Blood transfusion
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Donor for a blood transfusion |
Blood transfusion is the process of transferring
blood or blood-based products from one person into the
circulatory system of another. Blood transfusions can be life-saving in some situations, such as massive blood loss due to
trauma, or can be used to replace blood loss that can occur during
surgery. Blood transfusion may also be used to treat a severe
anaemia or
thrombocytopenia caused by a
blood disease.
Early attempts
The first historical attempt at blood transfusion was described by the 15th-century chronicler
Stefano Infessura. Infessura relates that, in
1492, as the
Pope Innocent VIII sank into a coma, the blood of three boys was infused into the dying pontiff's veins at the suggestion of a physician. The boys were ten years old, and had been promised a
ducat each. All three died.
Roman Catholic authors take pains to discredit Infessura's account, accusing him of anti-papalism.
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World War II syringe for direct interhuman blood transfusion |
With
Harvey's discovery of the circulation of the blood, more sophisticated research into blood transfusion began in the
17th century, with successful experiments in transfusion between animals. However, successive attempts on humans continued to have fatal results.
The first fully-documented human blood transfusion was administered by Dr.
Jean-Baptiste Denys on
June 15,
1667. He transfused the blood of a
sheep into a 15-year old boy (the boy later died, and Denys was accused of murder).
The first successes
The science of blood transfusion dates to the first decade of the
19th century, with the discovery of distinct
blood types leading to the practice of mixing some blood from the donor and the receiver before the transfusion (an early form of
cross-matching).
In
1818, Dr.
James Blundell, a British
obstetrician, performed the first successful transfusion of human blood, for the treatment of postpartum
hemorrhage. He used the patient's husband as a donor, and extracted four ounces of blood from his arm to transfuse into his wife. During the years
1825 and 1830, Dr. Blundell performed 10 transfusions, five of which were beneficial, and published his results. He also invented many instruments for the transfusion of blood. He made a substantial amount of money from this endeavour, roughly $50 million in
real dollars.
In
1840, at
St. George's Hospital Medical School in London, Samuel Armstrong Lane, aided by Dr. Blundell, performed the first successful whole blood transfusion to treat
hemophilia.
Development of blood banking
While the first transfusions had to be made directly from donor to receiver before
coagulation, in the
1910s it was discovered that by adding
anticoagulants and
refrigerating the blood it was possible to store it for some days, thus opening the way for
blood banks. The first non-direct transfusion was performed on
March 27,
1914 by the
Belgian doctor
Albert Hustin, who used
sodium citrate as an anticoagulant. The first blood transfusion using blood that had been stored and cooled was performed on
January 1,
1916. It was performed by the
Royal Army Medical Corps (RAMC), and the procedure was very successful.
The first academic institution devoted to the science of blood transfusion was founded by
Alexander Bogdanov in
Moscow in
1925. Bogdanov was motivated, at least in part, by a search for eternal youth, and remarked with satisfaction on the improvement of his eyesight, suspension of balding, and other positive symptoms after receiving 11 transfusions of
whole blood.
In fact, following the death of
Vladimir Lenin, Bogdanov was entrusted with the study of Lenin's
brain, with a view toward resuscitating the deceased
Bolshevik leader. Tragically, but perhaps not unforeseeably, Bogdanov lost his life in
1928 as a result of one of his experiments, when the blood of a student suffering from
malaria and
tuberculosis was given to him in a transfusion. Some scholars (e.g. Loren Graham) have speculated that his death may have been a suicide, while others attribute it to blood type incompatibility, which was still incompletely understood at the time.
[See Bernice Glatzer Rosenthal. New Myth, New World: From Nietzsche to Stalinism, Pennsylvania State University, 2002, ISBN 0271025336 pp. 161-162.]There is an
urban legend concerning one of the pioneers of blood transfusion research, Dr.
Charles Drew. Drew's research led to the discovery that blood could be separated into
blood plasma and
red blood cells, and that the components could be frozen separately. Blood stored in this way lasted longer and was less likely to become contaminated. His untimely
death after an
automobile accident is commonly believed to have resulted partly from delayed access to emergency blood transfusion treatment because of his
race. The popular
television series
M*A*S*H once aired an
episode (see Season 2, Episode 9 - "Dear Dad ... Three") propagating this legend. Contemporary eye-witness accounts, however, contradict that version.
Compatibility
Great care is taken in
cross-matching to ensure that the recipient's
immune system will not attack the donor blood. In addition to the familiar human
blood types (A, B, AB and O) and
Rh factor (positive or negative) classifications, other minor
red cell antigens are known to play a role in
compatibility. These other types can become increasingly important in people who receive many blood transfusions, as their bodies develop increasing resistance to blood from other people via a process of
alloimmunization.
