USG axillary block

[Antibiotix2006]

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Interesting article last month on ultrasound blocks.

http://journals.lww.com/anesthesiol...n_of_the_Minimum_Effective_Anesthetic.10.aspx

Any of you attempt to recreate this? I usually do about 6-8 mls for the interscalene and a little more for the axillary but have never gone down to 1 ml/nerve. Itching to try it out though 😀

What are the minimum amounts of LA you have used for various blocks?

 

[kmurp]

I am curious. We just got an ultrasound am I am attempting to get comfortable with it. OK so far. I too am interested in to opportunity to decrease volume. For shoulder surgery, I also want to maximize pain control postop.

So, my question is, what duration of pain relief do you see with an ISB with less than 10ml of local?

 

[periopdoc]

Exactly why would I want to use the smallest amount of LA possible in a low risk block like this? To increase the risk of a failed block if sub-optimally placed? To increase the risk of the block wearing off before the surgery is over?

It is interesting to see what you CAN get away with, but is reminds me of the studies of LMA for obese people getting laparoscopic surgery. Interesting, but why would I want to apply that to my practice?

- pod

 

[Planktonmd]

Exactly why would I want to use the smallest amount of LA possible in a low risk block like this? To increase the risk of a failed block if sub-optimally placed? To increase the risk of the block wearing off before the surgery is over?

It is interesting to see what you CAN get away with, but is reminds me of the studies of LMA for obese people getting laparoscopic surgery. Interesting, but why would I want to apply that to my practice?

- pod

👍
Well said.

 

[Antibiotix2006]

kmurp : depending on the additives and concentration, anything from 12 - 24 hours. Anything more and the orthopods get worried.

Periopdoc : Why would you want to give a larger dose of a drug if you can get just the same effect with a smaller volume and change of technique? If the findings of that article can be replicated consistently why not embrace the change? Do you give drugs to a patient just because you 'can' ?

 

[Planktonmd]

kmurp : depending on the additives and concentration, anything from 12 - 24 hours. Anything more and the orthopods get worried.

Periopdoc : Why would you want to give a larger dose of a drug if you can get just the same effect with a smaller volume and change of technique? If the findings of that article can be replicated consistently why not embrace the change? Do you give drugs to a patient just because you 'can' ?

Volume is a security measure to make sure that your block is going to work well and long enough.
Most people work in an environment where a failed block creates too much disruption and wasted time that I doubt they will feel comfortable with these exotic small volumes with or without ultrasound.
But, if you are in a teaching institute and you don't have surgeons breathing down your neck while trying to do these blocks, I think you should by all means try every exotic technique imaginable and please make sure you tell us about your results.

 

[periopdoc]

Periopdoc : Why would you want to give a larger dose of a drug if you can get just the same effect with a smaller volume and change of technique?

Because minimal effective drug dosage is only one of the considerations I have when determining how I will perform a particular procedure. I also consider the time it will take me to perform the procedure, the risk that if my technique is suboptimal the results will be suboptimal, and most importantly the real and theoretical risks of using a higher dose.

If this were a study that demonstrated a smaller minimum effective dose of local anesthetic for cervical transforaminal injections or cervical sympathetic blocks, I would be "itching to try it out" even if it added 5-10 additional minutes to my block time. The therapeutic window is small enough to make dose the primary concern.

For an axillary block, minimizing the dose is really low on the priority list because the therapeutic window is so big. If a different technique takes an additional five minutes of time then it isn't worth it for such a low-risk procedure, especially if it ultimately turns out that the technique has suboptimal results for some patients.

If the findings of that article can be replicated consistently why not embrace the change?

Fallacious argument #1.

They have not been replicated yet, but if they are I will consider the results in the light of my above discussion on dosage/time/risk.

This study was not powered to answer the question "Is 1 ml of 2% Lidocaine per nerve sufficient for surgery on a population of individuals." That would require a much larger population, with more varied baseline characteristics, than the 11 patients that were ultimately enrolled in this study. This study was powered to determine the theoretical minimum dose that could be effective. It is a starting point, not a definitive study and thus I am not "itching to try it out."

I think that studies like this are very elegant. I also think that performing blocks with minimal local anesthetic is very elegant. However, it may not be practical for day to day implementation. I love elegant anesthesia when it works, but I prefer to be a practical anesthesiologist who uses elegant techniques when appropriate.

Do you give drugs to a patient just because you 'can' ?

Fallacious argument #2 (with snide overtones to boot)

but since you asked, I will bring up my own fallacious argument in response. The evidence suggests that 0.4 mg/kg of rocuronium is as effective at acheiving neuromuscular blockade as higher doses such as 0.9 or 1.2 mg/kg. Do you give more than 0.4 mg/kg rocuronium when starting a case? Why? Do YOU give drugs to a patient just because you can?


