The Gift of Life: How hospitals use donated blood to save animal lives.
Recently at our hospital we have been seen many cases that require blood transfusions. The most common reason to give a blood transfusion is a low number of red blood cells (RBCs) which are responsible for transporting oxygen from the lungs to body tissues. RBCs are measured as a percentage of the entire blood volume (normally 35-50%). If this value is very low we can give them blood from another animal of the same species to help get oxygen to their tissues while their body heals. The blood can’t just come from any animal; a rigorous screening is necessary to make sure the blood transfusion does not cause problems in the patient’s body.
Dumpling is a 2 year old female spayed English Bulldog that was hit by a car after she accidently slipped out of a loose collar. She ran across the street and was struck by an SUV travelling fast down the street. She was in pain, breathing rapidly and actively bleeding from a deep wound to her left thigh. The owners reported that she had soaked 2 whole bath towels with blood on the way over. She was in and out of consciousness and very critical. Her RBC value was 22%, a very critical level. She needed blood! She had lost a very large amount of blood and was continuing to hemorrhage; she was breathing rapidly trying to get more oxygen to her tissues; she was in shock – all great reasons for a blood transfusion. But what do we do now? Where do we get this blood from? How do you chose who gives the blood? How is this blood given? How much blood do they need?
Where do hospitals get blood?
Most emergency hospitals, including VESCONE, have a blood stock on hand for times of need. This blood is obtained through commercial supply companies or from a list of blood donors that are patients of the hospital. Blood donors are young, healthy animals above a certain weight that have undergone a thorough veterinary assessment, full blood work and infectious disease screening.
What are the different blood types?
Prior to Dumpling’s blood transfusion we had to make sure that she was going to accept her transfusion. Just like with humans, animals have blood types. “Blood type” just refers to proteins on the surface of the red blood cell to which the immune system reacts. If you give a patient a transfusion of the wrong blood type they may react to that blood as “abnormal” or an “invader” and try to destroy it causing a host of problems including the possibility of anaphylactic shock and death. Therefore the first important step is to know the blood type of the donor (the healthy animal) and recipient (Dumpling, who was hit by a car). Dumpling was blood type DEA 1.1. Dogs have two main blood types, DEA 1.1 and DEA 1.2 and as more research is performed we are finding additional blood types (DEA 1.3 through DEA 1.7) however these additional types do not seem to be important when giving blood transfusions. (Cats have 3 blood types, A, B and AB) Luckily for Dumpling the two stored blood bags from a previous donors were also DEA 1.1. Which one do we use?
How do you make sure the blood is a match?
Even if the two animals are the same blood type, sometimes their immune system will still react to the new RBCs as “abnormal.” Prior to any transfusion, in addition to making sure the blood types are the same, we have to make sure that the blood we are going to give isn’t going to cause a problem in the specific patient. This process is called “cross-matching” when we place the donor and recipients blood together in a test tube to make sure that it doesn’t react abnormally. Dumpling’s blood was compatible with the first donor that was tested, so now we could go forward with a transfusion.
How is the blood given?
Blood is given just like any fluid, injected through a tube into the vein. Blood products are typically given slowly over 4 hours. During this process the patients are still monitored every 30 minutes to ensure that they are not reacting to the new blood.
How did our sample case react?
Luckily for Dumpling, the bleeding had slowed down enough and she responded well to her transfusion. She overcame many hurdles during her hospital stay including surgery to fix her leg and multiple important tests to make sure she did not have any other complications after being struck by a moving vehicle. Surprisingly, she was otherwise unscathed and after multiple days of hospitalization and supportive care, pain control and blood monitoring she was discharged from the hospital.
There are many reasons for giving a blood transfusion and unfortunately they don’t all have the same happy outcome. Some patients continue to lose blood and need multiple transfusions. Some, despite the best efforts that medicine has to offer, succumb to their underlying disease. For all of these patients, the use of blood transfusion has proved invaluable to their care and is an integral part of their therapy, keeping them alive and their tissues oxygenated so that healing and recovery can occur.