Screening for infection
A number of
infectious diseases (such as
HIV,
syphilis,
hepatitis B and
hepatitis C, among others) can be passed from the donor to recipient. This has led to strict human blood transfusion standards in developed countries. Standards include screening for potential risk factors and health problems among donors by determining donor
hemoglobin levels, adminstering a set of standard oral and written questions to donors, and laboratory testing of donated units for infection. The lack of such standards in places like rural China, where desperate villagers donated plasma for money and had others' red blood cells reinjected, has produced entire villages infected with HIV.
As of mid-
2005, all donated blood in the
United States is screened for the following infectious agents:
[American Association of Blood Banks. Standards for Blood Banks and Transfusion Services, 18th ed. American Association of Blood Banks, Bethesda, MD.]*
HIV-1 and
HIV-2*
Human T-lymphotropic virus (HTLV-1 and HTLV-2)
*
Hepatitis C virus
*
Hepatitis B virus
*
West Nile virus*
Treponema pallidum (the causative agent of
syphilis)
When a person's need for a transfusion can be anticipated, as in the case of scheduled surgery,
autologous donation can be used to protect against disease transmission and eliminate the problem of blood type compatibility.
Processing of blood prior to transfusion
Donated blood is sometimes subjected to processing after it is collected, to make it suitable for use in specific patient populations. Examples of post-donation processing include:
*
Leukoreduction, or the removal of stray
white blood cells from the blood product by filtration.
Leukoreduced blood is less likely to cause
alloimmunization (development of antibodies against specific blood types), and less likely to cause febrile transfusion reactions. Also, leukoreduction greatly reduces the chance of
cytomegalovirus (CMV) transmission. Leukoreduced blood is appropriate for:
[Evidence-based recommendations for the use of WBC-reduced cellular blood components. Ratko TA; Cummings JP; Oberman HA; Crookston KP; DeChristopher PJ; Eastlund DT; Godwin JE; Sacher RA; Yawn DH; Matuszewski KA. Transfusion 2001 Oct;41(10):1310-9.]**Chronically transfused patients
**Potential transplant recipients
**Patients with previous febrile nonhemolytic transfusion reactions
**CMV seronegative at-risk patients for whom seronegative components are not available
*
Irradiation. In patients who are severely immunosuppressed and at risk for transfusion-associated
graft-versus-host disease, transfused red cells may be subjected to irradiation with at least 2500
Gy to prevent the donor T lymphocytes from dividing in the recipient.
[Quality control of blood irradiation: determination T cells radiosensitivity to cobalt-60 gamma rays. Goes EG; Borges JC; Covas DT; Orellana MD; Palma PV; Morais FR; Pela CA. Transfusion. 2006 Jan;46(1):34-40.] Irradiated blood products are appropriate for:
**Patients with hereditary immune deficiencies
**Patients receiving blood transfusions from relatives in directed-donation programs
**Patients receiving large doses of
chemotherapy, undergoing
stem cell transplantation, or with
AIDS (controversial).
*
CMV screening.
Cytomegalovirus, or CMV, is a
virus which infects
white blood cells. Many people are
asymptomatic carriers. In patients with signficant immune suppression (eg recipients of
stem cell transplants) who have not previously been exposed to CMV, blood products that are CMV-negative are preferred.
Leukoreduced blood products can substitute for CMV-negative products, since the removal of white blood cells removes the source of CMV transmission (see
leukoreduction above).
Blood transfusions can be grouped into two main types depending on their source:
*
Homologous transfusions, or transfusions using the stored blood of others.
*
Autologous transfusions, or transfusions using one's own stored blood.
Blood can only be administered
intravenously. It therefore requires the insertion of a
cannula of suitable caliber. Before the blood is administered, the personal details of the patient are matched with the blood to be transfused, to minimize risk of transfusion reactions. With the recognition that
clerical error (eg administering the wrong unit of blood) is a signficant source of
transfusion reactions, attempts have been made to build
redundancy into the matching process that takes place at the bedside.
A unit (up to 500 ml) of blood is typically administered over 4 hours. In patients at risk of
congestive heart failure, many doctors administer
furosemide to prevent fluid overload.
