Stability of coagulation factors in feline fresh frozen plasma intended for transfusion after 1 year of storage.

OBJECTIVES: The most common use of plasma transfusion is for haemostatic purposes, but coagulation factor activities in stored feline plasma are unknown. The concentration and stability of coagulation factors I (fibrinogen), II, V, VII, VIII, IX, X, XI and XII in feline fresh frozen plasma (fFFP) stored for 1 year were studied. METHODS: Fifty-five units of fFFP were produced from 55 fresh whole-blood donations obtained from indoor healthy blood donor cats. Twenty-one units were stored for <2 weeks (T0) and 34 were stored for 1 year (T1). After the completion of storage, specific coagulation factor activities for factors II, V, VII, VIII, IX, X, XI and XII were tested using modified one-stage activated partial thromboplastin or prothrombin time assays. Fibrinogen was determined using the Clauss method. RESULTS: Significantly decreased activities were observed for factors II (T0: 101.94% ± 19.06%; T1: 73.23% ± 39.06% [P = 0.001]), VII (T0: 102.78% ± 24.69%; T1: 60.08% ± 38.17% [P <0.001]), VIII (T0: 77.52% ± 30.39%; T1: 50.32% ± 23.8% [P = 0.001]), XI (T0: 88.76% ± 22.73%; T1: 66.28% ± 22.2% [P = 0.001]) and XII (T0: 89.50% ± 21.85%; T1: 55.46% ± 23.18% [P <0.001]) when comparing units at time 0 and after 1 year of storage. No significant difference was observed for factors IX (T0: 84.86% ± 29.35%; T1: 71.37% ± 22.23% [P = 0.064]) and X (T0: 96.24% ± 25.1%; T1: 83.91% ± 49.54% [P = 0.236]). Unexpectedly, a significant increase was observed for factor V (T0: 71.94% ± 24.14%; T1: 97.89% ± 62.33%; P = 0.046). Fibrinogen was 2.76 ± 1.09 g/l at T1. Factors VIII, XII and VII had the lowest mean activities after 1 year. CONCLUSIONS AND RELEVANCE: Although a decrease in most coagulation factors activities was noted with storage, 1-year-old fFFP was haemostatically active in vitro. The most suitable factors for quality control assessment of fFFP are factors VII and VIII. Approximately 13-20 ml/kg of fFFP is required to administer a minimum of 10 IU/kg coagulation factor activity.

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.

Quantitative assessment of infusion pump-mediated haemolysis in feline packed red blood cell transfusions.

OBJECTIVES: Haemolysis caused by the use of peristaltic infusion pumps (PIPs) has been described in human and canine packed red blood cells (pRBCs). The aim of this study was to evaluate the effects of two different linear PIPs on the haemolysis of feline pRBC units stored for a long time. METHODS: Feline pRBC units stored with adenine, dextrose, mannitol and sodium chloride (SAGM) were manufactured. After 35-42 days of storage at 2-4°C, a line administration system with a 180 µm filter was attached to every pRBC bag, the system was drained by gravity alone (8 drops/min) and a 1.3 ml sample was collected (G). A NIKI V4 pump was then used at a flow rate of 25 ml/h, the flow was stopped when the infusion system was filled with blood coming from the infusion pump and another 1.3 ml sample was collected (NK). Finally, an Infusomat FmS pump was evaluated, collecting another 1.3 ml sample (IM). Packed cell volume (PCV) was measured in all samples by microhaematocrit centrifugation, total haemoglobin (HGB) was measured using a specific haemoglobin analyser and, after centrifugation, free HGB was determined by spectrophotometry. The percentage of haemolysis was calculated. Friedman's test was used to compare the samples. RESULTS: Fifteen feline pRBC units were evaluated. The average degree of haemolysis for sample G (gravity-assisted) was 1.12%. Comparison of the degree of gravity-assisted haemolysis with haemolysis in PIP NK (1.13%) and IM (1.14%) samples revealed no significant differences, with differences of only 0.01% and 0.02%, respectively. CONCLUSIONS AND RELEVANCE: The results of this study demonstrate that the use of two common PIPs in veterinary hospitals does not produce levels of haemolysis that are significantly different than that caused by gravity alone during transfusion of feline pRBCs at a rate of 25 ml/h.