From the Guidelines
A standard unit of blood for transfusion in adults typically contains approximately 250-350 milliliters (mL) of whole blood or red blood cells. Most commonly, adults receive packed red blood cells (PRBCs), which have had most of the plasma removed, resulting in a volume of about 300 mL per unit, as per the guidelines for blood transfusion 1. The exact volume may vary slightly between blood banks and institutions. When transfused, this single unit is expected to raise the hemoglobin level by approximately 1 g/dL or the hematocrit by about 3% in an average-sized adult. Key considerations for blood transfusion include:
- The patient's clinical condition, rather than laboratory values alone, with consideration of symptoms, hemodynamic status, and underlying medical conditions.
- Monitoring of vital signs before, during, and after the transfusion to detect any potential transfusion reactions.
- The use of specialized filtered tubing sets for administration.
- Discussion of alternatives to transfusion with the patient before surgery, and documentation of this discussion, as recommended by guidelines 1. The decision to transfuse one unit at a time, and checking the patient's Hb before each unit transfused, unless there is ongoing bleeding or a large deficit that needs correcting, is also crucial 1.
From the Research
Volume of One Unit Blood Transfusion for Adult Adults
- The volume of one unit of blood transfusion is not explicitly stated in the provided studies 2, 3, 4, 5, 6.
- However, it is mentioned that transfusion-associated circulatory overload (TACO) is a common cause of mortality associated with blood products, which suggests that the volume of blood transfused can be a critical factor 2, 3, 5, 6.
- The studies focus on the complications and risks associated with blood transfusion, such as TACO and transfusion-related acute lung injury (TRALI), rather than the specific volume of one unit of blood transfusion 3, 4, 5, 6.
- Therefore, there is no direct evidence to provide a specific volume for one unit of blood transfusion for adult adults based on the provided studies.