Background on Stored Blood

Blood transfusions save millions of lives every day in the US and across the globe. First attempted in the 1600s, it was not until the 1800s that the first successful human transfusion was performed.  Since then, improvements in blood typing, donor screening, pathogen testing, and processing and storage methods have radically improved the clinical benefits of blood transfusion and reduced the risks. Today it is one of the most commonly performed procedures in the world.

The average human body stores about 5.6 liters of blood. As it circulates through the body several times each minute, it accomplishes a variety of functions.

Here are a few:

Blood is made up of several components such as plasma, platelets, white blood cells and red blood cells.  Typically, donated blood is separated into components and patients receive just the components of the blood needed to treat their particular condition. This approach to treatment, referred to as blood component therapy, allows several patients to benefit from one unit of donated whole blood. In some clinical situations, the use of whole blood may be preferred to component therapy, but stored components remains the method of transfusion therapy used in most hospitals.

Red Blood Cells (RBCs) are perhaps the most recognizable component of whole blood and give blood its red color.  A unit of RBC is prepared from whole blood by separating out the plasma and platelets and having the white blood cells (leukocytes) filtered out. RBCs contain hemoglobin, a complex protein containing iron that carries oxygen through the body.  Generated in the bone marrow, RBCs are continuously produced and broken down in a healthy circulatory system.

The ability to store RBCs and other components for extended periods of time has dramatically expanded the availability and use of transfusion as a life-saving therapy.  However, as soon as whole blood is collected from a donor, red blood cells begin to degrade.  RBCs experience progressive biochemical and biomechanical changes during storage, collectively called the “storage lesion”, that result in compromised physiological functions.  The US FDA stipulates that red blood cells may be stored for no more than 42 days with proper refrigeration and additive solutions.  In other countries, storage is limited to just 35 days.  By storing blood under oxygen-depleted conditions, the Hemanext Storage System aims to reduce this degradation and improve the function of an RBC by removing a primary root cause of this degradation — oxidative damage.