#2964. Blood Film Examination

Science, level: Middle
Posted Fri Oct 31 12:48:35 PST 2003 by Daniel Haun (dhaun@lsuhsc.edu).
LabPartners
LSU Health Sciences Center, New Orleans. LA
Materials Required: web access
Activity Time: one period
Concepts Taught: applied science - medical diagnosis

Blood Film Examination Lesson Plan
LabPartners- Blood Film Examination
Blood Smear Lesson Plan.doc
8/12/03
Grade Level(s): 6,7,8,9,10
Subject: Science/ biology
Objectives:
The student will be able to:
1. Successfully identify the different white blood cells in the exercise
2. Calculate the percentage of each type of cell
3. Determine which cell type(s) fall into the abnormal range
4. Answer the review questions or choose the correct diagnosis using the web
links as a reference.
Description:
This web-based science activity allows the student to directly experience the
evaluation of human blood films in the diagnostic process. First, the students will
learn to recognize common examples of White Blood Cells and thereby learn the
names and characteristics of the cells (knowledge). By correctly selecting the
cell types, they will demonstrate comprehension. In the exercise they will directly
experience the use of this skill (application). And finally, they will analyze the lab
finding in light of the patient symptom by using available web resources.
Definitions:
The types of WBCs: Neutrophils, Lymphocytes, Monocytes, Eosinophils,
Basophils.
Neutrophils -bacteria killing white blood cells
Lymphocytes - antibody producing white blood cells
Monocytes -white blood cells which ingest and destroy bacteria
Eosinophis -white blood cells present in parasitic and allergic reactions
Basophils -white blood cells normally present in low numbers
Background information:
White Blood Cells, Red Blood Cells and blood platelets are the three cellular
components which make up the blood. Each cellular element functions in a
unique way. The red blood cell carries oxygen, the platelets initiate blood
clotting and the white blood cells (WBCs) are the soldiers of the immune system.
The WBCs are the only cellular component of the blood which are subdivided into
functional categories. They are as follows: Neutrophils, Eosinophils, Basophils,
Monocytes and Lymphocytes. The neutrophil (neutral staining they stain neither
red nor blue) belongs to a family of white cells called granulocytes these cells kill
bacteria. The eosinophil (pick up red portion of dye) and the basophil (pick up
blue portion of dye) also belong to the granulocytic family and are associated
with allergic reactions. The largest white cell is called a monocyte and its
purpose is to ingest and destroy bacteria. The lymphocyte, which is the smallest
Blood Film Examination Lesson Plan
LabPartners- Blood Film Examination
Blood Smear Lesson Plan.doc
8/12/03
white cell is involved in immune surveillance and antibody formation. The cells
are classified according to their cellular composition and staining characteristics.
Proper identification and classification of each white cell is important in
determining the kind of disease a person has. Each white cell has plays a unique
role in protecting people from infectious agents.
Prerequisites:
The student must be able to calculate percentages and use a web browser.
Materials needed:
Very little preparation is necessary. The teacher should access the site and
explore a bit to become familiar with the navigation. It helps to maximize the
browser window (using the F11 key for PCs).
1. Computer with access to the internet
2. Your Hospital Laboratory -- Outreach Website
www.mclno.org/labpartners/index.htm
3. Calculator - to calculate percentages
Procedures:
1. Pre test: The pre test is administered and collected.
An examination is provided for the pre test and post testing assessment. Data
from the analysis of two questions must be submitted for the cash award. We
are specifically interested in pretest and post test data expressed in whole
numbers from these two questions:
7. Most laboratory tests are performed by _____
a. professional laboratory scientists
b. nurses
c. doctors
d. none of the above
8. I would rate the danger of catching AIDS in a health care career as _____
a. extremely low
b. moderately low
c. moderately high
d. very high
2. Introduction
Introductory comments:
The hospital laboratory applies scientific inquiry to answer questions about
health. Laboratory tests are performed by professionals called Medical
Technologists or Clinical Laboratory Scientists. The clinical laboratory places
more than 70% of the information on a typical patient's chart. But the laboratory
is mostly hidden from the public
Blood Film Examination Lesson Plan
LabPartners- Blood Film Examination
Blood Smear Lesson Plan.doc
8/12/03
It is useful to get the student's attention by having them imagine a problem that
a family member might have. Using a family member will open the student to the
emotion and make them more receptive.
"Suppose that your little brother or sister was very short of
breath and was brought to the hospital for evaluation. The
doctor might order some blood tests and one test would be to
evaluate a thin smear of their blood."
