Superior Laryngeal Nerve Block

[powermd]

---

Members do not see this ad.

Can you get recurrent laryngeal nerve anesthesia from a SLN block? If so, does it manifest as hoarseness/stridor/adducted cords? Much as we talk about this block, and read about it, I never performed one in residency, since none of our attendings routinely did it for fiberoptic intubations. I'm planning on adding it to my armament for the oral boards, and perhaps for actual practice too, so I'd like to have a better feel for possible complications.

What's been your experience with this block?

 

[maceo]

recurrent nerve is blocked with a simple transtracheal block with 4 percent lido. very effective

I dont believe you can get the rln with a sln nerve block. The sln nerve block when i do it i walk off the hyoid bone and inject a small amount of local there bilaterally. I rarely do this ever.

 

[Jeff05]

RLN may be effectively blocked by anesthetizing the tracheal mucosa that it innervates with a transtracheal block.

the SLN may be blocked by holding some viscous lido soaked qtips in the pyriform fossa.

 

[powermd]

RLN may be effectively blocked by anesthetizing the tracheal mucosa that it innervates with a transtracheal block.

the SLN may be blocked by holding some viscous lido soaked qtips in the pyriform fossa.

If you block the RLN bilaterally, why don't you get stridor?

 

[Planktonmd]

If you block the RLN bilaterally, why don't you get stridor?

A transtracheal block is basically blocking the sensory nerve endings of the recurrent nerves it also causes a motor block to the vocal cords but that motor block is not complete or dense enough to cause stridor.
If you block the recurrent nerves directly (like what happens if a surgeon injects local anesthetics in the thyroid area after thyroidectomy) then you will get a complete motor block of the cords and stridor.

 

[powermd]

A transtracheal block is basically blocking the sensory nerve endings of the recurrent nerves it also causes a motor block to the vocal cords but that motor block is not complete or dense enough to cause stridor.
If you block the recurrent nerves directly (like what happens if a surgeon injects local anesthetics in the thyroid area after thyroidectomy) then you will get a complete motor block of the cords and stridor.

Thanks Planck, what I'd really like to know is what is the risk of getting a complete motor block of the RLN with a superior laryngeal block. It would seem to me that 5 mL of local at each site could certainly be enough to track down to the RLN.

 

[Planktonmd]

Thanks Planck, what I'd really like to know is what is the risk of getting a complete motor block of the RLN with a superior laryngeal block. It would seem to me that 5 mL of local at each site could certainly be enough to track down to the RLN.

Correct.
And this is why many people limit the amount to 2-3 cc on each side.

 

[CanGas]

I don't know about the US boards but the general rule for the Canadian boards is don't do anything that you have not done before. It is completely obvious when an examinee is talking about something they have no practical experience with. Sure for the rare complications and procedures, state what your book learning tells you but tell me this, if you have made it through 3 years of residency (and how many awake FOB intubations) WITHOUT ever doing a SLN block, do you really think it is necessary to do one on your orals?

Here at least the examination is one of competence and not looking for all the fancy stuff. My best strategy is to just visualize the patient there in front of me and just say what I would usually do.

CanGas

 

[Planktonmd]

I don't know about the US boards but the general rule for the Canadian boards is don't do anything that you have not done before. It is completely obvious when an examinee is talking about something they have no practical experience with. Sure for the rare complications and procedures, state what your book learning tells you but tell me this, if you have made it through 3 years of residency (and how many awake FOB intubations) WITHOUT ever doing a SLN block, do you really think it is necessary to do one on your orals?

Here at least the examination is one of competence and not looking for all the fancy stuff. My best strategy is to just visualize the patient there in front of me and just say what I would usually do.

CanGas

Excellent advice.