A Methodical Approach to Interpreting the Platelet Parameters of the Complete Blood Count

Kathy Doig; Michelle Butina

doi:10.29074/ascls.30.3.194

Kathy Doig, PhD, MLS(ASCP)^CM SH(ASCP)^CM⇑
1. Professor Emeritus, Biomedical Laboratory Diagnostics Program, Michigan State University, E. Lansing, MI
Michelle Butina, PhD, MLS(ASCP)^CM
1. Associate Professor, Medical Laboratory Science Program, University of Kentucky College of Health Sciences, Lexington, KY

Address for Correspondence: Kathy Doig, PhD, MLS(ASCP)^CM SH(ASCP)^CM, 354 Farm Lane, Rm. N322, E. Lansing, MI 48824, 517-353-1985, doig{at}msu.edu

List the platelet parameters of a complete blood count (CBC) and additional special tests of platelet age.
Describe the principle of analysis for each of the platelet parameters of the CBC.
Describe the steps for interpretation of the platelet values on a CBC.
Recognize results consistent with spurious platelet values and recommend procedures to correct them.
Given CBC results, apply a methodical approach to thoroughly interpret each platelet value using the diagnostic heuristic provided below.

Abstract

Consistent use of a methodical approach to interpreting complete blood count (CBC) results can help detect spurious results that require remedy before results are reported. It can also help ensure that no clinically important information is overlooked during diagnostic interpretation of the results. The steps for interpreting the platelet portion of the CBC are:

Interpret the total platelet count relative to the reference interval.
Examine the mean platelet volume and compare to the reference interval.
Examine the platelet distribution width and compare to the reference interval.
Examine the platelet distribution histogram for evidence of interferences. Take steps to correct these and reassess Steps 1-3 based on the revised results.
Examine the immature platelet fraction and compare to the reference interval.
Correlate the numerical parameters with platelet morphology.
Correlate platelet results with red blood and white blood cell parameters and conduct clinical assessment of the patient's values.

Explanations for conducting the evaluations are provided and the steps are applied to example cases to demonstrate the approach to interpreting the platelet parameters of the CBC.

ABBREVIATIONS: CBC - complete blood count, rbc-red blood cell, RBC-red blood cell count, MCV-mean cell volume, plt-platelet, PLT-platelet count, RDW- red blood cell distribution width, RNA-ribonucleic acid, wbc-white blood cell, μL-microliter

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