Ultrasound is the bomb

[nap$ter]

I've had great success with supraclavicular blocks for shoulder surgery, although I use relatively larger volumes (usually about 40ml).

with that volume you're just flooding the sheath from helm to hilt and increasing your risk/dose - why not just do the interscalene with less volume?

ultrasound has made volume blocks relatively unneccessary - precise finesse... i use 10-15 mL for isb for shoulders.

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[nap$ter]

Dude i use US every day. I teach attendings, fellow residents US guided blocks.
Today i did an infraclav cath, femoral cath, hand block and an interscalene for a shoulder reduction in pre-op , by the time the lady got to the OR the shoulder was reduced the orthopod didn't even pull on it.

I love US but all the goodness doesn't cloud my judgement: there's actually no proof of superiority of the technique.

Btw Jet do you combine US with NS or are you going strait US?

huh? imho a resident that purports to teach attendings should at least provide the facts. there are a hundred studies demonstrating at the very least superiority in time to block completion and better success rates with ultrasound compared to ns.

just for example:

Analgesic efficacy of ultrasound-guided regional anesthesia: a meta-analysis.
Gelfand HJ, Ouanes JP, Lesley MR, Ko PS, Murphy JD, Sumida SM, Isaac GR, Kumar K, Wu CL.
J Clin Anesth. 2011 Mar;23(2):90-6.

 

[jetproppilot]

Dude i use US every day. I teach attendings, fellow residents US guided blocks.
Today i did an infraclav cath, femoral cath, hand block and an interscalene for a shoulder reduction in pre-op , by the time the lady got to the OR the shoulder was reduced the orthopod didn't even pull on it.

I love US but all the goodness doesn't cloud my judgement: there's actually no proof of superiority of the technique.

Btw Jet do you combine US with NS or are you going strait US?

I'm still combining US with NS since I'm new. A cupola times tho I had the needle right where I wanted it, turned on the NS, no twitch, after a minute or so squirted the local in anyway sans twitch..both times had great blocks. Can't really explain that. (??) Especially since both times this happened the NS had worked ok on a block just 30 minutes or so prior.

I'm getting to the point that I don't think I need the nerve stimulator....maybe that's wishful thinking.

 

[BLADEMDA]

I'm still combining US with NS since I'm new. A cupola times tho I had the needle right where I wanted it, turned on the NS, no twitch, after a minute or so squirted the local in anyway sans twitch..both times had great blocks. Can't really explain that. (??) Especially since both times this happened the NS had worked ok on a block just 30 minutes or so prior.

I'm getting to the point that I don't think I need the nerve stimulator....maybe that's wishful thinking.

Jet,

Here is my humble opinion


1. Safety is only enhanced by combining NS with U/S. It can't hurt to use it. Sometimes the needle tip can be tricky to see and case reports show even experienced operators may misjudge the needle tip. It's okay to inject local if there is no twitch as the worst case scenario is a failed block. The chance of injecting into the nerve with no twitch is very rare
(but I know about the rat studies and sciatic nerve). However, if the NS shows less than 0.2 and you think the tip is right on top of the nerve then why not back up a mm or two.

2. Success- the gurus speculate that nerve stimulation along with U /S may help block the inferior trunk of the brachial plexus. Sometimes even if you are in the right spot via u/s the NS can help ensure a good block to the ulnar nerve by getting a good distal twitch to the hand.
The gurus say even with u/s supraclavicular blocks may benefit from NS use due to the variable location of the inferior trunk. It isn't always located in the corner pocket

 

[dhb]

Analgesic efficacy of ultrasound-guided regional anesthesia: a meta-analysis.
Gelfand HJ, Ouanes JP, Lesley MR, Ko PS, Murphy JD, Sumida SM, Isaac GR, Kumar K, Wu CL.
J Clin Anesth. 2011 Mar;23(2):90-6.

Quoting for the study which is my opinion too:

"It should be noted that these studies
were performed at centers where providers performing the
procedures were likely to be highly skilled in ultrasoundguided
techniques; thus, their conclusions may reflect gains
had by the most experienced of providers and these results
may or may not be generalizable to other anesthesiologists.
In addition, the definition of “success” was somewhat
arbitrary and another definition for success may provide
different results"

I should have added that i don't think it (US vs NS) makes a difference in experienced providers.

 

[dhb]

A cupola times tho I had the needle right where I wanted it, turned on the NS, no twitch, after a minute or so squirted the local in anyway sans twitch..both times had great blocks. Can't really explain that. (??).

My 2 cents on this is that very often with the NS you are actually intrafascicular or even intraneural, some studies show no adverse effect of intraneural injection.

How many people go down to 0.2mA to check intraneural position when they get a good response at 0.5mA? I never did it although i would now due to recent evidence.
NS is an imperfect tool, i rely more on what i see with US.
The advantage of US is clearly the reduction on volume you can achieve i'm routinely using 10cc by 1-2cc aliquotes with a low pressure injection.

