Skip to content

Add your earlier progress to your account?

From before you signed in, this browser has:

Which plan do you want to keep?

You answered the plan questions before you signed in, and those answers don't match the plan saved on your account.

SettingSaved planNew answers

Study progress is waiting to be saved

Donors, collection and donor reactions

16 min

Skills you'll build4 skills
  • Accept or defer a donor from history, medications, physical findings, and deferral records
  • Calculate a reduced collection volume and its matching anticoagulant volume
  • Distinguish vasovagal and citrate-related donor reaction patterns
  • Name the eligibility and testing rules that differ for directed and autologous donations

Try first

Try first

A plateletpheresis donor has a platelet count of 245 × 10⁹/L, vital signs within the limits and a clear history, apart from aspirin taken yesterday for a headache. Can this collection supply platelets for transfusion?

Keep going to see the reasoning.

Right. Keep going to follow the reasoning.

Keep going to see the reasoning.

Keep going to see the reasoning.

Get the idea

Use the explanation to check your first decision.

Donor eligibility checks

The collection facility decides eligibility before every donation. It confirms the donor's identity and deferral record, reviews the interval since earlier donations, asks about health, medications and exposures, and completes a physical assessment.1 Each check must be met separately. A plateletpheresis donor who recently took a drug that impairs platelet function cannot supply platelets for transfusion, even with an adequate count.2

Federal minimum for a routine allogeneic donorLimit
Oral temperature37.5 °C or lower
Blood pressureSystolic 90–180 mm Hg, diastolic 50–100 mm Hg
PulseRegular, 50–100 beats/min
Hemoglobin, female donor12.5 g/dL or higher
Hemoglobin, male donor13.0 g/dL or higher
Weight50 kg or more

Reduced-volume collections

A standard set holds 63 mL of anticoagulant for 450 mL of blood. A physician may approve an autologous donor who weighs less than 50 kg for a reduced volume, and the anticoagulant is reduced in proportion:1,3

collection volume (mL) = donor weight (kg) ÷ 50 × 450

anticoagulant volume (mL) = collection volume (mL) ÷ 450 × 63

A set is changed only by a manufacturer-compatible, facility-validated method. A standard set that receives too little blood with its full anticoagulant becomes an RBC Low Volume unit, and only red cells are prepared from it.3,4

Donor reactions

A vasovagal reaction brings pallor, sweating, nausea, light-headedness, a slow pulse and low blood pressure. The collection stops, and the donor lies flat with the legs raised when appropriate. During apheresis, citrate returned to the donor binds ionized calcium. Perioral tingling, chills, cramps and carpopedal spasm follow. Citrate delivery slows or stops under medical direction, because severe hypocalcemia can cause an arrhythmia.3,5

Directed and autologous donations

A directed donor completes the full allogeneic eligibility process, and the donation receives every required test. FDA reports that directed donations may carry higher infectious-marker rates.6 Cellular components from a blood relative are irradiated. A shared HLA haplotype can let donor T lymphocytes engraft and cause transfusion-associated graft-versus-host disease.7 An autologous donor may qualify with a hemoglobin of 11.0 g/dL or higher when the responsible physician documents that the collection is safe. Moving an autologous unit into allogeneic inventory requires full allogeneic eligibility and testing.8

