I didn't mention this in my earlier reply, but I'll throw in a real-world example.

Driving up I-5 between LA and San Fransisco, I saw a large cloud of dust appear about 1-1.5 miles ahead. Pulling closer I saw a vehicle in the center median (2 lanes on either side, dirt patch down the center). Pulled over, and a car behind me did as well. She was a nurse, at the time I was just and EMT.

Go over to the car, one of the passengers is standing up, walking around, dazed, freaking out. Glance at her and walk to the one still on teh ground. Vehicle is upright, damage on sides and bottom, obvious roll-over. Patient on the ground is on her back, staring straight up, blood from nose/mouth, non responsive.

Crowd gathering from other vehicles. Eventually a doc and a few firefighters show up before the local cops and about 30 min later, EMS.

But in that time, the nurse and I gloved up, I had a gown on, used an ambu bag, c-collar, oropharyngeal airway, and did CPR for about 15 minutes til one of those FF's came and switched out. Blood spraying every time we squeezed the bag, got everywhere. Used my suction device (a turkey baster, works OK and costs a ton less than real medical supply) numerous times. We ended up working on her about 40 minutes til EMS got there, at which time they hooked up the EKG and the medics, along with the off-duty physician, called the code.

Someone at some point started to help the passenger, but I really didn't pay much attention.

So, my first aid kit has a LOT. But, all of it is EMT-B level. I do have an IV now, but don't really anticipate using it (heck, it might be expired).