Autotransfusion or autologous blood transfusion is the collection of blood from a hemorrhaging trauma victim, its preparation, and its reinfusion. Autotransfusion was first used by Blundell in 1818 in women with postpartum hemorrhage (1). Reports on the use of autotransfusion for thoracic trauma date to 1917 (2) and for abdominal trauma to 1927 (3). The development of blood banking cooled the enthusiasm for autotransfusion; however, shortages of homologous blood and concerns about infectious complications renewed interest in the procedure in the 1970s. Collection of blood for autotransfusion can be performed by physicians, nurses, and trained technicians in emergency departments, operating rooms, and intensive care units.

Autotransfusion offers several advantages over transfusion of homologous blood. The patient is not exposed to bloodborne infectious disease, there is no risk of transfusion reaction, and the blood is immediately available. The advantages of recycling fresh, warm, autologous blood outweigh the potential disadvantages of clotting abnormalities, renal and pulmonary complications, and the inadvertent infusion of blood contaminated with bacteria.

The equipment needed to perform autotransfusion can be assembled quickly, and the process of collection, preparation, and reinfusion of blood can be easily performed even in the traumatized pediatric patient. Autotransfusion may offer the advantage of being lower in cost than transfusion of banked blood, but this depends on the relative costs of the equipment for autotransfusion compared with those for the transfusion of banked blood. When smaller volumes of blood are transfused, autotransfusion may be slightly more expensive. The physician will have to weigh the potentially higher cost of autotransfusion against the risks associated with the transfusion of banked blood (3).

In children, as in adults, the torso is often the target of both intentional and accidental trauma. Traumatic hemorrhage into the thoracic cavity is most often the result of bleeding from the lung parenchyma, the intercostal vessels, or the internal mammary arteries (4). However, the source of the bleeding may be the heart or great vessels or, in cases of diaphragmatic injury, the abdominal organs. Bleeding into the abdominal cavity can be the result of injury to solid organs such as the spleen and liver or injury to intra-abdominal vessels.

Hemothorax and hemoperitoneum can result in exsanguinating hemorrhage. Additionally, hemothorax may result in raised intrathoracic pressures, which in turn cause impaired venous return to the heart. Hemothorax may also cause impaired gas exchange secondary to compression of the ipsilateral lung.

The shed blood recovered from the peritoneal and thoracic cavities behaves somewhat differently than blood that is lost to external hemorrhage in that it does not clot as readily (5). It is felt that this is due to defibrination from contact with a serosal surface, especially with hemothorax. This fact favors using intracavitary blood for autotransfusion. Additionally, autotransfused blood has higher levels of 2,3-diphosphoglycerate than banked, homologous blood (6), which makes it more effective for tissue oxygen delivery.

In addition to patients who are in shock as a result of hemorrhage and have had minimal if any response to crystalloid therapy, blood replacement should be considered for those patients who are deemed to have lost 30% or more of their
circulating blood volume as well as those who have lost lesser amounts of blood but have evidence of ongoing hemorrhage (6) (Table 30.1). In adults, 30% of the circulating blood volume is approximately 1,500 mL. In children, the amount of blood loss necessary to cause significant hemorrhage varies with both age and size. Circulating blood volume is about 8% to 9% of body weight in young children, as opposed to 7% in adults. This typically amounts to 80 mL per kilogram of body weight.

In the traumatized adult patient, hemothorax is the most common cause of shock. The major indication for autotransfusion is hypotension associated with hemothorax, especially when there is ongoing blood loss. Other potential indications include a stable hemothorax, emergency thoracotomy, and intra-abdominal injury from hepatic, splenic, or vascular injury without hollow viscous injury.

Autotransfusion is contraindicated when the blood is collected from injuries that are more than 4 hours old or in the presence of large clots. Likewise, contamination of the blood with intestinal contents or a communication between the abdomen and the chest represent contraindications to ED autotransfusion (6,7). Other conditions that are contraindications to autotransfusion are known coagulopathy or disseminated intravascular coagulation (DIC); sepsis; pulmonary, pericardial, and mediastinal infections; and malignant neoplasms. Blood containing wound irrigants, such as Betadine, or topical hemostatic agents, such as thrombin, should not be salvaged (8). Using blood recovered from traumatic hemoperitoneum is controversial. In most cases, this blood should not be used in the ED setting because it is impossible for the resuscitation team to determine whether the blood is contaminated with bowel contents. However, in some circumstances this may be the only blood available for the patient. In such cases, the potential benefits of transfusion clearly outweigh the risks (9). Blood recovered from a hemoperitoneum may be used for intraoperative transfusion.