An "autologous"
donation occurs when a person donates his or
her own blood for personal use. This means
that, since the blood is not be be used for
anyone else, then units positive for
infectious agents and units with irregular
blood group antibodies are still acceptable
for autologous donation.
However,
because of the potential risk for a clerical
error with mistransfusion of an autologous
unit in the inventory, units positive for
hepatitis B (HBsAg) and human
immunodeficiency virus (HIV) are not allowed
into the Blood Bank. If an autologous unit
is collected but not used by the
patient-donor, then it is destroyed.
There are
three other ways, aside from the "predeposit"
of blood as outlined above, to make use of
the patient's own blood:
1.
Hemodilution: the patient's
blood is collected prior to surgery and
replaced with a plasma expander. The theory
is that any bleeding during surgery will
lose fewer RBC's. Then the previously
collected, higher hematocrit blood can be
given back to the patient following surgery.
2.
Cell Saver: this device is
used to collect blood in the operative field
during surgery, wash it, and return it with
saline to the patient. This will work as
long as the operative field is not
contaminated with bacteria or with malignant
cells.
3.
Wound drainage: blood is
collected from cavities (such as a joint
space into which bleeding has occurred) and
returned through a filter (which removes big
items like thrombi and tissue fragments, but
does not remove inflammatory chemical
mediators or cytokines).
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A "directed"
donation occurs when the potential recipient
of blood or blood products designates
certain persons to donate specifically for
his or her use. In general, blood collected
from directed donations is no safer than
that of the general blood supply because of
the stringent screening and testing of
volunteer donors that ordinarily occurs.
Additional
problems with directed donations include:
1.
Confidentiality of the donor is difficult to
maintain.
2.
The donor
may not want to answer the exclusionary
questions of the blood safety form and
health questionnaire properly.
3.
This
procedure is not cost-effective.
4.
There are
contraindications, such as an increased risk
for transfusion-asscociated graft versus
host disease (TAGVHD), alloimmunization of
potential recipients of transplants, and
increased risk for hemolytic disease of the
newborn in mothers receiving blood from
fathers.
There is a
small but significant risk for TAGVHD in
persons receiving blood from relatives,
because of similar genetic makeup. TAGVHD is
fatal, with no effective treatment. Thus,
all units of blood collected by directed
donation typically undergo gamma irradiation
to destroy any white blood cells that could
cause TAGVHD. This adds significantly to the
cost of blood processing, and these units
must be discarded if not used within 24
hours.
Patients who
request directed donations from family and
friends often do not realize the pressure
such a request can place upon an individual
who does not qualify to donate blood. That
individual, if answering the questions in
the interview properly, will be excluded
from donating, which will result in family
members asking questions about why the blood
was not accepted. The alternative is
answering the questions untruthfully and
compromising the safety of the blood
products collected.
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