Autologous Blood Donation
Autologous blood donation is the process of donating one's own blood prior to an elective surgical or medical procedure to avoid or reduce the need for an allogeneic blood transfusion (from a volunteer blood donor).
Blood transfusions are given to restore lost blood, to improve clotting time, and to improve the ability of the blood to deliver oxygen to the body's tissues. There are some disadvantages to traditional allogeneic blood transfusions. Although strict regulations are in place to ensure correct matching by blood type, errors in this process can lead to the transfusion of mismatched blood, which can cause a serious and sometimes fatal adverse reaction called transfusion reaction. In addition, while donated blood is rigorously tested for infectious agents such as human immunodeficiency virus (HIV) and hepatitis, there is always a chance that an infectious disease may be transmitted via allogeneic transfusion.
The donation and transfusion of autologous blood has arisen as an alternative to allogeneic blood transfusion. Autologous donation is indicated for an elective surgical or medical procedure in which the likelihood of a blood transfusion is high. Such procedures include surgery on the heart, blood vessels, bones, and chest.
Some of the advantages of autologous blood donation include:
- The patient is assured that the blood is an exact match to his or her blood type, thereby avoiding transfusion reaction.
- There is no risk of inadvertently transmitting infectious agents.
- Autologous blood donations supplement the community blood supply.
- The process of donating blood promotes blood cell production by bone marrow.
- The patient is often reassured by the knowledge that his or her own blood will be used if a blood transfusion becomes necessary.
Some disadvantages to autologous blood donation do exist, which include:
- Contamination of autologous blood with infectious agents is possible during the donation process.
- There is a possibility that a patient's blood will be mislabeled or that allogeneic blood will be inadvertently transfused.
- Autologous blood donation costs more to process and store.
- Blood may be transfused unnecessarily because an autologous blood supply exists.
- Unused units of autologous blood are usually disposed of; approximately 44% of autologous donations remain unused after surgery.
Autologous blood donations account for approximately 5% of all blood donated in the United States each year.
The most common form of autologous donation is called preoperative autologous blood donation (PABD). PABD is generally indicated when there is a reasonable
The PABD process is similar to the process of donating allogeneic blood. A tourniquet is placed on the upper arm to increase the pressure in the arm veins and make them swell and become more accessible. Once a suitable vein is identified, the area where the needle will be inserted is sterilized by washing with soap solution or an iodine-containing antiseptic. The donor lies on a bed or cot during the procedure, which takes about 10 minutes. Blood is collected in sterile plastic bags that hold one pint (450 ml). The bags contain an anticoagulant to prevent clotting and preservatives to keep the blood cells alive.
The collected blood may then be transfused during and/or after surgery in a similar manner to allogeneic blood. If the amount transfused is less than anticipated or if no blood was necessary, then the autologous blood is generally disposed of (since the restrictions placed on volunteer donors are stricter than those on autologous donors). If the patient's surgery is postponed, the donated blood may be frozen and stored until the procedure is rescheduled.
Acute normo-volemic hemodilution (ANH) is a variant of autologous donation in which a volume of the patient's blood is removed directly before surgery and replaced with fluids so that any blood lost during surgery has a lower red blood cell count (i.e., the red blood cells have been diluted). The removed blood is then reinfused after surgery. Advantages to ANH are that no processing and storage costs are necessary and the risk of contamination during processing is reduced.
Blood may also be collected during surgery (intraoperative blood salvage, or IBS) or after surgery (postoperative blood salvage, PBS). IBS is commonly used during cardiac, bone, transplant, and trauma surgery and involves the use of specialized equipment to collect and process the blood before reinfusion. PBS involves the collection of blood from drainage tubes, although generally this volume is small.
Patients must meet certain selection criteria before donating their own blood for future use. In the case of PABD, there must be sufficient time before the procedure to safely collect enough blood. A patient must be medically stable, have no active infection, and have a close-to-normal red blood cell count to quality for PABD.
