CRNI Blood Transfusion 2 — Questions and Answers

Question 1: Which blood type is considered the universal plasma donor?

Type O negative
Type AB positive
Type A positive
Type AB negative (Correct answer)

Correct answer: Type AB negative

Type AB plasma is universal donor plasma because it contains no anti-A or anti-B antibodies, making it safe for all recipients.

While type O is the universal red blood cell donor (no A or B antigens), type AB is the universal plasma donor because AB plasma contains neither anti-A nor anti-B antibodies. Transfusing plasma with antibodies against the recipient's red cell antigens can cause hemolysis. AB negative is preferred over AB positive to minimize Rh sensitization risk, though in emergencies AB positive plasma may be used. This concept is crucial for emergency situations where the patient's blood type is unknown and fresh frozen plasma is needed immediately.

Question 2: What is the recommended initial flow rate when beginning a blood transfusion for the first 15 minutes?

Wide open to complete quickly
50 mL/hour
2 mL/minute or less (Correct answer)
125 mL/hour

Correct answer: 2 mL/minute or less

Blood transfusions should begin at 2 mL/minute or less for the first 15 minutes to allow early detection of transfusion reactions before a significant volume is infused.

The first 15 minutes of any blood transfusion are the most critical monitoring period. The rate is kept at approximately 2 mL/min (about 50 mL total in 15 minutes) so that if a severe reaction occurs, minimal volume has been infused. Most fatal hemolytic reactions manifest within the first 50 mL. The nurse must remain with the patient during this initial period, monitoring for signs of reaction including fever, chills, back pain, chest tightness, and hypotension. After 15 minutes without adverse signs, the rate can be increased to complete the unit within 4 hours.

Question 3: A patient's pre-transfusion type and screen reveals an unexpected antibody. What is the appropriate nursing action?

Cancel the transfusion order
Proceed with type-specific blood
Notify the blood bank for antigen-negative compatible units (Correct answer)
Request O-negative emergency release blood

Correct answer: Notify the blood bank for antigen-negative compatible units

When unexpected antibodies are detected, the blood bank must identify the antibody and provide antigen-negative, crossmatch-compatible units to prevent hemolytic reactions.

Unexpected antibodies (alloantibodies) develop from prior transfusions, pregnancies, or transplants. Common examples include anti-Kell, anti-Duffy, and anti-Kidd antibodies. When detected, the blood bank must identify the specific antibody, then locate and crossmatch donor units that are negative for the corresponding antigen. This process may take additional time, so the nurse should communicate urgency to the blood bank. Simply providing type-specific blood is insufficient as it may contain the offending antigen. O-negative blood is reserved for emergencies when there is no time for crossmatching.

Question 4: Which transfusion reaction typically occurs 5-10 days after the transfusion?

Acute hemolytic reaction
Febrile non-hemolytic reaction
Delayed hemolytic transfusion reaction (Correct answer)
Anaphylactic reaction

Correct answer: Delayed hemolytic transfusion reaction

Delayed hemolytic transfusion reactions occur 5-10 days post-transfusion due to an anamnestic antibody response to donor red cell antigens.

Delayed hemolytic transfusion reactions (DHTRs) occur when a patient with a previously formed alloantibody (often at undetectable levels at the time of crossmatch) receives antigen-positive blood. The anamnestic immune response produces detectable antibody levels within 5-10 days, leading to extravascular hemolysis. Symptoms include unexplained decrease in hemoglobin, mild jaundice, fever, and positive direct antiglobulin test. DHTRs are generally less severe than acute hemolytic reactions but must be documented for future transfusion planning. The antibody should be added to the patient's permanent blood bank record.

Question 5: What temperature should blood products be stored at in the blood bank prior to transfusion?

Room temperature (20-24 degrees C)
1-6 degrees C (Correct answer)
Below 0 degrees C
8-12 degrees C

Correct answer: 1-6 degrees C

Packed red blood cells must be stored at 1-6 degrees C in monitored blood bank refrigerators to maintain viability and prevent bacterial growth.

Red blood cell products are stored at 1-6 degrees C in continuously monitored blood bank refrigerators with alarm systems. This temperature range preserves red cell viability and function while inhibiting bacterial growth. Storage at temperatures below 1 degree C can cause freezing and hemolysis, while temperatures above 6 degrees C promote bacterial proliferation. Platelets are stored at 20-24 degrees C with agitation (hence higher bacterial contamination risk), and fresh frozen plasma is stored at -18 degrees C or below. Temperature monitoring is a critical quality control measure, and any temperature excursions must be investigated and documented.

Question 6: When should blood bank compatibility testing specimens be collected relative to transfusion?

Any time before the transfusion
Within 72 hours of the scheduled transfusion (Correct answer)
Within 24 hours only
Within 7 days of the scheduled transfusion

Correct answer: Within 72 hours of the scheduled transfusion

Pre-transfusion specimens must be collected within 72 hours of the scheduled transfusion for patients who have been transfused or pregnant within the past 3 months.

AABB standards require that pre-transfusion specimens be collected within 72 hours (3 days) of the scheduled transfusion for patients who have been transfused, pregnant, or undergone transplantation within the past 3 months. This timeframe accounts for the possibility of new alloantibody development from recent antigenic exposure. New antibodies can develop rapidly (within days) and may not be detected on older specimens. For patients with no recent antigenic exposure history, some institutions may allow slightly longer specimen validity, but 72 hours is the widely applied standard.

CRNI Blood Transfusion 2

Which blood type is considered the universal plasma donor?