A massive transfusion generally refers to replacing a very large quantity of a patient's blood, such as half or all of the blood that would normally be in the person's body at a given time, in less than 24 hours. People who have sustained a major trauma are the most likely to need a massive transfusion, and this is usually an emergency situation. Massive transfusions have additional possible complications due to the volume of blood being transfused.
Massive blood loss can be a major crisis, and the medical team must work quickly and efficiently to stop the bleeding and stabilize the patient. The need for transfused blood is determined by many factors, including a patient's blood oxygen consumption. Providing a steady supply of oxygen in the blood to all the patient's tissues without over-stressing the patient's system is the ultimate goal.
Both under-transfusion and over-transfusion of blood can be dangerous for the patient because under-transfusion may cause a lack oxygen and over-transfusion can overwhelm the system with donor blood. Donor blood is often stored, and stored blood has decreased amounts of some components and chemicals and increased amounts of others. Patients who receive a massive transfusion may become deficient in or build up large amounts of chemicals, such as potassium and citrate. The patient's blood will need to be carefully monitored to ensure that these levels do not become dangerous. Patients receiving a massive transfusion may also require blood components such as platelets or plasma in addition to the regular transfusion.
Whenever possible, patients will receive blood products from donors of an identical blood type. If the patient's blood type is unknown, which is particularly likely in a major emergency that might require a massive transfusion, type O negative blood will be used. This is the universal donor type of blood, which people of all other blood types can accept without danger. Once the patient's blood type has been identified, the transfusion should be switched to that blood type for the rest of the transfusion.
There is a special protocol that medical professionals need to follow for a massive transfusion. Communication between the attending medical team and the blood bank is very important so that the patient receives a steady supply of the correct type of blood. To minimize the risk of miscommunication, only one attending physician should be responsible for communicating with the blood bank per patient, and only one blood bank technologist should be responsible for the patient's blood products.