3. Begin the exercise
The student will access the website and enter the student's portal. Start with
number 1, the introductory presentation(s). Two options are available, either
choose a short web-based slide presentation or view two, three minute video
clips. The clips are available in three sizes and download time varies with file size
and connection speed. If you have doubts about the speed of the connection,
simply use the presentation option. Here is a direct link.
http://www.mclno.org/labpartners/heme_movies/index.htm
When the presentation is finished, you will return and can then select option 2
(complete the blood smear exercise) Again, it is useful to maximize your window
before starting the exercise.
4.0 Completing the Blood Smear Exercise
4.1 Student will access the website and enter the student's portal.
4.2 The student will select the first of the two patients offered.
4.3 Explain to the student the importance of the presenting symptom (e.g.
"shortness of breath").
4.4 Let student click to start the exercise.
4.5 WBC identification (differential) process will begin. The student might first
review the help screens and then come back to select the cell type by clicking
the appropriate box.
4.6 Twenty-five cells are presented and the student will identify each WBC by
clicking on the correct cell type.
4.7 If the cell is identified correctly, the program will proceed to the next cell.
4.8 If cell is misidentified the "oops" screen will appear. The help screen provides
coaching slides that explain important cell appearances and can be accessed at
any time.
4.9 The "oops" screen will continue to appear until the cell is correctly identified.
Once all 25 cells have been identified correctly the tally slide will appear with the
total number of each cell type counted.
4.10 Students will then calculate the percentage of each cell type seen (a help
screen is also available to assist with the calculation).
Blood Film Examination Lesson Plan
LabPartners- Blood Film Examination
Blood Smear Lesson Plan.doc
8/12/03
4.11 The student is then asked by the program to select the cell type that is
abnormal by comparing the percentage obtained with the provided "reference
range".
4.12 Once correctly identified, the student is then prompted to answer the
review questions using the provided web links.
4.14 The student records the answers and keywords on the Handout /
Worksheet.
4.15 The student can then complete the exercise for the second patient.
4.15 The post-test can then be administered.
Conclusion: The teacher can then lead a discussion about the diagnostic
process. The white blood cells play an important role in the immune response
and the blood film examination reveals much about the status of the immune
systems. Observing an elevated or decreased number of one cell type, often
points the doctor to a direct and correct diagnosis. In performing these types of
analyses, the laboratory generates important and practical scientific data.
Assessment:
1. Completion of the exercise will demonstrate that the student has acquired cell
recognition skills (psychomotor). The exercise allows for practice and making
errors while learning but all cells must ultimately be correctly identified to
reach the end.
2. Evaluate the accuracy of the calculation. The exercise does not check the
calculation.
3. The student should come to the correct diagnosis and answer the review
questions correctly by using the search engine or links. Patient number one
has bronchial asthma. Patient number two has an appendicitis and the correct
answers to the review question is selection three bacterial infection.
4. The pretest/ post-test will measure the cognitive and affective impact of the
exercise. Questions 1-5 measure cognitive impact and the correct answers
are as follows: Q1: b. to fight bacterial infections; Q2: d. none of the above
Q3: a. eosinophils; Q4: b. They are cell fragments that control bleeding; Q5:
b. they contain the blood's hemoglobin, which is red in color. Our study is
especially interested in the measuring the change in students perception
about safety in health care careers and knowledge of laboratory science.
Questions 6-10 focus on this perception. In fact, every hospital has a
laboratory staffed with professional laboratory scientists and there are many
applied science career opportunities for people with two-year and four-year
degrees in laboratory science.
Blood Film Examination Lesson Plan
LabPartners- Blood Film Examination
Blood Smear Lesson Plan.doc
8/12/03
Cross curriculum ideas:
Surveying the environment: The Blood film examination has similarities with
environmental survey techniques. With the blood film, the survey is of the
patient's blood with the results pointing to the health or state of the patient. In
the case of an ecosystem, the survey points to the heath of the environment.
Mathematics: The exercise illustrates the practical application of the
percentage calculation.
Health: The exercise introduces several new words to the student's vocabulary
and illustrates the relationship of symptom, lab finding and diagnosis. It also
introduces the concept of becoming one's own advocate as a patient. By
becoming knowledgeable about finding information on clinical conditions, the
patient can ask better questions and monitor their own care. This is in keeping
with a major initiative by the Joint Commission on Accreditation of Healthcare
Organizations called "Speak Up".