blood bank

Which of the following group B antigens is generally associated with a mixed field reaction?

B3 is characterized by a weaker than usual reaction with anti-B and by a mixed field reaction with the same reagent. B is characterized by a strong reaction with anti-B. Bm and Bx are characterized by a weaker than usual reaction with anti-B but no mixed field reactions.

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 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

Which of the following blood components will provide the best source of fibrinogen for a patient with hypofibrinogenemia?

Cryoprecipitate Cryoprecipitate is the only concentrated fibrinogen product available and is used to treat patients with congenital or acquired fibrinogen defects.

An antibody to which platelet antigen is most commonly encountered in blood bank?

HPA-1a

What step must be performed before a rejuvenated blood unit may be transfused to the patient?

The unit must be washed.

While ABO, Rh, Kell, Duffy, Kidd, SsU are clinically significant, which of the following antibodies generally react at only the Coombs phase (also known as Antihuman Globulin phase)?

Kell, Duffy and Kidd antibodies

When collecting routine blood product donations, the venipuncture site is first cleaned with:

0.7% Iodophor compound

The concentration of sodium chloride in an isotonic solution is:

0.85 %

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% 7 units 77 units 4 units 1 unit

1 unit

Severe blood loss causing circulatory collapse and shock usually first occurs when what percentage of blood is lost?

30 to 40%

For which of the following antibodies is the DAT most likely to be NEGATIVE when testing a newborn for possible HDFN?

Anti-A,B While the DAT is positive in many cases of ABO HDFN, the DAT is most likely to be negative in ABO HDFN versus the other options. It's possible that the washing done as part of the DAT may break the bonds between anti-A,B and the newborn's poorly developed A (or B) antigens. Alloantibody HDFN, such as anti-D, anti-c, or anti-K is more likely to yield a positive DAT.

Using an exclusion protocol that requires only one homozygous cell to exclude antibodies, three antibodies have not been excluded in the panel shown below. Two of the antibodies are anti-E and anti-K, what is the third antibody that is possible (has not been excluded)? Anti-c Anti-Jka Anti-Jkb Anti-C

Anti-Jkb

Of the following blood group antibodies, which has been most frequently associated with severe cases of hemolytic disease of the fetus and newborn (HDFN)?

Anti-K

A D-positive mother with a D-negative fetus eliminates the possibility of HDFN due to the: D antigen ABO antigen system Lewis antigen system Rh antigen system

D antigen

For which of these reasons would a molecular method not be used? Determine blood type when the DAT is positive Complex Rh genotypes (weak D expression) Donor antibody screening Type fetal blood

Donor antibody screening it should be donor antigen screening

Persons with hemophilia A or hemophilia B that demonstrate inhibitors should be given which of the following products?

Factor VIIa is used for persons with hemophilia A or hemophilia B that demonstrate inhibitors.

Louisa is a healthy 24-year-old woman that wants to donate blood today. Her hemoglobin, temperature, blood pressure, and pulse are all within the acceptable limits for donating. She's in good health and not taking any medications. She recently divorced her spouse who was a hemophiliac that regularly received factor concentrates. Can Louisa donate blood today?

Maybe, depending on Louisa's last sexual contact with her ex-spouse.

What procedure utilizes leukapheresis to collect the buffy coat from whole blood?

Photopheresis

Anti-U antibodies can be produced by which of the following genotypes?

S-s-

Donated red cell units contain which substance to stabilize the pH of the unit during storage?

Sodium biphosphate

Which of the following can be used to confirm if someone has the Bombay phenotype?

Ulex europaeus

On a quiet evening shift at a small hospital, you encounter a specimen with a positive antibody screen. As per your current laboratory protocol, you check for agglutination at the immediate spin phase of testing; and then again at the antihuman gloubulin (AHG) phase of 37°C. According to your laboratory guidelines, a single homozygous cell may be used to rule out an antibody. Based on the following 3-cell screen performed by tube, which of the following clinically significant antibodies are you unable to rule out? Anti-Fya, -D Anti-Lua, -Lea, -Fya, -C Anti-Lea, -Fya, -C Anti-Fya, -C, -Lub

anti-Fya, -C, -Lub The correct answer is anti-Fya, anti-C, and anti-Lub. This is a fairly basic panel, but it involves further thought. First, it asks you to determine which antibodies are not ruled out. Upon completing the rule-outs on screen cell #3, one must then evaluate those remaining antibodies that have not been ruled out for clinical significance. Eliminate choice A immediately, because D is ruled out based on cell #3 at the clinically significant phase of 37°C. Next, it asks you to assess which of the antibodies that have not been ruled out are clinically significant. Of the remaining choices (B, C, and D), you can immediately rule out choices B and C, because both choices contain antibodies that are not clinically significant (anti-Lua, -Lea). Two antibodies that you are unable to rule out at the clinically significant phase of 37°C are contained in the only remaining answer choice, which is choice D. Anti-Fya and anti-C also happen to be clinically significant, because they are reactive at 37°C and can impact the patient in vivo.