I was also debating on whether to entirely skip the setup and drop directly into the POV of the protagonist as he is coming to at the hospital, or maybe start with smatterings of consciousness as he is brought in, but this seemed like it would be too confusing. Anyway here is the first 13..

SECOND CHANCE

The air was brisk and clear, a typical October night, the wind rustling through the dying leaves and crickets chirruping serenely in the forest. Harsh lights illuminate the UAB West emergency entrance.

A heavyset black security guard leans comfortably on the beige brick of the front wall, his fleshy left hand gripping a worn and well read paperback, his right hand periodically moving a smoldering cigarette up to his mouth and then mechanically flipping the ashes onto the ground. The guard stretches, exhaling a long stream of smoke into the moist night air, he glances briefly at his watch, noting it's 3:00 AM, his shift half over. He returns his gaze to his grubby book and takes another drag on his cigarette. Sliding doors beside him open and a petite young black woman, in nurses pink scrubs, pokes her head out.

“Car crash coming in Horace, might wanna finish your break.”, she chides, then slips back into the lobby and returns to her seat behind the admissions desk.

OK. I'm OK with coming at this first scene from the POV of someone who is going to be (I assume) unimportant to your story. I've done that a couple of times myself. Just be sure you don't penetrate too deeply into who they are or I'll want them to become important. No last names, no time spent making us really care very much about them or how they feel or how hard their lives are or what they look like.

About the POV switch, make sure it happens at a natural breaking point--a chapter or scene break.

And if you wrote the protagonist's POV in smatterings of consciousness I think I would be very annoyed with you. In fact, if you wrote from his POV without him being "all there" I'd probably have a hard time believing that he is aware enough to be a reliable Point of View from which to show the scene--what with all those pain killers fogging his mind and such.

About your fragment, it's not bad.
The first line bothers me a little, for a couple of reasons:
1. The first line begins in past tense, but the rest of the fragment is in present tense. And I'd question the wisdom of writing in present tense, mostly because I don't particularly like it--which would make it my opinion, I suppose.
2. That first line tends to contradict the setting for the rest of the scene. You introduce me to fall in the forest, then zoom in on a hospital emergency room entrance. I don't normally associate forests and hospitals. If you want me to you've got to get me there with some more in depth scene-setting.

1. The name of the hospital having initials immediately jerks me out of the story.

2. Okay, I know you are going to roll your eyes at this but please - Can you consider not saying "black security guard"? It is depending on stereotype to build your character. Say something like "very dark skinned" or "yellow toned" or something besides just black. Some African American men are insulted to be called just "black." (I know a guy from south africa who is insulted to be called "african american" and then says "I'm a black African!") It is just touchy. Find another way to describe your characters as individuals instead of stating their race off the bat. Also, its like saying we have nurses and then we have black nurses -- see the problem there? No, I am not being oversensitive.

I understand the issue with "black", obviously being a white male I tend to be less aware of those issues than someone that isn't a white male. Replacing it with ebony skinned or something to that effect would definately be better.

Ask yourself, are their racial characteristics critical to the story? If not, then perhaps it would be best to let the reader apply their unconscious assumptions and/or stereotypes to the story. No need for you to do it, when we're all so clearly capable of jumping to assumptions or stacking up stereotypes on our own.

One of the best examples I've seen of this is in one of Sue Grafton's books (no idea which one). She writes something along the lines of "The electrician came at 9:00. She was done half an hour later." This totally unobtrusively slips in the gender information - a sentence like "The female electrician came at 9:00" would be just awful.

Saying "The black security guard" follows the same pattern as "the female electrician" but it is way harder to work in race information than gender. I don't know how to do that - but "black security guard" has the same overtones to me as a phrase like "female electrician" or "girl mechanic" would.

I don't think I'm explaining this right. But would you ever write "the white security guard"? No. (unless to distinguish him from his black coworker, maybe.)

Racial characteristics are a slightly special case, of course, but not that special. Just as it is a bad idea to hit the reader over the head with loving descriptions of absolutely trivial matters such as the hairstyle and eye-color of various characters for no reason other than because the author hopes that specific actors will play those roles when it is made into a movie, so too skin-color/eye-shape/nose-length.

Now, the fact that he's a heavyset smoker leaning against the wall while he reads a paperback tells us something possibly important about the scene, so I don't have a problem with it. I suppose that the fact that the nurse is "petite" might be interesting if that implies that she is unusually physically attractive. Since petite is used this way in certain circles, it could pass...but only with people who understood "petite" to mean "almost a supermodel", which is hardly the entire English speaking world.

Both characters are basic wind dressing to make the hospital entrance a little more interesting and from my visits to the late night emergency room, I can say that an overweight security guard smoking is pretty much the norm around here.

On the issue of petite, it was simply there to give an idea to the reader what she may look like. In my personal experience most nurses (yes this is a generalization) are, um, heavy set, due to the amount of time they spend at the hospital and the lack of time they have for physical exercise. Also they generally have to eat on the run and tend to have to eat less than healthy food. So by describing her as petite I was conflicting the image of a late night desk nurse that in my mind and I assumed that of the readers mind. A clear situation of my own personal experiences unnecessarilly coloring my writing.

I know there are some significant tense problems. I've gone back a tuned different parts at different times and haven't sat down and gone through the whole thing to unify the tense. I know that's a pretty lame excuse...