PAD question; nerves in blood vessels?

[Plumrose15153, LPN]

I noticed that advanced stages of peripheral artery disease involves pain for the poor patient even at rest. In juxtaposition to patients new to the dx process in which rest relieves the pain and walking/movement exacerbates it. Could the rationale be due to nerves being irritated with movement of the vasculature?

[la_chica_suerte85, BSN, RN]

Well, if it's arterial, what kind of blood is carried in the arteries? If you cut circulation off to something and that blood isn't going where it should, why would it start to hurt? It's much more simple than things moving around and irritating nerves.

Peripheral Arterial Disease - Cardiovascular Disorders - Merck Manuals Professional Edition

[KatieMI, BSN, MSN, RN]

No, nerves are not getting "irritated" by muscle movements. Instead, they are rather being tricked into percepting very multiple results of hypoxemia and inflammation (elevation of lactate level, for only one example - imagine how your legs would feel next day after going your personal equivalent of triatlon) as pain stimuli. The abundant pain receptors in arterial walls work mostly in cases of acute thrombosis, not PAD, as far as modern evidence shows.

The question is, in reality, extremely interesting and we do not yet have much know about why under even mild hypoxia some people experience pain (often in parts of the body which are otherwise entirely normal), some experience surge of endorphins (the cause of euphoria many athletes experience while exercising, which is perceived by others as severe pain without any pleasure components whatsoever), etc. In any case, PAD- related pain is a really, really bad thing, as it is rather poorly treated by anything except nerve blocks. These poor souls pretty commonly have "residual pain" even after blood flow restored.

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.mdpi.com/1422-0067/16/5/11294/pdf&ved=0ahUKEwi7jpmRnJfPAhUMxYMKHUoIBUEQFghoMA8&usg=AFQjCNGtcCVhOxX-BRA1XVdyFaQ5Fq4diw&sig2=5z8tW0x7xedk6TfFDlq1wQ