SUCCESS! In Clinical Laboratory Science - Blood Bank: Antibody Identification, Transfusion Therapy, Transfusion Reactions

A postpartum female is bleeding because of disseminated intravascular coagulation (DIC). The attending physician orders cryoprecipitate for fibrinogen replacement. The freezer inventory contains the following cryoprecipitate: 6 bags Group A, 8 bags Group O, 6 bags Group AB, 12 bags Group B How many bags (units) should be thawed and pooled to provide 2 g of fibrinogen? A. 2 B. 4 C. 8 D. 10

C. 8 C. Cryoprecipitate provides a source of fibrinogen and fibronectin in addition to factors VIII and XIII. This component is indicated for use in bleeding disorders associated with hypofibrinogenemia, such as DIG, when excessive fibrinogen consumption is occurring. Each unit contains an average of 250 mg of fibrinogen or 0.25 g. The AABB Standards require a minimum of 150 mg per individual collection. The amount of pooled product to administer is calculated by the formula: Total grams desired/ 0.25 g per unit = Total number of cryoprecipitate units to administer 2g/ 0.25 g per unit = 8 Units

A physician calls the blood bank and wants an additional unit of RBC crossmatched for a patient. Several specimens from that patient are identified that have been drawn over the past month. Which of the following available samples is the oldest acceptable specimen that may be used for crossmatching? A. 1 day old B. 4 days old C. 1 week old D. 1 month old

A. 1 day old A. According to AABB Standards, specimens used for antibody screening and crossmatching must be less than 3 days old if the patient has been transfused or pregnant within the past 3 months. Either serum or plasma may be used. The specimen must be labeled properly at the bedside at the time of collection. Specimens are required to be retained for only 7 days posttransfusion.

A resident physician hand-delivers a blood sample, drawn by the attending physician, for pretransfusion testing from a patient who is difficult to draw. The sample is unlabeled. One should A. Discard the sample and request that the resident obtain a new sample, adhering to proper guidelines for labeling B. Label the specimen with the information the resident provides C. Label the specimen with information from the accompanying transfusion request form D. Request the sample be returned to the nursing station to be labeled

A. Discard the sample and request that the resident obtain a new sample, adhering to proper guidelines for labeling A. The most critical step to ensuring safe transfusion is obtaining a properly labeled blood sample from the correct patient. Transfusion accidents due to ABO mismatches are usually the result of a patient receiving the wrong blood. The identity of the patient must be verified, both verbally and by comparison of the wristband with the transfusion request form. Tubes must be labeled properly at the bedside with the full name, another acceptable identifier such as the medical record number, and the date.

Occasionally, patients have an anaphylactic reaction to a specific immunoglobulin class during a transfusion. Which immunoglobulin class is most often implicated? A. IgA B. IgD C. IgE D. IgG

A. IgA A. Some people are genetically deficient in IgA. If these individuals have anti-IgA in their plasma, they may suffer a severe anaphylactic reaction when subsequently exposed to IgA in donor plasma. Once these people are identified, they must receive IgA-deficient components such as multiple-washed or frozen-thawed RBC or components drawn from IgA deficient donors.

select the blood component of choice for treatment. Hemorrhagic episode during intensive chemotherapy A. Platelet concentrate B. RBC C. Cryoprecipitate D. Fresh-frozen plasma

A. Platelet concentrate Platelet concentrates are used to correct thrombocytopenia following chemotherapy. Fresh whole blood is seldom available. Specific components are instead provided to give the patient exactly what is needed and conserve blood resources.