Follow the bench demonstration

Sources for this step
References
  1. Electronic Code of Federal Regulations. Title 21, §§630.5, 630.10, 630.15, and 630.20. Accessed September 27, 2026. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-F/part-630
  2. Electronic Code of Federal Regulations. Title 21, §640.21(b)-(d). Accessed September 27, 2026. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-F/part-640/subpart-C/section-640.21
  3. Electronic Code of Federal Regulations. Title 21, §§606.160, 606.170, 640.4, and 640.24. Accessed September 27, 2026. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-F
  4. Association for the Advancement of Blood & Biotherapies. Circular of Information for the Use of Human Blood and Blood Components. June 2024. Accessed September 27, 2026.
  5. International Society of Blood Transfusion, International Haemovigilance Network, Association for the Advancement of Blood & Biotherapies. Standard for Surveillance of Complications Related to Blood Donation. December 2014. Accessed September 27, 2026.
  6. US Food and Drug Administration. Important Information About Directed Blood Donations that are Not Medically Indicated. October 23, 2023. Accessed September 27, 2026.
  7. Association for the Advancement of Blood & Biotherapies. Standards for Blood Banks and Transfusion Services. 35th ed. AABB; 2026. Effective April 1, 2026. Accessed September 27, 2026. https://www.aabb.org/standards-accreditation/standards/blood-banks-and-transfusion-services
  8. US Food and Drug Administration. Determining Donor Eligibility for Autologous Donors of Blood and Blood Components Intended Solely for Autologous Use: Compliance Policy, Guidance for Industry. August 2016. Accessed September 27, 2026.

Watch one

Read each decision and its explanation.

Dorothy Clotworthy, 71, a retired piano teacher, weighs 45 kg and has a hemoglobin of 12.1 g/dL. Her surgeon has prescribed an autologous donation before her knee replacement. The collection set holds 63 mL of anticoagulant for 450 mL of blood.

How much anticoagulant comes out of the set before collection?

  1. Confirm the prescription for autologous use, the responsible physician's approval and a hemoglobin of at least 11.0 g/dL. All three are on record.

    A donor under 50 kg is outside the routine limit, so the collection requires documented physician approval.

  2. Collection volume = 45 kg ÷ 50 × 450 = 405 mL.

    The set's 450 mL assumes a 50 kg donor, so the volume scales with weight.

  3. Anticoagulant volume = 405 mL ÷ 450 × 63 = 56.7 mL.

    The anticoagulant must keep the same ratio to the blood collected.

  4. Anticoagulant removed = 63 − 56.7 = 6.3 mL.

    The set contains 63 mL, so the excess is removed.

  5. Make the change by the facility's validated method and record both volumes.

    A commercial set may be changed only as its instructions and a validated procedure allow.

Collect 405 mL with 56.7 mL of anticoagulant. Remove 63 − 56.7 = 6.3 mL from the set.

Practice this skill

Your turn

Problem 1 of 3 · Hints available

An approved autologous donor weighs 40 kg. The collection set holds 63 mL of anticoagulant for 450 mL of blood. What anticoagulant volume matches the reduced collection volume?

Incorrect. That is the volume removed from the set: 63 − 50.4 = 12.6 mL. The collection keeps 50.4 mL to match 360 mL of blood.

Correct. 40 ÷ 50 × 450 = 360 mL of blood, and 360 ÷ 450 × 63 = 50.4 mL of anticoagulant. The set is adjusted only by a manufacturer-compatible, facility-validated method.

Incorrect. Keeping the full 63 mL with only 360 mL of blood leaves excess citrate for the volume collected. The anticoagulant falls in proportion: 360 ÷ 450 × 63 = 50.4 mL.

Hint
  1. Start with the blood volume a 40 kg donor can give.
  2. The anticoagulant is reduced by the same fraction as the blood.

Review Reduced collection volume

Problem 2 of 3 · Hints available

During plateletpheresis, a donor reports perioral tingling and then develops carpopedal spasm. Pulse and blood pressure are unchanged. Which mechanism best fits?

Incorrect. A vasovagal reaction brings pallor, sweating, light-headedness, bradycardia, and hypotension, and this donor's pulse and blood pressure are unchanged.

Incorrect. A needle injury to a nerve causes pain or tingling in the punctured arm. Perioral tingling followed by carpopedal spasm is a systemic pattern.

Correct. Citrate returned to the donor binds ionized calcium, and the falling ionized calcium causes perioral tingling and then muscle spasm. The collection slows or stops citrate delivery under medical direction, because severe hypocalcemia can progress to an arrhythmia.

