A red cell unit was warmed in an unapproved device before a rapid transfusion. The patient then has red urine and plasma hemoglobin is raised. The clerical check, repeat ABO/Rh and DAT are all as expected (DAT negative). The most likely cause is:

Heat damage to the red cells (nonimmune hemolysis)

An ABO-incompatible acute hemolytic reaction

A febrile nonhemolytic transfusion reaction

A delayed hemolytic reaction from anti-Jka

During a transfusion given under pressure, a patient suddenly coughs and becomes cyanotic and hypotensive, and air is seen in the tubing. After stopping the infusion, the patient should be placed:

On the left side, with the head down

On the right side, with the head up

Flat on the back, with the legs raised

Sitting upright, with the legs down

During rapid transfusion of many refrigerated units through a central line, a patient's core temperature falls to 34 °C and an arrhythmia develops. Which measure would have prevented this?

An approved, monitored blood warmer

Warming the units in a microwave oven

Adding warm saline into each blood bag

Choosing units collected within 5 days

Fifteen minutes into a platelet transfusion, a patient has rigors, a temperature rising from 36.9 °C to 39.6 °C and blood pressure falling to 80/40 mmHg. The clerical check is correct and the plasma is not hemolyzed. Besides stopping the transfusion, what is the key next step?

Culture the platelet bag and the patient's blood

Treat it as a febrile reaction and observe

Give an antihistamine and restart the unit

Test the patient for anti-IgA antibodies

Adverse effects: nonimmunologic reactions

9 ASCP MLS practice questions on Adverse effects: nonimmunologic reactions, part of Blood Banking. The first 9 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Hard
A red cell unit was warmed in an unapproved device before a rapid transfusion. The patient then has red urine and plasma hemoglobin is raised. The clerical check, repeat ABO/Rh and DAT are all as expected (DAT negative). The most likely cause is:
1. AAn ABO-incompatible acute hemolytic reaction
2. BA febrile nonhemolytic transfusion reaction
3. CHeat damage to the red cells (nonimmune hemolysis)
4. DA delayed hemolytic reaction from anti-Jka
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Answer: C · Heat damage to the red cells (nonimmune hemolysis)
Overheating destroys red cells before they enter the patient, causing hemoglobinemia and hemoglobinuria without an antibody. A negative DAT, a correct clerical check and matching ABO types point away from immune hemolysis. Other nonimmune causes include freezing, hypotonic or dextrose solutions in the line, and pressure from small needles or pumps. Only approved, monitored blood warmers should be used.
- A: An ABO-incompatible reaction would show an error in the clerical check or ABO types, usually with a positive DAT.
- B: A febrile reaction causes fever without hemoglobinuria.
- D: A delayed reaction appears days later, with a positive DAT and a new antibody.
Question 2 · Hard
During a transfusion given under pressure, a patient suddenly coughs and becomes cyanotic and hypotensive, and air is seen in the tubing. After stopping the infusion, the patient should be placed:
1. AOn the right side, with the head up
2. BOn the left side, with the head down
3. CFlat on the back, with the legs raised
4. DSitting upright, with the legs down
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Answer: B · On the left side, with the head down
Air entering a vein can lodge in the right ventricle and block outflow to the lungs. Lying on the left side with the head down helps keep the air in the right heart and away from the pulmonary outflow. Oxygen is given, and air may be removed through a central line. Closed plastic bags and careful line handling have made air embolism rare.
- A: The right side with the head up is the opposite of the recommended position.
- C: Lying flat does not trap the air away from the pulmonary artery.
- D: Sitting upright lets air move toward the pulmonary outflow and the brain.
Question 3 · Hard
During rapid transfusion of many refrigerated units through a central line, a patient's core temperature falls to 34 °C and an arrhythmia develops. Which measure would have prevented this?
1. AWarming the units in a microwave oven
2. BAdding warm saline into each blood bag
3. CAn approved, monitored blood warmer
4. DChoosing units collected within 5 days
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Answer: C · An approved, monitored blood warmer
Cold blood given fast, especially through a central line close to the heart, can cause hypothermia and arrhythmias, and it worsens coagulopathy. An FDA-cleared blood warmer with a temperature monitor and alarm warms blood safely during massive transfusion. Uncontrolled heating, such as a microwave or hot water, can hemolyze red cells. Hypothermia also slows the metabolism of citrate.
- A: Microwaves heat unevenly and can hemolyze red cells.
- B: Adding fluid to the bag is not a safe or approved warming method.
- D: Fresh units are just as cold as older ones.
Question 4 · Medium
