LabCe blood bank
When collecting routine blood product donations, the venipuncture site is first cleaned with:
0.7% Iodophor compound A 0.7% iodophor compound is used as the first disinfectant method as it removes surface debris and bacteria and can begin the initial germicidal action on resident skin bacteria. 70% isopropyl alcohol is sufficient to be used in routine venipuncture procedures, but extra germicidal action is needed for resident skin bacteria when collecting blood donations to prevent contamination. 70% isopropyl alcohol should not be used alone or as the first step when preparing a venipuncture site for blood donations. A 10% povidone-iodine solution is used as a secondary antiseptic for blood donation venipunctures, following 0.7% iodophor compound. 2% Chlorhexidine may be used to cleanse the skin in venipunctures for blood donors who are sensitive to the iodophor and povidone-iodine solutions. Venipuncture sites for individuals who are sensitive to iodine-based compounds should then be cleaned with 70% isopropyl alcohol. This process is not typically used as it takes longer to clean the skin and has demonstrated improved germicidal action when compared to the iodophor and povidone-iodine procedure.
At many hospitals, patients with sickle cell disease are given phenotypically matched units of blood. This policy is often used to help prevent alloimmunization to common RBC antigens in patients who are regularly transfused. A patient who regularly comes to your hospital demonstrates the following phenotype on her RBCs: C antigen positive; E antigen-negative; K antigen positive. The patient's doctor requests a single unit of crossmatched packed RBCs. Based on the antigen prevalence indicated below, how many units of ABO compatible packed RBCs will you phenotype to find one to transfuse to this patient? Antigen frequencies C antigen positive: 68% E antigen positive: 22% K antigen positive: 9%
1 unit STEP 1: Since 22% of donors are positive for E antigen, 78% are negative for E antigen. 78% expressed as a decimal is 0.78 STEP 2: The reciprocal of 0.78 is calculated as follows (1/0.78) = 1.3 1.3 compatible units should be antigen typed to find a single unit negative for E antigen. Rounding to the closest whole number gives you the correct answer choice of 1. An alternate method to determine the number of units to antigen type is to solve for x using a ratio. In this case the ratio would be: 78/100 = 1/x 78x = 100 x = 1.28 or approximately 1 unit
FFP that has been thawed at 30 - 37°C and maintained at 1 - 6°C must be transfused within ___________ after it has been thawed.
24 hours FFP that has been thawed at 30-37°C and maintained at 1-6°C must be transfused within 24 hours. After the initial 24 hours have elapsed, thawed FFP and PF24 may be re-labeled as "Thawed Plasma" and stored at 1-6°C for up to 4 more days (not to exceed 5 days). Thawed plasma contains stable coagulation factors (i.e. fibrinogen, prothrombin) but reduced amounts of the following coagulation factors: factor V, VII, VIII, and X. FFP prepared from whole blood units (CPD, CPDA-1, CD2D) must be frozen with 8 hours from collection. PF24 must be frozen within 8-24 hours of collection.
A person who lived in the United Kingdom between the years of 1980 and 1996 for 3 or more months is indefinitely deferred from donating blood or blood products based on an increased risk of which of the following?
Creutzfeldt-Jakob disease (CJD) and/or variant Creutzfeldt-Jakob disease (vCJD) The correct answer is CJD and/or vCJD. If a potential blood donor spent more than 3 months in the United Kingdom between 1980 and 1996, or 5 or more years in France from 1980 to the present, they are indefinitely deferred due to an increased risk of CJD and/or vCJD. If they have ever been diagnosed with CJD or vCJD, they are permanently deferred.
HLA antibodies are responsible for which of the following transfusion reactions?
Transfusion-related acute lung injury (TRALI) Transfusion-associated circulatory overload is caused by the inability of a patient's circulatory system to handle the additional workload from the transfused product. It occurs when the volume or rate of transfusion is too high.
Unless an alternative has been approved by the FDA, what is the expiration and storage temperature of rejuvenated (non-frozen) RBC's?
24 hours; 1 °C to 6 °C The correct expiration date/time after rejuvenation is 24 hours, although rejuvenated RBCs can also be frozen and maintained at -65 °C. If the product is not frozen, it should be stored like other packed RBCs at 1 °C up to 6 °C.In cases where the rejuvenated cells are frozen, the expiration date is 10 years if collected in CPD or CPDA-1. If rejuvenated cells are frozen and collected with AS-1, the expiration date is 3 years.