A transfusion of which of the following is least likely to transmit HIV, HCV, or HBV? A. Pooled plasma, solvent/detergent treated B. Cryoprecipitate C. Leukocyte-reduced RBCs D. Platelets

A. Pooled plasma, solvent/detergent treated A. Viral inactivation methods such as the use of a solvent/detergent combination have eliminated the risk of transmission of viruses with a lipid envelope in clotting factor concentrates. This method has been applied to group-specific frozen plasma. Pooled plasma, solvent/detergent-treated is much safer than the other components listed from the standpoint of HIV, HBV, and HCV, because the process destroys lipid-enveloped viruses. It does not destroy non-lipid-enveloped viruses such as parvovirus B19. However, it has been withdrawn from the market in the United States and is not currently being used. Another approach to safety is "FFP-Donor Retested," which means that the FFP (fresh-frozen plasma) has been held for 90 days or more and released only after the donor has been retested negative for infectious disease markers. It is not a pooled product. The retesting should show that the donor was not in an infectious window period when the plasma was drawn.

Which of the following will be incompatible in the crossmatch? Donor / Recipient A. Group A, D-negative / Group A, D-positive B. Group O, D-positive / Group A, D-positive C. Group AB, D-positive / Group A, D-positive D. Group A, D-positive / Group A, D-negative

C. Group AB, D-positive / Group A, D-positive C. The crossmatch consists of testing donor cells with recipient serum. A group A individual will have anti-B in his/her serum, which will agglutinate AB cells. D-positive cells given to a D-negative person may cause antibody stimulation, but there will not be a visible reaction without a preformed antibody.

A patient with an anti-K and an anti-Jka in her plasma needs 2 units of RBC for surgery. How many group-specific units would need to be screened to find 2 units of RBC? The frequency of Jk(a+) is 77%; the K+ frequency is 10%. A. 6 B. 10 C. 20 D. 36

B. 10 B. The percentage of compatible blood is obtained by multiplying the frequencies of antigen negative. In this instance, one wants to find Jk(a-), K- blood. The incidence of Jk(a+) blood is 77%; therefore, the incidence of Jk(a-) blood is 23%. Likewise, K+ incidence is 10%; Kwould be 90%. Multiply these two frequencies together to get the frequency for Jk(a-), K- units: 0.23 X 0.90 = 0.21, or an incidence of 21 units in 100. Divide 2 by this figure because 2 units are needed: 2 + 0.21 = 9.5, or 10 units must be screened to find 2 compatible units.

A patient has a hemoglobin value of 8.1 g/dL. The surgeon wants to raise the hemoglobin to 10 g/dL before surgery. How many units of RBC need to be administered to this patient to raise the hemoglobin to the required level? A. 1 B. 2 C. 3 D. 4

B. 2 B. In general, one unit of red blood cells should raise a patient's hemoglobin by 1 g/dL. In this instance, a 2-g/dL rise is required, so two units would need to be given. This rule is true for patients of average size. A very large or heavy individual with an expanded blood volume may require additional units to attain the same level. Conversely, a pediatric patient may require less.

A male trauma victim whose blood type is group AB, D-negative has a negative antibody screening test. He has been transfused with both of the group AB, D-negative units in inventory within the last hour. He is now in surgery and expected to need large amounts of blood. Of the following available units in inventory, which type should be given next? A. 30 units of group O, D-positive B. 26 units of group A, D-positive C. 10 units of group O, D-negative D. 5 units of group A, D-negative

B. 26 units of group A, D-positive B. A group AB individual can receive red blood cells from donors of all ABO groups. Because the patient does not have anti-D, it would be best to next select group A, D-positive units because the need for large amounts of blood is anticipated. These units should be given as RBCs, because the plasma has anti-B. If necessary, the patient may be later switched to group O, D-positive RBCs. It would not be wise to deplete the D-negative supply, because D-negative women of child-bearing age may need blood and should not be exposed to the D antigen. The decision to transfuse D-positive blood to a D-negative patient must be approved by the physician in charge of the transfusion service.

