Autotransfusions, cell salvage, xenotransfusions and transfusion in other species

Question 1

What is xenotransfusion in veterinary medicine, and which species is commonly involved in this procedure?

Answer 1

Xenotransfusion is the transfusion of blood from one species to another. In veterinary medicine, it often involves cats receiving a transfusion of dog red cells or whole blood, although it can be performed in other species.

Question 2

What are the blood types in cats and why is blood typing essential for feline transfusions?

Answer 2

Cats have blood types A, B, and AB. Blood typing is crucial due to the presence of naturally occurring alloantibodies, which, if mismatched, can cause severe acute or delayed haemolytic reactions during transfusion.

Question 3

Why is the blood transfusion process considered more challenging in feline patients compared to dogs?

Answer 3

Feline blood transfusions are considered challenging due to smaller size, physiological differences, and the prevalence of naturally occurring alloantibodies. Blood donation in cats often requires sedation, and blood typing is essential even for the first transfusion.

Question 4

What challenges are outlined for the collection and supply of feline blood products, as mentioned by Deschamps et al. (2022)?

Answer 4

Challenges include the lack of a closed collection system for felines, difficulties in aspiration techniques impacting cell quality, higher costs compared to canine blood, and the lower demand for feline blood products, which may discourage blood banks

Question 5

Why is informed owner consent crucial before performing a xenotransfusion, and what risks should be highlighted?

Answer 5

Informed owner consent is essential to prevent potential litigation. Risks, including acute anaphylaxis with a 66% mortality rate in sensitized cats, delayed haemolytic transfusion reactions, and associated clinical complications, should be clearly communicated.

Question 6

What is emphasized regarding the patient’s veterinary record after a xenotransfusion, and why?

Answer 6

It is crucial to highlight a xenotransfusion in the patient’s veterinary record and emphasize its importance to the owner. This ensures that the information is passed on to future veterinary surgeons who may treat the cat.

Question 7

When can a delayed haemolytic transfusion reaction be expected post-xenotransfusion, and how should it be managed?

Answer 7

A delayed haemolytic transfusion reaction is expected within 4-6 days post-xenotransfusion. If non-regenerative anemia persists, follow-up transfusions with feline cells may be necessary.

Question 8

What practical considerations are highlighted for the administration of a xenotransfusion, and what volumes are typically advised by the International Society for Feline Medicine (ISFM)?

Answer 8

There are no specific guidelines, so xenotransfusion follows homologous transfusion guidelines. ISFM advises volumes of 25 ml PRBC and 30-50 ml whole blood, with caution even for seemingly compatible transfusions as pre-xenotransfusion cross-matching may not reliably predict adverse reactions.

Question 9

What is autotransfusion, and who was credited with the first known documented autotransfusion?

Answer 9

Autotransfusion, also known as autologous transfusion, involves re-infusing blood derived from the individual themselves. The first known documented autotransfusion was credited to Dr. James Blundell in 1818, who initially experimented on canines before humans.

Question 10

What are the types of autotransfusion, and briefly explain each?

Answer 10

Pre-operative autologous donation (PAD): Involves collecting blood before elective surgery for anticipated blood loss.
Acute normovolaemic haemodilution (ANH): Blood is collected before surgery and immediately replaced with crystalloid and colloid solutions.
Direct re-infusion: Simple technique for intra-cavitary bleeding in veterinary medicine.
Cell salvage: Complex process where shed blood during surgery is collected, processed, and concentrated erythrocytes are transfused back to the patient.

Question 11

What is the purpose of pre-operative autologous donation (PAD), and what are some challenges associated with its use?

Answer 11

PAD is used before elective surgery with anticipated blood loss. Challenges include changes in surgery scheduling, potential for patient-developed anemia, and storage lesion formation, leading to declining popularity in human medicine.

Question 12

Explain the process of acute normovolaemic haemodilution (ANH) and its application.

Answer 12

ANH involves collecting blood immediately before surgery and replacing the patient’s circulating volume with crystalloid and colloid solutions. This dilutes the blood lost during surgery, reducing red cell and clotting factor concentrations.

Question 13

Describe the direct re-infusion technique used in veterinary medicine and its reported complications.

Answer 13

Direct re-infusion involves collecting blood from intra-cavitary bleeding, anticoagulating if necessary, and re-infusing after passing through a blood filter. Reported complications include hypocalcemia, haemolysis, and coagulopathy.

Question 14

What factors should be considered when determining the appropriateness of autotransfusion in cases of haemorrhage due to neoplasia?

