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http://evolve.elsevier.com/Warekois/phlebotomy CHAPTER 14 Special Collections and Procedures
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213
BLOOD DONOR COLLECTION
Blood donation is a vital link in the health care system, and the phlebotomist plays a central role in the
collection of donated blood. Blood banks collect
and store donated blood for use in both emergency
and scheduled transfusions. Guidelines for uniform
collection procedures and safeguards have been
established by the American Association of Blood
Banks (AABB) and the U.S. Food and Drug Administration (FDA).
Potential donors must be screened to ensure
that the donation is not harmful to the donor or
the recipient. Donors must be at least 17 years old
(16 years in some states), weigh a minimum of
110 pounds, and not have donated blood in the past
8 weeks. Donor screening is usually done by the
phlebotomist. All information provided during the
screening is condential. The screening process is
performed every time a person donates blood.
Screening involves the following:
• Registration. The donor must provide his or her
name, date of birth, address, other identifying
information, and written consent. All informa-
tion must be kept on le for at least 10 years.
• Interview and medical history. This is done in pri-
vate by a trained interviewer. All responses are kept
condential. Potential donors may be rejected for a
variety of reasons, including exposure to human
immunodeciency virus (HIV) or viral hepatitis,
current drug use, or cardiovascular conditions.
• Physical examination. The donor’s weight, tem-
perature, blood pressure, pulse, and hemoglobin
level are determined. Hemoglobin is usually
measured with a drop of whole blood from a dermal puncture. A hematocrit may be substituted
for the hemoglobin determination.
Collection Procedure
Blood is collected by the unit, whose volume is 400 to
500 mL, or approximately 0.5 liter (Figure 14-2). It is
collected directly into a sterile plastic bag, which
hangs below the collection site and lls by gravity.
The weight of the lled bag triggers a clamp that
stops the collection. A 16- to 18-gauge needle is used
for collection. This large needle speeds the collection
and prevents hemolysis.
A large vein in the antecubital area is used for
donor collection. The site is cleaned rst with soap
and water and then with iodine. After the puncture,
the needle is secured to the arm with tape to prevent
motion during the collection. The donor is in-
structed to pump his or her st to increase ow.
(Hemoconcentration may result from this action,
but this is not a concern with blood collected for
transfusion.) The phlebotomist stays with the donor
during the collection and observes for any signs of
distress, anxiety, or pale skin. After needle removal,
the phlebotomist instructs the patient to apply rm
pressure to the site and bandages the site when the
bleeding has stopped.
Autologous Donation
An autologous donation is blood donated by a
patient for his or her own use later. Patients planning surgery often make autologous donations before the procedure. This may reduce the likelihood
of complications and may be especially useful for
patients with rare blood types. Because multiple
units might be needed during surgery, patients may
need to donate several times. A patient can donate
as often as every 72 hours, assuming that his or her
health is good. Hemoglobin is checked during the
donation series and should not fall below 11 g/dL.
FIGURE 14-2 A unit of blood has a volume of approximately
400 to 500 mL.
Copyright 2016, 2011, 2007, 2002 by Saunders, an imprint of Elsevier Inc. All rights reserved.
Therapeutic Phlebotomy
Therapeutic phlebotomy is the removal of blood
from a patient’s system as part of the treatment for
a disorder. The principal disorders treated by therapeutic phlebotomy are polycythemia, a disease
characterized by excessive production of red blood
cells (RBCs), and hemochromatosis, an excess
of iron in the blood. In both cases, periodic removal
of a unit of blood may be part of the treatment
program. Because such a large volume must be
removed, therapeutic phlebotomy is performed in
the donor center, although a special area may be set
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CHAPTER 14 Special Collections and Procedures http://evolve.elsevier.com/Warekois/phlebotomy
aside for this purpose. This blood cannot be used for
transfusion in most instances.
