Currently, feline packed red blood cells (pRBCs) are stored at refrigeration temperatures for a maximum of one month. This brief storage time leads to wastage of expired pRBC units and limits the ability of clinics to store and have ready access to blood products from less common feline blood types such as type B and AB. In human medicine, freezing of pRBCs allows for extended storage for up to 10 years and increases availability of blood in situations with an unpredictable need for RBC units, in addition to allowing access to a greater variety of blood types. Glycerol and hydroxyethyl starch (HES) respectively have been successfully mixed with human and dog pRBCs prior to freezing to preserve the red blood cells. The addition of glycerol requires removal of the glycerol from the thawed red blood cells prior to transfusion;
HES does not need to be removed prior to transfusion, making this substance more attractive as a storage medium. This study is designed to compare the effectiveness of glycerol and HES solutions for the preservation of frozen feline pRBCs utilizing established protocols in human and canine medicine. The effects of the glycerol and HES on the red blood cells will be evaluated by testing various parameters including the degree of red blood cell destruction post-thawing and the appearance of the red blood cells after thawing. The primary investigators’ hypotheses are that feline pRBCs can be frozen long-term and both HES and glycerol can be used as protectants during the freezing process.