When to transfuse red blood cells in the National Health Service (NHS)?

From the Guidelines

The NHS recommends transfusing red blood cells when a patient's hemoglobin level falls below 7 g/dL in most hospitalized patients, or below 8 g/dL in patients with cardiovascular disease or those experiencing symptoms of anemia. For patients undergoing orthopedic surgery or with active bleeding, the threshold may be higher at 8-9 g/dL. Transfusion should be considered at higher hemoglobin levels (9-10 g/dL) for patients with acute coronary syndrome. Each unit of packed red blood cells typically raises hemoglobin by approximately 1 g/dL in an average-sized adult.

Key Considerations

• Transfusions should be administered one unit at a time, followed by reassessment of the patient's clinical status and hemoglobin levels before deciding on further units.
• This restrictive transfusion strategy helps minimize unnecessary transfusions and associated risks such as transfusion reactions, infection transmission, and iron overload.
• The decision to transfuse should always be individualized based on the patient's clinical condition, symptoms, and underlying cause of anemia rather than solely on hemoglobin levels.
• Patients should be monitored during and after transfusion for signs of adverse reactions including fever, chills, rash, or respiratory distress, as suggested by studies 1, 2, 3.

Clinical Guidelines

• The AABB recommends adhering to a restrictive transfusion strategy (7 to 8 g/dL) in hospitalized, stable patients (Grade: strong recommendation; high-quality evidence) 2.
• The AABB suggests adhering to a restrictive strategy in hospitalized patients with preexisting cardiovascular disease and considering transfusion for patients with symptoms or a hemoglobin level of 8 g/dL or less (Grade: weak recommendation; moderate-quality evidence) 2, 4.
• RBC transfusion is indicated for patients with evidence of hemorrhagic shock, and may be indicated for patients with evidence of acute hemorrhage and hemodynamic instability or inadequate oxygen delivery, as stated in the clinical practice guideline 3.

From the Research

Red Blood Cell Transfusion Thresholds

• The decision to transfuse red blood cells in the National Health Service (NHS) should be based on a restrictive transfusion strategy, considering transfusion when the hemoglobin concentration is less than 7 g/dL for most patient populations 5, 6, 7.
• For patients undergoing cardiac surgery, a threshold of 7.5 g/dL may be considered, while for those undergoing orthopedic surgery or with preexisting cardiovascular disease, a threshold of 8 g/dL may be used 5, 7.
• In critically ill children, a restrictive transfusion strategy with a threshold of less than 7 g/dL is recommended 5.
• For children with congenital heart disease, the transfusion threshold should be based on the cardiac abnormality and stage of surgical repair, ranging from 7 g/dL to 9 g/dL 5.

Clinical Context and Patient Preferences

• The overall clinical context, patient preferences, and alternative therapies should be considered when making transfusion decisions about an individual patient 5, 6, 7, 8.
• Red blood cell transfusions should be tailored to the patient's needs, taking into account factors such as age, underlying medical conditions, and symptoms of anemia 8, 9.

Appropriateness of Red Blood Cell Transfusions

• A retrospective study found that the majority of red blood cell transfusions in non-bleeding patients were performed outside recommended indications, highlighting the need for education on appropriate indications for transfusion 9.
• The most frequent causes of inappropriate red blood cell transfusions included no hemoglobin determination pre-transfusion, absence of anemia signs/symptoms pre-transfusion, and liberal transfusion triggers 9.