Retrospective evaluation of unexpected events during collection of blood donations performed with and without sedation in cats (2010-2013)

Why some canine and feline blood donors do not make the cut: A cohort study

BACKGROUND

While there has been extensive investigation into the selection and retention of human blood donors, veterinary research in this area is limited. This study aimed to identify the reasons for the rejection and withdrawal of canine and feline blood donors from a blood donation programme.

METHODS

Records of cats and dogs presenting as prospective blood donors and/or donating between 2014 and 2019 were analysed. Reasons for rejection at sign-up were categorised into medical and temperament. Reasons why animals left before retirement age were categorised into medical, temperament and owner related.

RESULTS

Data from 362 dogs and 134 cats were analysed. Cats (20.8%) were more likely to be rejected than dogs (5.2%) at sign-up, mostly due to medical reasons. Both species often left the blood donor service early due to temperament reasons. Owner and medical reasons for leaving early were also common.

LIMITATION

This was a retrospective study with subjective assessment of temperament.

CONCLUSIONS

Inability to donate due to temperament and medical reasons is common. When recruiting blood donors, it should be recognised that a fairly high proportion will not be successful. Owner understanding and motivation are essential to ensure successful selection and retention of donors, which allows amortisation of recruitment costs.

Hematological Parameters from the Feline Blood Donor to the Blood Unit: What Changes Are to Be Expected?

Simple Summary

Feline blood donation requires sedation to allow for good blood collection, avoiding venous damage and unnecessary donor stress. In the present study, we describe the variation of hematological parameters in a population of healthy blood-donor cats that underwent the same sedation protocol, including medetomidine, alfaxalone, and butorphanol. Significant differences in hematological parameters were observed between unsedated and sedated cats; particularly, the mean red blood cell count, hemoglobin concentration, hematocrit value, mean corpuscular volume, and red blood cells distribution width were significantly lower in sedated cats than in conscious ones, thus confirming that sedation is a critical procedure in cats. No significant differences for the main hematological parameters were observed between sedated cats and feline blood units, suggesting that the dilution with the conservative–anticoagulant solution (ratio 1:7) exerts negligible effects on these parameters with respect to samples of sedated animals.

Abstract

Feline blood donation requires sedation to allow for good blood collection, avoiding venous damage and unnecessary donor stress. In the present study, we describe the variation of hematological parameters in a population of 74 healthy blood-donor cats that underwent the same sedation protocol, including medetomidine, alfaxalone, and butorphanol. Changes in hematological parameters were evaluated in blood samples collected from conscious cats (group A), sedated cats (group B), and feline whole-blood units (FBUs) (group C). Significant differences were observed between unsedated and sedated cats: the mean RBC count, HGB, HCT, and RDW were significantly lower in sedated cats than in conscious ones, with a difference of 17.95%, 18.42%, 28.21%, and 10.00%, respectively. In accordance with previously reported data, our results confirm that sedation is a critical procedure in cats that can affect most of the hematological parameters. The second finding of our study is that no significant differences for the main hematological parameters were observed between sedated cats and FBUs, thus suggesting that the dilution with the conservative–anticoagulant solution exert negligible effects on these parameters with respect to samples of sedated animals. This hematological change must be taken into consideration since such parameters are important to define the quality of FBUs.

Feline blood donation adverse reactions: classification and description of acute and delayed reactions in a donor population

OBJECTIVES

This article aims to analyse the safety of feline blood donation by describing the frequency and nature of any adverse reactions and their causes, as well as propose measures to decrease the incidence of adverse reactions.

METHODS

In this prospective study, any blood donor adverse reactions detected by the clinical staff during and immediately after donation were recorded. The owners of the cats were also surveyed by a veterinary practitioner or veterinary nurse 5 days after donation, using a predefined questionnaire to assess for any clinical or behavioural changes. Data were collected between January 2019 and March 2020 from blood donors enrolled in an animal blood bank programme.

RESULTS

Of 3690 blood donations from 1792 feline donors assessed, post-donation reactions were reported in 1.14% (n = 42): 0.22% (n = 8) were acute reactions, which included weakness, pallor, tachypnoea and open-mouth breathing; and 0.92% (n = 34) were delayed post-donation reactions, with 0.16% involving cutaneous (haematomas and skin rashes, n = 6), 0.68% involving behavioural (n = 25) and 0.08% involving digestive (emesis and inappetence, n = 3) signs.

CONCLUSIONS AND RELEVANCE

The low incidence of post-donation reactions in this study is encouraging, suggesting that a well-established protocol and competent staff can help to ensure a high level of safety in a feline donor programme and, in turn, increase the confidence of cat owners.

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

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.

Comparison of a closed system and an open system for blood collection in feline donors

OBJECTIVES

This research aimed to evaluate the performance of a closed blood collection system and to compare it with an open system in terms of feasibility, tolerability by the donor, quality of blood collected and bacterial contamination.

METHODS

Eight feline blood donors were prospectively and randomly subjected to both collection methods. Heart rate (HR), respiratory rate (RR) and blood pressure (BP) were evaluated before sedation, after sedation and after blood collection. The duration of the donation, the formation of a hematoma, and the degree of hemolysis and packed cell volume (PCV) of each blood unit were evaluated. Aliquot samples were aseptically collected from each unit and tested for bacterial contamination by culture and PCR on days 0, 14 and 28 of storage.

