continue nitro after no relief from pain?

medicaltransient

medicaltransient

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I just cleared up from a call where my pt refused the 2nd round of nitro after the first round did not effect pain. The pt had a change in morphology on the shock room table and a stemi alert was called. I have read conflicting reasearch on the effectiveness of nitro via google scholar. I was once reprimanded for not continuing nitro on a pt that got asa, 1 round nitro, heparin, brelenta and 100 of fentanyl.

Do you guys continue to give nitro if it is not effective in decreasing pain?
 
In general, i would definitely continue nitro even if the first dose was ineffective if I am treating cardiac pain...but not if the patient refuses. Document document document
 
Depending on protocols, nitro x3 then move on to fentanyl. Nitro has no real data backing it's efficacy, but a big goal is to have the pt in as little pain as possible. If they refused more than 1 dose, I'd go straight to an analgesic.
 
After 3 I usually alternate between nitro and (we only carry morphine) 2mg morphine until pain is gone (bp ect) or we get to the ER
 
If it's not helping then I don't see a reason to keep giving it. I usually try to get two NTG doses before going to Fentanyl/Morphine, though depending on their presentation I sometimes go straight to narcotics.

Also, you carry Brilinta and heparin?
 
So are you giving Nitro as an analgesic or to reduce preload and thus reduce myocardial oxygen demand?

For those that abandon nitro after three sprays, how do you know the patient doesn't need a therapeutic dose of 6 or 8 sprays before we bring the mvo2 low enough to reduce the pain sensation? When people are on NTG infusions of 200+ ug/min, that is a whole lot more than 1 SL spray every 3-5 mins. The whole magic "three sprays" was inadvertently adopted by the EMS community as some sort of bench mark ... it originated from instructions given to patients with a NTG Rx, ie, "if you take three sprays and the pain doesn't go away you should call 911." It was never intended to serve as a treatment guideline for health professionals.


Just my 1.7 cents (exchange rate)
 
The primary reason for NTG is vasodilation, to hopefully increase perfusion to the cardiac muscles. Not to decrease pain- pain relief is a good side effect and a good indicator that it is working. I would talk the pt into taking the NTG, and document thoroughly if they still refused

I prefer MS over fentanyl due to its superb ability to increase venous capacitance, reduce preload, and thus reduce myocardial O2 demand. Again, pain relief is great and a goal, but reperfusion and reducing the workload of the heart is my ultimate goal.
 
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Always continue NTG; I also tell the patient it is NOT for pain relief but to help relieve the work the heart is doing.

Never had anyone refuse more doses
 
Would I continue to use NTG after "no relief" occurs after just one dose? Yes, as long as the patient doesn't refuse and still refuses after being told why we use it. Pain relief with NTG, if it occurs, is a nice benefit but I would expect that opiates would do a far better job of that.
 
Thanks guys! I think I'm going to practice giving it more aggressively for only definite cardiac in etiology pain.
 
My understanding is that NTG actually has a minimal effect in increasing blood/oxygen supply. This is because diseased coronary vessels are obstructed and already maximally dilated, so are affected little by NTG. The primary benefit of NTG is on the demand side of the equation: myocardial wall tension is decreased due to reductions in preload and (to a lesser extent) after load. Also, flow in the smaller vessels likely is increased via reductions in wall tension.*

I used to think that the higher BP limits you sometimes see in NTG protocols were overcautious. In reality though, they make sense: if NTG doesn't actually dilate the coronaries much, then coronary perfusion in these patients is MAP dependent. You only get so much benefit from reducing wall stress, after that, by lowering BP further you are just reducing the driving pressure from the aortic root into the coronaries. Considering NTG hasn't been shown to really work, it makes good sense to be selective about who you use it in.

As for whether you should you keep giving NTG if it doesn't seem to be helping the pain, it makes much more sense to me to target a change in BP than it does an arbitrary number of doses. Say, a drop in MAP of 20%, not to go below a MAP of 70. Something like along those lines. Of course it's very difficult to "titrate" a BP with SL tabs.



*This actually may explain why studies have (so I'm told, I haven't read much about this myself) found little benefit from NTG, though it appears to many to help a lot in some conditions: most patients with severe CAD will have imbalances in Mvo2 supply:demand that can't be adequately fixed by attempting to reduce demand through NTG; you need to increase supply and nitro isn't as good at that as we used to think. On the other hand, patients with a lesser degree of disease or those who imbalance is due more to increased SNS tone may appear to benefit from NTG. Or maybe those with better collateral vasculature do benefit from increased supply due to NTG, and this is just a fairly small subset of patients. Without having read the literature, I suspect that NTG does benefit certain subsets of patients, just not the CAD population as a whole. I don't know if any of this is true; just thinking out loud here.
 
Heh, I just read this post the other day and then I read the updates for the protocols in Santa Clara County. They just changed it to this.

Administer Nitroglycerin 0.4 mg SL/TM every 3-5 minutes to a max of 5 doses, as long as pain persists, and if SBP is above 100 mmHg
Click to expand...
http://www.sccgov.org/sites/ems/Documents/emsupdate2015/Module2Protocol.pdf Page 4 That part is literally bolded just like in my quote.

My preceptor and I had a discussion about this, but since we both agreed that the goal of NTG isn't really to get rid of pain, it wasn't a very long discussion.
 
Thurston county in washington state has protocols to continue giving nitro i think every 3-5mins untill there is either relief or the systolic bp drops to <90 or close to it.
 
RefriedEMT said:
Thurston county in washington state has protocols to continue giving nitro i think every 3-5mins untill there is either relief or the systolic bp drops to <90 or close to it.
Click to expand...

The same in Delaware. When reviewing charts it was common to see paramedics administer 10+ SL NTG on longer transports.
 
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