If CB has TOS??- she might have the venous type- where the compressions will tend to block off the blood supply.
{ swelling/color changes happen often with that version of TOS & and a tendency for possible clots- so the need to get it sorted out is important}

There can be arterial, venous, nerves, and various anatomy that could be causing compressions. Could be scalenes, pec minor, out of the norm large bones or ligaments, etc

CB are you reading on the TOS forum too? useful links and such?
Members on both RSD & TOS forums have both- so they might be able to help you sort out the differences.

ps - with TOS raising the arms up or out too far will cause the blood flow to be stopped in the arms - mine will stop in 30 sec if I do the "stick em up" "test" like being robbed or arrested
my TOS is mostly mild/arterial