Questions ~ Why are these questions pertinent to why not to give CT contrast?

We are in the process of redoing our contrast history forms. There are several questions we ask that I have no idea why the answers, whether yes or no, are pertinent to whether we give the contrast or not.

Obviously if they are diabetic we need to know, obviously if they are allergic to iodine or shellfish we have to know.

Okay...why do we need to know if they have high blood pressure? If they do we give the contrast anyway. Hypertensive pts are at increased risk for CIN, depending on the state of their kidneys. I see it more as a heads-up for us as caregivers. Article:

http://www.ncbi.nlm.nih.gov/sites/en...&dopt=Abstract

Why do we need to know if they have had a heart attack?This article addresses prevention of complications post-acute MI, but also covers HTN and other conditions r/t admin of contrast. http://eurheartjsupp.oxfordjournals..../7/suppl_G/G13 Chest pain? Irregular heart beat? If the answer is yes we give the contrast anyway.

We ask if they've had multiple myeloma Here's an article addressing the question of mult. myeloma and contrast admin: http://radiology.rsnajnls.org/cgi/co...ract/183/2/519 , enviromental allergies, asthma? Yes, you give the contrast, but you are now aware that the pt is at increased risk for CIN and you have obtained the OK (either from your Radiologist or pre-set protocols) to go ahead and give. Risk VS benefit.
Again, if the answer is yes we give the contrast anyway.

What questions do you ask? Does anyone know why any of the above questions are pertinent in regards to the contrast that we give anyway? Here's a good article r/t potential problems caused by contrast admin: http://www.aafp.org/afp/20021001/1229.html

Thanks for any help you can give or any opinions about why these particular questions are important in regards to contrast?