Can someone give an idea of the frequency of having to switch types due to low supply?

In particular neg swithced to rh pos blood

thanks

It is very rare for us (even though we threaten it occasionally). We are a medium sized hospital and transfuse about 300 RBC units a month. Sometimes if we threaten to give RH positive blood the doctor will want to hold off on transfusion until we can get Rh negative from ARC.

We are about a 220 bed hospital. We stock 10-12 O neg units. We can switch in an emergency if we have 6 units or less left on the shelf and the patient is male or a female >50 years.

We are a medium size hospital - we transfuse 700-800 red cells monthly - we have an active ED, an active oncology unit and an active dialysis unit. We usually switch Rh-hr types about once a month - we swap ABO groups more frequently. We evaluate each switch on a case by case basis with the guidelines outlined by my Medical Director.