SPECIAL SPECIMEN HANDLING
Cold Agglutinins
Cold agglutinins are antibodies often formed in re-
sponse to infection with Mycoplasma pneumoniae,
a cause of atypical pneumonia. The antibodies created by the immune system during the infection
may also react with RBCs at temperatures below
body temperature, causing them to stick together,
hence cold agglutinins (agglutination is the process of sticking together). Because the agglutinins
attach to RBCs at cold temperatures, the specimen
must be kept warm until the serum is separated from
the cells to avoid falsely lowering the agglutinin
levels. A patient with cold agglutinins is sometimes
asymptomatic, but the presence of the antibodies
can cause problems if the patient’s body temperature falls. This may occur when a patient undergoes
cardiopulmonary bypass, for example, which requires cooling the patient to slow the metabolic
activity of the heart. If the patient has undetected
cold agglutinins, this hypothermia will cause
dangerous agglutination of red blood cells. A presurgical screening is therefore sometimes required
to detect these cold agglutinins.
To collect a cold agglutinin sample, prewarm a
plain red-topped tube (containing no gel) in a 37° C
incubator for 30 minutes. To keep the specimen
warm, it can be wrapped in an activated heelwarmer pack or placed in the incubator. Deliver the
specimen as quickly as possible to the laboratory.
redissolve when warmed. These samples should be
collected and handled in the same manner as a cold
agglutinin sample.
Chilled Specimens
A number of tests require that the specimen be
chilled immediately after collection (Box 14-3).
Chilling is used to prevent chemical changes that
would alter test results. The sample should be
placed in crushed ice or in an ice and water mixture
and immediately delivered to the laboratory. The
temperature should be 1° C to 5° C, and the sample
should be transported to the laboratory for testing
within 5 minutes of collection (Figure 14-3). A
lactic acid sample should also be collected without
a tourniquet, and without the patient making a st,
since both of these can raise lactic acid.
Light-Sensitive Specimens
Exposure to light can break down or alter certain
blood constituents (Box 14-4). Specimens to be
tested for these constituents must be protected from
light after collection. This is done by wrapping the
tube in aluminum foil immediately after collection
(Figure 14-4). An amber-colored microtube can
Cryofibrinogen and Cryoglobulin
Warm collection and storage are required for two
other types of samples: cryobrinogen (an abnormal
type of brinogen) and cryoglobulin (an abnormal
serum protein). Both precipitate when cold and
BOX 14-3 Tests Requiring Chilled Specimens
• Adrenocorticotropic hormone
• Ammonia
• Arterial blood gases
• Glucagon
• Gastrin
• Homocysteine
• Lactic acid
• Parathyroid hormone
• Pyruvate
FIGURE 14-3 Samples that must be kept cold should be placed
in crushed ice or in an ice and water mixture with a temperature of
1° to 5° C.
BOX 14-4 Blood Constituents That are Light
Sensitive
• Beta-carotene
• Bilirubin
• Porphyrins
• Vitamin A
• Vitamin B
Copyright 2016, 2011, 2007, 2002 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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the date, time, and identication of the handler
(Figure 14-5).
The National Institute on Drug Abuse (NIDA)
has established requirements for patient preparation
and specimen handling in COC samples. These
requirements include the following:
• The purpose and procedure of the test must be
explained to the patient.
• The patient must sign a consent form.
• The patient must present picture identication.
• The specimen must be labeled appropriately to
FIGURE 14-4 Samples that must be protected from light should
be wrapped in aluminum foil immediately after collection.
Amber-colored tubes also can be used.
establish a COC.
• The specimen must be sealed in such a way that
any tampering can be identied.
• The specimen must be placed in a locked con-
tainer before transport to the testing site.
• The recipient must sign for delivery of the
BOX 14-5 Time-Sensitive Blood Constituents
specimen.
215
• Adrenocorticotropic hormone (ACTH)
• Ammonia
• Brain natriuretic peptide
• Lactate
• Platelet aggregation
• Prostatic acid phosphatase
be used for dermal collection (e.g., of bilirubin
samples).
Time-Sensitive Specimens
Some analytes are unstable or volatile. Because of
this, the tests must be performed rapidly after the
sample is taken. Box 14-5 lists analytes that are
time sensitive.
