I've modified my stethoscope to double as a spiked flail.
Most of my coworkers just carry a small folding knife for utility purposes. I can't imagine anyone pulling one in a fight...it would take too long to tie their left hand to their opponent's and find a radio station playing Michael Jackson's "Beat It."
Never worked at a place that allowed self defense type equipment to be carried. A small locker is ok, but someone would likely have words with you if your waltzed in with a big ol' sheath knife. I know people that carry big flashlights on their belt, but that looks like a pain.
I have also worked with people that carried a gun on the ambulance and I was not entirely pleased by that.
In most places carrying any sort of weapon (and yes a knife is a weapon but let's leave that out) isn't going to be allowed. Boston EMS carries handcuffs but I never saw the need for that either, there's not much that Kerlix and a spitsock can't solve.
I'll largely agree with Merck, but I'll note that when I was working as a security guard in a BAD part of town, I successfully used my clipboard (The same one I carry now) as both a defensive shield and as an offensive weapon. You could probably do the same with a toughbook...but unlike my clipboard, it probably wouldn't still work as a toughbook after.
I've carried a gun every day for 10 years, yet, if I go into work as a paramedic, somehow people assume that I would somehow be a liability if I carried a gun.
I would love to be able to defend myself. I wish real life were like television where if you mind your own business and comply with bad guys, everything is ok. Unfortunately, a lot of people like Tom Givens or Claude Werner (former LEO/FBI guys) who are actually doing massive work breaking down the DOJ statistics are concluding that resistance rather than compliance with crime has higher survival rates.
Real life is not tv. People on tv walk up and give you a choice to hand over your drug box and then if you do, they leave you alone. In real life, criminals don't like witnesses. Even if you comply, you may still get injured or killed. I shouldn't have to jeopardize my own safety in order to help others.