Answer 14

There is debate about the appropriateness of autotransfusion in neoplasia-related haemorrhage, considering the potential risk of increasing metastatic disease. This decision should be carefully discussed with the owner.

Question 15

List the equipment required for blood collection during centesis for autotransfusion.

Answer 15

Ultrasound
Clippers
Swabs and skin disinfectant solution
Sterile gloves
Fenestrated drape
Centesis catheter or similar
Three-way tap
Sterile syringe caps
Needle-free valve
Intravenous extension set
Syringes (pre-filled with anticoagulant if necessary)
Blood collection bag containing anticoagulant
Blood administration set or blood filter

Question 16

Explain the contraindications to cell salvage in autotransfusion.

Answer 16

Contraindications to cell salvage include sepsis, situations where not enough blood can be collected, and when processing times will be too long. In small animals, a minimum collection time of 30 minutes is recommended for sufficient blood production.

Question 17

What are the advantages and disadvantages of direct re-infusion in autotransfusion?

Answer 17

Advantages:

Large volumes can be collected and re-infused rapidly.
No specialist equipment is required.
Simple and inexpensive.
Guarantees blood compatibility.
Disadvantages:

Risk of contamination during blood collection.
Potential organ perforation during centesis.
Blood may contain clots, neoplastic cells, or emboli.
Risk of haemolysis due to erythrocyte damage.

Question 18

What are the advantages of autotransfusion in veterinary medicine?

Answer 18

Lifesaving in emergencies where compatible blood products are unavailable.
No need for blood typing or cross-matching.
Decreased risk of immune-mediated transfusion reactions.
Can be performed pre, intra, or post-operatively.
Does not deplete the stock of blood products.
Replaces lost blood constituents in the same proportion.
Cost-efficient for owners of large-breed dogs.

Question 19

What are the eight equine blood types, and how are they denoted?

Answer 19

The eight equine blood types are denoted by the following capital letters: A, C, D, K, P, Q, U, and T.

Question 20

How many possible equine erythrocyte phenotypes exist, and why is there no universal equine blood donor?

Answer 20

There are a possible 400,000 equine erythrocyte phenotypes. There is no universal equine donor due to the diversity in blood types and the absence of naturally occurring antibodies in approximately 90% of horses.

Question 21

What is Donkey factor, and why is it significant in blood donation between horses and donkeys?

Answer 21

Donkey factor is an erythrocyte antigen specific to donkeys and mules, not expressed in horses. Donkeys cannot donate to horses due to the risk of sensitization and hemolysis. However, the reverse (horse to donkey) is considered acceptable.

Question 22

What is Neonatal Isoerythrolysis (NI), and what blood types are commonly associated with it in horses?

Answer 22

NI occurs when foals born to mares inherit antigens that cause sensitization. It is associated with Aa and Qa antigens, but also with Qrs, Qb, Qc, Da, Db, Dc, Ka, Pa, and Ua.

Question 23

What is recommended to prevent NI in foals, and how is incompatibility tested after birth?

Answer 23

Alloantibody testing of the mare’s serum is recommended before foaling. After birth, a major cross match (mare serum and foal RBC) and Coombs test on the foal are conducted. Additionally, the jaundice foal agglutination test is performed.

Question 24

What factors should be considered when selecting an equine blood donor?

Answer 24

A suitable equine blood donor should be healthy, weigh at least 450kg, be skeletally mature, have no reproductive history, possess a good temperament, be transfusion naïve, and be up-to-date on vaccinations.

Question 25

What are the recommended screening tests for equine blood donors, and how often should they be conducted?

Answer 25

Equine blood donors should be screened annually for equine infectious anaemia (EIA), equine viral arteritis (EVA), and hepaciviruses. In endemic regions, six-monthly testing is preferred, and additional tests for brucellosis, piroplasmosis, glanders, and dourine are recommended.

Question 26

How is the total blood volume calculated in horses, and what is the recommended maximum blood donation volume?

Answer 26

Total blood volume is calculated as 8% of the horse’s body weight (in liters). Horses can safely donate a maximum of 20% of their total blood volume, with 15% preferable.

Question 27

What are the indications for red cell transfusions in horses?

Answer 27

Red cell transfusions are indicated in cases of acute blood loss exceeding 30% of the horse’s total blood volume, PCV dropping below 18%, traumatic injuries, mycotic infections, and chronic blood loss.

Question 28

What precautions should be taken during blood transfusion in horses, and what adverse reactions can occur?

Answer 28

Precautions include product inspection, warming/thawing, administration into a dedicated line, sterile technique, passage through a blood filter, a four-hour time to product discard, and recipient monitoring. Adverse reactions can include febrile and allergic reactions, with a reported incidence of 16%.

