Keywordsblood transfusion, coagulopathy, major hemorrhage, massive transfusion, tranexamaic acid
A 50-year-old man presents to the emergency department after falling from the roof of his house. He is tachycardic (heart rate of 120 beats per minute) and normotensive (blood pressure of 130/88 mm Hg), with a grossly distended abdomen on arrival. His Glasgow Coma Scale score is 15, and computed tomography suggests intraabdominal bleeding. The decision for emergency laparotomy is made and, on opening of the abdomen, the blood pressure falls to 60/30 mm Hg. He requires 6 units of red cells before hemostasis is achieved 1 hour later.
No universal agreement exists on the definition of the term massive transfusion. It seeks to quantify the blood and blood products that are used during the management of major hemorrhage. Some of the definitions include the following:
Replacement for blood loss of more than 150 mL/min
Replacement of 5 units or more in 3 hours
More than 10 units of red blood cells replaced over 24 hours
Total blood volume replaced over 24 hours
Half of total blood volume replaced over 4 hours
Massive transfusion and related complications are the result of therapy for acute blood loss, which necessitates rapid replacement of intravascular volume with crystalloid, non–red blood cell (RBC) colloids, blood, and blood products. The most common circumstance leading to massive transfusion is major trauma. Other situations include the following:
Major obstetric hemorrhage
Major vascular surgery/injury
Radical oncologic surgery
Orthopedic/spinal reconstructive procedures
It has been noted that the incidence of massive transfusion is on the decline, as early recognition and aggressive management of hemorrhage and the associated coagulopathy have resulted in the use of less blood products.
Circumstances that enhance and may contribute to the development of transfusion-related complications include the following:
Use of anticoagulants
Clotting factor deficiencies (hereditary, dilutional, or acquired; consumption of clotting factors; extracorporeal membrane oxygenation and circulatory assist devices)
Use of a cell-saver or autotransfusion device
Loss of up to 30% of the blood volume is usually well tolerated in children and young adults. Signs of hypovolemia may be subtle and include a small to moderate increase in heart rate and decrease in pulse pressure.
Any patient who requires acute, massive intravascular volume replacement is at risk for complications related to massive transfusion. Infants and neonates appear to be at increased risk owing to the immaturity of their native coagulation systems. The following complications are likely to occur:
Hypokalemia or hyperkalemia
A more complete list of generally recognized complications is provided in Box 48.1 .
Increased citrate load (hypocalcemia)
Transfusion-associated circulatory overload (TACO)
Hemolytic transfusion reactions
Febrile nonhemolytic reactions
Transfusion-related acute lung injury (TRALI)
Microembolization or microaggregate formation leading to acute respiratory distress syndrome
Transfusion-related diseases (bacterial and viral)
Delayed hemolytic reactions
Change in red blood cell deformability
Transfusion-related iron overload
Patient outcome depends on early recognition, the rate and severity of blood loss, and timely intervention. Neonates and infants have laboratory values that are outside the adult reference ranges for the integrity of coagulation (especially prothrombin time [PT] and partial thromboplastin time [PTT]). As such, normal laboratory values for adults do not measure neonatal hemostatic competence, and comparisons must be made with caution.
Management goals are to maintain the quantitative and qualitative integrity of intravascular volume. Oxygen-carrying capacity and hemostasis are of primary importance. In the face of massive volume loss, these goals can be met only by transfusing whole blood or components of fractionated whole blood. The components commonly used and their dosage are detailed in Table 48.1 .
|Blood Component||Dosage in Major Hemorrhage|
|Red blood cells||Aim to maintain hemoglobin at >80 g/L (10 g/L in patients with cardiovascular disease)|
|Fresh frozen plasma||15 mL/kg|
|Cryoprecipitate||5–10 mL/kg (max. 300 mL)|
|Platelets||1 adult bag|
|Factor concentrates||Use after consultation with hematology|