Hint
  1. Ask what an apheresis instrument returns to the donor along with the cells.
  2. Check which reactions the steady pulse and blood pressure fit.

Review Donor reactions

Problem 3 of 3 · On your own

A first-time whole-blood donor, a 36-year-old man, weighs 72 kg. His oral temperature is 36.9 °C, blood pressure 124/78 mm Hg and pulse regular at 56 beats/min. His hemoglobin is 12.7 g/dL, and his history raises no deferral. What is the decision today?

The pulse limit is 50 to 100 beats/min and regular. A pulse of 56 beats/min meets it.

12.5 g/dL is the limit for a female donor. A male donor needs 13.0 g/dL or higher.

A male allogeneic donor needs a hemoglobin of 13.0 g/dL or higher. His other findings are within the limits, and each check must be met separately.

History and vital signs are separate checks from the hemoglobin. A hemoglobin below the limit defers the donor even when the other results are acceptable.

Review Donor qualification

Use it

Read the case evidence, then make each decision. The step is complete without it.

  • Marisol Stirling, 34, who coaches a youth soccer team, gives whole blood for her brother's planned hip surgery as a directed donation.
  • She weighs 58 kg, her hemoglobin is 13.1 g/dL, and her vital signs are within the limits.
  • The collection set holds 63 mL of anticoagulant for 450 mL of blood.
  • At 350 mL she turns pale and sweaty and says she feels light-headed. Her pulse is 48 beats/min and her blood pressure 86/52 mm Hg.
  • The collection stops at 350 mL.
Decision 1 of 3

Which reaction fits, and what comes first?

Pallor, sweating, light-headedness, a slow pulse and low blood pressure are a vasovagal pattern. The collection stops, and her vital signs are monitored under the emergency procedure.

A whole-blood collection returns no citrate to the donor. Citrate reactions come from apheresis and start with tingling and cramps.

A hematoma shows as pain, swelling or bruising at the needle site. Her signs are systemic.

Review Donor reactions

Decision 2 of 3

The bag holds 350 mL of blood with the set's full 63 mL of anticoagulant. What can be prepared from it?

The blood contains excess citrate for its volume. The Circular of Information limits a low-volume collection to red cells.

Kept the full anticoagulant for a smaller draw

A standard set holds 63 mL of anticoagulant for 450 mL of blood. Drawing only 360 mL without removing the matching 12.6 mL leaves excess citrate for the volume collected, and a standard set that receives too little blood becomes an RBC Low Volume unit that can yield red cells only.

The Circular defines a low-volume range for a standard set, and a collection within it still yields red cells.

A standard set that receives too little blood with its full anticoagulant becomes an RBC Low Volume unit. Only red cells are prepared from it.

Review Whole-blood collection controls

Decision 3 of 3

Her brother's surgeon asks whether the unit can skip infectious-disease testing, since the donor is family. How is the unit handled?

A directed donation receives every test a routine donation receives. FDA reports that directed donations may carry higher infectious-marker rates.

Assumed a directed donation is safer than routine inventory

A directed donation goes through the same allogeneic eligibility assessment and testing as any other donation, and FDA reports that directed donations may have higher infectious-marker rates. A blood relative's cellular components also need irradiation, because a shared HLA haplotype can allow transfusion-associated graft-versus-host disease.

A directed donation is tested like any allogeneic donation. Red cells from a sibling are irradiated, because a shared HLA haplotype can allow transfusion-associated graft-versus-host disease.

Full testing is correct. A cellular component from a blood relative also needs irradiation, and the label shows that requirement through issue.

Review Directed donation

As a directed donation from a sibling, the unit needs full allogeneic testing and irradiation regardless of the volume collected. Stopping at 350 mL made it an RBC Low Volume unit, and her slow pulse and low blood pressure fit a vasovagal reaction.

For reference

Sources checked