Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

The 3 Nitro BS – Part I

Chris Kaiser of Life Under the Lights has written an article for JEMS called EMS Provider Questions 3-Dose Nitro Rule. This has also inspired Kelly Grayson of A Day in the Life of an Ambulance Driver to add his comments in Just So We’re Clear on the Concept . . . .

Clarity is the one thing that never was a part of treatment with NTG (NiTroGlycerin or GTN – GlycerylTriNitrate in Commonwealth countries).

Why have medical professionals stop at 3 NTG?

When I taught ACLS (Advanced Cardiac Life Support), I would tell the doctors, nurses, and medics taking the course that the reason is to encourage them to switch to IV NTG as quickly as practical.

In other words, I did the right thing – I lied. ACLS does not contain any explanation for this requirement. At one point, they left it out of the guidelines, but there was no explanation for this either. Yes, I did read the full guidelines, so when the What if . . . ? ninnies would criticize me, I could comfortably say, If you can find it, I will apologize and change my ways. Until then, you do not know what you are talking about.

I don’t know how tired their lips were when they finally stopped looking or if they ever did look beyond the ACLS flow chart for dummies algorithm that allows them to avoid reading the text. I never did have to apologize to anyone, because I knew what I was talking about and they did not know what they were talking about. Unfortunately, a couple of revisions ago, the 3 NTG rule was added back into ACLS.

There is still no explanation.

What did they have to say in the 2005 Guidelines?

Nitroglycerin
Nitrates are used for their ability to relax vascular smooth muscle. Nitroglycerin is the initial treatment of choice for suspected ischemic-type pain or discomfort (see Part 8: “Stabilization of the Patient With Acute Coronary Syndromes”).
[1]

Maybe there is some sort of footnote over there to explain this. If you read the text, there are footnotes for almost everything, because the AHA (American Heart Association) wants to show us what the evidence is for their guidelines. And they are not Standards Of Care – the ACLS guidelines are guidelines, which are meant to be deviated from when there is a good reason to deviate from the guidelines. I will look at that in Part II.

But first, the next sentence from the ACLS guidelines contains some important information –

IV nitroglycerin is also an effective adjunct in the treatment of congestive heart failure from any cause,55 [1]

From any cause –

Systolic heart failure and diastolic heart failure and when both occur in the same individual. There is no reason to worry about excluding diastolic heart failure, but we do need to continually reassess our patients.

Back to the problem of NTG witchcraft –

nitrate-induced hypotension typically responds well to fluid replacement therapy.[1]

Again, no reference to support this claim.

This is not medicine. This is alternative medicine.

Evidence – we don’t need no stinkin’ evidence!


Original cartoon

The truth is that nitrate-induced hypotension typically responds well to benign neglect.

It does not matter what we do – IV fluid boluses, Trendelenburg position, epinephrine, sing silly songs, watch Marx Brothers movies, eat chicken soup, et cetera. The nitrate-induced hypotension typically goes away before any of these treatments would have any effect – except the epinephrine, which is the final solution for cardiac chest pain/

The patient is temporarily hypotensive, begin the usual witchcraft!

Hurry up – before he gets better on his own!

Be very careful using dangerous treatments, such as IV fluid boluses, Trendelenburg position, or epinephrine. These all have dangerous side effects and are not as beneficial as benign neglect.

Remember, it does not matter what you do in the rare case of hypotension that follows administration of NTG – unless you do something baseless, reckless, and irresponsible such as IV fluid boluses, Trendelenburg position, or epinephrine.

What?

You disagree?

I am shocked/

Provide some research to support your claim.

No. Not some anecdote that you assume is related to the NTG, but actual evidence.

What?

There isn’t any?

I am shocked/

Is that because we give NTG so rarely that nobody could ever design a study to look at this?

Are we really that gullible?

I am shocked/ I think I need a nitro, but first some protective epinephrine, a bit of Trendelenburg position, and a nice fluid challenge to ward off the evil spirits.

To be continued in Part II and maybe several more parts.

Footnotes:

[1] Nitroglycerin
2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care
Part 7.4: Monitoring and Medications
Medications for Cardiovascular Support
Free Full Text with link to PDF Download

These are the 2005 guidelines, but they do not contradict the 2010 guidelines.

.

Comments

  1. interesting article. having been a nurse for about 25 years i did see a grain of something resembling truth in it. for most of it, you have managed to rehash the obvious. if you think of it, nitroglycerin does not have the half life, of say, plutonium, and the effects will wear off sooner or later. and unless someone is severely symptomatic from preload reduction and subsequent hypotension, there is not much i would do. it does go without saying that in the event of what may be a right sided mi, i would not use it anyway. and the aha guidelines are just that-GUIDES. none of this is holy writ, or any other kind of writ.

    • SEAN,

      interesting article. having been a nurse for about 25 years i did see a grain of something resembling truth in it.

      What parts do you think are not true?

      for most of it, you have managed to rehash the obvious.

      If it is so obvious, then why do so many doctors, nurses, and medics defend this 3 nitro limit?

      if you think of it, nitroglycerin does not have the half life, of say, plutonium,

      People generally don’t think about it. They worry. They avoid things that make them worry. Patients receive inadequate care.

      and the effects will wear off sooner or later.

      People are afraid that it will not wear off until it is “too late.”

      and unless someone is severely symptomatic from preload reduction and subsequent hypotension, there is not much i would do.

      Never mind doing “not much,” you shouldn’t do anything to the patient.

      it does go without saying that in the event of what may be a right sided mi, i would not use it anyway.

      In the event of RVI (Right Ventricular Infarction), the patient should be preloaded with a lot of fluid before giving nitro. Dry lungs are one of the expected assessment findings of RVI.

      and the aha guidelines are just that-GUIDES. none of this is holy writ, or any other kind of writ.

      Unfortunately, there are a lot of doctors, nurses, and medics who view guidelines as rules that must not be deviated from. This is part of the reason for writing about this.

      .

  2. the truth to me is in the reason for writing this in the first place. the truth is, it is redundant and anyone with any clinical expertise knows this and does not need reminding of what what you wrote here. that is the grain of truth to which i was referring. you are right about some things, though. hydrating someone with a right sided mi is beneficial before giving nitrates to avoid hypotension. and as far as not doing anything, what you would do is watch. if someone is responding to a treatment with what are known effects of the treatment, i would observe and monitor that person to see how far this response goes and what needs to be done about it. that’s the care they need. it is not inadequate, but highly attuned to the situation at hand. one of the good things about nitro is that it can be TURNED OFF. the half life is short and people usually respond to what could be a decent perfusing pressure when you do. but there is danger in doing this as well. applying and removing the same exogenous stimulus is not therapeutic. i think it gives people the idea that we are doing something, as your article mentioned.

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