A resident physician on the trauma team runs a pretransfusion blood sample from a male trauma victim to the blood bank and wants 6 units of blood to be issued immediately. He indicates that he is willing to sign for uncrossmatched blood. He also indicates that he wants 6 units ready at all times. The patient has been admitted to this institution previously for GI bleed. What should be the next step in the workup of this emergency department patient? A. Prepare 6 units uncrossmatched group B, D-positive whole blood. B. Check blood bank records for any previous patient information. C. Type and screen the patient sample. D. Prepare 6 more units of uncrossmatched group O blood.

B. Check blood bank records for any previous patient information. B. The first step in any pretransfusion work-up is to check the blood bank records for previous information on the patient. This information must match the ABO group and Rh type on the sample obtained currently. This helps to ensure that patients are not given the wrong blood type. A mismatch may indicate that the wrong patient was drawn or the label was incorrectly applied. After the initial release of 6 units of uncrossmatched group O blood, there should be ample time to at least check records and obtain an ABO group and Rh type on the patient sample before more blood is required.

Although use of autologous blood transfusions generally has several advantages, which of the following is not avoidable? A. Transmission of disease B. Clerical error C. Allergic reactions D. Graft-versus-host disease

B. Clerical error B. Autologous transfusions are the safest form of transfusion available, although they are not always the most practical. When administered properly, they eliminate disease transmission, immunization to foreign antigens, allergic reactions, and graft-versus-host reactions. Clerical error is still a significant risk. An AABB survey revealed that 1.2% of respondents reported an erroneous autologous transfusion. Although preoperative autologous collection is feasible for elective surgery, this form of autologous transfusion is not possible in cases of unexpected or massive blood loss. Intraoperative blood collection is another form of autologous transfusion used during operations where the estimated blood loss is great. Another advantage of autologous transfusions is that allogeneic donor blood is available for other patients.

A specimen of blood is received in the blood bank with request slips initialed by the phlebotomist. The tube has the patient's first and last name and medical records identification number on the label. What else must be on the tube label as required by AABB Standards? A. Patient's room number B. Date of phlebotomy C. Initials of phlebotomist D. Attending physician's nam

B. Date of phlebotomy B. Sufficient information for unique identification of the patient (including two independent identifiers) and the date of sample collection must be on the label. The phlebotomist's signature or initials must appear on either the tube of blood or on the request slips. It is not necessary for both to be signed. The physician's name, the patient's room number, and the time of the phlebotomy may be helpful but are not required by AABB Standards

Given that a patient's antibody screening test is negative, which of the following may cause a false positive result in a compatibility test? A. Incorrect ABO typing of the donor or patient B. An alloantibody against a low frequency antigen on the donor cells C. Prior coating of IgG antibody on the donor cells D. All the above

C. Prior coating of IgG antibody on the donor cells C. A false positive crossmatch could occur if the donor has a positive direct antiglobulin test (DAT). A DAT should be done on the donor cells and, if positive, the unit should be removed from inventory. Another possible cause of a false positive crossmatch could be contaminants in dirty glassware causing clumping of red cells. The other responses are true positives. If a strong incompatibility is immediately present, one should check the ABO type of the patient and the donor. If the antibody screening test was negative, one might suspect an antibody against a low-incidence antigen on the donor's cells.

The crossmatch is performed using A. Donor's serum and recipient's red cells B. Donor's red cells and recipient's serum C. Donor's serum and reagent red cells D. Recipient's serum and reagent red cells

B. Donor's red cells and recipient's serum B. The crossmatch is performed by testing the serum of the recipient with a suspension of the donor's red blood cells. The serum and red cells are usually tested at the immediate-spin (IS) phase to detect ABO mismatches, if the patient has no history of having unexpected antibodies in his/her serum and the current antibody screen is negative. Additional testing is done at 37°C and antiglobulin phases to detect the presence of clinically significant antibodies, if the patient has a positive antibody screen or a histoiy of ever having an unexpected antibody in his/her serum. Because clinically significant antibodies (other than anti-A and anti-B) are almost always detected during the antibody screening test, AABB Standards sanctions performing only the immediate-spin crossmatch (for ABO compatibility) when the patient has a negative antibody screening test. An antiglobulin crossmatch must be performed when a patient has a positive antibody screening test because of a clinically significant antibody, or if the patient has a history of a clinically significant antibody. Compatible units must also be phenotyped for the corresponding antigen and shown to be negative. When an antiglobulin crossmatch is performed, potentiating media such as albumin, polyethylene glycol (PEG), or LISS may be added to the test system to enhance sensitivity and/or decrease incubation time

