What are the notes on blood transfusion?

From the Guidelines

Blood transfusion is a life-saving intervention that should be used judiciously, taking into account the patient's individual needs and circumstances.

Key Considerations

• Indications for red blood cell (RBC) transfusion include evidence of hemorrhagic shock, acute hemorrhage with hemodynamic instability or inadequate oxygen delivery, and a hemoglobin (Hb) level < 7 g/dL in critically ill patients 1.
• Restrictive RBC transfusion strategies (transfusing when Hb < 7 g/dL) are generally as effective as liberal strategies (transfusing when Hb < 10 g/dL) in critically ill patients with hemodynamically stable anemia, except possibly in patients with acute myocardial ischemia 1.
• Decision to transfuse should be based on an individual patient's intravascular volume status, evidence of shock, duration and extent of anemia, and cardiopulmonary physiologic parameters, rather than relying solely on Hb level 1.
• Single-unit transfusions are recommended in the absence of acute hemorrhage 1.

Special Considerations

• Critically ill patients requiring mechanical ventilation: consider transfusion if Hb < 7 g/dL, as there is no benefit to a liberal transfusion strategy 1.
• Resuscitated critically ill trauma patients: consider transfusion if Hb < 7 g/dL, as there is no benefit to a liberal transfusion strategy 1.
• Patients with acute coronary syndromes: RBC transfusion may be beneficial if anemic (Hb < 8 g/dL) on hospital admission 1.

General Principles

• Blood transfusion is a scarce and costly resource that should be used appropriately to ensure quality of service provision 1.
• Anaesthetists should be familiar with indications and appropriate use of blood and blood components, and liaise with haematology specialists and local blood sciences laboratory as needed 1.

From the Research

Blood Transfusion Overview

• Blood transfusions are generally safe but can carry considerable risks 2
• The physiologic goal of blood transfusion is to restore adequate tissue oxygenation when the demand exceeds the offer 3
• Blood transfusion is a common therapeutic intervention in hospitalized patients, with numerous indications including anemia and coagulopathy 4

Transfusion Reactions and Adverse Events

• Transfusion reactions can be serious and it is essential that physicians remain up to date with the current literature and are aware of the pathophysiology, initial management, and risks of each type of transfusion reaction 3
• The most frequent transfusion reactions include alloimmunizations, febrile non-hemolytic transfusion reactions, and allergic transfusion reactions 3
• Transfusion-related acute lung injury, transfusion-associated circulatory overload, and septic transfusion reactions are less frequent but can be severe 3

Prevention and Management of Transfusion Reactions

• The best way to prevent transfusion reactions is to avoid unnecessary blood transfusions and maintain a transfusion-restrictive strategy 3
• Any symptom occurring within 24 h of a blood transfusion should be considered a transfusion reaction and referred to the hemovigilance reporting system 3
• The initial management of blood transfusion reactions requires early identification, immediate interruption of the transfusion, early consultation of the hematologic and ICU departments, and fluid resuscitation 3

Transfusion Guidelines and Practices

• Clinical practice guidelines for transfusion of blood components, such as RBCs, platelets, and plasma, are necessary for the practice of evidence-based medicine 5
• The development of clinical practice guidelines involves assessing the value of transfusion therapy based on well-designed and appropriately powered randomized, controlled trials, and interpreting systematic reviews by individuals with expertise in transfusion medicine 5
• Implementation of clinical practice guidelines can be challenging, but is essential for optimizing patient care and improving patient outcomes 5

History and Evolution of Blood Transfusion

• Blood transfusion became a relatively safe and practicable procedure following the discovery of blood groups and the realization that citrate was a safe and effective anticoagulant 6
• The concept of transfusing whole blood to remedy a deficiency of any constituent has been superseded by the idea of transfusing only that component of blood which is needed 6
• Advances in molecular biology have characterized the antigens concerned and the genes that determine them, and have improved the safety of blood transfusion by reducing the risk of viral transmission 6