Administering blood products and/or their components is commonplace in many aspects of medicine. From emergency departments to maternity hospitals all over the world, we administer either components of or whole blood transfusions to patients. In emergency medicine specifically, patients suffering from multisystem trauma injuries, as well as specified medical emergencies, often require immediate replacement of the blood lost. Administering blood to these patients helps bridge the gap between the resuscitation bay and the operating theatre, where definitive treatment can be achieved.
The four components of blood administered to patients are: packed red cells (these being type O, Rh antibody-negative cells to avoid immune reactions), fresh frozen plasma, cryoprecipitate/fibrinogen, and platelets. Each institution’s massive transfusion protocol may vary slightly, but in general, as soon as a patient reaches certain haemodynamic criteria (eg low BP with high pulse) with an adjoining severe bleed or mechanism of injury, the protocol will be triggered by a senior clinician. This is a multi-disciplinary response involving the department’s clinicians, the medical laboratory, and the haematologydepartment.
Most emergency departments keep 1-2 units of refrigerated packed red cells in the department, and after warming, these can be administered to a patient urgently. Prior to this, if not already, the patient’s own blood is sent to the lab for a type and cross-match study to identify what blood type the patient should receive. This reduces the need for continuing administration of the limited resource of type O negative.
Sometime after activation of an MTP and administration of the warmed crystalloid fluids or packed red cells (if available), a cooler from the medical laboratory/blood bank will arrive to the activating department. Dependent on institution protocol, this cooler will normally contain 1-2 more units of packed red cells (O-) and 1 unit of fresh frozen plasma. Subsequent coolers delivered will contain more packed red cells and cryoprecipitate or platelets depending. MTPs are only stopped when a senior clinician recognises no further need for replacement of blood products.
Low antibody titer O negative whole blood transfusions are becoming more commonplace worldwide for patients experiencing major haemorrhage in the emergency department. These transfusions contain all of the necessary components of lost blood, which are regularly delivered separately to patients. These transfusions had historically fallen out of favour compared to component based therapy, but after promising results from military application have been returning steadily for use in emergency departments and prehospital care worldwide. It has been shown by numerous studies that patients receiving whole blood transfusions as an adjunct to component therapy have lower 24-hour mortality, in-hospital mortality, and major complications. This represents a major advancement in the science of resuscitative care of the critically ill/injured and emergency medicine.
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