False negative results at the antiglobulin phase of an antibody screening test are most likely due to A. Excessive washing of the red cells B. Inadequate washing of the red cells C. Warm autoantibody present in the patient's serum D. Failure to allow the blood to clot properly

B. Inadequate washing of the red cells B. Although there are many potential sources for error in performing an indirect antiglobulin test, the most common error leading to a false negative reaction is the failure to wash the red blood cells adequately before the addition of AHG reagent. Traces of free human globulin can neutralize the AHG reagent. Red cells known to be coated with IgG antibody (Coombs' control cells, check cells) are added to all negative tests. Agglutination of these control cells confirms that AHG was present in the system and that proper washing procedures were performed.

A transfusion reaction is reported by the nursing unit on patient A. D. The nurse reports that the patient had chills, fever, and back pain within a few minutes of starting the unit. The nurse asks what s/he should do All paperwork checks on this transfusion reaction are OK. The pretransfusion sample has straw-colored plasma. The posttransfusion sample has red-tinged plasma. This is indicative of a(an) A. Uncomplicated transfusion B. Intravascular transfusion reaction C. Error in which drugs have been infused with the blood D. Febrile transfusion reaction

B. Intravascular transfusion reaction B. Red-tinged plasma is indicative of hemolysis. When this is seen in the posttransfusion sample but not in the pretransfusion sample, it is evidence that an intravascular hemolytic transfusion reaction has occurred. The antibody attached to antigen on the patient's RBCs, and the resulting antigen-antibody complex activated the complement cascade. This resulted in hemolysis of the coated RBCs in the patient's vasculature. Other likely laboratory findings in this situation include hemoglobinuria and decreased plasma haptoglobin. Although intravascular hemolysis can be seen in situations where a drug has been administered with the blood, there are several possible causes of an intravascular hemolytic transfusion reaction. In the scenario given, there is no evidence that would suggest any particular cause

What is the component of choice for someone who needs a RBC transfusion when there is a history of febrile transfusion reactions? A. RBCs less than 5 days old B. Leukocyte-reduced RBCs C. RBCs 30 to 35 days old D. Frozen RBCs that have been thawed and deglycerolized

B. Leukocyte-reduced RBCs B. Febrile reactions are brought about by the interaction of antibodies in the recipient directed against antigens on donor leukocytes or by cytokines secreted by leukocytes. The antigens involved are both the HLA and granulocytespecific antigens. Leukocyte-reduced RBCs are the component of choice for a patient with repeated febrile transfusion reactions. Although frozen RBCs that have been thawed and deglycerolized are considered leukocyte reduced, the cost and time involved in preparation make them an unpractical choice

Which of the following is acceptable to be given intravenously with a blood transfusion? A. 5% dextrose in water B. Physiologic saline C. Ringer's solution D. Potassium chloride in saline

B. Physiologic saline B. Physiologic saline is the only generally acceptable solution that is allowed to be added to blood or blood components. Ringer's solution causes small clots to develop in anticoagulated blood, and 5% dextrose causes red cell lysis. Other solutions and medication should not be added to blood unless they have been proved safe and are sanctioned by the FDA

Which of the following would not cause a positive hemagglutination reaction in the crossmatch? A. Incorrect ABO grouping of the donor B. Unexpected antibodies in the recipient serum C. A positive DAT on the recipient red cells D. A positive DAT on the donor red cells

