1-46. MASSIVE TRANSFUSION
a. Definition of Massive Transfusion.
(1) Massive transfusion may be defined as rapid infusion of blood in
amounts approaching or exceeding replacement of the recipient's total blood volume,
within a 24-hour interval. This is encountered in surgical and medical emergencies in
cardiac and vascular surgery, especially when extracorporeal circulation is used. The
exchange transfusion of an infant is also a massive transfusion.
(2) An antibody present in the original recipient sample may be weakened
or not detectable in a subsequent posttransfusion specimen because of the dilution
effect of massive transfusion. It is especially important, in this case, to select blood that
is negative for the corresponding antigen by typing the units with a reagent antiserum
b. The Planned Massive Transfusion.
(1) Obtain a specimen of the patient's blood well in advance of the
scheduled surgery for ABO, Rh typing, and antibody-detection test. Antibodies,
detected, should be identified at this time. If hypothermia is to be used, special care
must be given to identification of antibodies detected at room temperature.
(2) Obtain a sufficient amount of blood from the patient for the compatibility
tests 72 hours or less before the scheduled transfusion. Frozen serum collected more
than 72 hours prior is not adequate.
(a) lnterdonor compatibility testing is not required. Donor units
containing unexpected antibodies should not be used.
(b) If additional units are required within a 72-hour period,
crossmatching may be done with the immediate pretransfusion sample. Any time, after
that, a new sample must be obtained from the patient.
1-47. TECHNIQUES FOR CROSSMATCHING
(1) There are a variety of techniques available for crossmatching. Since
some antibodies will react by certain methods but not by others, techniques should be
chosen to include at least two incubation temperatures and media.