2. ★ Hospital & laboratory organization
○ Departments within the laboratory
3. Anatomic Pathology
★ The clinical laboratory is usually organized under the pathologist in a
department called pathology services.
★ The anatomic section would include anatomic pathologists, histotechnologists,
and cytotechnologists, who perform studies of surgical specimens and cellular
differentiation of cancerous cell types and their morphology.
★ The anatomic pathology section differs from the clinical pathology section,
which would include all the departments of the medical laboratory where body
fluids and samples from the body are processed.
★ Both the anatomic and the clinical pathologists have a M.D. degree.
4. Clinical Pathology
★ In larger facilities, supervision of the clinical departments of the laboratory
may be provided by a pathologist who will often be a clinical pathologist,
rather than an anatomic pathologist.
★ There will then likely be a laboratory manager at the top of the laboratory
organizational chart who supervises the day-to-day operations of the
laboratory.
★ The laboratory manager may or may not be a medical laboratory
professional; some hold graduate business degrees and are concerned
mainly with the monetary flow of the laboratory and the effectiveness and
economy of providing services.
5. ★ In some laboratories, a chief technologist coordinates the daily
functions of the laboratory for the laboratory manager.
★ The chief technologist would manage department supervisors, such
as the supervisor of hematology and coagulation.
★ The department supervisors may have supervisors for each shift,
because the laboratory is most often open 24 hours per day, 7 days
per week.
★ Then the technologists would be under the direction of the
department supervisor and would in turn supervise the other
technologists and technician-level employees.
7. Hematology
★ Descriptively, hematology means “study of blood.” The Greek word root haema
literally means “blood,” and the suffix –ology means “study” or “science” of a
particular clinical site or body part.
★ An adult human has 5 to 6 liters of blood in the body.
★ Human blood and the blood of other vertebrates is composed of plasma and
formed elements such as red blood cells (erythrocytes), white blood cells
(leukocytes), and platelets (thrombocytes).
★ Most laboratory examinations are performed on blood samples and may include
the liquid or the solid portion.
★ Blood carries nutrients for the cells and oxygen for delivering needed materials to
the cells; blood also removes toxic waste products and carbon dioxide from the
body.
★ Specialized proteins derived from the immune system are also found in the plasma.
The function of white cells is chiefly as a defense against bacteria, viruses, fungi,
and protozoa that invade the body.
8. ★ The basic test performed in the hematology laboratory is the complete blood
count (CBC).
★ The CBC procedure is used to analyze a sample for the number, size, and
shape or type of both white and red blood cells.
★ It is useful in determining various types of anemia, infection, and abnormalities
of the bone marrow where the cells originate.
★ There are a number of methods for determining and calculating values for a
CBC, ranging from totally automated systems to manual counts. Other tests
commonly completed in the hematology department would include cell counts
from cerebrospinal (CSF) fluid, pleural fluid from around the cavity containing
the lungs and heart, parietal fluid from the abdominal (peritoneal) cavity,
dialysate fluid (from dialysis), and synovial fluid from the joints.
9. ★ Many major diseases may be determined from the CBC. In some cases,
cancer may be discovered or overwhelming infections of either viral or
bacterial infections are found. Dietary and genetic types of anemias may
be diagnosed from red blood cells, and cancer of the bone marrow
(leukemias) of many types may be found here. Also, deficiencies and
abnormalities of the platelets (thrombocytes) that aid in clotting may be
evaluated.
10. Coagulation
★ Coagulation is often combined with the hematology department, but
coagulation testing is extremely important for treating a number of chronic
diseases, so it can be treated as a separate department.
★ Coagulation tests are performed by using the liquid portion of blood, and the
specimen requires that an anticoagulant be added to the sample to prevent
clotting.
★ The clotting factors, of which a number remain in the plasma, enable the
laboratory worker to determine abnormalities in clotting of the blood.
11. ★ Bleeding and clotting problems may be genetic or environmental or may be
created by medically treating a person to prolong the clotting time, to prevent
clots that lead to stroke or heart attack.
★ The body also is in a precarious position as blood must be maintained as a liquid
but must be able to clot in regions where tissue damage may cause bleeding.
★ While there are a number of tests to determine abnormalities of clotting or to
monitor the medication of a patient to prolong the coagulation time, there are
two tests that are performed on a routine basis: the prothrombin time (PT) and
the activated partial thromboplastin time (APTT).
★ One of these lines of testing involves the use of extremely potent anticoagulants
that may be injected in an extremely small area of the brain, lung, or heart to
dissolve clots that may be life threatening. If treated quickly enough, emboli
(clots) that can cause certain strokes and heart attacks and emboli of the lungs
may be quickly dissolved, thereby minimizing tissue damage to these organs
12. Immunohematology (blood banking)
★ The blood bank provides for a safe blood supply for patients requiring
transfusions.
★ Units of blood are screened for communicable diseases and are stored in
conditions making contamination of the blood unlikely.
★ Some diagnostic tests are performed by the blood bank, but its chief tasks are to
store and test blood for compatibility before transfusing it into the patient.
★ Blood products are also a vital part of a full-service blood bank. Some patients
require transfusions of white blood cells as well as red blood cells. Platelet
transfusions for patients who are deficient in levels of platelets (thrombocytes)
required for forming a functional clot may receive platelet-rich plasma. Certain
clotting factors are also concentrated for use by patients with abnormal clotting
mechanisms.