What is the maximum interval during which a recipient sample may be used for compatibility testing if the patient has recently been transfused or was pregnant within the past 3 months?
3 days
Which of the following is the proper temperature to use when crossmatching in the presence of a cold antibody?
37º C Most antibodies that are inactive at 37º C and active only below 37º C (i.e. cold reactive antibodies) are of little clinical significance. If a nonspecific cold antibody or cold agglutinin is suspected, warm the sample and testing reagents, including saline, to 37º C. Only do reaction readings at AHG; bypassing the optimum reaction temperature prevents activation and binding of the cold antibody.
A standard blood donation of 450-500 mL requires a minimum anticoagulant-preservative solution volume of:
63 mL The minimum volume of 63 mL of anticoagulant-preservative ensures that the donated blood product contains an appropriate anticoagulant-to-blood ratio. 57 mL of anticoagulant-preservative will not allow the donated blood unit to have enough anticoagulant to ensure a proper anticoagulant-to-blood ratio. 70 mL of anticoagulant-preservative is the maximum volume allowed to ensure proper anticoagulant-to-blood ratio. 82 mL of anticoagulant-preservative is too high and will result in an improper anticoagulant-to-blood ratio.
Donor and recipient blood samples must be kept for at least how long after transfusion?
7 days
Which of the following fresh frozen plasma ABO types would be suitable for transfusion to an AB negative patient?
AB negative and AB positive only. FFP should be ABO compatible with the patient's red blood cells. It can be given without regard to Rh type because it does not contain cells with the D antigen for the recipient to react to. Additionally, donors are screened for clinically significant antibodies, so Rh-negative donors should not have anti-D in their plasma.
When processing umbilical cord blood samples for hematopoietic progenitor cells (HPC), what tests are performed on both the mother's blood and cord blood?
ABO & Rh
What is the cause of MOST severe acute hemolytic transfusion reactions? Please select the single best answer Rh incompatibility ABO incompatibility Cold agglutinins Delayed hypersensitivity
ABO incompatibility Incompatibility in blood groups other than ABO may also cause acute hemolysis, but the reactions are rare and not usually as severe.
Leukocyte reduction may be performed at the same time as which step in blood component collection?
At the same time the additive solution is added Leukocyte reduction can be performed at the same time as the additive solution is added if an additive solution is used. The light spin creates a platelet-rich plasma. White blood cells are denser than platelets, so they will migrate to the area below platelets during this preparation phase. The platelet-rich plasma aliquot is centrifuged at a heavy spin, not the red cell portion. Because the white blood cells would not be present in this aliquot, leukocyte reduction is not needed. The plasma is removed from the platelet-rich plasma bag, which does not contain white blood cells. Because of this leukocyte reduction is not needed.
During routine inspection, a unit of unexpired blood was noticed to have a black color with numerous small clots. What is the likely cause for this observation?
Bacterial contamination Bacterial contamination can manifest itself in several ways including: the presence of clots, darker purple-black color of blood unit, unit can appear cloudy, hemolysis may be present. A unit that was frozen inadvertently should be discarded and would be hemolyzed upon returning to normal storage temperature.
Persons who have received a dura mater transplant are not eligible to donate blood and are permanently deferred. This is due to an increased risk of which of the following?
CJD or vCJD Persons who have received dura mater (brain lining) grafts are permanently deferred due to an increased risk of exposure to Creutzfeldt-Jakob (CJD) disease and variant CJD (vCJD).
What is the FIRST thing blood bank staff should do when investigating a transfusion reaction?
Check for clerical errors in all steps of the pre- and post-processes.
What is the MOST common cause of acute hemolytic transfusion reactions? Please select the single best answer Testing errors Clerical errors Donor IgG immune antibodies Blood administration errors
Clerical errors
What is the fundamental purpose of the full, pre-transfusion crossmatch?
Detect antibodies in recipient serum/plasma that react with donor red blood cells. The purpose of performing a crossmatch is to determine whether or not donor RBCs are compatible for transfusion by testing the donors' RBCs against the recipient serum (or plasma) which may contain alloantibodies that can potentially react with these donor RBCs. The crossmatch is a final check of ABO compatibility between both donor and the recipient. The donor and recipient may not have the same blood type based on product selection and inventory.
