process by which research evidence, collective clinical experience, and the user friendly rendering of testing results are integrated to evaluate patient care outcomes. | View Page |