Donors, collection and donor reactions
16 min
- 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
Get the idea
Each check stands on its own
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 Passing one check covers none of the others. 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 donor | Limit |
|---|---|
| Oral temperature | 37.5 °C or lower |
| Blood pressure | Systolic 90–180 mm Hg, diastolic 50–100 mm Hg |
| Pulse | Regular, 50–100 beats/min |
| Hemoglobin, female donor | 12.5 g/dL or higher |
| Hemoglobin, male donor | 13.0 g/dL or higher |
| Weight | 50 kg or more |
A smaller draw keeps the ratio
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 falls 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
Two reactions in the chair
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
References
- 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
- 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
- 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
- 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.
- 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.
- US Food and Drug Administration. Important Information About Directed Blood Donations that are Not Medically Indicated. October 23, 2023. Accessed September 27, 2026.
- 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
- 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
Dorothy Pembleton, 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?
- 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 rests on a documented physician approval.
- Collection volume = 45 kg ÷ 50 × 450 = 405 mL.
The set's 450 mL assumes a 50 kg donor, so the volume scales with weight.
- Anticoagulant volume = 405 mL ÷ 450 × 63 = 56.7 mL.
The anticoagulant keeps the same ratio to the blood it will meet.
- Anticoagulant removed = 63 − 56.7 = 6.3 mL.
The set already holds 63 mL, and the excess is what comes out.
- Make the change by the facility's validated method and record both volumes.
Only the set's instructions and a validated procedure give authority to change a commercial set.
Your turn
Use it
- Marisol Quintero, 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.
The clue that settled this case is the directed donation from a sibling. It brings the full allogeneic testing and the irradiation requirement, whatever volume was collected. The stop at 350 mL turned the unit into RBC Low Volume, and her slow pulse and low blood pressure named the reaction.
Results
- 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
To review
6 questions from this step will come back in Review.
Next step: Releasing and storing componentsReview nowOpen the part
Keep
Sources checked
The rest of this step
A short briefing, a demonstration at the bench, 3 practice problems and a short case.
A free account opens the rest and keeps your progress.