A Methodical Approach to Interpreting the Red Blood Cell Parameters of the Complete Blood Count

A methodical approach to interpreting the panel of complete blood count (CBC) results helps to ensure that spurious results are detected and corrected before results are reported and helps to ensure that no results are overlooked in a diagnostic analysis of the results. The steps to interpreting the red blood cell (rbc) parameters are: Interpret the hemoglobin value relative to the appropriate reference interval. Interpret the mean cell volume relative to the reference interval. Interpret the mean cell hemoglobin concentration relative to the reference interval. Interpret the red blood cell distribution width relative to the reference interval. Examine the red blood cell morphology, if available, and correlate morphology with instrument parameters for consistency and quality purposes. Also, review for additional diagnostic findings. As a final check on the numerical parameters, examine the rbc count, hematocrit, mean cell hemoglobin, and calculate the Rule of Three to ensure that the above interpretations are correct. Use related test results when available, particularly reticulocyte parameters, to verify CBC findings and add diagnostic information. Interpret the rbc parameters for diagnostic significance and correlate with results of white blood cell and platelet parameters. Explanations for conducting the evaluations are provided and the above steps are applied to examples to demonstrate this approach to interpreting the rbc parameters of the CBC. ABBREVIATIONS: CBC - complete blood count, CRC-corrected reticulocyte count, dL-deciliter, fL-femtoliter, rbc-red blood cell, RBC-red blood cell count, HB-hemoglobin, HCT-hematocrit, g-gram, IRF-immature reticulocyte fraction, MCV-mean cell volume, MCH-mean cell hemoglobin, MCHC - mean cell hemoglobin concentration, MLS-medical laboratory scientist, pg-picogram, plt-platelet, PLT-platelet count, RDW-red blood cell distribution width, RNA-ribonucleic acid, RPI-reticulocyte production index, wbc-white blood cell, WBC-white blood cell count, μL-microliter