Would doctors check for pernicious anemia with standard hospital bloodwork for a 58 yr old female admitted with confusion?

They likely would. Yes, pernicious anemia would likely be tested as it could be one of possible explanations for confusion. If it is treated early, further damage may be prevented.
Because . It can be treated before there is too much damage.
Pernicious anemia. Checking blood count is routine as part of the comprehensive workup for delirium or confusion.