I don't tend to carry any 1st aid gear (but 2 of my coworkers tote a lot of it), but I do always have latex gloves, more for roadside mechanic work but would serve for medical use if needed.

edit-> looking at that link reminds me a of a friend who got hit by a car while commuting and got a compound fracture of his femur, and he was worried about the bone pieces cutting his femoral artery. I don't know what to pack for that; he just clamped his hand on his upper thigh until EMTs came. I guess if you had tourniquets you could ask someone to help apply it.

Would you use a tourniquet if you didn't know an artery was cut?