A patient with myelodysplastic syndrome has received about 40 red cell units over 2 years. Which test is most used to monitor iron overload?
1. AHemoglobin A2 level
2. BSerum iron alone
3. CReticulocyte count
4. DSerum ferritin
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Answer: D · Serum ferritin
Each red cell unit adds about 200 to 250 mg of iron, which the body cannot excrete, so 40 units add roughly 8 to 10 g. Serum ferritin is followed regularly, and MRI estimates iron in the liver and heart more accurately. Chelation is usually considered once ferritin stays above about 1,000 ng/mL (1,000 µg/L) or after about 20 units. Untreated iron overload damages the heart, liver and endocrine glands.
- A: Hemoglobin A2 is used to diagnose beta-thalassemia trait.
- B: Serum iron varies widely and does not reflect total body stores.
- C: The reticulocyte count measures marrow output, not iron stores.
Question 5 · Hard
Fifteen minutes into a platelet transfusion, a patient has rigors, a temperature rising from 36.9 °C to 39.6 °C and blood pressure falling to 80/40 mmHg. The clerical check is correct and the plasma is not hemolyzed. Besides stopping the transfusion, what is the key next step?
1. ATreat it as a febrile reaction and observe
2. BGive an antihistamine and restart the unit
3. CCulture the platelet bag and the patient's blood
4. DTest the patient for anti-IgA antibodies
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Answer: C · Culture the platelet bag and the patient's blood
High fever with rigors and hypotension during a platelet transfusion strongly suggests bacterial contamination. The bag is Gram stained and cultured, blood cultures are taken from the patient, and broad-spectrum antibiotics are started. The supplier is told at once so that other components from the same donation can be quarantined. Matching organisms in the bag and the patient confirm a septic reaction.
- A: High fever with hypotension needs a sepsis workup, not observation alone.
- B: Restarting a possibly contaminated unit could be fatal.
- D: Anti-IgA causes anaphylaxis without fever.
Question 6 · Easy
Which component carries the highest risk of bacterial contamination and septic transfusion reactions?
1. ARed blood cells
2. BCryoprecipitate
3. CFresh frozen plasma
4. DPlatelets
Answer and explanation in LearnFree account
Question 7 · Medium
Which patient is at greatest risk of transfusion-associated circulatory overload?
1. AA healthy adult given 1 unit over 2 hours
2. BA 25-year-old bleeding heavily after a car accident
3. CAn 84-year-old in heart failure given 2 rapid units
4. DA child receiving one dose of platelets
Answer and explanation in LearnFree account
Question 8 · Hard
A 50-year-old man with alcoholic cirrhosis and bleeding varices receives 8 units of plasma and 4 units of red cells over 70 minutes. He then develops perioral tingling, muscle twitching and a prolonged QT interval. Blood pressure is stable, the lungs are clear and the temperature is 36.8 °C. Results: potassium 4.2 mmol/L, total calcium 8.6 mg/dL (2.15 mmol/L; reference 8.6-10.2 mg/dL), ionized calcium 0.76 mmol/L (reference 1.12-1.32 mmol/L), magnesium 1.4 mg/dL (0.58 mmol/L; reference 1.7-2.2 mg/dL). The most likely cause and treatment are:
1. AHypothermia; use an in-line blood warmer
2. BCirculatory overload; give a diuretic
3. CCitrate toxicity; give IV calcium
4. DHyperkalemia; give insulin and glucose
Answer and explanation in LearnFree account
Question 9 · Medium
Which finding best separates transfusion-associated circulatory overload (TACO) from transfusion-related acute lung injury (TRALI)?
1. AA positive DAT and hemoglobinuria in TACO
2. BHypotension and a normal BNP in TACO
3. CHypertension and a raised BNP in TACO
4. DFever and a low BNP in TACO
Answer and explanation in LearnFree account

Adverse effects: nonimmunologic reactions

A red cell unit was warmed in an unapproved device before a rapid transfusion. The patient then has red urine and plasma hemoglobin is raised. The clerical check, repeat ABO/Rh and DAT are all as expected (DAT negative). The most likely cause is:

During a transfusion given under pressure, a patient suddenly coughs and becomes cyanotic and hypotensive, and air is seen in the tubing. After stopping the infusion, the patient should be placed:

During rapid transfusion of many refrigerated units through a central line, a patient's core temperature falls to 34 °C and an arrhythmia develops. Which measure would have prevented this?

A patient with myelodysplastic syndrome has received about 40 red cell units over 2 years. Which test is most used to monitor iron overload?

Fifteen minutes into a platelet transfusion, a patient has rigors, a temperature rising from 36.9 °C to 39.6 °C and blood pressure falling to 80/40 mmHg. The clerical check is correct and the plasma is not hemolyzed. Besides stopping the transfusion, what is the key next step?

Which component carries the highest risk of bacterial contamination and septic transfusion reactions?

Which patient is at greatest risk of transfusion-associated circulatory overload?

Which finding best separates transfusion-associated circulatory overload (TACO) from transfusion-related acute lung injury (TRALI)?