Usage of "a"

[Our Tort System]

Hi,
Just came across this sentence:

A freshly showered, shaved, and uniformed Lieutenant Keyes pulled himself into the room and sealed the pressure door behind him

Is the word "a" required here, or can we dispense with it?
If we can dispense with it, how would the meaning of the sentence change with it out?

Thanks!
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If it's not easy, don't do it!
That's how I got where I am.

[Beeesneees]

Freshly showered, shaved and uniformed, Lieutenant Keyes pulled himself into the room and sealed the pressure door behind him.

Note the additional comma in the alternative sentence without the 'a'.

The basic meaning of the sentence doesn't change without it. The technique of adding the 'a' is a subtle one used by the author to add interest to the sentence. It is the same as saying,
It was a freshly showered, shaved, and uniformed Lieutenant Keyes who pulled himself into the room and sealed the pressure door behind him. It is in contrast to the state of him the last time we saw him in the story. I suspect that before this, he was either in the act of showering, about to step into the shower or looking rather grubby, dishevelled and in need of a clean-up.

It's hard to explain any clearer than that because it is so subtle a difference.
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Cheers m' dears!

[Our Tort System]

I think I see what you mean, Bev
Thanks for help!
_________________
If it's not easy, don't do it!
That's how I got where I am.