Individuals who donate blood are generally given fluids and/or light refreshments to prevent possible side effects such as dizziness and nausea. Iron supplements may be prescribed to prevent or treat anemia (low red blood cell count).
Complications associated with autologous blood donation are similar to those associated with allogeneic blood donation. These include dizziness, fainting, profuse sweating, hyperventilation, and/or low blood pressure. (This collection of symptoms is called a vasovagal response.) Among patients with heart disease, there is an increased risk of cardiac complications after donating blood.
Risks associated with autologous blood transfusion include transfusion reaction if an allogeneic blood transfusion was inadvertently given and transmission of infectious agents if the blood became contaminated. Symptoms of transfusion reaction include general discomfort, anxiety, breathing difficulties, dizziness, itching, fever, headache, rash, and swelling. Patients who are given too much blood can develop high blood pressure, which is a concern for people who have heart disease. Very rarely, an air embolism is created when air is introduced into a patient's veins through the tubing used for intravenous infusion.
If a patient loses enough blood during a surgical or medical procedure to warrant a blood transfusion, a transfusion of autologous blood will under normal circumstances
Morbidity and mortality rates
One study found the risk of a complication requiring hospitalization to be one in approximately 17,000 among autologous blood donors, and one in approximately 200,000 among volunteer blood donors. The most common complication is a vasovagal reaction, although approximately 12% of patients requiring hospitalization have angina (chest pain resulting from inadequate supply of oxygen to the heart). There is a higher chance of a vasovagal reaction with autologous blood donation than with allogeneic blood donation.
Allogeneic blood is a more commonly used alternative to autologous blood and accounts for 95% of all blood donations in the United States. Patients may also choose to have blood donated by family or friends, a process called directed donation. For patients who are interested in avoiding a blood transfusion, alternatives include:
- Volume expanders. Certain fluids (saline, Ringer's lactate solution, dextran, etc.) may be used to increase the volume of blood.
- Blood substitutes. Much research is currently being done into compounds that can replace some or all of the functions of blood components. One such compound, called HBOC-201, or Hemopure, is derived from bovine (cow) blood and is showing promise as a substitute for red blood cell transfusion.
- Bloodless surgery. It may be possible to avoid excessive blood loss through careful planning prior to surgery. Specialized instruments can minimize the amount of blood lost during a procedure.
Henry, D. A., et al. "Pre-operative Autologous Donation for Minimizing Perioperative Allogeneic Blood Transfusion." Cochrane Review, Issue 1 (January 20, 2003).
Vanderlinde, Elizabeth S., Joanna M. Heal, and Neil Blumberg. "Autologous Transfusion." British Medical Journal, 324 (March 30, 2002): 772–5.
American Association of Blood Banks. 8101 Glenbrook Rd., Bethesda, MD 20814. (301) 907-6977. <http://www.aabb.org>.
American Red Cross. 431 18th St., NW, Washington, DC 20006. (202) 639-3520. <http://www.redcross.org>.
"Autologous Blood as an Alternative to Allogeneic Blood Transfusion." American Association of Blood Banks, January 2002 [cited March 19, 2003]. <http://www.aabb.org/All_About_Blood/FAQs/4>.
"Preoperative Autologous Blood Donation (PABD)." Health Technology Advisory Committee, September 2000 [cited March 19, 2003]. <http://www.health.state.mn.us/htac/pabd.htm>.
"Transfusion Alert: Use of Autologous Blood." National Heart, Lung, and Blood Institute, [cited March 19, 2003]. <http://www.nhlbi.nih.gov/health/prof/blood/transfusion/logo.htm>.
Stephanie Dionne Sherk
WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?
Blood may be donated at a hospital or a blood donor center. The procedure of blood donation is generally performed by a nurse or phlebotomist (a person trained to draw blood).
QUESTIONS TO ASK THE DOCTOR
- What is the chance that I will require a blood transfusion for my upcoming surgical procedure?
- Do I qualify to be an autologous blood donor?
- Where will blood collection take place and how many units should I donate?
- What will happen to my donated blood if my surgery is postponed or cancelled?