C. A positive DAT on the recipient red cells C. The crossmatch is performed using the recipient's serum and the donor's red blood cells. Therefore, a positive DAT on the recipient's cells will not affect the crossmatch results. A positive reaction may be obtained when the recipient has an antibody directed against a corresponding antigen on the donor's red cells. If this is a lowfrequency antigen, the crossmatch may be incompatible and the antibody screening result negative. A positive reaction may also indicate that the donor's red cells are coated with human globulin. This can be confirmed by performing a direct antiglobulin test (DAT) on the donor's red cells. Units of blood demonstrating a positive DAT should be returned to the collecting facility.

What antibody, labile both in stored serum and the patient's plasma, is a frequent cause of delayed hemolytic transfusion reactions? A. Anti-A B. Anti-D C. Anti-Jka D. Anti-K

C. Anti-Jka C. Kidd antibodies are generally IgG, complement dependent, and warm reacting. However, they are usually weak and labile. Because of this, they may go undetected in pretransfusion testing and the patient may inadvertently be transfused with antigen-positive blood, leading to a delayed transfusion reaction.

At the end of an antiglobulin test, IgGcoated control cells are added to the negative tests and centrifuged. What does it mean if no agglutination occurs? A. Test is valid. B. Antiglobulin reagent was working properly. C. Cells were not washed thoroughly. D. Control cells are contaminated.

C. Cells were not washed thoroughly. C. If the antiglobulin test was performed properly and the antiglobulin reagent is working properly, the IgG-coated control red blood cells should be agglutinated; thus, this test is invalid. Unagglutinated cells after the addition of the control cells might mean that the cells were not washed well and that the antiglobulin reagent has been neutralized or that the antiglobulin reagent may have been omitted. The test must be repeated if this happens

Hemolytic transfusion reactions are the most serious type of reactions to blood transfusion. The majority of hemolytic transfusion reactions are caused by _________ errors. A. Blood typing B. Antibody identification C. Clerical D. Crossmatching

C. Clerical C. The majority of deaths due to hemolytic transfusion reactions are caused by clerical errors, not laboratory errors. Patients, blood samples, and lab records, if misidentified, may lead to the wrong ABO type blood being administered to the patient. These deaths most often occur in areas of high stress, such as in emergency departments and surgical suites.

For the following conditions (questions 180-184), select the blood component of choice for treatment Hypofibrinogenemia A. Platelet concentrate B. RBC C. Cryoprecipitate D. Fresh-frozen plasma

C. Cryoprecipitate Cryoprecipitate also contains an average of 250 mg of fibrinogen per unit, as well as Factor XIII and fibronectin, and currently it is primarily used to treat hypofibrinogenemia. Although Factor V deficiency is rare, it can present severe manifestations leading to hemarthrosis

For the following conditions (questions 180-184), select the blood component of choice for treatment von Willebrand disease A. Platelet concentrate B. RBC C. Cryoprecipitate D. Fresh-frozen plasma

C. Cryoprecipitate There are three parts to the factor VIII molecule: F VIII:C, F VIII:Ag, and F VIILvW. Individuals manifesting the X-linked (gene earned on the X chromosome) disorder known as hemophilia A are deficient in F VIILC. The clinical severity, resulting in hemorrhage either spontaneously or following trauma, depends upon the level of F VIILC present. Deficiency in F VIILvW is known as von Willebrand disease. It is not X-linked and is the most common inherited coagulopathy. Deficiency in F VIILvW results in impaired platelet adhesion and aggregation, leading to prolonged bleeding. Cryoprecipitate contains both F VIILC and F VIILvW and may be used for treatment of these disorders, although it is not the preferred treatment. F VIII concentrates have become safer with improved viral inactivation processes, and some now have therapeutic amounts of F VIILvW as well