13. ★ Units of blood are tested for the ABO grouping and the Rh type, as well as for
the presence of HIV or hepatitis infection.
★ The basic tests for determining if a unit of blood is compatible with a patient
are blood group and type.
★ Determination of compatibility is performed by a test called antibody-antigen
reactions.
★ Certain maternal tests are performed for expectant mothers to determine if
they have Rh or ABO incompatibility between the mother and the fetus, and
the mother is monitored throughout her pregnancy in some cases.
14. Clinical chemistry
★ Hundreds of chemistry examinations for the blood are performed daily in most
chemistry laboratories.
★ It is not cost-effective to perform all of the chemistry procedures that may be
ordered, as some are required at such low volumes that it is economically wise to
send these to a reference laboratory. The majority of procedures are performed on
a daily basis.
★ Many of these tests are grouped together in panels or groups of tests that help to
differentiate between various disease states.
★ The large automated instruments used are extremely accurate and specific for
many acute and chronic diseases.
★ This department provides more definitive result used in rapid diagnosis than almost
any other laboratory section, as the routine tests are available quickly and at any
time.
15. ★ The presence of many different types of organic and biochemical constituents in
the blood and other body fluids aids in diagnosing various diseases. For instance,
if the kidneys are not properly functioning, there will be an inordinate level of toxic
wastes in the liquid portion of the blood, either serum or plasma, indicating that
the kidneys are not ridding the body of waste products. And in some cases,
malfunction of the kidneys may cause the loss of materials such as minerals and
proteins that the body should be reabsorbing and using in its metabolism.
★ When certain tissues are damaged, enzymes peculiar to a particular tissue or
organ will cause a rise in certain enzymes as the cells die, giving a clue as to the
tissues being damaged.
★ Tests for therapeutic drug levels and drugs of abuse are commonly performed in
the clinical chemistry department.
★ Some large hospital laboratories may have several sections within the chemistry
department that perform only certain specific and specialized procedures.
16. Serology (Immunology)
★ Serological tests to determine the immune response to an organism are
performed in several sections of the laboratory and not in a single
department.
★ The immune system is the basis of protecting the body from invasions by
microorganisms such as bacteria, viruses, and parasites such as protozoa.
★ When the body is attacked, the immune system leaps to the body’s defense,
and its activity in protecting itself gives information that can be used to
diagnose the illness.
17. ★ White cells attack organisms directly, but the blood will contain proteins called antibodies when an
organism is introduced into the body. These antibodies are almost completely specific to a
particular organism, with some exceptions, and if the laboratory worker tests for these antibodies, it
is an indirect test for infection by specific antigens (the organism is the antigen in infections).
★ Allergy tests utilize several mechanisms to determine the products to which a patient may suffer an
allergic reaction when coming in contact with the body. This is also a serological test.
★ Other serological tests are available to test for the toxins produced by certain organisms. In some
cases, a direct test is done by testing for the actual organism itself (bacterial, viral) rather than by
testing for antibodies produced against the organism or for the toxins it produces.
★ The serology procedures are evolving rapidly as new technology emerges, and immunologic
hormones, lymphokines, and monokines from certain lines of white cells have been isolated and
are used to treat diseases that were previously untreatable, such as certain types of cancers.
★ Sophisticated instrumentation is being developed to utilize the increasingly larger numbers of
antibodies in increasingly smaller quantities that may be used to fight certain infections and
diseases. This department could grow exponentially in coming years with new developments.
18. Microbiology
★ Detecting the presence of and identifying pathogenic (disease-causing)
microorganisms is the focus of the microbiology laboratory.
★ Microbiological studies represent one of the earliest efforts to detect and treat
human diseases in the laboratory. The early development of the microscope
by Antonie van Leeuwenhoek in the late 1600s gave a boost to correlating the
presence of microorganisms and certain diseases, as the device enabled a
visual picture of causative germs.
19. ★ Clinical microbiology includes the study of bacteria, viruses, fungi, and
parasites.
★ In the case of parasitology, protozoa may be visualized and the eggs of
many intestinal parasites found in the stool; this facilitates the diagnosis of
a parasitic infection.
★ Bacteriology is a major area of most laboratories, and only the larger
microbiology departments perform other than routine growing of and
identification of bacteria on a nutritive medium from specimens obtained
from the patient. Most bacteria can be grown on selective and differential
media that are developed to provide materials needed for specific bacteria
to grow and reproduce. Not all strains of bacteria have the same nutritive
requirements, so a number of types of media are required to grow a wide
variety of organisms. Some bacteria, in particular Treponema pallidum,
which causes syphilis, cannot be cultured on commercial media, so other
methods of identification are required.
20. ★ Clinical microbiologists additionally perform an important role in determining
the appropriate antibiotic for the physician’s use in treating diseases.
★ Injudicious use of antibiotics for viral infections such as colds leads to a
greater variety of organisms not susceptible to the medication, and hospitals
are often the source of infections in patients who are treated in the facility.
★ Many infectious bacterial organisms are now being identified with new and
emerging technology, where the sequence of DNA is specific for identifying
various species of microorganisms.
★ But microbiology relies mostly on the skills and intuitive knowledge of the
technologist or microbiologist. Many microbiologists earn a master’s or
doctoral degree, enabling them to perform at a higher level of expertise.
