Red Blood Cell Transfusion

Indications:
        Treatment of anemia in cases too severe to be treated by nutritional replacement or iron
        Loss of 10-15% of total blood volume during surgery
        Correction of perioperative anemia
        Hypotension associated with bleeding

The Transfusion Trigger:
           Generally is having a hemoglobin of 7 g/dl or less.
           If the patient has cardiac problems it is set at 10 g/dl

Why is having a low Hemoglobin and being anemic harmful?
           Hemoglobin transports Oxygen from the lungs to the tissues
           And transports Carbon dioxide from the tissues to the lungs
           Without enough hemoglobin the tissues do not get enough Oxygen and their is a build up of Carbon dioxide. This causes the tissues to become hypoxic and will begin to die. 

How does the body compensate for low hemoglobin levels?
         When hemoglobin levels get below 7 g/dl the heart starts to beat faster to pump blood through the body at a faster rate since their is less blood in the body.
                     This is why those patients with heart problems need to have a transfusion trigger that is higher (like 10 g/dl) because their heart cannot compensate.
          The tissues have a stronger affinity for Oxygen and will grab more of it as the Hemoglobin molecule passes by.

The risk of death from anemia is when the hemoglobin level reaches 3 g/dl. The body cannot compensate for the lack of oxygen and the body begins to shut down. Prolonged levels of a Hemoglobin of 3 or less usually results in death.

Red Blood Cell (RBCs) Transfusions:
        One unit of RBCs can increase the Hemoglobin by 1 g/dl and can be life saving in patients with severe anemia or bleeding.