Chapter 18
Blood Product Sources
Sally Lester
Pilchuck Veterinary Hospital, Seattle Veterinary Specialists, Seattle, Washington, USA
Introduction
While transfusions are becoming more prevalent in veterinary medicine, there are no accepted guidelines that determine when transfusions are necessary, nor are there regulations that govern the acquisition of blood products from animals. The United States Food and Drug Administration (USFDA) does consider blood products to be a biological product (APHIS agreement #04-9100-859-MU; FDA serial #225-05-7000). Other regulations apply to European facilities (Coleman 2010). The state of California is the only state at the present time that requires a blood bank to obtain a biologic license (United States Veterinary Biological Product License) as of 2010. Whether this applies to in-hospital, as well as commercial, blood banks has not been answered. As there are no regulations regarding blood product acquisition, it is necessary for the individual practitioner, clinic, or hospital to establish their own guidelines and to be diligent in their evaluation of the source of their blood products.
The primary reason for performing a transfusion is to provide a means of oxygen transport in an animal that has a deficit in hemoglobin as a result of either acute or chronic blood loss. Considerations for transfusions should include evaluation of the duration of the anemia, clinical signs associated with the anemia, and the physical and biochemical parameters of the animal. The level of hemoglobin used to determine the need for a transfusion in human medicine has varied and the currently suggested level is 7–8 g/dL (70–80 g/L) (Carlson et al. 2012). In veterinary medicine, this level has not been established and is expected to vary among species (Kisielewicz et al. 2014).
Standard operating procedures
Standard operating procedures (SOPs) (Box 18.1) are a requirement of quality management systems whether they pertain to testing or clinical applications. The purpose of a SOP is to ensure that the same procedures will be applied regardless of the personnel administering the procedure, and they should be established in any blood bank. For example, the SOP for administration of a transfusion should include the following information: the name of the protocol, date it was developed, and author, as well as the effective date of the protocol and revision date, should that apply. The protocol should require recording of the recipient animal’s clinical assessment, temperature, respiratory rate, heart rate, and capillary refill time, as well as the body condition, weight, evidence of trauma, diagnosis, and relevant complete blood count (CBC) and biochemical data. The total volume and method of administration of the blood products should also be included, such as by gravity or fluid pump, including the type of fluid pump. A checklist included in the protocol will help ensure all relevant information is collected. If transfusions are to be performed at the hospital, then decisions must be made regarding how to obtain those blood products and which products will be available for use (Beal 2004a; Couto 2007; Tocci and Ewing 2009).
Sources of blood products
Commercial blood banks
There are many commercial blood banks that provide blood products, especially in large metropolitan areas, as well as some emergency clinics that also provide blood products. The availability of the blood products, as well as the clinician’s assessment of the reliability and quality, are the main factors that determine the blood product source. The larger commercial blood banks will either have donors on site or will establish a large donor pool. Donors are sought out by recruitment of willing dog and cat owners through public advertisement or the clinic database.
It is the responsibility of the practitioner choosing to perform the transfusion to ensure the safety of the blood products, whether they are obtained commercially or by an in-hospital blood banking program. For blood products obtained through commercial blood banks, asking certain questions will assist with determining product safety. The first set of questions pertain to the physical building and whether the blood bank maintains its own donors, and if so, whether the animals are housed appropriately, in accordance with both state and federal regulations regarding experimental/laboratory animals. The next set of questions relate to the protocol established to determine that the animals are free of disease. Considerations should include type and frequency of pathogen testing, as well as physical examinations. Included in these questions should be the use of medications such as parasite preventatives and vaccinations. It is also prudent to determine whether there is a plan for the animals after retiring from the donor program. If animals are recruited for the blood bank and are privately owned, the steps that are in place to determine the health and maintenance of these animals, including exposure to diseases, should also be questioned. Finally, it is important to determine whether there is a consistent supply of blood products, as well as the timeliness of delivery of these products after an order is placed.