Legal and Forensic Specimens
Blood specimens may be collected for use as
evidence in legal proceedings, including alcohol
and drug testing, deoxyribonucleic acid (DNA)
analysis, or paternity or parentage testing. Such
samples must be handled with special procedures
designed to prevent tampering, misidentication, or
interference with the test results.
The most important concept in handling forensic
specimens is the chain of custody (COC), a protocol that ensures that the sample is always in the
custody of a person legally entrusted to be in control
of it. The chain begins with patient identication
and continues through every step of the collection
and testing process. COC documentation includes
special containers, seals, and forms, as well as
Legal Alcohol Collection
Collection for alcohol testing is most common in
emergency departments. This collection requires
special handling to prevent alteration of the test
results. Important features of alcohol testing include the following:
• The site must not be cleaned with alcohol, as this
would falsely elevate the result. Instead, use
soap, water, and sterile gauze or another nonalcoholic antiseptic solution.
• Tubes must be lled as full as the vacuum allows
to minimize the escape of alcohol from the
specimen into the space above.
• Note on the requisition form that the site was
cleansed with soap and water or another a nonal-
coholic solution.
BLOOD SMEARS
Blood smears are made to allow microscopic
examination of the blood cells. The blood smear is
used for determining the proportion of the various
blood cell types, called a differential count; count-
ing reticulocytes; and performing special staining
procedures.
FLASHBACK
You learned about blood cell types in Chapter 7.
Blood Smear Preparation
Blood smears are usually prepared following dermal puncture. Slides are made in pairs. Figure 14-6
illustrates a good smear, as well as several examples
Copyright 2016, 2011, 2007, 2002 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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CHAPTER 14 Special Collections and Procedures http://evolve.elsevier.com/Warekois/phlebotomy
FIGURE 14-5 Chain of custody documentation includes special containers, seals, and forms, as well as the date,
time, and identification of the handler. (From Kaplan LA, Pesce AJ: Clinical chemistry: Theory, analysis, correlation,
ed. 5, St. Louis, 2010, Mosby.)
of unacceptable smears. Procedure 14-2 outlines
how to prepare blood smears.
Malaria Smears
Malaria is caused by blood-borne protozoa of
the genus Plasmodium. A patient with malaria
has cycles of fever and chills that coincide with
the life cycle of the parasite in the bloodstream.
Malaria is diagnosed with a blood smear, drawn
as a stat or timed collection just before the onset
of fever or chills. The test requires two to three
regular smears, plus a thick smear. To make the
thick smear, use a larger drop of blood, and
spread it out to only about the size of a dime
(Figure 14-7). The sample must be allowed to
Copyright 2016, 2011, 2007, 2002 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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A
217
B
FIGURE 14-6 Blood smear slides. A, A good smear. B, Several examples of unacceptable smears. (From
Rodak BF, Fritsma GA, Keohane E: Hematology: Clinical principles and applications, ed. 4, St. Louis, 2012,
Saunders.)
dry for at least 2 hours; it is then stained to reveal
the parasites.
REVIEW FOR CERTIFICATION
Routine phlebotomy specimens are often collected
in the early morning for inpatients and nursing home
patients because most patients are in the basal state
at that time. A 12-hour complete fast may be
required for some tests, especially glucose and
triglycerides. The phlebotomist must ensure that
the patient has complied with the fast and note any
irregularities on the requisition. Timed specimens
include the 2-hour postprandial test for diabetes mellitus and the GTT for diabetes mellitus, gestational
diabetes, hyperglycemia, and hypoglycemia. TDM
tests are timed to coincide with the peak or trough of
serum drug levels. Testing for the presence of microorganisms in the blood requires a BC, with collection at timed intervals from multiple sites, using
aseptic collection of the proper volume. Units of
blood may be collected for donation to the blood
bank or for use by the patient during later surgery.
Therapeutic phlebotomy removes blood from the
patient, most often to treat polycythemia or hemochromatosis. Samples to test for cold agglutinins,
antibodies formed against Mycoplasma pneumoniae,
must be kept warm after collection, as must those for
cryobrinogen and cryoglobulin. Other specimens
may require chilling or protection from light.
