Nitro is just symptom relief?

[Off Label]

https://www.ncbi.nlm.nih.gov/pubmed/26024432

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4665872/

To the OP, there is some evidence that challenges the directives you posted. Here are just two, the first being just an abstract, sorry. You very well may have a point in the extremely conservative use of the drug in the pre-hospital setting. People are prescribed NTG and walk around with it in their pockets every day.

The problem is that when an agency writes a policy or directive, they own the problems with it and must justify the difficulties with it. I'm with you in principle. At the very least, as an antihypertensive in the setting of subendocardial ischemia, NTG, if it is all there is, is pretty valuable.

[paramedicmike]

Literature is mixed at best.  For everything one can find in support of it, and there is some that seems to show evidence in support of NTG use in ACS, there is other evidence that shows no clear benefit.  I found these as a nice review of the literature.  They're pretty current with updates completed last year.  Sources are cited.

Relief of Chest Pain with Nitroglycerin - Is it Predictive of Coronary Artery Disease or Cardiac Chest pain?

Nitroglycerin Use in the Initial Management of Ischemic Chest Pain From Acute Myocardial Infarction

As Off Label has noted there is a demonstrated benefit to NTG in certain circumstances.  What's not clear, and more to the point of the OP, is if there is any benefit to it's use prehospitally in ACS.

Going back to the original questions asked by the OP specifically regarding therapeutic value.  Pain relief can indeed be therapeutic (barring any additional or unintentional side effects from the meds).  However, given how the rest of the conversation has progressed so far I'm not convinced that pain relief is the kind of therapeutic value being chased by OP.  Also as OP has directly asked, "Does it increase prehospital survival rates like ASA?"  The evidence doesn't clearly support this.  There is some evidence to suggest it might (in an exceptionally small number of people over 48 hours if used early enough).  But there is nothing out there that clearly states "NTG use in prehospital ACS treatments saves lives".  If there was we wouldn't be having this discussion.  OP wouldn't be having the discussion with his/her medical director and governing body.  If there was evidence we'd be doing it with every ACS patient we encountered. 

Disappointing as that may be for all of us who have dedicated ourselves to doing the right thing, or what we thought was the right thing, for our patients we work with what the literature shows us: There is no evidence it saves lives in the field.

When what we do every day is an effort to save people's lives that idea can be a bitter pill to swallow (or let dissolve under your tongue).

I'm still intrigued by the idea of a RCT on prehospital NTG use and outcomes. 

[Off Label]

21 hours ago, paramedicmike said:

  But there is nothing out there that clearly states "NTG use in prehospital ACS treatments saves lives".  If there was we wouldn't be having this discussion.  OP wouldn't be having the discussion with his/her medical director and governing body.  If there was evidence we'd be doing it with every ACS patient we encountered. 

Disappointing as that may be for all of us who have dedicated ourselves to doing the right thing, or what we thought was the right thing, for our patients we work with what the literature shows us: There is no evidence it saves lives in the field.

When what we do every day is an effort to save people's lives that idea can be a bitter pill to swallow (or let dissolve under your tongue).

I'm still intrigued by the idea of a RCT on prehospital NTG use and outcomes. 

But there's no evidence  that it doesn't, and more importantly, that, as used, that it does harm. And that is really a large part of the nature of medicine in general. Remember MAST pants and how everyone thought we were doing such a great job using them? We were also so convinced 20 years ago that we had volume resus in trauma figured out and that has been completely re-thought.

At the end of the day, though, there is a net increase in survival across the board, despite ourselves. Something is working.

[paramedicmike]

I agree with your points.  I'm not saying don't use it when indicated.  I'm answering the OPs questions as directly as I can.  Does it save lives?  There's no clear evidence that it does.  Does it have therapeutic value beyond pain relief?  There's no clear evidence that it does.  These are the same positions held by the OP's medical director and governing body.  Based on the current literature this is what we have to work with.

I also don't think that improvements we're seeing are despite ourselves.  Research advances leading to practice changes (e.g. ASA use), more emphasis on door to balloon (or, more importantly, symptom onset to balloon as is being practiced in some areas) and more all contribute to a better patient outcome.  We, all of us from specialists to the grunts on the streets, are collectively working towards improving patient outcomes.

At the end of the day the evidence we have to support our practice is one of our biggest justifications as to what we do and why.  It can defend or support us medically and legally.  Yes, there is much in medicine yet to be studied to the point of showing clear benefit or detriment.  Yes, there seems to be a dearth of EMS oriented evidence based medicine.  Yes, new evidence will change our practice.  Yes, in many cases we continue to go with what seems to work despite clear evidence one way or another.

Let's be clear, though.  OP asked a couple of specific questions in what appears to be a quest to support an idea not shared by either his/her medical director or governing body.  The evidence we have is the evidence we have.  Until the questions posed are studied more specifically we have to go with what we have available.  And what we have available supports both the medical director and governing body.

Lastly, since we're sharing research links, I also found this from December, 2015.  Interesting read.  I learned a few things.  And that's what we do.  We read.  We study.  We learn new things (even if we sometimes don't like what we're learning).