Blood banking procedures
Type and screen. Whenever possible, samples from both mother and infant should be obtained for initial ABO group and Rh (D) type determination.
Investigations on the maternal sample should include:
ABO group and Rh (D) type.
Screen for atypical red cell antibodies by an indirect antiglobulin technique (IAT).
Investigations on the infant (or umbilical cord) sample:
ABO group and Rh (D) type.
Direct antiglobulin test performed on neonatal red cells.
In the absence of maternal serum, infant's serum is screened for atypical antibodies by an IAT.
Type and cross-match. In addition to ABO group and Rh (D) type, this includes mixing donor red blood cells (RBC) and maternal or infant serum (or both) to inspect for any reaction. Infants rarely make alloantibodies in the first 4 months of life so there is no need to repeat cross-matching during that period unless the patient has been exposed to exchange transfusion or repeated plasma infusions.
Routine blood donation
Voluntary blood donations are from screened donors with a negative history for potentially blood transmissible diseases. All blood donors are tested using serological enzyme immunoassays (EIAs) and nucleic amplification testing for viral risks that include:
HIV: types 1 and 2.
Hepatitis viruses B and C (HBV and HCV).
Human T-cell lymphotrophic viruses (HTLV-I/II).
West Nile virus (WNV).
Trypanosoma cruzi EIA antibodies. Cause of Chagas disease.
Treponema pallidum (syphilis) EIA or microhemagglutination testing is still required.
Testing for the following bloodborne viruses is not routinely done: cytomegalovirus (CMV), hepatitis A virus, hepatitis G virus (HGV; also known as GB virus-C [GBV-C]; no proven disease association), Torque teno virus (TTV or transfusion-transmitted virus; no proven disease association), Epstein-Barr virus (EBV), and human herpes virus 8 (HHV8 or KSHV; associated with Kaposi sarcoma and with multicentric Castleman disease and primary effusion lymphoma in HIV-infected patients).
The residual risks of transfusion per unit transfused are estimated to be:
HIV and HCV: 1 in 1,800,000 units.
HBV: 1 in 220,000 units.
WNV: 1 in 350,000 units (during mosquito-borne community outbreaks).
For perspective, selected comparative mortality odds ratios are anesthesia: 1/7,000–1/340,000; flood: 1/455,000; and lightning strike: 1:10,000,000.
Donor-directed blood products. Blood provided by a relative or friend of the family for a specified infant. This technique cannot be used in the emergency setting because it takes up to 48 h to process the blood for use. No evidence indicates that donor-directed transfusion is safer than blood provided by routine donation. Mothers may not be ideal donors because maternal plasma frequently contains a variety of antibodies (against leukocyte and platelet antigens) that could interact with antigens expressed on neonatal cells. Similarly, transfusions from paternal donors present a risk because the neonate may have been passively immunized against paternal blood cellular antigens (by transplacental transfer of maternal antibodies against paternal antigens).
Autologous blood donation
In adults, safety of transfusion is markedly enhanced with the use of autologous blood collected preoperatively.
The fetoplacental blood reservoir contains a blood volume of approximately 110 mL/kg and 30–50% of this ...
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