Blood transfusion procedure - define and information

Blood transfusion is a therapeutic procedure to administer BLOOD or blood products. Blood transfusions may be autologous (self-donated), when the timing of the need for blood permits planning, or allogeneic (volunteer donor). The transfusion of blood or blood products takes place intravenously, through a sterile needle inserted into a VEIN. Receiving a transfusion may take 10 to 20 minutes, depending on the blood product, condition of the recipient’s veins, and the urgency with which the person needs the blood product. Frozen blood products are thawed, and most blood products are brought to body temperature, before administration.

BLOOD RECLAMATION DURING SURGERY

Many hospitals use BLOOD reclamation, also called blood collection, procedures to collect, cleanse, and return to the person during the OPERATION blood lost during a major surgery such as orthopedic, transplant, or OPEN HEART SURGERY. This practice reduces the need for blood transfusions.

Blood Type Compatibility

Though physicians attempted blood transfusions as early as the 17th century, many hazards and failures accompanied the procedure until researchers discovered blood types in the early 1900s. The techniques to allow consistent detection of BLOOD TYPE, called type and cross-match, finally became available in the 1950s. Doctors then were able to routinely match the blood type and rhesus (Rh) factor of donors to recipients and blood transfusions became a standard element of medical care. Transfusion of whole blood and cellcontaining blood products such as red blood cells (erythrocytes) requires blood type compatibility between donor and recipient; transfusion of other blood products such as PLASMA, ALBUMIN, and CLOTTING FACTORS does not.

Blood transfusion Reaction

Blood type incompatibility, though uncommon in transfusion, can lead to reactions spanning the spectrum from mild to fatal. Comprehensive type and cross-match procedures of donor and recipient blood types prevent most blood incompatibility, though situations of extreme urgency (in which thorough type and cross-match is not possible) and occasionally human error result in incidents in which a blood transfusion recipient receives blood that is incompatible with his or her blood type. As well, blood may contain antigens that conventional type and cross-match procedures do not detect. People who have health conditions (such as SICKLE CELL DISEASE, THROMBOCYTHEMIA, and HEMOPHILIA) that require frequent or numerous transfusions often develop antibodies to other antigens commonly present in blood, increasing their risk for transfusion reaction.

Symptoms of transfusion reaction develop within 24 hours of receiving blood, though often begin during the transfusion, and may include

• FEVER
• chills
• URTICARIA (hives)
• PAIN in the lower back
• generalized physical discomfort

Mild transfusion reactions resolve with minimal medical intervention, such as medications to relieve fever and discomfort. Moderate to severe transfusion reaction may require CORTICOSTEROID MEDICATIONS to thwart the body’s IMMUNE RESPONSE. Rarely, transfusion reaction can progress to thromboembolism that blocks the flow of blood through key arteries, including in the LUNGS to cause PULMONARY EMBOLISM, and cardiovascular SHOCK. Such severe complications are potentially fatal and require emergency medical treatment for the specific complications.

Transfusion-Transmitted Infections

Despite comprehensive screening tests and procedures, blood-borne infections remain a risk of blood transfusions. Screening can detect pathogens and antibodies that indicate the presence of infection for a number of blood-borne health conditions including HIV/AIDS, HEPATITIS (HVA, HVB, HVC), and SYPHILIS. Screening tests are only marginally successful at detecting other infections such as CYTOMEGALOVIRUS (CMV) and human T-lymphotropic virus (HTLV). Other pathogens are able to escape detection, notably those responsible for west Nile virus, MALARIA, and CREUTZFELDT-JAKOB DISEASE (CJD) as well as various BACTERIA.

Nearly all infections involve a time gap, the infection’s INCUBATION PERIOD, during which the INFECTION is present in the blood though has not yet caused symptoms or antibodies. The risk for transfusion-transmitted infections is highest for blood donated during this phase of infection. Some blood banks are using a technology called nucleic acid testing (NAT), also called nucleic acid amplification testing, that can detect a virus’s genetic material in the blood. This allows detection of the infection before the IMMUNE SYSTEM develops antibodies, shortening the window of time during which the PATHOGEN is present and infectious but undetectable.

See also BLOOD AUTODONATION; BLOOD DONATION; BONE MARROW DONATION; BONE MARROW TRANSFUSION; DISSEMINATED INTRAVASCULAR COAGULATION (DIC); HEMAPHERESIS; STEM CELL.

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