There's a lot of small issues within the dialogue, easy to miss, but could do with correcting. For example, Nurse Lweis' first line "I know there is something going on" could do with being "I know there's something going on". Then "There is something very odd going on around here", same problem. I noticed a few of these throughout the script, and tightening them up could make the dialogue sound more realistic.
The meaning in the line that Murdock mentioned "This makes five in the last six months that even I’m aware of" could be straightened out with a simple comma to indicate a pause... "This makes five in the last six months, that I'm even aware of". I've also switched around "even" and "I'm", although the "that even I’m aware of" could be removed altogether.
All in all though, I like this and I'm interested to see what happens next. But... If this is the opening scene of a feature, it just doesn't feel right. It almost seems like there should be a scene or two before this, at the moment it seems like you're just shoving these facts at us, via the voices of these two people and the facts don't really relate to anything.
Perhaps the opening scene could be Nurse Lewis and her team trying to revive a patient, the patient dies, Nurse Lewis asks "Who was overseeing this mans treatment?", somebody checks the charts and replies "Doctor Kamatayan", BAM!, we're into this scene. Of course, you may have already done this... there's a number 3 at the top of every page on the doc...
Good start though, hope to see more!