RESULTS

There was no significant difference between collection methods for HR and RR at any time point. Before sedation, the mean systolic BP was significantly higher with the closed system (closed 169 mmHg, open 137 mmHg; P = 0.003). The average duration of collection was significantly shorter with the closed system (closed 3 mins 10 s, open 8 mins; P = 0.035); however, the prevalence of a successful blood collection with a single venipuncture and hematoma formation were not significantly different between systems. The mean unit PCV was significantly higher with the open system (closed 31%, open 34%; P = 0.026). On bacterial culture, 15/16 units were negative at all time points (closed 7; open 8). Using PCR, 5/16 units were positive for Ralstonia species for at least one time point (closed 3; open 2).

CONCLUSIONS AND RELEVANCE

Our designed closed system appears to be well adapted to feline blood collection and was well tolerated by the donors, performing similarly to an open system, and could represent a valuable clinical device for the development of a feline blood bank, namely feline blood storage.

Xenotransfusion of canine blood to cats: a review of 49 cases and their outcome

OBJECTIVES

To describe the use of a xenotransfusion protocol, the outcome of xenotransfusion in recipient cats and to assess owner memory of the xenotransfusion.

MATERIALS AND METHODS

Cats administered xenotransfusions in two hospitals between January 2016 and July 2018 were included. Adherence to xenotransfusion protocol, cause of anaemia, blood type, packed cell volume (PCV), transfusion volume, transfusion reactions, PCV 12 hours after transfusion and survival to discharge were recorded. Owners of surviving cats were questioned to assess if they remembered that a xenotransfusion had been performed.

RESULTS

Forty-nine cats underwent the xenotransfusion protocol. The most common causes of anaemia were surgical blood loss (n = 17), immune-mediated haemolytic anaemia (n = 14) and neoplasia (n = 14). Median PCV before transfusion was 10%. Six cats (12%) had febrile non-haemolytic transfusion reactions. Median PCV 12 hours after transfusion was 25%. Ten cats (20%) died or were euthanased within 24 hours of xenotransfusion. A delayed haemolytic transfusion reaction occurred in 25 of 39 (64%) cats manifesting as icterus in 15 cats after a median of 1.9 days and haemolytic serum in 19 cats after a median of 2 days. Of the 18 cats alive at 1 week after discharge, 15 (83%) were still alive at a median of 173 days after xenotransfusion. All owners contacted remembered that their cats had received a xenotransfusion.

CLINICAL SIGNIFICANCE

Xenotransfusion of canine packed red blood cells to cats is possible but haemolysis should be expected between 1 and 6 days after transfusion.

Pet owners' awareness of animal blood banks and their motivations towards animal blood donation

The general public's awareness of, and attitude to, canine and feline blood donation is poorly understood. Increasing understanding of pet owners' thoughts about donation may allow more effective blood donor recruitment. The aims of this study were to investigate pet owners' awareness of small animal blood donation and their attitude and motivations regarding their pet being a blood donor. A mixed methods approach was used, with data collected from 158 pet owners attending a first-opinion veterinary clinic using a written questionnaire of closed and open questions. Most owners were unaware that dogs and cats could donate blood (70 per cent). However, 89 per cent stated they would be willing to let their pet donate blood if they were suitable. This was more likely if the owner did not work full time and less likely if they were aged over 71 years. Thematic analysis of owners' motivations and deterrents towards pet blood donation resulted in four key themes: 'Beneficence', the desire to help others; 'Necessity of service', a recognition of the requirement for blood products; 'Reciprocity', a hope that if they participated this would result in blood products being available for their pet; and 'Reservations and concerns'.

Twelve autologous blood transfusions in eight cats with haemoperitoneum

OBJECTIVES

The objectives of this study were to describe the clinical use and outcome of autologous transfusions in cats with intracavitary haemorrhage.

METHODS

A retrospective descriptive study was performed. Computerised medical records of a single referral centre were searched for cats receiving an autotransfusion. Medical records were evaluated for underlying disease process, autotransfusion technique, autotransfusion volume, time period over which the autotransfusion was given, packed cell volume (PCV) pre- and post-autotransfusion, percentage rise in PCV, use of other blood products and any complications of the procedure. Survival to discharge and survival at 2 months was documented.

RESULTS

Between July 2012 and March 2018 a total of 12 autotransfusions were performed in eight cats. All patients were diagnosed with haemoperitoneum. Four of the eight cats were diagnosed with abdominal neoplasia, three had postoperative haemorrhage and one had a traumatic haemoperitoneum. Three cats received more than one autotransfusion. Blood was collected using a 23 G butterfly catheter and 20 ml syringe in 7/12 collections, a 23 G needle and 20 ml syringe in 2/12 collections and directly into syringes from the open abdomen at the time of surgery in 3/12 collections. A median volume of 50 ml (range 25-80 ml) was collected and administered, meaning a median volume of 16.5 ml/kg (range 9-26 ml/kg) was administered. The autologous transfusions were given over a median of 3 h (0.25-6 h). Five cats were given another blood product alongside the autotransfusion. Median percentage PCV increase was 5% (range 1-7%). Anticoagulant was used in 5/12 autotransfusions. No clinically relevant adverse effects were reported. Six of the eight cats survived to discharge. Two month survival was 60% (3/5).

CONCLUSIONS AND RELEVANCE

Autologous transfusion appears to be a safe and effective technique for stabilising cats with haemoperitoneum. This technique allows rapid and cheap provision of blood and avoids the need for an allogenic blood donor.