# What's the nerve that is stimulated by intubation?



## G00CH 53 (Jun 19, 2011)

So my class is preparing for the dreaded NR! We have mountains of study guides. Some of these guides are based off of questions that other classes encountered on the test. Not to be sneaky, but here it is:

What's the nerve that is stimulated by intubation?

Now, all of us immediately thought it was the Vagus nerve, but apparantley that's not correct. Can anyone shed some light on this?


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## Lifeguards For Life (Jun 19, 2011)

G00CH 53 said:


> So my class is preparing for the dreaded NR! We have mountains of study guides. Some of these guides are based off of questions that other classes encountered on the test. Not to be sneaky, but here it is:
> 
> What's the nerve that is stimulated by intubation?
> 
> Now, all of us immediately thought it was the Vagus nerve, but apparantley that's not correct. Can anyone shed some light on this?



What were you told is the correct answer?

This sounds like quite a silly thing to be discussing in class. EMS dumbs things down to the point of being absurd and false.

Intubation, as well as several other practices can simulate a number of sympathetic, parasympathetic, cranial nerves innervating the hypopharynx, larynx, or trachea, each with their own predictable physiological responses.

To suggest that only one nerve is stimulated, furthermore to ask which one without describing what happens when it is stimulated is quite silly.


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## G00CH 53 (Jun 19, 2011)

Lifeguards For Life said:


> What were you told is the correct answer?
> 
> This sounds like quite a silly thing to be discussing in class. EMS dumbs things down to the point of being absurd and false.
> 
> ...



Couldn't agree more! Now as a class, and even our instructor, we all went through everything and really the Vagus nerve was the only thing that did make sense. Other than a gag reflex lol! So we're all still searching for the correct (answer).


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## usalsfyre (Jun 19, 2011)

While multiple nerves are stimulated, the vagus (cranial nerve X) is the one you use pretreatment to prevent negative effects from in the case of pediatrics.

Where are you getting your info from?


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## Lifeguards For Life (Jun 19, 2011)

usalsfyre said:


> While multiple nerves are stimulated, the vagus (cranial nerve X) is the one you use pretreatment to prevent negative effects from in the case of pediatrics.
> 
> Where are you getting your info from?



I'm pretty sure the vagus nerve was the only nerve really addressed in PM classes, was in mine at least. (with regards to intubation)


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## J. Burdett (Jun 19, 2011)

G00CH 53 said:


> So my class is preparing for the dreaded NR! We have mountains of study guides. Some of these guides are based off of questions that other classes encountered on the test. Not to be sneaky, but here it is
> What's the nerve that is stimulated by intubation?
> 
> Now, all of us immediately thought it was the Vagus nerve, but apparantley that's not correct. Can anyone shed some light on this?




There is a problem with that question. The vagus, hypoglossal, and trigeminal nerves are stimulated by intubation. Possibly the facial nerve also, I can't remember. So you weren't really wrong. If the question had read "What cranial *nerves* are stimulated by intubation?" your answer would have been incorrect.


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## usalsfyre (Jun 19, 2011)

Lifeguards For Life said:


> I'm pretty sure the vagus nerve was the only nerve really addressed in PM classes, was in mine at least. (with regards to intubation)


Because EMS seemingly refuses to take appropriate measures to counteract the negative effects of laryngoscopy. In the current educational model, if your not going to do anything about it, ignore it.

For NR purposes though it's nearly always the vagus.


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## G00CH 53 (Jun 19, 2011)

usalsfyre said:


> Because EMS seemingly refuses to take appropriate measures to counteract the negative effects of laryngoscopy. In the current educational model, if your not going to do anything about it, ignore it.
> 
> For NR purposes though it's nearly always the vagus.



Appreciate all the responses everyone!


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## MrBrown (Jun 19, 2011)

usalsfyre said:


> Because EMS seemingly refuses to take appropriate measures to counteract the negative effects of laryngoscopy. In the current educational model, if your not going to do anything about it, ignore it.



Brown is unable to find reference to such practice outside the US; it's not practised here by our Intensive Care Paramedics or Ambulance (PRIME) Doctors who perform RSI, none of Brown's associates who are Senior Anaesthetic Registrars or Consultant Emergency Physicians say it is necessary either.

Could it be that said negative effect is really somebody who does not know how to intubate properly and is being overly aggressive at fossicking around in somebodies gob?


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## Smash (Jun 19, 2011)

MrBrown said:


> Brown is unable to find reference to such practice outside the US; it's not practised here by our Intensive Care Paramedics or Ambulance (PRIME) Doctors who perform RSI, none of Brown's associates who are Senior Anaesthetic Registrars or Consultant Emergency Physicians say it is necessary either.
> 
> Could it be that said negative effect is really somebody who does not know how to intubate properly and is being overly aggressive at fossicking around in somebodies gob?



Actually it does happen.  On Page 87 of the 2009-2011 Clinical procedures the RSI protocol states to premedicate using IV fentanyl prior to administering other medications.  Most people are of the misapprehension that the fentanyl is used to assist with sedation.  Indeed, it probably does, but the actual rationale that an opiate is administered in RSI is to blunt the sympathetic response to laryngoscopy that can cause a spike in ICP.  I forget the exact doses required, it's something like 10mcg/kg I think, but you can completely eliminate sympathetic repsonse with fentanyl.  And of course, poking plastic into someone is painful, so it's a kind thing to do also.