Question 29

What is the current state of knowledge regarding blood types in small mammals, reptiles, and avian species?

Answer 29

There is little published information on blood types in these species, except for chickens. Genome sequencing suggests some amphibian and reptile species may share blood group antigens with humans.

Question 30

What is unique about the blood groups of ferrets based on the study by Manning and Bell (1990)?

Answer 30

Ferrets, among studied species, show no evidence of naturally occurring erythrocyte alloantibodies. Red cell transfusions in ferrets have failed to produce any erythrocyte antibodies, suggesting either no blood groups or weak ones.

Question 31

What assumptions are made in the absence of comprehensive knowledge about blood groups in exotic species?

Answer 31

The assumption is made that a donor of the same species should be suitable for transfusion. Performing a major cross match before red cell transfusion is recommended to detect incompatibilities.

Question 32

What are the indications for blood transfusion in exotic species, and what typical mechanisms lead to these indications?

Answer 32

Indications include hemorrhage, anemia, coagulopathies, and hypoproteinemia. Typical mechanisms include parasitism, infections, neoplasia, renal disease, and nutritional deficiencies.

Question 33

Why might triggers for blood transfusion be more conservative in exotic species, and what are some typical triggers?

Answer 33

Conservative triggers are due to the lack of availability of blood products and the difficulty in finding donors. Typical triggers include a rapid decrease in PCV below 15%, lack of response to conventional fluid resuscitation, ongoing hemorrhage, collapse due to blood loss, and a loss of 30% (mammals) or 40% (avians) of blood volume.

Question 34

How is blood collection done in exotic species, and what anticoagulants are commonly used?

Answer 34

Blood is collected directly into an anticoagulant-lined syringe. Citrate-based anticoagulants are suitable, with a ratio of 1 ml anticoagulant to 7-9 ml whole blood. Heparin can also be used but should be given soon after collection.

Question 35

How is blood administration done in exotic species, and what considerations are essential during transfusion?

Answer 35

Blood transfusions are given intravenously or intraosseously. The blood should be warm, filtered, and administered slowly, with close monitoring. Administration sites vary among species, and the transfusion should be completed in under four hours.

Question 36

What is the recommended volume of blood to transfuse in exotic species, and how is it estimated?

Answer 36

The volume of blood to transfuse is estimated at 20 ml/kg, increasing PCV by approximately 10%. For reptiles and avians, an initial rate of 2.5-5 ml/kg/hr is recommended, and for small mammals, a protocol similar to stable dogs is used.

Question 37

What parameters should be monitored during and after a blood transfusion in exotic species, and why is empirical data lacking for transfusion triggers?

Answer 37

Vital signs appropriate for the species should be monitored, including temperature, pulse, respiratory rate, mucous membrane color, and more. Empirical data is lacking, and the decision to transfuse should be made by someone experienced with the species, considering various parameters.

Question 38

What ABO system is present in monkeys and apes, and what do A and B represent?

Answer 38

Monkeys and apes have an ABO system similar to humans. A and B represent specific antigens, and O represents erythrocytes without A or B

Question 39

How are monkey ABO group antigens different from humans, and where are these antigens located?

Answer 39

Monkey ABO group antigens are not on the erythrocyte surface but are on epithelium, vascular endothelium, and in some secretions, including saliva.

Question 40

What method is commonly used for blood typing in primates, and how does it differ from canine and feline blood typing?

Answer 40

A gel test technique is used for AB typing, focusing on identifying anti-A/B serum alloantibodies in the plasma, unlike canine and feline tests that look for the presence of red cell antigens.

Question 41

Why might blood typing be less utilized in veterinary settings for primates, and what is recommended for previously transfused individuals?

Answer 41

Compatibility is often evaluated with a major and minor cross match. Transfusion-naïve individuals may be transfused without prior compatibility testing, but cross-matching is recommended for previously transfused individuals.

Question 42

What condition in elephants necessitates transfusions, and what are the characteristics of Elephant Endotheliotropic Herpes Virus-Haemorrhagic Disease (EEHV-HD)?

Answer 42

Transfusions in elephants are used to treat EEHV-HD, characterized by widespread vasculopathy, endothelial cell destruction, hemorrhage, and coagulation pathway activation.

Question 43

In the absence of commercial blood banks, how is blood collected and stored for elephants in group settings?

Answer 43

In group settings, whole blood is collected, separated, and stored on-site. Platelet-rich plasma is considered a supportive therapy, and fresh frozen plasma can be stored for immediate use.

