Transfusions and Blood Donor Program

Author: Cyndi Lynn Sheridan, CVT, VTS (ECC)

Blood transfusions are delivered often in the emergency and critical care setting. From patients with trauma, to immune mediated diseases, to even rodenticide ingestions, we find ourselves administering blood products frequently.

During the pandemic, we saw an increase in pet ownership. With the increase in pet ownership, there was an increase in the demand for blood products. The blood banks across the country had a challenging time keeping up with this demand which resulted in many specialty hospitals developing an in-house blood bank of their own.

Blood donors should be young healthy adults, lean, and have a good temperament. They should weigh >50 lb for dogs and >10 lb for cats. They should have no history of prior transfusions. Before becoming a blood donor, we set up and meet and greet. We discuss the step by step donation process and go over any questions or concerns the owners have. We obtain a blood sample for a complete blood count, chemistry panel, and perform infectious disease screening. As long as the patient’s physical examination and blood work are within normal limits, we are able to utilize them as donors. Donors at PASE are currently used on an emergency basis. We order blood and receive monthly shipments from a commercial blood bank but often use these units up and then require the donor's support.

Prior to each donation, a small sample of blood is obtained for a packed red blood cell count to ensure the donor is eligible to donate. The predonation PCV should be ≥ 40% in dogs and ≥ 35% in cats. (Silverstein et al. 409-415) For cats, we typically have to administer a sedative in order to facilitate the blood donation. Dogs are typically more cooperative so sedation is often not necessary. The donor is placed in lateral or sternal recumbency (dependent upon the preference of the phlebotomist). The jugular vein is generously clipped and aseptically prepped. Strict aseptic technique is maintained during the entire procedure. The collection of blood can be performed via gravity (typically in dogs) or suction/aspiration (typically in cats). The donor’s vitals are closely monitored during the donation process.

Fresh whole blood is the main component we achieve when performing blood donations. This component contains all cellular and plasma components of blood. It can be processed into packed red blood cells and plasma to allow for specific blood component therapy for optimal use. Specific transfusion therapy dictates that only the deficient components are provided. What this means is that patients that are anemic receive packed red blood cells, those that are coagulopathic receive plasma, thrombocytopenic patients receive platelets, and hypoalbuminemic receive albumin. (Silverstein et al. 409-415) This allows for maximization of donors and products.

Although blood transfusions are usually safe, there are some potential risks involved and therefore should never be given without a clear indication or before exhausting other alternative therapies. Adverse reactions can occur during or even after the transfusion. Most reactions can be avoided by appropriate collection/storage, careful donor selection, performing blood typing and crossmatching, and administering only necessary blood components.

The most common sign of a transfusion reaction is fever, followed by vomiting and hemolysis. If a reaction is suspected, the transfusion should be stopped immediately. Hemolytic reactions can be fatal, therefore is the most concerning. Before the transfusion is started, baseline vitals are obtained. This includes the patient's temperature, heart rate, pulse quality, respiratory rate and effort, mucous membrane color, capillary refill time, mentation, and ideally blood pressure. These vitals are then reassessed five minutes after starting the transfusion and then again every fifteen minutes for the first hour, then hourly until the transfusion is complete. The response to the transfusion is monitored by obtaining a PCV and total protein reading before and after the transfusion and evaluating the patient’s overall clinical assessment. 

Overall, transfusions may be life saving in the emergent or critically ill patient. The risk/benefit ratio should be considered before the use of blood products. Patients should be appropriately screened and component therapy should be utilized when possible.