Product verification
Blood banking facilities and hospitals acquiring blood products should be aware of and record information to verify the quality of the blood products (Table 18.1). There are considerations regarding the viability of blood products and whether the product with the longest shelf life is always shipped. Charges for shipping should also be considered as most commercial banks will have extra charges for overnight, rushed, or expedited shipments. Product viability is related to temperature control of the product, sterility, and the method of collection, including leukoreduction and preservation fluids. The blood bank facility should maintain records that include adverse reactions that were encountered during the blood collection, as well as information on product deterioration (e.g., color changes). The clinic obtaining the blood products should maintain a usage log that includes the date the blood product was received, whether the product was discarded or used, the animal that received the product, and whether adverse reactions were noted during blood product administration (Howard et al. 1992; Beal 2004a; Oakley 2005; Couto 2007; Prittie 2010; Mackin 2010).
Table 18.1 Blood product verification information
| Product | Expiration date | Shipping | Product quality assessment | Tracking and use log |
| Packed red blood cells | Will depend on anticoagulant and red cell preservative used | Overnight or two business days Should be shipped cold to maintain 2–6°C | Sterility assessments Log of adverse reactions | Used to assure availability of product |
| Fresh frozen or frozen plasma | Will depend on the type of product | Ship on dry ice overnight; product must arrive frozen | Same as above | Same as above |
Examples of commercial blood banks
There are a variety of commercial animal blood banks that are in operation and most provide information about their collection procedures and facilities on their websites (Box 18.2). These blood banks vary in their function, with some serving local regions and others not-for-profit enterprises, while some are large commercial ventures operating nationally. There are numerous large commercial facilities in operation at the time of writing. These commercial blood banks also serve as suppliers for blood collection sets for in-hospital use, although blood collection sets can also be ordered directly from the suppliers (Figures 18.1–18.3).
Figure 18.1 A leukoreduction blood collection system. The pink circular object is the filter used for removal of white blood cells.
Figure 18.2 Feline blood collection system.
Figure 18.3 Canine blood collection system.
There are many other blood banks that serve their immediate region and are usually associated with an emergency or specialty practice within the area. Local veterinary associations can provide contact information for regional blood bank facilities. As stated previously, it is the responsibility of the veterinary practice to evaluate the commercial sources of blood products prior to their use. Many veterinary schools maintain a blood donor program, but these programs are often used for in-hospital or teaching purposes only. However, veterinary schools can be a valuable source of information for others establishing a blood banking program.
Considerations for establishing an in-clinic blood bank
Transfusion demand
Transfusion products have a finite life span. If the demand for blood products is limited, then many products will expire and this will cause a financial burden, as well as subject animals and staff to a time consuming and unnecessary procedure. Plasma products have a longer life span than red cell products, and since the shelf life of fresh frozen plasma is 1 year and frozen plasma is 5 years, if stored appropriately, these products are much less likely to be discarded.
Blood product demand is typically not consistent; estimates based on monthly use of products are simply estimates. There will be some months that practices will double or triple the average use of the blood products, while other months there might be no need for these products. In order to avoid the scenario of discarding expired blood products, the practice could provide other local facilities with blood products that are near expiration.
Ultimately, the most effective way to develop an in-hospital blood bank is to use a combination of commercial sources along with in-hospital collections (Table 18.2). Commercial sources can be used, in addition to scheduled collections, as well as on-call donors if there is a sudden demand or need for fresh blood products (e.g., fresh whole blood) (Oakley 2005).
Table 18.2 Considerations for establishing an in-hospital blood bank
| Specialty practice | Emergency practice | Rural practice | Urban practice | |
| Demand | Immune-mediated hemolytic anemia patients or surgery patients | Trauma patients | Often variable: none to sudden demand | Low consumption, but options for referral to specialty or emergency practice |
| Maintenance of blood product supply | Mixture of in-hospital donor animals and commercial sources | Mixture of in-hospital or on-call donors and commercial sources | On-call donors | Not needed |
| Number of animals required | Minimum of 18 dogs and 10 cats in the donor pool (dependent upon caseload) | Minimum of 15 dogs and 8 cats in the donor pool (dependent upon caseload) | Minimum of 4–5 donor dogs | Not needed |
Procuring animals
Most in-hospital blood banks rely on a combination of sources, but are usually dependent on employees’ animals or animals that are procured specifically to be donors (Box 5). Employee turnover might be an issue in utilizing employee animals. In general, it is best to use client-owned, employee-owned, or fostered animals, and then rely on commercial blood banks to satisfy periods of increased demand (Lanevschl and Wardrop 2001; Helm et al. 2010).
