Question about sensitivities

Hey all--this is sort of a micro question, don't know if anyone here will know but thought I'd put it out there.

I'll give a little context for my questions--I am an inpatient NP and I work on a surgical team. Many of my patients have chronic wounds. I also take care of a lot of paraplegic patients with chronic indwelling catheters. I spend a LOT of my time managing patients with infections, and some of my patients are chronically colonized with some nasty resistant bugs. I work with infectious disease a lot, and some of my patients are treated very aggressively with multiple antibiotics, and some we are very conservative with--it usually depends on the clinical status of the patient. The data I have to work with is very important for managing these patients. Obviously, vital signs, patient history, general status, wound/urine appearance, etc. And then there is the all important culture data.

And here is where my question is--

When a specimen is sent for culture and sensitivities, what determines which bugs will actually get MICs tested? I find that staph aureus, e. coli, and enterococci are pretty much always tested, and sometimes alpha and beta heme strep are. Less often are coagulase negative staph tested and corynebacterium are almost never tested without specific request. My feeling on it is, hey, there is a bug growing, we should find out what antibiotics cover it. I know that coag neg staph is often a contaminant as are some other bugs, but when you have like a deep bone culture from the OR, if there is micro growth it is probably real. Especially if the patient has clinical s/s of infection. Additionally, I am wondering why oral agents aren't automatically tested in some cases. I find myself encountering situations where a patient has osteo, or deep tissue infections and I either don't have any sensitivity data OR I don't have sensitivity data for any oral agents.

It is very frustrating to have a patient's discharge held up because, even though we waited 3 days for culture growth, for some reason certain microbes had no MICs tested so I have to specifically request them from the micro lab. And if I don't ask "please test with agents that can be given orally" maybe my final culture data will show 3 bugs that can be covered by a quinolone, but the diptheroids for some reason were only tested with pcn (and it's resistant), vanco, and gent...so, the patient needs to either stay in the hospital till we request further sensitivities, or we have to have them follow up in a few days, hopefully to give another oral agent and not to place a picc.

I've had some weird conversations with micro--they don't seem to understand my goal (get the patient an appropriate oral regimen or get a picc if needed)--I mean, the information they give me literally directs patient care in many cases. I feel like I'm missing something. Does anyone here encounter situations like this or know what I'm talking about?

Thanks for reading,

Kan