For which patient could you find 3 compatible units of Red Blood Cells from a shelf of 22 random units?

To determine which patient could have three compatible units of red blood cells available from a shelf of 22 random units, it is essential to consider the patient's blood type and the presence of antibodies.

In the case of a patient with type O positive blood and anti-Fya, the presence of the anti-Fya antibody means that any unit containing the Fya antigen (which is found in various phenotypes) would be incompatible. However, type O blood does not have A or B antigens, making it more easily matched across different random units. Given that the majority of random units are likely to be either type O or have different antigen profiles, it increases the likelihood of finding compatible units despite the presence of anti-Fya.

Since anti-Fya is relatively less common than other antibodies, there can still be many units available that do not express the Fya antigen, thereby meeting the compatibility criteria for the patient. The prevalence of type O positive blood in the donor population also aids in finding compatible units.

Conversely, patients with other blood types and their associated antibodies, such as anti-Jka, anti-D, and anti-f, are more likely to experience difficulties finding compatible units due to the higher rarity of the specific antigen profiles they require. For example