Essential components of compatibility testing include all of the following EXCEPT: Please select the single best answer Antibody screen on recipient's serum Major crossmatch or computer crossmatch ABO and Rh typing of recipient Direct Antiglobulin Test (DAT)
Direct Antiglobulin Test (DAT) A direct antiglobulin test (DAT) is used to detect in-vivo sensitization of red blood cells with IgG or complement components. Cases in which this test is used include hemolytic disease of the fetus and newborn, hemolytic transfusion reaction, and autoimmune or drug-induced hemolytic anemia. AABB Standards do not require a DAT for pretransfusion testing. Studies have looked into whether or not a routine DAT would benefit patient outcomes and have shown that they do not have a positive impact on the patients. All recipients have compatibility testing, including ABO grouping, Rh typing, antibody screen, and a crossmatch.
Platelet products will be prepared from a whole blood donation. What must be used to prevent potential contamination of the platelets with skin cells and bacteria?
Diversion pouch A diversion pouch is used to physically capture and holds the initial blood collected in a blood donation since the initial blood contains epidermal skin cells and any bacteria present. 70% isopropyl alcohol is not a sufficient antiseptic for the skin during a blood donation. The attached segments allow pre-transfusion testing to occur in a closed system for donated red cells. Donated platelets do not undergo pre-transfusion testing, though, and do not have attached segments. Irradiation is used to prevent donor T-lymphocytes from multiplying and causing transfusion-associated graft-versus-host-disease; it is not used to prevent contamination.
The antigen marker most closely associated with transmission of HBV infections is
HBeAg The presence of HBeAg connotes active replication of hepatitis B virus, with a high degree of infectivity.
Which is the first marker (antigen or antibody) which will become positive after exposure to Hepatitis B?
HBsAg HBsAg is detectable 2 to 12 weeks post-exposure during the acute stage and becomes undetectable in 12 to 20 weeks after the development of anti-HBsAg. HBeAg appears after the HBsAg and, in recovering patients, disappears before HBsAg. IgM anti-HBc is the first antibody to appear, and it persists for about 6 months.
Which of the following tests has been recommended by the FDA to replace the HIV-1 p24 antigen test in the screening of donated blood for infectious diseases?
HIV-1 NAT
The chief purpose of performing a serologic crossmatch is to:
Identify recipient antibodies against donor cells Patient serum is mixed with donor red blood cells to check for recipient antibodies against the donor's cells. Antibodies in the donor plasma are detected at the blood center with an antibody screen. Antibodies in the recipient are detected by the antibody screen. The antibody screen of a donor performed by the blood center uses a pooled screening cell containing all of the clinically significant antigens to detect alloantibodies present in the donor that may harm a recipient.
Which occurrence is a medical error?
Incompatible blood is transfused into a patient during surgery.
What is the purpose of adding citrate to donated red cell units?
It prevents coagulation. Citrate chelates calcium, preventing coagulation in the red cell unit; it also stabilizes the red cell membrane. Sodium biphosphate is added to stabilize the pH of the unit during storage. Adenine functions as a substrate for ATP synthesis in red blood cells. Dextrose helps in ATP generation by the glycolytic pathway.
An 82-year-old male is a long-time resident of a local nursing facility. He has been to your hospital multiple times over the years and has historically demonstrated antibodies against the K and Fya antigens. He has returned to your hospital following a 2-year absence, and his antibody screen is as follows. Which of the following red blood cells would you crossmatch for this patient?
K negative; Fya negative This patient does not currently demonstrate any antibodies, but his historical clinically significant unexpected antibodies cannot be ignored. He must receive units that lack the K and Fya antigens.
A patient with a documented history of febrile nonhemolytic transfusion reactions (FNHTRs) should receive __________ blood components.
Leukoreduced Pre-storage leukocyte reduction prevents febrile non-hemolytic transfusion reactions that occur due to cytokine and intact fragmented membrane accumulation during storage. Irradiation is only required if the donor unit is from a blood relative of the recipient, or the donor unit is HLA-matched for the recipient CMV-negative units are only required for individuals who are immunosuppressed, such as premature infants and recipients of organ or hematopoietic stem cell transplants. The risk of transmitting CMV through blood products can be decreased through leukoreduction. CMV-negative units will not prevent a febrile reaction. Hemoglobin S is not routinely tested for in donated red cell units. Units negative for Hemoglobin S are only a primary concern for infant recipients. Hemoglobin S-negative units will not prevent a febrile reaction.
Which of the following sources of error will give a false negative result in antihuman globulin testing?
