But better testimony about all this is furnished by Holy Scripture , which tells us beforehand when it says , Their idols are silver and gold, the work of men's hands. Eyes have they and will not see; a mouth have they and will not speak; ears have they and will not hear; noses have they and will not smell; hands have they and will not handle; feet have they and will not walk; they will not speak through their throat. Like unto them be they that make them. Nor have they escaped prophetic censure; for there also is their refutation, where the Spirit says , they shall be ashamed that have formed a god, and carved all of them that which is vain: and all by whom they were made are dried up: and let the deaf ones among men all assemble and stand up together, and let them be confounded and put to shame together; for the carpenter sharpened iron, and worked it with an adze, and fashioned it with an auger, and set it up with the arm of his strength: and he shall hunger and be faint, and drink no water. For the carpenter chose out wood, and set it by a rule, and fashioned it with glue, and made it as the form of a man and as the beauty of man , and set it up in his house, wood which he had cut from the grove and which the Lord planted, and the rain gave it growth that it might be for men to burn, and that he might take thereof and warm himself, and kindle, and bake bread upon it, but the residue they made into gods, and worshipped them, the half whereof they had burned in the fire. And upon the half thereof he roasted flesh and ate and was filled, and was warmed and said: 'It is pleasant to me, because I am warmed and have seen the fire.' But the residue thereof he worshipped, saying, 'Deliver me for you are my god.' They knew not nor understood, because their eyes were dimmed that they could not see, nor perceive with their heart; nor did he consider in his heart nor know in his understanding that he had burned half thereof in the fire, and baked bread upon the coals thereof, and roasted flesh and eaten it, and made the residue thereof an abomination, and they worship it. Know that their heart is dust and they are deceived, and none can deliver his soul . Behold and will you not say, 'There is a lie in my right hand?' 2. How then can they fail to be judged godless by all, who even by the divine Scripture are accused of impiety? Or how can they be anything but miserable, who are thus openly convicted of worshipping dead things instead of the truth ? Or what kind of hope have they? Or what kind of excuse could be made for them, trusting in things without sense or movement, which they reverence in place of the true God?
Thanks for the question.
There isn’t a great answer. Overall, after reading this literature, I am not convinced that contrast has any effect on renal function (with the massive caveat that none of the available literature can really answer this question).
Patients with low GFRs were included in a number of these studies, especially the larger reviews. In patients with worse baseline renal function, you are more likely to find a creatinine elevation on repeat testing, but that might be completely explained by the larger normal day to day variance in creatinine in CRF patients.
Right now, I think the answer is the same for everyone (including patients with GFRs <30). If you need a contrast study for an important diagnosis, you should get it. If the study isn’t necessary, you don’t get it.