Packed red blood cells (PRBCs) are a commonly used component derived from donated whole blood. They restore the body’s capacity to transport oxygen and are frequently transfused to address conditions where a patient’s red blood cell count is insufficient.
What Exactly Are Packed Red Blood Cells?
Packed red blood cells (PRBCs) are a concentrated preparation obtained from whole blood. Whole blood is collected from a donor and centrifuged to separate components by density. Red blood cells settle at the bottom, while most plasma, platelets, and white blood cells are removed.
A typical PRBC unit has a volume between 250 and 320 milliliters and a high concentration of red blood cells, with a hematocrit ranging from 50% to 70%. Red blood cells transport oxygen from the lungs to the body’s tissues and carry carbon dioxide back to the lungs.
This oxygen-carrying capability comes from hemoglobin, an iron-containing protein within each red blood cell. Hemoglobin binds with oxygen in the lungs and releases it where needed throughout the body.
Unlike whole blood, PRBCs deliver a high concentration of oxygen-carrying cells. This approach allows medical professionals to provide patients with precisely the blood product they require. Removing other components reduces the risk of certain transfusion reactions and allows for more efficient use of donated blood.
When Are Packed Red Blood Cells Transfused?
PRBC transfusions are indicated when a patient’s body cannot adequately deliver oxygen to its tissues due to a shortage of healthy red blood cells. This condition, known as tissue hypoxia, often arises from severe anemia or significant acute blood loss.
Patients with severe anemia, from chronic conditions like kidney failure or specific blood disorders, often require PRBC transfusions. Symptoms such as fatigue, weakness, shortness of breath, and reduced exercise tolerance indicate compromised oxygen-carrying capacity.
Transfusion is considered when hemoglobin levels fall below a certain threshold, such as 7 to 8 grams per deciliter. Acute blood loss from trauma, major surgery, or severe gastrointestinal bleeding is another common indication.
In these situations, the goal is to replace lost red blood cells to restore circulating blood volume and oxygen supply to organs and tissues. Transfusions help prevent further deterioration and support recovery.
The Transfusion Process and Patient Safety
The process of transfusing packed red blood cells involves several steps to ensure patient safety. Before any transfusion, rigorous checks ensure compatibility between donor blood and recipient.
Blood typing determines the patient’s ABO and Rh blood group to prevent adverse reactions. A cross-matching test mixes a small sample of the patient’s blood with donor blood to confirm no harmful interactions.
This laboratory step acts as a final compatibility check. At the patient’s bedside, two healthcare professionals perform an identification check, verifying the patient’s name and date of birth against their identification band and the blood product label.
Once checks are complete, PRBCs are administered intravenously, taking two to four hours per unit. Patients are closely monitored during transfusion, especially during the initial 15 minutes, when most immediate reactions might occur.
Vital signs such as temperature, pulse, and blood pressure are regularly assessed. Blood transfusions are safe, though mild reactions like fever, chills, or hives can occur. These reactions are manageable and rarely severe.
Safety protocols, from donor screening to patient identification and ongoing monitoring, significantly reduce the risks associated with PRBC transfusions.