2021 ISFM Consensus Guidelines on the Collection and Administration of Blood and Blood Products in Cats

Abstract

Practical relevance: Blood and blood products are increasingly available for practitioners to use in the management of haematological conditions, and can be lifesaving and therapeutically useful for patients with anaemia and/or coagulopathies. It is important for feline healthcare that donors are selected appropriately, and transfusions of blood or blood products are given to recipients that will benefit from them. Complications can occur, but can be largely avoided with careful donor management and recipient selection, understanding of blood type compatibility, and transfusion monitoring.

Clinical challenges: Feline blood transfusion, while potentially a lifesaving procedure, can also be detrimental to donor and recipient without precautions. Cats have naturally occurring alloantibodies to red cell antigens and severe reactions can occur with type-mismatched transfusions. Blood transfusions can also transmit infectious agents to the recipient, so donor testing is essential. Finally, donors must be in good health, and sedated as appropriate, with blood collected in a safe and sterile fashion to optimise the benefit to recipients. Transfusion reactions are possible and can be mild to severe in nature. Autologous blood transfusions and xenotransfusions may be considered in certain situations.

Evidence base: These Guidelines have been created by a panel of authors convened by the International Society of Feline Medicine (ISFM), based on available literature. They are aimed at general practitioners to provide a practical guide to blood typing, cross-matching, and blood collection and administration.

Keywords: Transfusion; blood type; cross-match; plasma; transfusion reaction; xenotransfusion.

Figure 1

In-clinic cross-matching – macroscopic appearance. The tube on the right shows a compatible cross-match reaction where the red blood cells (RBCs) float off freely from the centrifuged ‘pellet’ of RBCs when the tube is rotated and rolled. The other two tubes show incompatible cross-match reactions with different grades of RBC agglutination (++ and ++++)

Figure 2

In-clinic cross-matching – microscopic appearance. (a) Microscopic appearance of rouleaux, in which the RBCs resemble stacks of coins; this is not of clinical concern and does not indicate a cross-match incompatibility. (b) Microscopic appearance of agglutination showing a disorganised mass of RBCs in clumps, indicating an incompatible cross-match reaction. Images courtesy of Nic llchyshyn, Dick White Referrals, Six Mile Bottom, UK

Figure 3

Local anaesthetic cream can be applied over the cephalic and jugular veins of the blood donor, after clipping the hair, for desensitisation of the skin before chemical restraint. A light occluding bandage (cellophane is used here) protects the area where the cream has been applied. Approximately 20-40 mins later an intravenous catheter is placed in the cephalic vein for drug administration (low doses of ketamine and diazepam or midazolam, for example). The cat can be placed in its transport carrier or a cosy cat kennel in a quiet room or ward during these 20-40 mins. The jugular vein site will be used for blood withdrawal

Figure 4

Equipment prepared for feline blood collection using an open collection system from a blood donor and administration to the recipient

Figure 5

Blood donor positioning for blood collection largely depends on the preference of the phlebotomist. (a) Here the sedated blood donor is in a sternal position. (b) This sedated donor has been placed in lateral recumbency with the neck extended. Blood pressure is being evaluated and monitored at the tail base, an intravenous catheter has been inserted in the cephalic vein and a whole blood sample has been collected (not shown) to check the donor’s packed cell volume (or haemoglobin concentration). The cat lies on a warming blanket and has a needle inserted to provide subcutaneous fluids after the donation. (c) Here the blood donor is in dorsal recumbency; the jugular vein site is being clipped ready for blood collection, with the jugular vein clearly visible. The venepuncture site is then prepared using an aseptic technique. Image (a) courtesy of Sophie Adamantos; image (c) reproduced, with permission, from Rudd

Figure 6

(a) Appearance of a syringe 1 h after blood collection, having been kept in an upright position at room temperature; the plasma has separated from the RBCs and is at the top of syringe. (b) The plasma from three 20 ml syringes, handled as in (a), has been transferred to a 50 ml human transfer bag. The RBCs remain in the syringes used for blood collection, ready to be transferred into another transfer bag to which 10 ml of an RBC preservative solution (such as saline–adenine–glucose–mannitol [SAGM]) is added to obtain a feline pRBC unit

Figure 7

Closed blood collection system (TEC 724 Kit; Futurlab) licensed for use in cats and in small animals. This is a medical device for veterinary use for collection of known volumes of blood from cats (in three steps of 20 ml each, for example). It is possible to use the device with donor cats of any size by connecting it to a butterfly needle of an appropriate gauge. (a) Equipment set-up before use. (b) Section of the equipment during collection, showing the 20 ml syringe (D) containing donor blood

Figure 8

An inline microaggregate filter (arrow) (Hemo-Nate 18 |jm filter; IMS) has been placed in the administration line from the unit of blood, as close to the patient as possible. A video showing blood collected via an open system being attached to a haemofilter in preparation for transfusion to a recipient is available as supplementary material (see pages 428–429)

Figure 9

(a) Monitoring of the recipient is performed frequently (every 5 mins) during the first 30–60 mins of a transfusion, as this is the most common time for a transfusion reaction to develop. (b) Later in the transfusion, monitoring frequency can be reduced based on the cat’s response and vital parameter data trends

Figure 10

This cat demonstrates facial swelling, which can occur as a transfusion reaction. However, more common reactions include vocalisation, an increase in body temperature, vomiting and salivation