What are the risks and benefits of getting a blood transfusion?

Risks and Benefits of Blood Transfusion

Blood transfusions should be used restrictively with a hemoglobin threshold of 7-8 g/dL for most patients, as this approach provides equivalent outcomes while reducing exposure to transfusion risks. 1, 2

Benefits of Blood Transfusion

• The primary benefit of packed red blood cell (PRBC) transfusion is rapid increase in hemoglobin and hematocrit levels, making it the only intervention for patients requiring immediate correction of anemia 1
• One unit of PRBCs (300 mL) typically increases hemoglobin by approximately 1 g/dL in an average-sized adult who is not actively bleeding 1, 2
• Transfusion can be lifesaving in cases of acute hemorrhage and when rapid correction of anemia is required to stabilize a patient's condition 1, 3
• In patients with severe anemia and uremia, raising the hematocrit by 25% may improve platelet margination and hemostasis 1

Risks of Blood Transfusion

• Blood product transfusion carries risks of exacerbating portal hypertension from volume expansion, bacterial and viral contamination, immunologic complications, and increased healthcare costs 1
• Transfusion-related lung injury is a serious complication, with rates increasing in conjunction with the number of transfusions and higher when platelets or plasma-containing blood products are utilized 1
• Analysis of cancer patients showed increased risks of venous thromboembolism (OR 1.60), arterial thromboembolism (OR 1.53), and mortality (OR 1.34) associated with PRBC transfusions 1, 2
• Other risks include transfusion reactions, congestive heart failure, bacterial contamination, viral infections, and iron overload 1, 4
• Transfusion-related iron overload can occur in patients requiring frequent transfusions over several years, though it's unlikely in patients receiving transfusions restricted to short treatment periods 1

Transfusion Thresholds and Guidelines

• A restrictive transfusion strategy with hemoglobin thresholds of 7-8 g/dL is recommended for most hemodynamically stable patients 1, 2
• For patients with preexisting cardiovascular disease, including coronary artery disease, a slightly higher threshold of 8 g/dL is suggested 1, 5
• Transfusion is rarely indicated when hemoglobin levels exceed 10 g/dL 2
• Transfusion decisions should be influenced by both hemoglobin concentration and symptoms (shortness of breath, dizziness, chest pain, orthostatic hypotension, tachycardia unresponsive to fluid resuscitation, or congestive heart failure) 1, 5

Special Considerations for Different Patient Populations

• For patients with coronary artery disease, a restrictive strategy with a hemoglobin threshold of 8 g/dL is recommended, with consideration for symptoms 1, 5
• Patients with coronary artery disease may be more vulnerable to anemia due to reduced oxygen delivery to potentially ischemic myocardium 5
• For patients eligible for organ transplantation, avoiding red cell transfusions when possible is specifically recommended to minimize the risk of allosensitization 1
• In patients with chronic kidney disease, the decision to transfuse should not be based on any arbitrary hemoglobin threshold but determined by the occurrence of symptoms caused by anemia 1

Strategies to Reduce Transfusion Risks

• Use of low-volume adult or pediatric blood sampling tubes is associated with a reduction in phlebotomy volumes and blood transfusion requirements 1
• Blood conservation devices for reinfusion of waste blood with diagnostic sampling can reduce phlebotomy volume 1
• Intraoperative and postoperative blood salvage may lead to significant reduction in allogeneic blood usage 1
• Reduction in diagnostic laboratory testing is associated with decreased phlebotomy volumes and blood transfusion needs 1

Practical Transfusion Approach

• PRBCs should be transfused by the unit with reassessment after each transfusion 2
• PRBCs must be crossmatched to confirm compatibility with ABO and other antibodies before transfusion 2
• Premedication (acetaminophen or antihistamine) is seldom required for patients not requiring long-term transfusion 2
• The presence of preexisting cardiovascular, pulmonary, or cerebral vascular disease may compromise a patient's ability to tolerate anemia and should factor into transfusion decisions 1