We found that certain specialties were not interested in our standard critical values and instituted their own for their patients. Not a big deal because there were not many. One in particular was Oncology. I don't remember their values but I do remember they were considerably lower than our standard critical values. They also indicated that they only wanted follow up notification if the values dropped significantly and they told us what a significant drop was. I'm sure you are aware that critical values is not a "one size fits all" and it is a case where flexibility can be your friend. Talk with them or better yet have your medical director talk with them and see what they would work best for them. I found over the years that a doctor to doctor conversation was often much more productive. Of course that assumes your medical director is willing to go to bat for you.