CLINICAL LAB SCIENEC

326
ESSENTIALS OF CLINICAL LABORATORY SCIENCE
almost routinely along with a urinalysis to assess a patient’s health. Changes in body
fluids signal malfunctions in the body ranging from minor to extremely serious
conditions. As is possible with a complete urinalysis, a number of conditions can be
easily determined by a complete blood count (CBC). The basic tests determine if an
infection is present or if a state of anemia is present. Coagulation is the process that
leads to clotting of the blood. Usually, a coagulation study is included in the hematology
section to determine if a person is likely to bleed spontaneously (hemorrhage)
of if the blood clots too readily, which might lead to a stroke or heart attack.
Students of clinical laboratory medicine should already have a basic knowledge
of the formation of blood and its functions from anatomy, physiology, and
other academic courses. The material presented is not intended to be a “how to”
for procedures in urine and body fluids analyses. However, this chapter’s “In the
Lab” activities will serve to combine the theory of the laboratory department
with the practice of several basic procedures.
Exploration of the basics in the background of laboratory medicine and
safety, and an overall orientation into the field of clinical laboratory medicine,
will help the student to become well-equipped to meet the challenge of this
demanding profession and achieve a meaningful level of knowledge required for
advancement and for improving skills. This chapter is designed to facilitate practical
classroom laboratory experience. The graphics show some of the equipment
the medical laboratory student will be using. It is important that the student possess
sufficient knowledge regarding safety in handling of human specimens and
a respect for the care that must be exercised to compile accurate reports used in
the treatment of patients.
Hematology
Hematological tests for routine purposes require a CBC. Several tests for anemia
are included in the CBC and provide a basic means for determining the type of
anemia. Most of these tests are done on automated instruments, which provide
a complete picture in just seconds. For practical training, it is important for a
student to be able to perform these tests manually to understand the functions
of the equipment and to know when a malfunction has occurred or if the results
do not match, as with a random error. Certain conditions of the blood may also
provide less-than-accurate results and lead to mistreatment or no treatment in a
patient needing medical attention.
A CBC contains a red blood cell (RBC) count, a white blood cell (WBC)
count, a hemoglobin (Hgb), and a hematocrit (Hct). Both the RBCs and the
WBCs are made into a thin smear and stained for examination under a microscope.
All the individual tests that make up a CBC should correlate with each
other, so in a case of either the RBCs or WBCs being normal or abnormal, the
results will fit together in a pattern that the technician or technologist will understand
following completion of a course in hematology.
Coagulation
Some patients receive medications that prevent the blood from clotting at a normal
rate, creating a prolonged coagulation time. This treatment helps to prevent
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