If you've got to deal with medical equipment on a regular basis, carry a few tools along with you so you can make small repairs as necessary. Allen wrenches are particular useful, since most braces, walkers, and wheelchairs are keyed to them.
Maintain a log of correspondence with your medical equipment vendor, and keep all your receipts, estimates, and all other paperwork. This information will be invaluable in the event that your medical equipment is not delivered when you need it.