Low pH of saline A low pH of saline is indicated as a false negative source of error in antihuman globulin testing. Dirty glassware, samples collected in gel separator tubes, and refrigerated specimens are all indicated as false-positive sources of error in antihuman globulin testing.
Which of the following viruses or diseases is screened for in blood donors only using questions asked during the donor screening and selection process?
Malaria
Which test is NOT used as a screen for retroviruses in donated blood? Please select the single best answer Antibody to HIV type 1 or type 2 Nucleic acid testing to detect HIV-1 RNA Antibody to HTLV types I and II Nucleic acid testing for HCV
Nucleic acid testing for HCV Positive results using NAT for HCV are approved by the FDA to confirm a reactive HCV antibody test. Also, hepatitis C is not considered a retrovirus. Three tests are currently used as a screen for retroviruses in donated blood: antibody to HIV type 1 or type 2 (anti-HIV-1/2), nucleic acid testing (NAT) to detect HIV-1 RNA, and antibody to HTLV types I and II (anti-HTLV-I/II).
All of the following are advantages of performing the computer crossmatch EXCEPT? Please select the single best answer Greater flexibility in staffing One determination of recipient's ABO group is made Better management of blood bank inventory Reduced volume of sample needed on large crossmatch orders
One determination of recipient's ABO group is made A requirement for the computer crossmatch is that there need to be two determinations of the recipient's ABO group. The preference is to have two separately drawn samples available for testing.
Which of the following might cause a false positive indirect antiglobulin test (IAT)?
Over-centrifugation Over-centrifugation may cause either a false positive result, (if centrifuged clumps cannot be completely dispersed) or a false negative result (if too much agitation is required for resuspension). Failure to adequately wash cells can leave unbound IgG which will neutralize antiglobulin reagent and cause a false negative result. High concentration of IgG paraprotein can leave unbound IgG which will neutralize the antiglobulin reagent and cause a false negative result. Delay in the addition of antiglobulin reagent may allow previously bound IgG antibody to dissociate from red cells and cause a false negative result.
When is a computer crossmatch acceptable?
Patient has no history of clinically significant antibodies detected and the antibody screen on the current sample is negative
Plasma exchange is the current treatment for all of these conditions, EXCEPT: Please select the single best answer Warm autoimmune hemolytic anemia (WAIHA) Diarrhea-associated hemolytic uremic syndrome (HUS) Thrombotic thrombocytopenic purpura (TTP) Pernicious anemia
Pernicious anemia Pernicious anemia is treated with monthly parenteral does of hydroxycobalamin not by plasma exchange. Currently, the most effective treatment for TTP, HUS, and WAIHA is plasma exchange.
What procedure utilizes leukapheresis to collect the buffy coat from whole blood?
Photopheresis Photopheresis utilizes leukapheresis to collect the buffy coat layer from whole blood. These cells are treated with 8-methoxypsoralen, exposed to ultraviolet A light and then reinfused into the patient. Photopheresis has been shown to be efficacious and has been approved by the Food and Drug Administration for the treatment of cutaneous T-cell lymphoma.
Which type of blood component is most implicated in bacterial contamination?
Platelets Platelets are the most common product implicated in bacterial contamination cases. This is because the room temperature storage requirement provides an adequate environment for bacterial growth.
An exchange transfusion has been ordered for a low-birth-weight infant. The physician has ordered irradiated Red Blood Cells for this purpose. Why is it necessary to irradiate the blood products for this patient?
To prevent transfusion-associated graft-versus-host disease (TA-GVHD)
Which of the following transfusion reactions can a diagnosis be more firmly established by evaluating B-type natriuretic peptide (BNP) levels before and after transfusion?
Transfusion Associated Circulatory Overload (TACO) Transfusion Associated Circulatory Overload (TACO) is difficult to distinguish from Transfusion Related Acute Lung Injury (TRALI). A post-transfusion to pretransfusion BNP ratio of 1.5 points is diagnostic of TACO.
All of the following are appropriate indications for the use of fresh frozen plasma (FFP) EXCEPT? Please select the single best answer Volume expansion Severe bleeding in the presence of significantly elevated PT secondary to vitamin K deficiency Replacement component after plasma exchange in patients with TTP or HUS Dilutional coagulopathy with significant active bleeding, and PT and PTT twice normal
Volume expansion Since each unit of fresh frozen plasma (FFP) carries with it the risk of transmitting blood-borne pathogens, and other products (such as normal saline or albumin) which do not carry this risk are available, FFP should not be used as a volume expander.