Legal or forensic samples require documentation
of the COC, a protocol that ensures that the sample
Copyright 2016, 2011, 2007, 2002 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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CHAPTER 14 Special Collections and Procedures http://evolve.elsevier.com/Warekois/phlebotomy
PROCEDURE 14-2
Blood Smear Preparation
1. Prepare the smears.
Place one drop of blood on a clean slide, ½ to
1 inch from the end, centered between the
two sides.
Place the edge of a second slide, the “spreader,”
onto the rst slide in front of the blood at a
25- to 30-degree angle, and draw it back to
just contact the drop.
Move the spreader slide forward, away from the
drop, in one continuous movement to the end
of the slide. The blood will be drawn along
over the slide.
To make the second slide, place a drop of blood
onto the spreader slide. Using the rst slide
as the spreader, repeat the procedure.
Dry and label the slides. Use pencil on the
frosted end; do not use pen, as ink may run
when the slide is stained.
2. Examine the smears.
An acceptable smear must have a feathered
edge, meaning that the cells appear to thin
out farther from the original drop. At the far
end, you should see a very thin transparent
layer. This is the area from which the differential count is made. See Figure 14-6 for
examples of blood smears. Table 14-3
describes common problems with smears
and their likely causes.
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219
FIGURE 14-7 The thick smear for a malaria sample. This blood smear uses a larger drop of blood and is spread
out only to about the size of a dime.
TABLE 14-3 Unacceptable Smears and Their Causes
Result Cause
Holes in the smear Dirty slide
No feathered edge Drop that is too large
Drop that is not placed close enough to the far edge of the slide
Spreader slide that is lifted before it reaches the end of the sample slide
Smear that is too thick and long Drop of blood that is too big
Angle of the spreader slide .30 degrees
Smear that is too thin and short Drop of blood that is too small
Angle of the spreader slide ,25 degrees
Streaks in the feathered edge Chipped or dirty spreader slide
Spreader slide that is not placed flush against smear slide
Drop of blood that is in front of the spreader slide
Uneven distribution of blood Uneven pressure on the spreader slide
Uneven movement of the spreader slide
Copyright 2016, 2011, 2007, 2002 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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CHAPTER 14 Special Collections and Procedures http://evolve.elsevier.com/Warekois/phlebotomy
BI BL IOG R AP H Y
American Diabetes Association: Standards of medical care in
diabetes, Diabetes Care 32:S13–S61, 2009.
Black JG: Microbiology principles and procedures, ed. 8, Hoboken,
N.J., 2012, John Wiley & Sons.
Blaney KD, Howard PR: Basic and applied concepts of blood
banking and transfusion practices, ed. 3, St. Louis, 2013, Mosby.
Burtis CA, Bruns DE: Tietz fundamentals of clinical chemistry and
molecular diagnostics, ed. 7, St. Louis, 2015, Saunders.
CLSI: Principles and procedures for blood cultures; Approved
guideline. CSLI document M47-A. Wayne, Pa., 2008, Clinical
and Laboratory Standards Institute.
CLSI: Procedures for the collection of diagnostic blood specimens by
venipuncture; Approved standard—sixth edition. CSLI Document
GP41-A6 (formerly H03-A6). Wayne, Pa., 2007, Clinical and
Laboratory Standards Institute.
Ernst DJ: Controlling blood culture contamination rates, Med Lab
Observer, May 2000.
Mayo Clinic Staff. Lactose intolerance, 2014. Retrieved from
www.mayoclinic.org/diseases-conditions/lactose-intolerance/
basics/tests-diagnosis/con-20027906.
Rodak BF, Fritsma GA, Keohane E: Hematology: Clinical prin-
ciples and applications, ed. 4, St. Louis, 2012, Saunders.
Tille PM: Bailey & Scott’s diagnostic microbiology, ed. 13,
St. Louis, 2014, Mosby.
is always in the custody of a person legally entrusted to be in control of it. Alcohol specimens must be
handled carefully to avoid contamination
of the sample with alcohol and prevent escape of alcohol from the blood.
Blood smears are used for differential counts, counting reticulocytes, and special staining procedures.