- pod

 

[proman]

Volume is a security measure to make sure that your block is going to work well and long enough.
Most people work in an environment where a failed block creates too much disruption and wasted time that I doubt they will feel comfortable with these exotic small volumes with or without ultrasound.
But, if you are in a teaching institute and you don't have surgeons breathing down your neck while trying to do these blocks, I think you should by all means try every exotic technique imaginable and please make sure you tell us about your results.

Are you kidding me? Our ATTENDING surgeons mop the floors of the ORs and transport the next patient to the OR (before anyone else is ready). They don't care if the block is done or not because they're not the ones fielding the midnight phone call for the guy in pain. If anything, it's the academic orthopods who are the unreasonable ones.

 

[Planktonmd]

Are you kidding me? Our ATTENDING surgeons mop the floors of the ORs and transport the next patient to the OR (before anyone else is ready). They don't care if the block is done or not because they're not the ones fielding the midnight phone call for the guy in pain. If anything, it's the academic orthopods who are the unreasonable ones.

So your Otho guys are usually in hurry to start a 7 hours hip replacement? 🙂

 

[periopdoc]

So your Otho guys are usually in hurry to start a 7 hours hip replacement? 🙂

Mine were, and even if my turnover was 5 minutes (not unheard of for me) they would complain that it was turnover that was keeping them in the hospital late. Thus I am doing a CT fellowship instead of regional because hard as it is to believe, yes CT surgeons are generally MORE reasonable than Orthopods.


- pod

 

[proman]

So your Otho guys are usually in hurry to start a 7 hours hip replacement? 🙂

They get pissed at anyone that keeps them from hammering. We have one guy who does 3 shoulders a day (slow by some standards but probably not bad for an academic center).

At least the cardiac guys have an understanding of their patient's physiology. I had one ortho resident ask why we don't redose antibiotic when they make multiple incisions. I quit trying to explain tissue penetration after 30 seconds.

 

[Trisomy13]

Mine were, and even if my turnover was 5 minutes (not unheard of for me) they would complain that it was turnover that was keeping them in the hospital late. Thus I am doing a CT fellowship instead of regional because hard as it is to believe, yes CT surgeons are generally MORE reasonable than Orthopods.


- pod

we have a mix of slow and very fast orthopods. they all want fast turnover, and one in particular will pace and hound us regarding the blocks. in his defense, he really WANTS the blocks, and is one of our biggest "customers" so we humor him when he looks like he is about to throw a tantrum. if he is willing to talk about a nerve block with his patients in his clinic, we're willing to hustle a little extra to get his blocks in and his cases started.

 

[jetproppilot]

Mine were, and even if my turnover was 5 minutes (not unheard of for me) they would complain that it was turnover that was keeping them in the hospital late. Thus I am doing a CT fellowship instead of regional because hard as it is to believe, yes CT surgeons are generally MORE reasonable than Orthopods.


- pod

HAHAHAHAHAHAHAHAHAHAHAHA

Thats a funny one, Dude.

 

[Bertelman]

They get pissed at anyone that keeps them from hammering. We have one guy who does 3 shoulders a day (slow by some standards but probably not bad for an academic center).

At least the cardiac guys have an understanding of their patient's physiology. I had one ortho resident ask why we don't redose antibiotic when they make multiple incisions. I quit trying to explain tissue penetration after 30 seconds.

Reminds me of the very brief conversation about NMBD I had a few weeks ago during a hip...

him- "Is this patient relaxed?"
me- "Yes, but they can be more relaxed if you need that."
him- "It's a yes/no question- they're either relaxed, or they aren't"

 

[bigeyedfish]

Our orthopods have a no regional policy. (Except the hand surgeon.) They don't want to wait the extra few minutes to start the case and they say "it will mask compartment syndrome." The other day one of our CA1's did a 5 hour humerus. Total knees are 6 hours. You gotta love academics.

 

[pgg]

Reminds me of the very brief conversation about NMBD I had a few weeks ago during a hip...

him- "Is this patient relaxed?"
me- "Yes, but they can be more relaxed if you need that."
him- "It's a yes/no question- they're either relaxed, or they aren't"

Heh. Ever try to explain to them why more muscle relaxant won't help if there's a tourniquet up? 🙂

 

[dhb]

Originally Posted by Bertelman
Reminds me of the very brief conversation about NMBD I had a few weeks ago during a hip...

Heh. Ever try to explain to them why more muscle relaxant won't help if there's a tourniquet up?

Tourniquets for hips a pretty uncomfortable i've heard 😉

 

[2win]

Reminds me of the very brief conversation about NMBD I had a few weeks ago during a hip...

him- "Is this patient relaxed?"
me- "Yes, but they can be more relaxed if you need that."
him- "It's a yes/no question- they're either relaxed, or they aren't"

👍👍👍