What is Transfusion Reactions?
Transfusion reactions are negative side effects that can happen when you receive a blood transfusion. These reactions can vary from mild to very serious or even life-threatening. You may experience these reactions either during the transfusion (referred to as acute transfusion reactions) or days to weeks after the transfusion (known as delayed transfusion reactions). These side effects could be related to your immune system or not related to it. Diagnosing a reaction can be difficult because the symptoms can be quite general and often overlap with other conditions. The most common symptoms include fever, chills, hives, and itching, which sometimes go away on their own or require minimal treatment. However, if you experience breathing difficulties, a high fever, low blood pressure, or red urine (from the breakdown of red blood cells), it could indicate a more serious reaction.
Several types of transfusion reactions exist, including acute hemolytic, delayed hemolytic, febrile non-hemolytic, anaphylactic, simple allergic, septic (from bacterial contamination), transfusion-related acute lung injury (TRALI), and transfusion-associated circulatory overload (TACO). If you suspect you’re having a transfusion reaction, it’s crucial to stop the transfusion immediately and inform both the blood bank and the doctor overseeing your treatment.
What Causes Transfusion Reactions?
Transfusion reactions, or bad reactions to blood transfusions, typically happen when the blood product being transfused doesn’t match properly with the recipient’s blood type. These can happen due to natural antibodies in the receiver’s blood, like anti-A and anti-B, which can cause acute hemolytic transfusion reactions, or negative reactions caused by the breakdown of red blood cells. These reactions can also occur due to antibodies that the body creates in response to foreign antigens, or substances that can trigger an immune response. These antibodies are responsible for many different types of reactions, including mild allergic reactions, febrile non-hemolytic reactions (reactions accompanied by fever but not involving breakdown of red blood cells), severe reactions like acute hemolytic and anaphylactic. Sometimes the antibodies in the donor’s blood can also cause reactions, and are thought to be involved in transfusion-associated lung injury (or TRALI, a rare but serious complication of transfusions).
Reactions can also happen without the immune system being involved. These are typically caused by the physical effects of the blood components or the spread of disease. For example, bacterial contamination can cause septic transfusion reactions, which can happen if bacteria or toxins are present in the blood product. There are many ways that this contamination can occur, including if the skin of the donor wasn’t properly cleaned before collection, if there were bacteria in the donor’s blood at the time of collection, or if the blood product wasn’t handled properly after being collected.
Transfusion reactions can also occur due to factors that aren’t related to the blood directly. For example, if too much blood is transfused, it can cause “transfusion-associated volume overload” (or TACO), which is when the heart is unable to pump blood efficiently due to too much fluid in the blood vessels. Transfusions can also cause hypothermia, or a dangerously low body temperature.
Risk Factors and Frequency for Transfusion Reactions
Reactions to blood transfusions can range from common mild allergic and febrile non-hemolytic reactions to rare occurrences like anaphylaxis, acute hemolytic, and sepsis. The most fatal events are often associated with TRALI, while long-term or later side effects usually result from disease transmission.
The severity and frequency of these reactions can vary based on factors like the type of reaction, the prevalence of disease in the blood donor population, and the level of aftercare the patient receives. Thankfully, due to better screening of donors, improved tests, and automated data systems, the risks and number of fatalities related to blood transfusions is decreasing.
Signs and Symptoms of Transfusion Reactions
Before a patient receives a transfusion, health professionals must fully understand their medical history and current health status. During the transfusion, vital signs, such as heart rate and blood pressure, are generally checked every 15 minutes. Some slight changes in these vital signs can be expected and are seen as normal, for instance:
- A temperature fluctuation of plus or minus 0.5 C
- Changes in breathing rate by up to plus or minus 5 breaths per minute
- Heart rate varying by plus or minus 10 beats per minute
- Blood pressure shifts of plus or minus 20 mm Hg
However, if these changes exceed the above limits, it doesn’t necessarily mean there’s a problem with the transfusion. But the healthcare staff should keep a close watch for any potential reactions. Abnormal reactions can include symptoms like hives, itching, significant fever, chills, low blood pressure, and difficulty breathing.
