Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5565_Библиотеки_им_академика_М_И_Перельмана.pdf
BLOOD COMPONENT STORAGE 13
C. 21 days. However, neither ACD nor CPD are routinely used as storage solutions.
CPDA is preferred to ACD or CPD and its use can add 2 weeks to the storage time.
________________________________ ________________________________
夝
Question 4: If RBCs are stored in CPDA-1 storage solution, what is the maximum
number of days the unit can be stored?
A. 5
B. 14
C. 21
D. 35
E. 42
D. 35 days.
________________________________ ________________________________
夝
Question 5: If RBCs are stored in an additive solution, what is the maximum number
of days the unit can be stored?
A. 5
B. 14
C. 21
D. 35
E. 42
E. 42 days. Most additive solutions contain varying concentrations of preserving
agents such as mannitol, dextrose, or adenine.
________________________________ ________________________________
夝
Question 6: Rejuvenating solutions, which often contain pyruvate, inosine, phos-
phate, and adenine, can extend the expiration date of CPDA-1 RBCs by ___ days.
A. 1
B. 3
C. 7
D. 10
E. 14
B. 3 days. The purpose of rejuvenating solutions is to replace depleted ATP and 2,3-
DPG. Inosine can be toxic; therefore, units prepared with a rejuvenating solution
containing inosine must be washed before administration.
14 PRACTICAL SELF-ASSESSMENT FOR TRANSFUSION MEDICINE PROFESSIONALS
________________________________ _______________________________
夝
Question 7: Which statement about cryopreservation of RBC units is true?
A. Liquid nitrogen is replacing glycerol as a commonly used cryopreservative.
B. If red cells freeze too slowly, ice crystals may damage the cells.
C. If red cells freeze too slowly, the cells may become dehydrated.
D. Glycerol protects red cells by coating the outer surface of the cells, preventing
them from freezing too slowly.
E. Glycerol is generally removed from thawed frozen RBC units only in larger
hospitals that have purchased the necessary equipment.
C. Extracellular water freezes faster than intracellular water. Glycerol readily pene-
trates the red cell membrane and acts intracellularly as an osmotic agent to prevent
dehydration as ice crystals form outside the cells.
________________________________ _______________________________
夝
Question 8: Which statement about Fresh Frozen Plasma (FFP) is true?
A. If frozen within 8 hours of collection, FFP can be stored for up to 5 years at −18
C or colder.
B. If stored at −65 C or colder, FFP can be retained for up to 10 years.
C. If not frozen within 8 hours of collection, levels of Factors VII and X are usually
greatly reduced.
D. If FFP is not frozen within 8 hours of collection, it can still be used but must be
labeled “Plasma Frozen Within 24 Hours After Phlebotomy.”
E. FFP may be stored at 1-6 C for up to 8 hours after thawing.
D. As previously mentioned, whole blood should be processed into components
within 8 hours of collection. If this is not possible, plasma can still be collected.
However, this component must be labeled because it is deficient in the labile coag-
ulation factors (especially Factors V and VIII)—how deficient depends on the time to
freezing.
________________________________ _______________________________
夝
Question 9: Which of the following is NOT found in significant amounts in Cryo-
precipitated AHF?
A. Factor I.
B. Factor VIII.
C. Factor X.
BLOOD COMPONENT STORAGE 15
D. von Willebrand factor.
E. Fibrinogen.
C. Cryoprecipitate contains significant amounts of Factor VIII, VWF, and fibrinogen.
Fibrinogen is also called Factor I; however, the term Factor I is rarely used.
________________________________ ________________________________
夝
Question 10: Which statement about blood component storage is true?
A. Refrigerators, freezers, and incubators should have monitoring systems that
monitor and record temperature continuously.
B. Refrigerators and freezers should have alarm systems that are triggered before
the temperature becomes unacceptable.
C. Temperature records must be maintained for at least 10 years.
D. Alternative storage in the event of system failure is not an acceptable substitute
for an independent emergency power source.
E. All of the above are true.
B. Alarm systems need to provide enough warning so that components can be
removed to a proper storage environment before temperatures rise (or fall) beyond
the acceptable range. Monitors should record the temperature at no more than 4
hour intervals and the temperature records should be maintained for at least 5 years.