 

[BLADEMDA]

Quoting for the study which is my opinion too:

"It should be noted that these studies
were performed at centers where providers performing the
procedures were likely to be highly skilled in ultrasoundguided
techniques; thus, their conclusions may reflect gains
had by the most experienced of providers and these results
may or may not be generalizable to other anesthesiologists.
In addition, the definition of “success” was somewhat
arbitrary and another definition for success may provide
different results"

I should have added that i don't think it (US vs NS) makes a difference in experienced providers.

I agree. My success rate is already 99 percent with NS so adding U/S just makes it more fun. But, I always worry about an intraneural injection as more than half my blocks get twitches at less than 0.2. U/S allows me to back up a mm or two while still maintaining a close proximity to the nerve. But the learning curve for NS blocks to achieve 99 percent is much greater than the curve for u/s. In addition, U/S allows me to do blocks more safely near the lung like supraclavicular. Another benefit is the likely reduction in phrenic nerve block with ISB by decreasing the volume from 25-30 to 10-20. On high risk patients I can inject 10 mls using u/s and still get a good block (duration of block is likely decreased though).

 

[dhb]

But the learning curve for NS blocks to achieve 99 percent is much greater than the curve for u/s. In addition, U/S allows me to do blocks more safely near the lung like supraclavicular. Another benefit is the likely reduction in phrenic nerve block with ISB by decreasing the volume from 25-30 to 10-20. On high risk patients I can inject 10 mls using u/s and still get a good block (duration of block is likely decreased though).

I agree on all counts.
I you're local doesn't spill anterior to the anterior scalene you should be able to avoid a phrenic nerve block. You can actually seen the phrenic nerve traveling ant to the scalene towards the carotid in many patients.

 

[nap$ter]

Quoting for the study which is my opinion too:

I should have added that i don't think it (US vs NS) makes a difference in experienced providers.

fair 'nuff. i disagree. i have done both and watched experts with both techniques, and ultrasound is faster, successful with fewer needle passes, allows for lower volumes to be delivered more accurately, fewer complications, greater overall success rate, etc..

ultrasound is by far superior to nerve stimulator techniques in regional anesthesia.

 

[Substance]

Well you are getting me wrong i did not say u/s can't make you better.

Post block nerve damage is in the order of 1/10.000 with most injuries resolving in 6 months. To prove superiority thus standard of care you'll need to enroll hundred of thousands of patients in each arm of your study.

The biggest problem with medicine is that every little change, no matter how obviously improved it may be, needs huge "studies" to convince us of its worth. Paralysis by analysis. Evidence is great and all, but sometimes you just need to take the bull by the horns and advance.

Taking something like US, which is through deductive reasoning alone better than landmarking, and doing a study to prove it is "better" is a waste of time and resources. And even if it is only marginally better, its still better than landmarking for that one patient who gets peripheral nerve damage, and to me that's worth it.

They didn't do a big study on whether chest x-ray was better than physical exam to detect pneumonia before they started using x-rays. It just made sense. I think the same argument applies here.

 

[dhb]

The biggest problem with medicine is that every little change, no matter how obviously improved it may be, needs huge "studies" to convince us of its worth. Paralysis by analysis. Evidence is great and all, but sometimes you just need to take the bull by the horns and advance.

Well the study posted didn't have big numbers because it was looking at RCT of US vs NS but there is a lot of published data on both techniques.
Like i've said US is great but i don't think you can dismiss a technique (NS) that has a proven track record for efficacy and safety.

 

[sevoflurane]

fair 'nuff. i disagree. i have done both and watched experts with both techniques, and ultrasound is faster, successful with fewer needle passes, allows for lower volumes to be delivered more accurately, fewer complications, greater overall success rate, etc..

ultrasound is by far superior to nerve stimulator techniques in regional anesthesia.

This.

 

[sevoflurane]

Well the study posted didn't have big numbers because it was looking at RCT of US vs NS but there is a lot of published data on both techniques.
Like i've said US is great but i don't think you can dismiss a technique (NS) that has a proven track record for efficacy and safety.

I don't think anybody is "dismissing" NS/landmark technique. In fact, everybody should know what to do when your COW/computer on wheels breaks down. Does USD add a layer of safety? Absolutely... without a doubt. Is it just as fast? In experienced hands... yes. I don't know why this is even a debate. It is obvious... especially in the 290 kg thick neck.

 

[dhb]

It is obvious... especially in the 290 kg thick neck.

I don't get that kind of patient

 

[epidural man]

I am GIDDY.

I know what you young stallions out there are saying:

"JET, WTF? I'VE BEEN DOING ULTRASOUND IN MY SLEEP FOR YEARS!!!"

I hear you man.

I'm joining you.

I agree...so satisfying for some reason.

As far as nerve stim - I really think it depends on the block. The femoral nerve is always in the same place - I have never seen it varied. But the brachial plexus at the level of C6 or supraclav or ax, I have seen it all over the place - and sometimes it doesn't look like what you think it should look like.

If you do ultrasound enough, you will be eventually see that sometimes you can't see crap - I think it has to do with patients different tissue properties and ultrasound propagation through it.

Today I did a radial nerve block right at or just below the elbow. At this level, there is always a lot of connective tissue and it is sometimes difficult to identify which bright white spot is the nerve. We stimulated it and got the appropriate twitch so we knew we were at the right spot.