An acceptable smear must have a feathered edge,
prepared by careful drawing of the blood drop
across the slide using another slide.
WHAT WO ULD YOU DO?
You should not perform the draw without recleansing the site, even though it will take more time. The
potential for contaminating the sample is signicant because your gloves are almost certain to be carrying some
bacteria. No matter what your coworker may say, the laboratory will not be able to perform the proper tests
with a contaminated sample. Take your time and do it right—that is the essence of good patient care.
AVOID THAT ERROR!
Mr. Brisco needed a therapeutic drug monitoring sample. In general, these samples should not be drawn into tubes with gel because the
gel can absorb the drug. Instead, a red-topped glass tube should have been used. Before redrawing, Thomas should check with the ordering physician to determine whether the gel will interfere with the specific drug being tested.
STUDY QUESTIONS
See answers in Appendix F.
1. Dene basal state.
2. List 10 factors that inuence blood composition.
3. What three things are timed specimens most often used to monitor?
4. What is a GTT?
5. What is TDM, and why would this be ordered?
6. Why are BCs ordered?
7. What collection technique is critical for meaningful BC results?
8. Describe the screening process a potential blood donor goes through.
9. What special handling procedure is necessary for cold agglutinin samples?
10. List ve tests that require transport on ice.
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11. Explain COC.
221
12. Describe the important features of blood alco-
hol testing.
13. Explain the procedure for preparing a blood
smear.
14. Describe the procedure for preparing a thick
smear to test for malaria.
15. List the disorders for which therapeutic phle-
botomy is used. Dene the diseases based on
the word roots, prexes, sufxes, or a combi-
nation of these.
CERTIFICATION EXAMINATION
PREPARATION
See answers in Appendix F.
1. Timed specimens are most frequently collected
to monitor
a. bilirubin.
b. medication levels.
c. cold agglutinins.
d. cryoglobulins.
2. A 2-hour postprandial test is used to test for
a. blood alcohol.
b. medication levels.
c. malaria.
d. diabetes mellitus.
3. Hyperglycemia means
a. decreased glucose.
b. decreased hemoglobin.
c. increased glucose.
d. increased hemoglobin.
4. For a 3-hour GTT, how many blood samples
will be collected?
a. 3
b. 4
c. 5
d. None of the above
5. Within what time period should a patient drink
the glucose solution required for a GTT?
a. 5 minutes
b. 10 minutes
c. 15 minutes
d. 20 minutes
6. The epinephrine tolerance test determines the
patient’s ability to
a. mobilize glycogen from the liver.
b. digest lactose.
Copyright 2016, 2011, 2007, 2002 by Saunders, an imprint of Elsevier Inc. All rights reserved.
c. metabolize carbohydrates.
d. metabolize medications.
7. BC collection involves
a. a peak and a trough sample.
b. an aerobic and an anaerobic sample.
c. a chilled sample.
d. an accompanying urine sample.
8. Therapeutic phlebotomies are commonly
performed on patients with
a. hemochromatosis.
b. leukemia.
c. polycythemia.
d. a and c.
9. To collect a cold agglutinin sample,
a. warm the sample tube for 30 minutes
before collection.
b. pack the sample tube in ice before
collection.
c. wrap the sample in aluminum foil after
collection.
d. pack the sample tube in ice after
collection.
10. Which specimen requires chilling during
transfer to the laboratory?
a. Cryobrinogen
b. Cryoglobulin
c. Ammonia
d. Cold agglutinins
11. When making smears for malaria,
a. prepare two regular smears only.
b. prepare two to three regular smears
and one thick smear.
c. prepare one thick smear only.
d. prepare one regular smear and one thick
smear.
12. It is necessary for a patient to fast for 12 hours
before
a. blood donation.
b. BC.
c. GTT.
d. therapeutic phlebotomy.
13. Factors inuencing blood composition include
all of the following except:
a. altitude.
b. gender.
c. age.
d. weight.
14. Which of the following specimens is not
sensitive to light?
a. Vitamin A
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b. Lactic acid
c. Beta-carotene
d. Bilirubin
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