What type of transfusion reaction is often diagnosed by a positive DAT and a gradual drop in the patient's hemoglobin level? A. Anaphylactic B. Febrile C. Delayed hemolytic D. Acute hemolytic

C. Delayed hemolytic C. A delayed hemolytic transfusion reaction isgenerally the result of a patient's second exposure to an antigen present on donor red blood cells. The patient at some time previously had been exposed to the antigen, and this is his/her anamnestic response. This reaction usually occurs from 3 to 14 days after transfusion and is accompanied by extravascular red blood cell destruction. Often the patient is asymptomatic. The DAT is usually positive in a delayed hemolytic reaction, because the reaction is extravascular and coated cells are present in the peripheral circulation. An acute hemolytic transfusion reaction is usually intravascular, and the coated cells are destroyed by complement, leaving the DAT negative or at most weakly positive. Anaphylactic and febrile reactions do not involve red blood cell antibodies and do not cause a positive DAT

A transfusion reaction is reported by the nursing unit on patient A. D. The nurse reports that the patient had chills, fever, and back pain within a few minutes of starting the unit. The nurse asks what s/he should do You tell the nurse to immediately A. Collect posttransfusion blood samples B. Monitor the pulse and blood pressure C. Discontinue the unit, keep the line open D. Page the patient's physician for instruction

C. Discontinue the unit, keep the line open C. The transfusion of the unit should be stopped, and the transfusionist should keep the patient's intravenous (IV) line open with physiologic saline in case medications must be given quickly to counteract the transfusion reaction. The unit must then be returned to the blood bank along with all of the transfusion set and any attached IVs, such as any physiologic saline that was being infused along with the unit. The patient's physician should be notified, but after the transfusion is discontinued and the new IV of physiologic saline has been hung. Monitoring pulse and blood pressure is a good idea but is not an immediate necessity.

What is the process of removing an antibody from the red blood cell membrane called? A. Absorption B. Adsorption C. Elution D. Immunization

C. Elution C. Elution is a process in which bound antibody is released from red blood cells. The eluate produced can then be further tested to identify the specificity of the antibody. Some elution methods use temperature, chemicals, or manipulation of the pH to dissociate antibodies from red cells.

A patient experiences severe rigors and goes into shock after receiving part of a unit of RBC. The patient's temperature, which was 37.5°C pretransfusion, is now 40.0°C. Which of the following is the most likely type of reaction? A. Hemolytic B. Anaphylactic C. Septic D. Embolic

C. Septic C. Although rigors and shock may be caused by hemolytic or anaphylactic reactions, bacterial sepsis is the most likely cause in this case. The sudden rise of the patient's temperature from normal to 40°C or above is typical of such an infection. Bacterial sepsis is an important cause of transfusion reactions, with about one-fourth of these reactions resulting in death.

The serum of a patient contains an antibody that reacts with all random donor cells and panel cells that have been tested. The best possibility to find compatible blood would be to test A. Grandparents B. Parents C. Siblings D. Spouse

C. Siblings C. Children inherit half their genetic characteristics from each parent. Because the parents are not identical in antigen composition (a situation only found in identical twins), the child cannot be totally compatible with either parent. Siblings, however, have access to the same genetic material from each parent and so may have identical genes and antigens. A spouse genetically would be equivalent to a random donor.

If 98% of the red blood cells are viable in a unit of RBC at the time of transfusion, what percentage of red cells will remain viable 28 days posttransfusion? A. 10% B. 30% C. 50% D. 70%

D. 70% D. Approximately 1% of transfused red cells are cleared daily from the circulation of a recipient. The clearance rate may be increased in patients with autoimmune hemolytic anemia, pernicious anemia, aplastic anemia, hemorrhage, splenomegaly, and fever. Transfused cells survive normally in patients with anemia because of intrinsic red cell enzyme defects, spherocytosis, and paroxysmal nocturnal hemoglobinuria

