Companion May 2012 - BSAVA

20 | companion
How to select and collect:
feline blood donation
Figure 3: Blood is withdrawn into a 20 ml syringe containing
2.5 ml of cpDA, and regularly mixed during collection. Use of
a three-way tap is highly recommended, although not seen
in this photograph
■■ The phlebotomist raises the vein and inserts the
butterfly needle into the jugular vein; this can be
directed caudally or cranially.
■■ The needle is attached to the three-way tap and
the syringe. The second assistant draws back on
the syringe to collect the blood. The syringe should
be regularly inverted to mix the blood thoroughly
with the CPDA (Figure 3).
■■ Once the first syringe is filled the three-way tap is
closed and the syringe disconnected before being
capped with a sterile needle.
■■ The second assistant then repeats the process
with the second and third syringes.
■■ Once complete, the butterfly needle is removed
and gentle pressure with a dry swab is applied
over the jugular vein. Any sedation is reversed
as necessary.
■■ If desired, the blood can then be transferred
aseptically into the blood collection bag.
The donor should be kept warm and carefully
monitored whilst they recover. Hartmann’s fluid is
administered intravenously – typically 2–3 times the
amount of blood that has been collected. This should
be administered as a 5–10 ml/kg bolus over 20
minutes and then the remainder at 4 ml/kg/h over the
next 2–3 hours. Food should be offered to the donor
as soon as possible.
Other options for collection
Other options are available for the collection of feline
blood, such as the use of a 50 ml syringe with
integrated blood collection bag. Although these may
be easier from the point of view that syringes do not
need to be changed, in the author’s opinion they pose
a number of difficulties. The use of a 50 ml syringe
results in increased pressure in comparison to a
smaller syringe and this can cause the vein to collapse
making blood collection very difficult.
Secondly, if for whatever reason it was not
possible to obtain the full 50 ml of blood, that which is
collected would be over-anticoagulated (in a 50 ml
syringe) and its use would risk complications for the
recipient (such as hypocalcaemia). By using two
20 ml and a 10 ml syringe the pheblotomist is
minimising the risk that any collected blood would
need to be discarded.
Once the blood is collected it should be used as
soon as possible, as the feline blood collection
technique is not closed and there is a risk of bacterial
contamination and growth. For further details on feline
blood administration and transfusion reactions the
reader is directed to ‘How to utilise blood products in
small animals’ companion April 2011 and is reminded
that use of an inline filter is essential (Figure 4).
Feline blood collection and transfusion is
achievable in general practice. It requires minimal
equipment and can often be a life-saving procedure
for the recipient. It is, however, important to follow an
established protocols to protect both the donor and
the recipient. ■
Figure 4: Use of an inline filter (such as a hemo-Nate) is
essential during blood transfusion in cats for removal of
any clots