what is the life span of a transfused red blood cell unit?

It depends on how long that RBC was in existence prior to being donated and transfused. The average lifespan of a normal RBC produced by your body is 90 days. Transfused ones are going to be less – 30 days or so since it is a combination of new and old cells that are being donated.

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It does not matter if it is transfused or not, All red blood cells have a limited life span of around 100 to 120 days. Red Cells carry oxygen to the tissues to use for function. It is important to have a Healthy hematacrit, which measures the red blood cells. Generally Female: 36.1-44.3%, Male: 40.7-50.3%