Client-owned animals
Owners who are willing to enroll their pets in a blood donor program want to help animals and are dedicated animal lovers, but many do not realize the demands these programs can place on themselves and their pets. It can be difficult for a client to maintain their level of enthusiasm to be part of a blood bank program when are being asked to give up time to transport their pet to the facility on a regular basis and wait during the blood collection. This is more of an issue with cats than with dogs, as transport can be stressful for both the owner and the cat.
The more specific donation times are, the easier it is for the client to plan; an on-call system would not be favorable to many clients. A specific time frame of every 3 months with a specific date such as “the third Thursday at 9 am” with reminders sent a week prior to the scheduled time or a calendar provided for the clients will help to maintain their compliance. It is important that the client stay with the animal initially, as the physical evaluation of the animal and history update prior to the blood collection can reveal problems that preclude obtaining blood, unfortunately making the trip unproductive for the owner and the animal. If the physical examination is satisfactory, the client can leave the animal and come back later, or the client can stay during the collection if that is the protocol used by the veterinary hospital. Some donor programs elect to have the owner remain present during the collection process. It is imperative that the procedure runs smoothly and that the collection process is as positive, comfortable, and efficient as possible. After one donation experience, especially if problems arose, the animal might be nervous about visiting the clinic and this can translate to reluctance on the part of the owner to continue with the program.
Sedation
Sedation is elective; it is possible to collect donations without sedation if time is spent training the animal and if a quiet and separate location is used for the collection (K. Yagi, personal communication 2013). If sedation is used, it should be tailored to the animal, and records maintained as to the dosage and effect of the protocol so that optimal sedation without significant side effects can be developed. Many sedation protocols use agents that can be reversed, but the animal can still experience a change in behavior that can concern owners regarding the effects of the blood collection. These effects can last more than 12 hours, which can lead owners to question whether donation is appropriate for their pet. Sedation is fairly commonplace during feline donations, more so than canine donations, but if a quiet calm atmosphere is maintained and the cat is acclimatized to the handlers, a conscious blood collection can be an option.
There are risks associated with not using sedation, which include sudden movements of the animal that can dislodge the needle or lacerate the jugular, rendering the blood product unusable if contamination or clot formation occurs or the volume collected is insufficient. Hematomas can form with or without sedation and are not a significant medical problem, but can be perceived by owners as an issue that could threaten their animal’s health.
Acquiring animals specifically for a blood donor colony
The acquisition of animals specifically for the purpose of maintaining an in-hospital donor program (“donor colony”) can be difficult (Box 18.3). Many foster and adoption programs do not wish to provide animals for a perceived “kennel situation”. Acquiring “retired” racing greyhounds or shelter animals can result in animals that have significant disease processes that will preclude their use as a donor and raise concerns regarding animal rights. Returning these animals or providing alternative homes will then result in additional stress both for the clinic and the animal. Breeders will be reluctant to sell animals into donor programs unless assured of the care the animal will receive, excluding this population as a viable source of donors. Establishing the clinic as an animal facility that has met the legal requirements for housing animals for specific purposes might improve the perception of the “donor colony” (Kulpa-Eddy et al. 2005).
An additional option is acquiring animals and arranging for foster care by hospital employees. The arrangement might include the hospital providing all of the medical care, food, and supplies, while the employee provides the home environment for the animal and the daily care. These animals can then be designated as on-call donors, as well as being regularly scheduled for donations. This method is more viable in practices with a steady employee base; frequent re-homing of these animals will be required otherwise (Mazzaferro 2007).
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