The surgery was for some retained shrapnel on the dorsum of his hand, just below the wrist.

Strangely, we knocked out his wrist extension - so for sure got the deep branch, but he had complete or partial sensation over the site. I'm thinking the superficial branch probably took off more proximal - although I usually can see (or think I can) branch below the elbow. Anyone have this problem before?

Also, I blocked the lateral antebrachial cutaneous nerve by finding the bicep tendon and dumping local deep and lateral to this - and did a field block as described in texts. That worked great. I also tried the medial antebrachial cutaneous by doing a ring or field block down at the distal 2/3s of the upper arm. This didn't work. How do you all block this nerve?

By the way, the reason I didn't do a brachial plexus block - I was trying to spare motor function to his arm for this minor surgery. I would like to perfect the technique of picking out the distal nerves that need blocked, rather than the shotgun approach of ax/Infraclav/supraclav.

In the pain clinic, I block the radial, ulnar, or medial nerve all the time. They are incredibly fun blocks to do. Also, we touch up ax blocks all the time with peripheral nerve blocks. One reason I like ax blocks is in general, they suck, so you get to touch them up because invariably, you miss a branch, and usually it is the branch you need most.

If you think US is fun JPP, wait till you do a median and ulnar nerve block. Giddy is a good description.

 

[Dejavu]

Just one thing to keep in mind for those in residency....

You don't know where you are going to practice.... and you MAY end up in a group that does not have access to an USD machine.

If you ONLY know how to do a block with USD, then you are handicapped.

You MUST learn how to do these blocks via a traditional landmark based approach.

This is coming from someone who uses USD daily.

Keep that in mind dudes....

I will second that. Even if you work in a place with a couple of US machines, someday one will be in use and the other will have a broken probe or something. Are you going to tell the surgeon you cannot proceed because you can't do the block? You will look like an idiot.

This is from an old guy who mostly does traditional blocks, but really is comforted to see the nerves floating in local anesthetic when I do US. Also, doing TAPS and Paravert blocks without US are scary to me (no data to support my fear though). Some blocks are made for US, but in most (fem, sciatic, psoas, interscalene, ax) the block can just as easily be done traditionally. To call yourself a well rounded anesthesiologist, you should be facile with both techniques. IMHO only.

 

[BLADEMDA]

I will second that. Even if you work in a place with a couple of US machines, someday one will be in use and the other will have a broken probe or something. Are you going to tell the surgeon you cannot proceed because you can't do the block? You will look like an idiot.

This is from an old guy who mostly does traditional blocks, but really is comforted to see the nerves floating in local anesthetic when I do US. Also, doing TAPS and Paravert blocks without US are scary to me (no data to support my fear though). Some blocks are made for US, but in most (fem, sciatic, psoas, interscalene, ax) the block can just as easily be done traditionally. To call yourself a well rounded anesthesiologist, you should be facile with both techniques. IMHO only.

Correct. No proven difference in safety between techniques and EXPERIENCED Anesthesiologists won't have any difference in block success either; but, it is fun to see the nerves and use the fancy machine.

I suspect the new group of graduates are more dependent on this technology for doing blocks than the old guard. That is quite understandable. It takes many, many more landmark based NS guided blocks to get as good as doing just a handful of U/S guided ones.

If you get a chance to do Traditional NS guided blocks in Residency embrace it. I predict in a few years only a handful of dinosaurs will let you do that type of block.

 

[BLADEMDA]

 

[BLADEMDA]

I do understand the evidence is clearly moving in the direction of U/S use for blocks. I embrace the technology as it's easy to use and very effective. However, don't discount experience and the type of block when choosing to perform NS only or U/S with NS. Here are two of many studies on the subject:


http://www.ncbi.nlm.nih.gov/pubmed/19587625

High-definition ultrasonography offers potential advantages in the administration of peripheral nerve blockade. The significant difference in major central nervous system local anesthetic toxicity observed in this study supports the use of ultrasound guidance in conjunction with peripheral nerve stimulation to provide brachial plexus peripheral nerve blockade in an academic, ambulatory anesthesia practice.



http://www.ncbi.nlm.nih.gov/pubmed/19535720
CONCLUSIONS:

Ultrasound reduced the number of needle passes needed to perform interscalene block and enhanced motor block at the 5 min assessment; however, we did not observe significant differences in block failures, patient satisfaction or incidence, and severity of postoperative neurological symptom

 

[sevoflurane]

Correct. No proven difference in safety between techniques and EXPERIENCED Anesthesiologists won't have any difference in block success either; but, it is fun to see the nerves and use the fancy machine.

I suspect the new group of graduates are more dependent on this technology for doing blocks than the old guard. That is quite understandable. It takes many, many more landmark based NS guided blocks to get as good as doing just a handful of U/S guided ones.

If you get a chance to do Traditional NS guided blocks in Residency embrace it. I predict in a few years only a handful of dinosaurs will let you do that type of block.

For those in residency... this post is worth it's weight in gold (or silver).

Push your attendings to let you do traditional landmark based approach. It will serve you well and make you a much better, well rounded regional anesthesiologist.