________________________________ ________________________________
夝
SUGGESTED READING
AABB, American Red Cross, America’s Blood Centers, and Armed Services Blood
Program. Circular of information for the use of human blood and blood compo-
nents. Bethesda, MD: AABB, 2008.
Carson TH, ed. Standards for blood banks and transfusion services. 27th ed.
Bethesda, MD: AABB, 2011.
Downes KA, Wilson E, Yomtovian R, Sarode R. Serial measurement of clotting fac-
tors in thawed plasma stored for 5 days (letter). Transfusion 2001;41:570.
Food and Drug Administration. Code of Federal Regulations, title 21, parts 610 and
640. Washington, DC: US Government Printing Office, 2011 (revised annually).
Roback JD, Grossman BJ, Harris T, Hillyer CD, eds. Technical manual. 17th ed.
Bethesda, MD: AABB, 2011.
In: Leonard G, Licata M.
Practical Self-Assessment for Transfusion Medicine Professionals
Bethesda, MD: AABB Press, 2012
3
Pretransfusion Compatibility Testing
QUESTIONS
Question 1: Which blood group antigen is NOT a protein antigen encoded directly
by a gene?
A. Rh group.
B. ABO group.
C. Kidd.
D. Kell.
E. Duffy.
________________________________ ________________________________
夝
Question 2: Which statement is true about the antibodies elicited by blood group
antigens?
A. IgG antibodies can cause direct agglutination during in-vitro tests.
B. IgG antibodies tend to be reactive at room temperature or below.
C. IgM antibodies are more likely to be active at body temperature, and are usu-
ally more clinically significant than IgG antibodies.
D. AHG reagent consists of rabbit antigens that bind to the antigen-binding
domains of IgG antibodies, leading to agglutination.
E. ABO antibodies are usually a mixture of IgG and IgM antibodies that are reac-
tive over a wide temperature range (room temperature to body temperature).
________________________________ ________________________________
夝
Question 3: ABO and Rh typing is routinely performed at the “immediate spin” step
without the need for incubation or AHG reagent. However, because a person may
have weakened D antigen expression and thus appear to be Rh negative on the
immediate spin, further steps (incubation at 37 C, wash, and then addition of AHG
reagent) must be performed for which group(s) of individuals?
18 PRACTICAL SELF-ASSESSMENT FOR TRANSFUSION MEDICINE PROFESSIONALS
A. Blood donors and apparently Rh-negative infants born to Rh-negative mothers.
B. Blood recipients and apparently Rh-negative infants born to Rh-positive moth-
ers.
C. Blood donors and apparently Rh-negative infants born to Rh-positive mothers.
D. Blood recipients and apparently Rh-negative infants born to Rh-negative moth-
ers.
E. All of the above require additional steps.
________________________________ _______________________________
夝
Question 4: Which of the following causes ABO reverse typing discrepancies?
A. Acquired B antigen in a group A individual.
B. Marrow transplant recipient.
C. Nonspecific agglutination from Wharton’s jelly.
D. IgM allo- or autoantibody with immediate spin reactivity.
E. Polyagglutinable red cells.
________________________________ _______________________________
夝
Question 5: Which of the following statements about the antibody detection
(screening) test performed in test tubes is true?
A. Group O RBCs are used for the testing.
B. The direct antiglobulin test detects antibodies present in the patient’s serum
that are not bound to the patient’s red cells in vivo.
C. The test has two distinct phases: immediate spin and incubation at 37 C.
D. The addition of a potentiator, such as low ionic strength saline (LISS), lengthens
the incubation time.
E. Antihuman globulin reagent is added directly after the immediate spin phase.
________________________________ _______________________________
夝
Question 6: If agglutination and/or hemolysis is/are detected during the antibody
detection test, antibody identification is performed. Which statement about antibody
identification testing is true?
A. The reagent RBC panel is smaller and more focused (ie, contains fewer types of
group O RBCs) than the RBC panel used for the antibody detection test.
B. The method used for antibody identification is similar to that of antibody detec-
tion, and neither test requires an autocontrol using the patient’s red cells and
serum.
C. If the autocontrol is positive, then a repeat antibody detection test should be
performed.
PRETRANSFUSION COMPATIBILITY TESTING 19
D. If the DAT is negative, the patient’s red cells can be phenotyped for the corre-
sponding antigen.
E. If the DAT is negative, the autocontrol needs to be repeated.
________________________________ ________________________________
夝
Question 7: Which of the following statements regarding the crossmatching of RBCs
is true?