Four units of fresh-frozen plasma have been ordered to correct factor V deficiency in a group O patient. One should thaw and issue _________ plasma. A. Group O only B. Group O and/or group A C. Group O and/or group AB D. Any blood group available

D. Any blood group available D. Large volumes of transfused plasma should be ABO compatible with the recipient's red blood cells. Isoagglutinins present in the plasma will attach to the corresponding antigen on the patient's red cells in vivo and cause a positive DAT and perhaps hemolysis. Plasma of any blood group can be given to a group O patient, because his/her red cells will not be agglutinated by anti-A or anti-B in donor plasma

Which of the following will the crossmatch do? A. Prevent immunization B. Prevent delayed transfusion reactions C. Guarantee normal survival of the red blood cells D. Frequently verify donor ABO compatibility

D. Frequently verify donor ABO compatibility D. The crossmatch, which is the recipient's serum with the donor's cells, will reveal only if the patient has a detectable antibody against some antigen on the donor cells. In the presence of a negative antibody screening test, an incompatible crossmatch at the immediate-spin phase will most likely be due to an ABO mismatch between the recipient's serum and the donor's cells. For this reason, AABB Standards mandate performing only the immediate-spin crossmatch when the patient has a negative antibody screening test and no history of clinically significant antibodies. The crossmatch will not guarantee in vivo response to the transfused red blood cells. Also, it will not detect all ABO typing errors, and it will not detect most Rh typing errors.

For the following conditions (questions 180-184), select the blood component of choice for treatment Liver disease A. Platelet concentrate B. RBC C. Cryoprecipitate D. Fresh-frozen plasma

D. Fresh-frozen plasma FFP can be used to correct the factor deficiencies found in liver disease (factors II, VII, IX, and X). Because all these are stable factors, the plasma need not be fresh even though FFP is commonly used.

For the following conditions (questions 180-184), select the blood component of choice for treatment Factor V deficiency A. Platelet concentrate B. RBC C. Cryoprecipitate D. Fresh-frozen plasma

D. Fresh-frozen plasma Treatment of choice is fresh-frozen plasma (FFP) because F V is a labile factor not found in Cryoprecipitate.

Which of the following is the component of choice when a physician is concerned about restoring or maintaining oxygen carrying capacity? A. Albumin B. Cryoprecipitate C. Whole blood D. Red blood cells

D. Red blood cells D. Red blood cells are the component of choice to maintain or restore oxygen-carrying capacity. This component has the least effect on blood volume and the maximum effect on the oxygen-carrying capacity of all the products available for transfusion. In some patients, increasing the total blood volume more than what is absolutely necessary could have a detrimental effect. Examples are patients with chronic anemia or congestive heart failure.

A postpartum female is bleeding because of disseminated intravascular coagulation (DIC). The attending physician orders cryoprecipitate for fibrinogen replacement. The freezer inventory contains the following cryoprecipitate: 6 bags Group A, 8 bags Group O, 6 bags Group AB, 12 bags Group B The patient is group A. Which cryoprecipitate units would most appropriately be used to treat this patient? A. Group A only B. Group AB only C. Group A and Group O D. Group A and Group AB

D. Group A and Group AB D. Plasma compatible with the recipient's ABO group is preferred when large volumes are transfused. Both group O and group B plasma contain anti-A that can cause a positive direct antiglobulin test (DAT) when infused into either group A or AB recipients. Compatibility testing is not required before cryoprecipitate administration. Plasma compatibility is not as important with cryoprecipitate as with platelet concentrates. Approximately 10 mL of plasma is in a cryo unit and 50 mL in a single platelet concentrate.

Which of the following blood types necessitates that a separate Rh control tube be set up when using a monoclonal anti-D reagent? A. Group O, D-positive B. Group A, D-positive C. Group B, D-positive D. Group AB, D-positive

D. Group AB, D-positive D. Monoclonal anti-D reagents are low-protein reagents, therefore, a negative reaction with antiA and/or anti-B (also low-protein) serves as a control. When the patient appears to be group AB, D-positive, it is necessary to set up a separate control. A drop of the patient's cell suspension with his/her own serum (autocontrol) or with 6-8% albumin makes a suitable control.

