Automated Blood Counts in Clinical Practice

Overview

Image courtesy of Ed Uthman (Flickr). CC BY

This is a problem-based tutorial on the interpretation of automated cytometry data in diagnosis of common hematologic conditions. version 1.0(i)


The purpose of this programme is to instruct medical students and practitioners on the significance and interpretation of blood indices that are now being reported by automated blood counters. These highly technical instruments are in wide use now in Ghana, and they provide information in addition to the standard haemoglobin and haematocrit; information that may be very helpful if they are understood.

Author(s): Prof. Ohene K. Opare-SemView Details of Author
Year: 2009
Keywords: automated cytometry, blood counts,
Licensing Condition:

cc-by-nc© 2009, KNUST

Unless otherwise noted, the content of this programme is licensed under the terms of a Creative Commons Attribution-NonCommercial 3.0 Unported License.

Disclaimer

 

Any medical information in this material is intended to inform and to educate and is not a tool for self-diagnosis or a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional. You should speak to your physician or make an appointment to be seen if you have questions or concerns about this information or your medical condition. 

 

Note: You assume all responsibility for use and potential liability associated with any use of the material. Material contains copyrighted content, used in accordance with international law. Copyright holders of content included in this material should contact the authors with any questions, corrections, or clarifications regarding the use of content. The Kwame Nkrumah University of Science and Technology (KNUST) and the Regents of the University of Michigan do not license the use of third party content posted to this site unless such a license is specifically granted in connection with particular content. Users of content are responsible for their compliance with applicable law.

 

Introduction

 

Welcome to Automated Blood Counts in Clinical Practice!

Introduction to the Course(video) - Dr. Engleberg interviews Dr. Opare-Sem about this programme.


The purpose of this programme is to instruct medical students and practitioners on the significance and interpretation of blood indices that are now being reported by automated blood counters. These highly technical instruments are in wide use now in Ghana, and they provide information in addition to the standard haemoglobin and haematocrit; information that may be very helpful if they are understood.

 

The cytometric data gives information about erythrocytes that cannot be fully appreciated from viewing a blood smear. Whereas a human may review a few hundred cells when viewing a smear, the cytometer collects data on thousands of cells and summarises it in the form of statistics. This programme will demonstrate how to use these statistics.

 

Objectives

 

To obtain maximum benefit from the programme, you are advised to go through the teaching cases with the following approach:

 

  1. Look at the normal RBC size distribution curve and normal blood smear.
  2. Procede to review the brief case synopses in each group (microcytic, normocytic, etc.) and review the panel of RBC indices.
  3. Click on the link to hear Dr. Opare-Sem's comments about the pathophysiology of the situation.
  4. Try to visualise what you think the RBC size distribution curve will look like, and then click on the link to view the curve.
  5. Try to visualise what the blood smear would look like, then click on the link to see the smear.

 

Lesson Content

 

AUTOMATED CYTOMETRY

FLOW CYTOMETRY:

A high-speed jet of a dilute suspension of blood cells flows perpendicularly to a sensor. The sensor may be an impedance (electric current) or light beam detector. As the each cell passes through, there is an interruption of the current or light beam that is proportional to cell size; the magnitude of this interruption is recorded.

 

Typically, 10,000 cells can be counted in 30 - 60 seconds, and several variables can be examined at the same time. Data is displayed in histogram/scattergram form.

 

IMAGE ANALYSIS:

High-speed optical analysis of fixed cells with memory of examined cells.

 

REVIEW CASES

 

 

SELF-EVALUATION (click here after you have completed the cases in the basic programme)


References

    Haematology Reference Materials

    The articles below provide an extended background on many points made by Dr. Opare-Sem in this programme:

    Articles from e-Medicine.com (available by direct link to the on-line resource)

        * Iron Deficiency

        * Anaemia

        * Macrocytosis

        * Megaloblastic Anaemia

        * Pernicious Anaemia

        * Folic Acid Deficiency

        * Haemolytic Anaemia

        * Cold Agglutinin Disease

        * Aplastic Anaemia

        * Pure Red Cell Aplasia

        * Haemolytic-Uraemic Syndrome

     

Credits

 

knust sealOhene K. Opare-Sem, B. Med. Sci, MD, FACP

School of Medical Sciences,

Kwame Nkrumah University of Science and Technology

Kumasi, Ghana

 

 

with the collaboration of:


umichN. Cary Engleberg, M.D.

Department of Internal Medicine,

University of Michigan Medical School

Ann Arbor, Michigan, USA

 

 

 

Acknowledgment

The cover image of microcytic erythrocytes was used in accordance with its Creative Commons license. The image was created and posted by Ed Uthman at flickr.com.

 

Most of the blood smear images used in this programme were borrowed and revised from images on the WebPath site at the University of Utah. For more information about the source and ownership of these images, the viewer is referred to: http://library.med.utah.edu/WebPath/HEMEHTML/HEMEIDX.html

 

 

 

This programme was produced with support from the following:

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