A. Crossmatch testing involves mixing donor serum with the patient’s red cells.
B. Abbreviated crossmatching (immediate-spin phase only) should not be per-
formed under any circumstances.
C. Agglutination and/or hemolysis must occur during at least two of the three
phases for the unit to be considered crossmatch incompatible.
D. If crossmatch testing is performed, there is no need to do antibody screening on
the potential recipient.
E. AHG crossmatching detects antibodies directed against low-incidence antigens
on donor red cells that may not have been present on the red cells used in anti-
body identification testing.
________________________________ ________________________________
夝
Question 8: Within how many days before transfusion should repeat testing be per-
formed for pregnant patients or patients transfused within the past 3 months?
A. 1
B. 3
C. 5
D. 7
E. 14
________________________________ ________________________________
夝
Question 9: Which of the following is an indication to perform direct antiglobulin
testing (DAT)?
A. If the autocontrol is negative during antibody identification testing.
B. Possible transfusion reaction workup.
C. Possible neonatal alloimmune thrombocytopenia workup.
D. If both the antibody screen test and autocontrol are negative.
E. All of the above are indications to perform a DAT.
20 PRACTICAL SELF-ASSESSMENT FOR TRANSFUSION MEDICINE PROFESSIONALS
________________________________ _______________________________
夝
Question 10: A patient has a positive autocontrol result during antibody identifica-
tion testing. Her DAT result is also positive. Which of the following pieces of infor-
mation is the LEAST helpful in determining the cause of her positive results?
A. Recent transfusion history of the patient.
B. Drug history of the patient.
C. Diagnosis.
D. Medical history.
E. Supplier qualification of the test kit manufacturer.
________________________________ _______________________________
夝
Question 11: Three common types of antiglobulin reagent used to perform the DAT
are anti-IgG, anti-C3d, and polyspecific antiglobulin (a mixture of anti-IgG and anti-
C3d). Which statement about direct antiglobulin investigation is true?
A. If the DAT is not immediately positive after the addition of polyspecific anti-
globulin with anti-C3d an elution should not be performed.
B. The elution procedure is performed only if the DAT is positive with anti-C3d.
C. The elution procedure causes antigen to dissociate from the red cell surface so
that it can be identified in subsequent steps.
D. The elution procedure typically involves the addition of low ionic strength
saline solution to the patient’s red cells.
E. After the eluate is buffered, agglutination cannot be used to identify the anti-
body.
________________________________ _______________________________
夝
Question 12: A patient has broadly reactive antibodies (panagglutinin) during the
antiglobulin phase of antibody identification testing. Regarding the next step in the
patient’s workup, which statement is true?
A. An adsorption procedure is not necessary for this patient.
B. If the patient has been transfused recently, his/her autologous red cells can be
used to remove the autoantibodies.
C. Typically, only one adsorption step is necessary to remove 99% or more of the
autoantibodies present.
D. Polyethylene glycol is typically used to treat red cells before adsorption.
E. For patients who have been recently transfused, allogeneic or differential RBCs
of known antigenic composition must be used for the adsorption.
PRETRANSFUSION COMPATIBILITY TESTING 21
________________________________ ________________________________
夝
Question 13: One method that can aid in the identification of an antibody involves
the incubation of panel RBCs with proteolytic enzymes, such as ficin. The net effect
is that some antigens are destroyed/inactivated resulting in no activity, while others
show enhanced activity. Which of the following antigens are destroyed/inactivated
by enzyme treatment?
A. Duffy.
B. Lewis.
C. Rh.
D. Kidd.
E. P1.
________________________________ ________________________________
夝
Question 14: Not only can antigens be inactivated, but specific antibody reactivity
can be markedly decreased from the patient’s serum by a process referred to as neu-
tralization. Which of the following is an example of neutralization?
A. Using saliva from a Lewis-positive individual to neutralize Lewis antigens on a
patient’s red cells.
B. Using fluid from echinococcus hydatid cysts to neutralize anti-P
1
in a patient’s
serum.
C. Using avian egg whites to remove HLA Class I antibodies.
D. Using chloroquine to remove Kell and Lutheran antibodies.
E. Using papain to remove ABO antibodies.
________________________________ ________________________________
夝
ANSWERS
Question 1: Which blood group antigen is NOT a protein antigen encoded directly
by a gene?
