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The blood bank types the patient’s
blood (ABO and Rh), screens for antibodies,
and holds the blood. If a rare antibody
is found, the physician usually is notified. If it is likely that
blood will be needed, the T&S order may be changed to a T&C.
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The blood bank does a T&S on the patient’s blood
and matches specific donor units to the patient. The cross-match involves testing the recipient’s
serum against donor blood cells. A T&C usually takes less than
1 h.
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The bank sets up blood immediately and usually holds it for 12
h. For routine requests, the blood is set up at a date and time
that you specify and usually held for 36 h.
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Voluntary blood donation is the mainstay of the blood system
in the United States. Donors usually are > 18 y old, are in good
health and afebrile, and weigh > 110 lb (50 kg). Donors are usually limited
to 1 unit every 8 wk and 6 donations per year. Patients with a history
of hepatitis, HBsAg positivity, insulin-dependent DM, IV drug abuse,
heart disease, anemia, or homosexual activity are excluded from
routine donation. Patients who may have transmissible diseases are
counseled about high-risk behaviors that may put the recipient of
the blood at risk. Donor blood is tested for ABO, Rh, antibody screen,
HBsAg, anti–hepatitis B core antigen, hepatitis C antibody,
anti–HIV-1 and -2, and anti–HTLV-1 and -2.
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Some patients undergoing elective surgery in which blood may
be needed use preadmission autologous blood banking (predeposit
phlebotomy). General guidelines for autologous banking include good
overall health, HCT > 34%, and arm veins that can accommodate
a 16-gauge needle. Patients can usually donate up to 1 unit every
3–7 d until 3–7 d before surgery (individual blood banks
have their own specifications), depending on the needs of the planned
surgical procedure. Iron supplements (eg, ferrous gluconate 325
mg PO tid) are usually given before and for several months after
the donation. The use of erythropoietin in this preoperative setting
is being investigated. Units of whole blood can be held for up to
35 d.
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A relative or friend can donate blood for a specific patient.
This technique cannot be used in the emergency setting because it
takes up to 48 h to process the blood for use.
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This system has some drawbacks: Relatives may be unduly pressured
to give blood; risk factors that would normally exclude the use
of the blood (hepatitis or HIV positivity) become problematic; and
the routine donation of blood for emergency transfusion may be adversely
affected. These units are usually stored as PRBC and released into
the general transfusion pool 8 h after surgery unless otherwise
requested.
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Transfusion-associated graft-versus-host disease (GVHD), a frequently
fatal condition, can be minimized ...