Plus-Hex CLINICAL
Introduction
Transfusion medicine has evolved greatly and RVNs are heavily involved in the storage ( Table 1 ), handling and administration of packed red blood cells ( PRBCs ). PRBC transfusions can save the lives of patients suffering from symptomatic anaemia , but they are not without risk ( Figure 1 , overleaf ).
Among canine patients , 3 – 28 % have a fatal reaction caused by the administration of a blood product ( Blois , 2016 ). Whether this is immunological or nonimmunological , the body will respond in one way or another ( Table 2 ).
RVNs can take appropriate steps to avoid transfusion risks to their patients by staying up to date with evidence-based practice , implementing updated strategies and understanding how blood and its components work .
What is blood ?
Blood is a fluid connective tissue found within the blood vessels of the circulatory system . It consists of blood cells and plasma , which is itself comprised of water , mineral salts and plasma proteins . They each carry out a specific task contributing to the overall role of blood ( Aspinall & Cappello , 2009 ).
Plasma is composed of 90 % water , within which many substances ( including carbon dioxide , glucose , mineral salts and amino acids ) are dissolved and then transported around the body . Together , they act as buffers to maintain the osmotic balance and internal pH of the blood , which allows the body ' s processes to function effectively .
In addition , plasma proteins ( large proteins unable to filter out of circulation ) ensure fluid is retained within the blood vessels , allowing regulation of osmotic pressure by osmosis . Plasma proteins play a major role in the control of blood pressure and blood volume .
Table 1 . Storage of blood products .
Blood product
Storage temperature
Duration of storage
Whole blood 2 – 6 ° C 8 hours maximum
Packed red blood cells
2 – 6 ° C 42 days ( or until expiry date )
Additional notes
• Gently agitate bag once a day to ensure sufficient mixing of red blood cells and anticoagulant and preservative solutions
Fresh frozen plasma
– 18 ° C 1 year ( then stored as frozen plasma )
• Do not store in plastic bags
• Store in a protective padded bag ( usually provided with the unit ) to prevent damage
Frozen plasma – 18 ° C 4 years • As above
Table 2 . Classifications of transfusion reactions that can occur during or after a PRBC transfusion .
Acute immunological
• Anaphylaxis ( type I hypersensitivity )
• Acute haemolytic ( type II hypersensitivity )
• Febrile , non-haemolytic
• Transfusion-related acute lung injury ( TRALI )
Acute non-immunological
• Haemolysis ( e . g . due to incorrect storage of blood unit , or administration – incorrect giving set use )
• Embolism
• Citrate toxicity
• Bacterial contamination
• Transfusion-associated circulatory overload ( TACO )
Delayed immunological
Delayed non-immunological
• Haemolytic ( 3 – 5 days post transfusion ) • Blood-borne Infectious agents ( more likely in feline patients , e . g . FIV / FeLV )
Volume 37 ( 4 ) • September 2022
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