A. Rh group.
B. ABO group.
C. Kidd.
D. Kell.
E. Duffy.
22 PRACTICAL SELF-ASSESSMENT FOR TRANSFUSION MEDICINE PROFESSIONALS
B. Antigens in the ABO (and Lewis) group are carbohydrate antigens, which are not
directly encoded by genes. However, the enzymes/transferases that add these carbo-
hydrates to type II chains are encoded by genes.
________________________________ _______________________________
夝
Question 2: Which statement is true about the antibodies elicited by blood group
antigens?
A. IgG antibodies can cause direct agglutination during in-vitro tests.
B. IgG antibodies tend to be reactive at room temperature or below.
C. IgM antibodies are more likely to be active at body temperature, and are usu-
ally more clinically significant than IgG antibodies.
D. AHG reagent consists of rabbit antigens that bind to the antigen-binding
domains of IgG antibodies, leading to agglutination.
E. ABO antibodies are usually a mixture of IgG and IgM antibodies that are reac-
tive over a wide temperature range (room temperature to body temperature).
E. Because of their pentavalent structure, IgM antibodies can directly cause aggluti-
nation, whereas IgG antibodies often require an agglutinating agent, such as antihu-
man globulin. IgG antibodies are more likely to be active at body temperature,
while IgM tends to be active at a lower temperature. This combination of IgG and
IgM antibodies leads to the wide temperature range of reactivity for antibodies to the
ABO antigens.
________________________________ _______________________________
夝
Question 3: ABO and Rh typing is routinely performed at the “immediate spin” step
without the need for incubation or AHG reagent. However, because a person may
have weakened D antigen expression and thus appear to be Rh negative on the
immediate spin, further steps (incubation at 37 C, wash, and then addition of AHG
reagent) must be performed for which group(s) of individuals?
A. Blood donors and apparently Rh-negative infants born to Rh-negative mothers.
B. Blood recipients and apparently Rh-negative infants born to Rh-positive moth-
ers.
C. Blood donors and apparently Rh-negative infants born to Rh-positive mothers.
D. Blood recipients and apparently Rh-negative infants born to Rh-negative moth-
ers.
E. All of the above require additional steps.
A. If a weak D positive donor gives his/her Rh-positive blood and only immediate
spin testing is performed, the results may falsely indicate that the donor’s blood is Rh
negative. A bag may be labeled Rh negative, even though it is truly Rh positive. If
this blood is transfused to a female of child-bearing potential, she can develop anti-
PRETRANSFUSION COMPATIBILITY TESTING 23
bodies to the weak D antigen, resulting in potential problems with future pregnan-
cies. If an infant appears Rh-negative on immediate spin and no further testing is
performed, the Rh-negative mother will not receive the additional Rh Immune Glob-
ulin. Further testing must be performed to determine if the infant is weak D in which
case the mother would receive additional Rh Immune Globulin.
________________________________ ________________________________
夝
Question 4: Which of the following causes ABO reverse typing discrepancies?
A. Acquired B antigen in a group A individual.
B. Marrow transplant recipient.
C. Nonspecific agglutination from Wharton’s jelly.
D. IgM allo- or autoantibody with immediate spin reactivity.
E. Polyagglutinable red cells.
D. These antibodies would cause discrepancies on reverse typing. Recall that
reverse typing tests the patient’s plasma (where these antibodies would be located)
against RBCs of known type. Forward typing tests the patient’s cells (after removing
the plasma) against commercially obtained antibodies of known specificity.
________________________________ ________________________________
夝
Question 5: Which of the following statements about the antibody detection
(screening) test performed in test tubes is true?
A. Group O RBCs are used for the testing.
B. The direct antiglobulin test detects antibodies present in the patient’s serum
that are not bound to the patient’s red cells in vivo.
C. The test has two distinct phases: immediate spin and incubation at 37 C.
D. The addition of a potentiator, such as low ionic strength saline (LISS), lengthens
the incubation time.
E. Antihuman globulin reagent is added directly after the immediate spin phase.
A. Group O RBCs should be used for the antibody detection test to prevent interfer-
ence by anti-A and/or anti-B in the patient’s serum.
________________________________ ________________________________
夝
Question 6: If agglutination and/or hemolysis is/are detected during the antibody
detection test, antibody identification is performed. Which statement about antibody
identification testing is true?