Now, whether or not that is actually _necessary_ is a whole different matter.  There is scant evidence that any premedication helps mitigate changes in ICP.  I for one don't mind fentanyl, I think it is probably synergistic with the sedative, and as noted, intubation is painful, so I think it is kind as well.  Other than that... meh.


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## usalsfyre (Jun 19, 2011)

Smash said:


> I forget the exact doses required, it's something like 10mcg/kg I think, but you can completely eliminate sympathetic repsonse with fentanyl.


:blink: I would hope so....

Our dose is 3mcg/kg. The theory is exactly what's described above. Another option is lidocaine, usually given IV (pretty ineffective) but more effective if used as a topical when aerosolized through a nebulizer or MAD device. Ideally they'd be used in conjunction, it's all part of a "neuro protective" RSI strategy, although as noted above it's all theoretical. To really study this you'd have to have non-intubated patients with bolts in place...not very likely to happen.


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## MrBrown (Jun 19, 2011)

Smash said:


> Actually it does happen.  On Page 87 of the 2009-2011 Clinical procedures the RSI protocol states to premedicate using IV fentanyl prior to administering other medications.  Most people are of the misapprehension that the fentanyl is used to assist with sedation.  Indeed, it probably does, but the actual rationale that an opiate is administered in RSI is to blunt the sympathetic response to laryngoscopy that can cause a spike in ICP.  I forget the exact doses required, it's something like 10mcg/kg I think, but you can completely eliminate sympathetic repsonse with fentanyl.  And of course, poking plastic into someone is painful, so it's a kind thing to do also.



Correct you are sir ... although where did you get our Clinical Procedures? 

It seems Brown was a bit mis-rationaled :unsure:



Smash said:


> Now, whether or not that is actually _necessary_ is a whole different matter.  There is scant evidence that any premedication helps mitigate changes in ICP.  I for one don't mind fentanyl, I think it is probably synergistic with the sedative, and as noted, intubation is painful, so I think it is kind as well.  Other than that... meh.



Brown's agrees, Brown was specifically referring to atropine which notes seems to still be liberally used in the US.

Brown is a very strong proponent of sedation, and adequate sedation at that so a bit of fentanyl mixed with the ketamine seems like a good idea


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## usalsfyre (Jun 19, 2011)

MrBrown said:


> Brown's agrees, Brown was specifically referring to atropine which notes seems to still be liberally used in the US.


Atropine is still recommended in <1yr olds I think, but pointless in adults. What I was referring to was the godawful number of EMS agencies that think 5mgs of midazolam with nothing else is adequate for an RSI.


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## Lifeguards For Life (Jun 19, 2011)

MrBrown said:


> Could it be that said negative effect is really somebody who does not know how to intubate properly and is being overly aggressive at fossicking around in somebodies gob?



Brown, you gotta teach me to talk like this


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## MrBrown (Jun 19, 2011)

usalsfyre said:


> Atropine is still recommended in <1yr olds I think, but pointless in adults. What I was referring to was the godawful number of EMS agencies that think 5mgs of midazolam with nothing else is adequate for an RSI.



That is very sad. We use fentanyl plus midazolam for RSI in patients with neurogenic cause for coma with GCS =< 10, everybody else gets fentanyl and ketamine.



Lifeguards For Life said:


> Brown, you gotta teach me to talk like this



You mean like how we had this bloke who we reckoned had something in his gizzard go poof which made him fall down, but then we reckoned upon further nosey-ing that it was really in his noggin?


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## Smash (Jun 19, 2011)

MrBrown said:


> Correct you are sir ... although where did you get our Clinical Procedures?


 h34r:





> Brown is a very strong proponent of sedation, and adequate sedation at that so a bit of fentanyl mixed with the ketamine seems like a good idea



Absolutely, adequate sedation and analgesia is vital.  Analgesia is just as important as sedation, so I too shudder when I see services just using midazolam or the like both pre and post intubation.  It's barbaric and inhumane, and if the medics aren't capable or the medical director is not willing, to use proper RSI they should not be doing it all.  RSI is something that has to be done correctly or not at all, half-arsed just doesn't cut it.

Your protocols are actually quite good for RSI, Brown.  I particularly like that you can use ketamine if desired.  I'd prefer to see roc rather than sux, but that seems to be something that is slow to catch on down under.  I'm also not a fan of push dose sedation and analgesia.  I much prefer to have an infusion running to avoid peaks and troughs of both.  Bolus first as a loading dose, then run the infusion.


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## MrBrown (Jun 19, 2011)

Smash said:


> half-arsed just doesn't cut it.



Oh well looks like that's Brown buggered .... *Brown slinks away slowly


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## medicsb (Jun 20, 2011)

The internal laryngeal nerve, which is a branch of the superior laryngeal nerve, which is a branch of the vagus innervates the mucosa superior to the vocal cords to the base of the tongue.  

The sensory portion of the gag reflex along with taste in the oral pharynx is supplied by the glossalpharyngeal nerve (CN 9).  (Motor portion is the vagus)

Hypoglossal n.  (CN 12)  is purely motor.

Trigeminal (CN 5) provides pain sensation to tongue and oral mucosa, sans poster 1/3 of tongue.


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