Testing for Transfusion Reactions
Determining whether someone is having an acute transfusion reaction, a negative response to a blood transfusion, starts by observing their signs and symptoms. Some examples of common signs and symptoms which might indicate potential issues are listed below:
* Urticarial (Hives)/Itching
Hives and/or itching can indicate an allergic reaction to the transfusion. Sometimes, these symptoms may be the start of a severe allergic reaction called anaphylaxis, which can be life-threatening. If these symptoms occur during a transfusion, it should be stopped immediately, and the patient should be carefully watched for any escalated symptoms.
* Fever/Chills
Having a fever or chills during a transfusion is typically associated with a mild reaction, where the body reacts to the foreign blood cells without any damage to the patient’s own cells. However, they could also be the start of a more serious reaction, such as an acute hemolytic reaction, where the recipient’s body attacks the donor blood cells; a Transfusion-Related Acute Lung Injury (TRALI), where the lungs react negatively to the transfusion; or a septic transfusion reaction caused by bacteria in the blood product. If the patient’s temperature rises by 1 degree Celsius or more from what it was at the start of the transfusion, the transfusion should be stopped. A significant temperature rise or intense symptoms like severe chills may indicate an acute hemolytic reaction or bacterial contamination.
* Trouble Breathing/Shortness of Breath
Shortness of breath or difficulty breathing can be a sign of several severe reactions including anaphylaxis, TRALI, and Transfusion Associated Circulatory Overload (TACO), where the body cannot handle the added volume of the transfusion. This symptom might also occur on its own without any other symptoms present.
* Low Blood Pressure
Low blood pressure can be seen with acute hemolytic reaction, septic transfusion reactions, anaphylaxis, and TRALI. It can also happen without any other signs of a transfusion reaction.
* Feeling Cold
Feeling cold might happen when a large amount of refrigerated blood products is transfused. The best response in such a situation is to warm up the patient and/or the blood product.
Treatment Options for Transfusion Reactions
If a person has a negative reaction during a blood transfusion, the procedure needs to be stopped right away. Medical professionals will usually keep the IV line open with a saline solution (a type of sterile water with added salt). To make sure that there weren’t any mistakes, they’ll double-check the bag of blood and the patient’s identification.
During this time, it’s important to closely monitor and record the patient’s vital signs every 15 minutes. A sample of blood should be taken from the patient after the transfusion and sent to a lab for testing. If possible, the bag and tubing used for the transfusion should also be sent for testing.
When the blood arrives at the lab, the technicians there will perform additional checks and tests. Even more importantly, they will make sure that the blood given in the transfusion wasn’t incompatible with the patient’s blood, which is one common cause of transfusion reactions.
Treatment for transfusion reactions usually involves supportive care, meaning the goal is to relieve symptoms and make the patient comfortable. For example, if a patient has a mild allergic reaction, they might receive an antihistamine, a type of medication that can help control allergies. If they have a fever (or high body temperature) after the transfusion that isn’t caused by the destruction of red blood cells, they might receive an antipyretic, a type of medication used to lower fevers.
What else can Transfusion Reactions be?
Some severe conditions can develop rapidly, such as:
- Anaphylaxis (a severe, potentially life-threatening allergic reaction)
- Disseminated intravascular coagulation (a condition that causes small blood clots to form throughout the body)
- Hemolytic anemia (a condition where red blood cells are destroyed faster than they can be made)
- Septic shock (a severe infection that causes a dangerous drop in blood pressure)
Possible Complications When Diagnosed with Transfusion Reactions
- Widespread blood clotting in small vessels (Disseminated intravascular coagulation)
- Damage to the lungs (Lung injury)
- Failure of the kidneys to function (Renal failure)
- Destruction of red blood cells (Hemolysis)
- Death
