shotgun knowledge from emergency geniuses

[tarotale]

It's been about 4 months or so since i transitioned into ED, and there are things we do routinely but i don't know why we do them. so i am just going to ask any random things I have been curious about here for shotgun answers; it would be nice to know the complete details, but whatever you can afford! For example, I asked surgery residents why they prefer LR over NS, and they basically said it's "voodoo bs"/tradition (lol).

1. Lactic acid: I know it's usually drawn in conjunction with bc, and if it means high, there's some infection going, but can you explain little bit more about that?

2. Why does ammonia and lactic acid have to be on ice (was it prolactin too?)

3. What are they checking when they do US free fluid in traumas? Obviously checking for fluids but where and why?

4. Ammonia induced encephalopathy, what's the pathology and how does it resolve with NG tube?

5. How does physician decide to give fluids to someone? Obviously someone who has CHF or on dialysis won't be getting any, but a healthy adult who came in for nvd, tachy, abd pain would most likely get some fluids, but what's the doc's guidance in who gets fluids?

6. How can you assess for appendicitis and gall stones? our ed doc told me to push on the opposite side of painful abd and if pt has pain, that could be a sign, but really, I'm interested in osteopathic manipulation (something DOs get trained in I hear) to lightly assess for couple important things.

That's all the questions I have so far. Let me know if you got any shotgun answers. Thanks!

[tarotale]

Everyone discussed great points for lactic acid indicators and the pathology of it. For US, it is important for a trauma because it provides information on where there is internal organ trauma especially and where it is.

Also, CO=SVxHR ; SV=preload, contactility and afterload. During hypotension, first thing I see is fluid resuscitation which improves preload. CVP is a diagnostic tool to evaluate preload. Secondly, with lactic acid. CHF,Renal failure and/or cerebral edema MDs use fluid resuscitation cautiously. If preload does not improve, afterload or contractility is what they target...pressors are used. Depending on what type of shock, indicates what pressor is used. MDs USUALLY never Rx pressors without filling the intavascular system d/t greater harm you can do with them.

I hope this helps.

sure did. makes sense why most of times we rarely see pressors but almost all the time, fluids start first.

[PedsED-RN]

US for trauma, looking for free fluid in abd help identify internal organ damage, as either something is bleeding (and how much based on amt of fluid), or perfed bowel leaking bowel contents into the peritoneum, etc. Gives an idea before something more definitive like a CT, but can be done at the bedside while other interventions are underway. I have read some articles on some docs questioning the true value of FAST exams, but it's non-invasive, no radiation, so why not?

I think the other questions were all pretty thoroughly answered so far, good luck =)