Presenter: Amanda Boag MA VETMB DipACVIM DipACVECC DipECVECC FHEA MRCVS, Clinical Director of Vets Now Ltd. Diplomate of the ACVECC and Founding President of ECVECC
Amanda Boag MA VetMb Dip ECVECC Dip ACVIM Dip ACVEEC FHEA MRCVS has more letters after her name than I ever thought was achievable and, after listening to last week’s webinar covering transfusion medicine, I am in awe of Amanda’s depth of knowledge and expertise. This webinar delivered practical advice on multiple aspects of transfusions which should prove invaluable next time to you are faced with the question: To transfuse or not to transfuse?
As the first successful blood transfusion was carried out dog to dog in 1665, its application in veterinary medicine came surprisingly late partly due to strict regulations on storing blood. However in 2005 the VMD created a framework for licensing blood banks for non-food producing animals, and in 2007 the Pet Blood Bank (PBB) was formed. The creation of the PBB meant that donors could be identified and screened outside of an emergency situation and blood could be taken at the convenience of the owner and vet. Once a unit of blood has been attained it can also be used to maximum benefit as it is split into fresh plasma and packed red cells which can be used separately to benefit two patients.
Deciding whether to use fresh plasma (which is immediately frozen to fresh frozen plasma (FFP)) or packed red cells is very dependent on the patient’s condition. For example a patient suffering from euvolaemic anaemia (reduced red cell mass with normal blood volume) as is seen in AIHA, would benefit from a transfusion with packed red cells. However patients with hypovolaemic anaemia (reduced red cell mass and reduced blood volume) will require their volume to be restored with non-blood fluids initially followed up with packed red cells or whole blood.
Clotting disturbances may also benefit from a transfusion. However Amanda explains that it’s key to understand the underlying cause for the disturbance before reaching for a blood giving set. Clotting factors remain intact in FFP so a patient suffering from a condition with a disturbance in the clotting cascade (associated with PT/PTT changes) wound benefit from a FFP transfusion. However patients suffering from platelet disturbances are unlikely to benefit from any kind of transfusion as only 10-20% of platelets actually survive a transfusion from a donor to recipient.
As well as containing clotting factors, frozen fresh plasma also contains protective inflammatory proteins so may also be useful in patients suffering from sepsis or SIRS where there is an overwhelming inflammatory process.
As a matter of interest it is significantly cheaper to buy a product known as stored frozen plasma. This is defined as either FFP which is greater than one year old, FFP which is not frozen quickly enough, or where FFP is refrozen. This can also be useful in cases or rodenticide toxicity as the vitamin K dependant factors remain intact within stored frozen plasma.
All I’ve mentioned within this blog is just the tip of the iceberg when it comes to the amount of advice and information delivered within Amanda’s webinar. So many questions could be asked about the process of transfusing patients including which patients should be transfused? How and when should these patients be transfused? How and when should we type and cross match our patients and how can we administer a transfusion as safely as possible? Amanda’s webinar delivers the answers to many of these questions and all in the space of one hour.
The Stethoscope (MRCVS)