Blood donation centers in different countries may have different guidelines about who can serve as a blood donor. Common
contraindications to being a blood donor include:
* previous malaria or hepatitis
* a history of intravenous drug abuse
* donors who have received human-derived pituitary hormones
* donors with high-risk sexual behaviour (variably defined)
* donors who have previously been transfused (12-month min. deferral)
Sometimes only parts of the blood are taken as a donation. Blood is made up mostly of
plasma,
red blood cells,
white blood cells and
platelets. Red cells, plasma and platelets can be donated separately in a process called
apheresis. Blood is usually separated into components after being donated to make the best use of it. Aside for red cells, plasma, and platelets, the resulting blood component products also include
albumin protein used to treat burns, clotting factor concentrates used to treat
hemophilia,
cryoprecipitate,
fibrinogen concentrate, and
immunoglobulins (
antibodies) for immunological disorders. Donation of whole blood is generally reserved for treating young children and in remote areas where the hospital summons donors when it needs them.
Donation of whole blood, as opposed to apheresis, eliminates transfusion-related risk of illness for the blood donor, aside from the minuscule chance of infection or perhaps of localized injury to the donor site. While there is a theoretical risk to the donor when they donate plasma and have red cells reinfused, this risk is eliminated by proper sterilization procedures. However, this caused public health disasters in China where this practice was often unregulated. Modern, well-run
blood plasma collection centers are completely safe. In some developed countries including the United States, they are maintained by pharmaceutical companies, using paid donors up to twice weekly; in others they rely on unpaid donors and are operated by non-profit organisations such as the
Australian Red Cross.
Donations are usually anonymous to the recipient, but products in a
blood bank are always individually traceable through the whole cycle of donation, testing, separation into components, storage, and administration to the recipient. This enables management and investigation of any suspected transfusion related disease transmission.
For the donor
Donating blood at a modern, well-run blood collection center is safe. The biggest risk is probably that of
vasovagal syncope, or passing out. A large study, involving 194,000 donations during a one-year period at an urban blood center, found 178 cases of syncope, for an incidence of 0.09%.
[A study of 178 consecutive vasovagal syncopal reactions from the perspective of safety. Newman BH; Graves S. Transfusion 2001 Dec;41(12):1475-9.] Only 5 of these incidents required
emergency room attention, and there was only one long-term complication. The best defense, as a donor, is being well-hydrated and remaining at the donation center for 10-15 minutes after finishing your donation, to make sure you are feeling well. Other risks to donors noted in one study included:
[Adverse effects in blood donors after whole-blood donation: a study of 1000 blood donors interviewed 3 weeks after whole-blood donation. Newman BH; Pichette S; Pichette D; Dzaka E. Transfusion 2003 May;43(5):598-603.]*Bruise at the needle site â€" 23 percent
*Sore arm â€" 10 percent
*
Hematoma at needle site â€" 2 percent
*Sensory changes in the arm used for donation (eg, burning pain, numbness, tingling) â€" 1 percent
*Fatigue â€" 8 percent
*Vasovagal symptoms â€" 5 percent
*Nausea and vomiting â€" 1 percentNote that none of these were severe enough to require medical attention in this study. Overall, blood donation is very safe. There is no risk of acquiring an infection at a modern, well-run blood donation center.
For the recipient
There are risks associated with receiving a blood transfusion, and these must always be balanced against the benefit which is expected. Risks can include:
*
Febrile non-hemolytic transfusion reaction. This is the most common adverse reaction to a blood transfusion. Symptoms include
fever and
dyspnea 1 to 6 hours after receiving the transfusion. Such reactions are clinically benign, causing no lasting side effects or problems, but are unpleasant for the patient. Furthermore, they must be carefully differentiated from hemolytic transfusion reactions or infection (see below).
*
Viral infection. The risk of viral infection is a common concern when receiving a blood transfusion. As noted above, the blood supply in developed countries is carefully screened for a number of infectious agents, in addition to careful screening of donors themselves. Nonetheless, viral transmission has been documented, albeit extremely rarely. The risk for acquiring
hepatitis B in the
United States is about 1 in 250,000 units transfused, and the risk of acquiring
HIV or
hepatitis C via a blood transfusion is currently (as of
2006) estimated at 1 per 2 million units transfused.
Bacterial infection is a much more common problem (see below)
*
Bacterial infection. Blood products can provide an excellent medium for
bacteria, and can become contaminated after collection while they are being stored. The risk is highest with
platelet transfusion, since platelets must be stored near room temperature and cannot be refrigerated. The risk of severe bacterial infection and
sepsis is estimated (as of
2001) at about 1 in 50,000 platelet transfusions, and 1 in 500,000 red blood cell transfusions.
[Bacterial contamination of platelet concentrates: incidence, significance, and prevention. Blajchman MA; Goldman M. Semin Hematol 2001 Oct;38(4 Suppl 11):20-6.]*
Acute hemolytic reaction. This is a
medical emergency resulting from rapid destruction (
hemolysis) of the donor red blood cells by host
antibodies. The most common cause is
clerical error (i.e. the wrong unit of blood going to the wrong patient). The symptoms are
fever and chills, sometimes with
back pain and pink or red urine (
hemoglobinuria). The major complication is that
hemoglobin released by the destruction of red blood cells can cause
acute renal failure.