Before blood is issued for transfusion, a patient's previous blood bank records must be reviewed. Which of the following is not included in this review process? A. ABO group and Rh type B. Clinically significant antibodies C. Serious adverse reactions D. Hepatitis testing

D. Hepatitis testing D. Reviewing the previous records of a patientmay help to confirm the identity of the current pretransfusion sample. Records should be checked for ABO group and Rh type, clinically significant antibodies that were present but may no longer be detectable, and adverse reactions to previous units transfused. ABO records from the past 12 months must be immediately available and retained for 5 years; antibody and adverse reaction records must be available indefinitely for review before issuing blood for transfusion. It is not necessary to check hepatitis records of the patient because the hepatitis status of the patient does not affect transfusion of blood to him as a recipient

A resident physician on the trauma team runs a pretransfusion blood sample from a male trauma victim to the blood bank and wants 6 units of blood to be issued immediately. He indicates that he is willing to sign for uncrossmatched blood. He also indicates that he wants 6 units ready at all times. The patient has been admitted to this institution previously for GI bleed. The resident says the victim has a donor card in his wallet indicating a group B, D-positive blood type. What should be done immediately? A. Issue 6 units of uncrossmatched group B, D-positive whole blood. B. Check patient and donor records to confirm the blood type, then issue 6 units of uncrossmatched group B, D-positive blood. C. Withhold blood until ABO and compatibility testing are completed. D. Issue 6 units of uncrossmatched group O RBCs

D. Issue 6 units of uncrossmatched group O RBCs D. Because time is of the essence when a trauma victim is severely hemorrhaging, blood bank personnel must respond promptly. Groupspecific blood may not be issued on the basis of previous patient or donor records. If the situation is so urgent as to preclude performing an ABO and Rh typing, or when a blood sample cannot be obtained, group O RBCs may be issued. The decision as to whether group O, D-positive or O, D-negative RBCs should be used will depend upon inventory and the age and sex of the trauma victim. Blood banks located in a trauma center should have a written procedures manual with well-defined criteria. All staff must be familiar with these guidelines.

A transfusion reaction is reported by the nursing unit on patient A. D. The nurse reports that the patient had chills, fever, and back pain within a few minutes of starting the unit. The nurse asks what s/he should do Which of the following directives would not be included in the additional activities you would request the nurse to do? A. Return the unit to the blood bank. B. Obtain a posttransfusion blood sample in EDTA. C. Obtain a posttransfusion urine sample. D. Obtain a fresh unit from the blood bank for immediate infusion

D. Obtain a fresh unit from the blood bank for immediate infusion D. Returning the unit to the blood bank and obtaining posttransfusion blood and urine samples is required by AABB Standards. No more blood or blood products should be transfused into the patient until the reaction has been investigated. If the patient has an antibody that caused the transfusion reaction, any red blood cell units transfused must be negative for the corresponding antigen.

A patient experiences severe rigors and goes into shock after receiving part of a unit of RBC. The patient's temperature, which was 37.5°C pretransfusion, is now 40.0°C Referring to the reaction described in question 171, the incidence of this type of reaction is highest with which of the following components? A. RBC B. FFP C. Cryoprecipitate D. Platelets

D. Platelets D. The incidence of bacterial sepsis is highest with platelet components. It is higher with pooled platelets than platelets collected by apheresis. Pooled platelets usually involve 6 or more donations from different donors, multiplying the chance of contamination. Most bacteria grow better at room temperature (the normal storage temperature for platelets) than refrigerator temperature. Sepsis from RBCs is usually due to Yersinia enterocolitica, which grows well at refrigerator temperature