Page 597 - Fluid, Electrolyte, and Acid-Base Disorders in Small Animal Practice

CHAPTER • 24

Blood Transfusion and

Blood Substitutes

Ann E. Hohenhaus

Blood transfusions have many things in common with Limited availability differentiates blood products from
fluid therapy. Like crystalloid and colloid solutions, blood crystalloid and colloid solutions. Crystalloid and colloid
products are not used to treat disease; they are supportive solutions are readily available because they can be
therapies given to correct deficiencies in the patient until manufactured according to market demand. Only a living
the underlying disease process can be treated. For exam- animal can produce blood, and the donor’s physiologic
ple, a red blood cell transfusion is given to replace red capability limits production. The small number of com-
blood cells lost as a result of a traumatic laceration. The mercial canine and feline blood banks providing a conve-
transfusion of red blood cells increases the oxygen-carry- nient source of blood for the veterinary practitioner
ing capacity of the blood, allowing for surgical repair of further limits availability of blood for transfusion
the laceration; it is not the primary treatment for hemor- (Box 24-1). Furthermore, blood products require a more
rhage. Likewise, sodium chloride is used to replace regulated storage environment and have a significantly
sodium, chloride, and water in a dehydrated patient with shorter shelf life than crystalloid or colloid solutions,
hypoadrenocorticism until adrenal hormones can be making blood a less convenient product to store and
replaced. use in a veterinary hospital.
The use of both blood transfusions and fluid therapy Nearly 20 years ago, veterinarians estimated costs
must be carefully assessed before inclusion in a patient’s associated with transfusions, but an exact analysis of cost
treatment plan, and the veterinarian should evaluate the is lacking. In 1992, the estimated cost of a 500-mL whole
risk/benefit ratio for each patient. Volume overload, elec- blood transfusion ranged from $25 to more than $300. 56
trolyte disturbances, and transmission of infection can The cost of 500 mL of lactated Ringer’s solution is
occur from administration of pathogen-contaminated about $1.
blood products or fluids. 31,66,130 Despite the potential Despite the fact that the first documented transfusion
negative effects of transfusion, most veterinarians view was given to a dog in 1665 by Richard Lower at Oxford
it as lifesaving therapy, allowing the transfusion recipient University, veterinary transfusion medicine scientifically
to receive other necessary treatments such as surgery, and technologically lags behind its counterpart in human
chemotherapy, or medical care. 56 medicine. 76 Information in this chapter is based on veter-
Three major differences exist between the more inary studies whenever possible. When none is available,
commonly used fluids and blood products. The currently accepted guidelines from human medicine will
differences between crystalloid or colloid solutions and be applied to the veterinary patient. The purpose of this
blood products are their immunogenicity, availability, chapter is to provide the reader with the following:
and cost. The immunogenicity of blood products stems 1. A basic understanding of the theory of blood compo-
from the proteins and cellular material in the blood. nent therapy
Because crystalloid solutions lack proteins and cellular 2. Information on the technical aspects of obtaining
material, they are not considered immunogenic; however, blood for transfusion
certain colloid solutions such as hydroxyethyl starch 3. Suggestions for the administration and monitoring of
have been reported to cause acute anaphylaxis in rare transfusions
instances in humans. 96 The mechanism of this reaction 4. A description of the clinical applications of a veterinary
is unknown. blood substitute

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