Question 44

Why is blood typing and cross-matching recommended for transfusions in elephants, and what is the common concern during pregnancy?

Answer 44

Blood typing and cross-matching are recommended due to potential anti-type antibodies transfer during pregnancy. A minor and major cross match are advised before transfusion.

Question 45

What blood group system do wild cats, including Puma lineage and wild domestic cat lineage, share with domestic cats?

Answer 45

Wild cats, like domestic cats, have the A/B blood group system. Studies suggest strong A/B prevalence in specific lineages.

Question 46

How reliable are A/B typing kits for domestic cats in identifying blood types in non-domestic cats, and what is recommended for donor-recipient compatibility?

Answer 46

A 2022 study suggests A/B typing kits may not reliably identify types in non-domestic cats. Cross-matching is recommended to establish donor-recipient compatibility.

Question 47

Why might Galapagos Sea Lions develop naturally occurring antibodies, and what is suggested by the cross-match test results?

Answer 47

Fighting between males may expose sea lions to conspecific erythrocyte antigens, leading to naturally occurring antibodies. Cross-match results suggest potential alloantibodies.

Question 48

How was a transfusion successfully administered to a camel, and under what circumstances can whole blood transfusions be beneficial for sharks?

Answer 48

A successful camel transfusion treated failure of passive immunity transfer. Sharks benefit from whole blood transfusions for severe bleeding following bite wounds.

Question 49

What is the purpose of using whole blood transfusions in stranded turtles, and what did the cross-match study reveal about cross-species transfusions?

Answer 49

Whole blood transfusions aid in the rehabilitation of stranded turtles. The cross-match study suggested incompatibilities between green turtles, cautioning against cross-species transfusions.

Question 50

How many blood group factors and systems have been identified in alpacas?

Answer 50

Six blood group factors (A, B, C, D, E, F) have been identified, assigned to five blood group systems (A, C, D, E, F).

Question 51

In the UK, what organization handles the processing and supply of alpaca blood products, and what restrictions are in place for supply?

Answer 51

Pet Blood Bank UK handles the processing and supply. The supply is restricted to the same herd from which the whole blood was collected to prevent disease transmission.

Question 52

What conditions in alpaca crias are the main indications for administering fresh frozen plasma (FFP), and when is a red cell transfusion recommended?

Answer 52

FFP is used for failure of passive transfer (FPT) of immunity in crias. Red cell transfusion is recommended for chronic anaemia when PCV reaches 10-15% and at 15-20% following an acute drop in PCV.

Question 53

Why is typing not typically utilized for alpaca transfusions, and what is recommended before a further transfusion in sensitized recipients?

Answer 53

Typing is not utilized because alpaca erythrocytes are not prone to agglutination. A cross-match is recommended after a previous transfusion and before a further transfusion to prevent sensitization.

Question 54

How many blood types have been identified in goats, and what is the guidance for red cell transfusions in goats?

Answer 54

At least five blood types (A, B, C, M, J) have been identified in goats. Red cell transfusions are recommended similarly to camelids, and goats can tolerate up to 50% blood volume loss.

Question 55

Is blood typing readily available for goats, and when is a cross match recommended in transfusion-naïve individuals?

Answer 55

Blood typing is not readily available. A cross match is not typically performed in transfusion-naïve individuals but is recommended in previously transfused goats.

Question 56

How many bovine blood groups are recognized, and why is cross matching recommended for previously transfused individuals?

Answer 56

Eleven bovine blood groups are recognized. Cross matching is recommended for previously transfused individuals as anti-J antibodies can develop after the first transfusion.

Question 57

What are the indications for red cell and plasma transfusions in cattle, and how is total blood volume calculated for large animals?

Answer 57

Indications are similar to other large animals. Total blood volume is calculated as 8% of body weight in kilograms.

Question 58

How many blood group systems are identified in sheep, and what is similar to the J system in cattle?

Answer 58

Seven blood group systems are identified. The R system in sheep is similar to the J system in cattle, a soluble antigen not constitutively expressed in the erythrocyte membrane.

Question 59

How many internationally recognized blood groups are there in pigs, and what is known about porcine alloantibodies?

Answer 59

There are 16 internationally recognized blood groups in pigs. Porcine alloantibodies are mostly agglutinins and uncommonly haemolysins.

Question 60

What general principles can be applied to pig transfusions, and what is the level of complexity for E and M blood groups in pigs?

Answer 60

General principles from other species can be applied. E and M blood groups in pigs have a similar level of complexity with many type-specific factors.