*
Anaphylactic reaction. An
anaphylactic (or severe allergic) reaction can occur at a rate of 1 per 30,000-50,000 transfusions. These reactions are most common in people with
selective IgA deficiency (although this condition is often
asymptomatic, and people may not know they have it until an anaphylactic reaction occurs). An anaphylactic reaction is a
medical emergency, requiring prompt treatment, and may be life-threatening.
*
Transfusion-associated acute lung injury (TRALI).
TRALI is a syndrome of acute
respiratory distress, often associated with
fever, non-cardiogenic
pulmonary edema, and
hypotension. It may occur as often as 1 in every 2000 transfusions.
[The association of biologically active lipids with the development of transfusion-related acute lung injury: a retrospective study. Silliman CC; Paterson AJ; Dickey WO; Stroneck DF; Popovsky MA; Caldwell SA; Ambruso DR. Transfusion 1997 Jul;37(7):719-26.] Symptoms can range from mild to life-threatening, but most patients recover fully within 96 hours, and the mortality rate from this condition is less than 10%.
[Transfusion-related acute lung injury: a neglected, serious complication of hemotherapy. Popovsky MA; Chaplin HC Jr; Moore SB. Transfusion 1992 Jul-Aug;32(6):589-92.] For more detail on this syndrome and its possible causes, please see the
dedicated Wikipedia page.
*
Volume overload. Patients with impaired cardiac function (eg
congestive heart failure) can become volume-overloaded as a result of blood transfusion, leading to
edema,
dyspnea (shortness of breath), and
orthopnea (shortness of breath while lying flat).
*
Iron overload. Each transfused unit of
red blood cells contains approximately 250 mg of elemental
iron. Since elimination pathways for iron are limited, a person receiving numerous red blood cell transfusions can develop
iron overload, which can in turn damage the
liver,
heart,
kidneys, and
pancreas. The threshold at which iron overload becomes significant is somewhat unclear, but is likely around 12-20 units of red blood cells transfused.
*
Transfusion-associated graft-vs-host disease (GVHD).
GVHD refers to an immune attack by transfused cells against the recipient. This is a common complication of
stem cell transplantation, but an exceedingly rare complication of blood transfusion. It occurs only in severely immunosuppressed patients, primarily those with
congenital immune deficiencies or
hematologic malignancies who are receiving intensive
chemotherapy. When GVHD occurs in association with blood transfusion, it is almost uniformly fatal.
[Transfusion-associated graft-versus-host disease and blood irradiation. Linden JV; Pisciotto PT. Transfus Med Rev 1992 Apr;6(2):116-23.] Transfusion-associated GVHD can be prevented by
irradiating the blood products prior to transfusion (see
Processing of blood products above).
Please see also:
*
Hospitals services*
The Serious Hazards of Transfusion(SHOT) Treatment of transfusion reactions
The most important step in treating a presumed transfusion reaction is to immediately stop the transfusion (saving the remaining blood and IV tubing for testing) and provide supportive care to the patient. More specific treatments depend on the nature and presumed cause of the transfusion reaction. Most
hospitals and
medical centers have transfusion reaction
protocols, which specify testing of the blood product and patient for
hemolysis, bacterial contamination, etc.
Veterinarians also administer transfusions to animals. Various
species require different levels of testing to ensure a compatible match. have 3 blood types,
cattle have 11, have 12, 16 and
horses have 34.
The rare and experimental practice of inter-species blood transfusions is a form of
xenograft.
There are currently no clinically acceptable
oxygen-carrying blood substitutes for humans; however, there are widely available non-blood
volume expanders and other blood-saving techniques. These are helping doctors and surgeons avoid the risks of disease transmission and immune suppression, address the chronic blood donor shortage, and address the religious objections of
Jehovah's Witnesses and others who have ethical objections to receiving transfused blood.
A number of blood substitutes are currently in the clinical evaluation stage. Most attempts to find a suitable alternative to blood thus farhave concentrated on cell-free hemoglobin solutions.
Blood substitutes could make transfusions more readily available in
emergency medicine and in pre-hospital
EMS care. If successful, such a blood substitute could save many lives, particularly in trauma where massive blood loss results.
*
Blood donation*
Blood doping*
Coombs test*
Phlebotomist*
Intravenous therapy*
Blood substitutes*
Luis Agote*
Norman Bethune
