Stupid question from Jet for ultrasound studs

[jetproppilot]

---

Members do not see this ad.

As an elder to most of you young studs out there, I was hesitant to convert to ultrasound guided peripheral nerve blockade since I was pretty deft at all the blind techniques to interscalene, femoral, popliteal, etc blocks.

CHANGE IS HARD. I was comfortable with the blind techniques!!! As ultrasound took hold, though, and more and more of my homies kept saying

DUDE....TAKE THE JUMP...IT'S AWESOME...

I did. Nearly two years ago now.

Know what, ultrasound studs?

YOU WERE RIGHT.

Back then I saw it as more laborious; just added superfluous technology to techniques I was already deft at...I didn't think my blocks could be better:

BZZZZT JET I'M SORRY YOU WERE

WRONG.

Yep.

I'll fess up.

My ultrasound guided blocks are superior to my blind nerve stimulator blocks (with one exception which...uhhhh....is why I'm posting this but we'll get to that in a minute)

More laborious I previously thought?

HAHAHAHAHAHAHAHA how wrong I was.

Our Holding Room R.N.s position and sedate the patient, program the ultrasound for depth of block and enter the patient's info into the machine, draw up the local anesthetic (now adding decadron) and attach the needle, prep the area, spew some sterile jelly on the site, then they text me so essentially I

walk into the holding area, grab the ultrasound wand, visualize what I need to visualize, guide the needle tip to whatever nerve bundle I'm looking at,

the local anesthetic is squirted in, and

I POP MY GLOVES OFF.

Unbelievably easy!!

BUT I'VE GOT A PROBLEM.

Femoral nerve blocks....a very easy blind nerve stim technique with good results...now that we do all US, I easily see the fascia ileaca and breach it, I see the artery and the nerve, and I easily get the medial twitch but have problems finding a good spot for the needle head to achieve True Patellar Tendon Twitch which I've found provides a better block.

I've moved past using the nerve stim for backup on interscalenes and popliteals but with femorals...I dunno man I'm not routinely hitting that SWEET SPOT so I'm still using the nerve stimulator concominant with US and always get the medial twitch right off the bat and have trouble finding a true patellar twitch.

WTF LADIES AND GENTLEMEN???

What am I missing? Where anatomically should my needle end be?

I thank you in advance for responses!!!!

 

[EdPierce]

I used to be more into regional than I am now, but I would never really get hung up on stim. i saw too many bad blocks result from looking and looking for the right stimulation. in my mind, it all boiled down to just seeing the anatomy as best you can and infiltrating the entire area. even today the block guys at my place say they cant explain why they cant get twitches when it looks perfect on us. no twitch does not mean bad block.

 

[drccw]

I always stim the femoral nerve... and always find it's location and apperance to be highly variable on ultrasound. A guy in my group just plops local down lateral to the artery, deep to the fascia.. no stim...

unfortunately,he's got the highest rate of failed blocks in our group.. in my mind primarily because we tend to only use 10-15 mls of local...

I always want two things on my femoral nerve blocks
1) patellar tendon twitch
2) I want to feel the pop of the fascia layer....

I've found that if I get that the only time I have a failed block is if I don't get that "pop" feeling...

More importantly, how did you get a holding nurse RN to do all that? Is her/his sole job just to assist with blocks or is he/she also a pre-op nurse.. how many blocks a day are you guys doing? We've gotten busier with our regional and our ortho guys are really pushing us to do the blocks in a block room (right now we do them in the OR). We're right now probably doing about 60-70 blocks a week... I keep telling them we're more than willing to do it, but the hospital has got to hire us a nurse to really help push things through...

drccw

 

[Orin]

What would you do if you didn't have the ultrasound and had that problem?

What would happen if you did what you used to, but just visualized where the needle is with the ultrasound?

Would you end up inside the nerve?

For what it's worth, my attendings coach me to slide under, aiming for the posteriolateral corner of the artery.

How long of a motor block do you get for dex with your femorals?

 

[climbingak]

I dont stim my femorals so Im not sure how to get you your twitch. I imagine (based on my stim days) that you either need to be deeper, or a little more lateral.

My technique is to put the US probe into the inguinal crease. I scan down the femoral artery until it begins to split into two (giving off the profunda). I block right before it gives off the profunda and this is usually where I best see the nerve. The femoral nerve is a long flat nerve that lies on top of that dome of a muscle lateral to the artery (iliacus muscle). So even if you dont see the nerve you know it lies on top of that muscle. So I approach laterally in plane and head right for the peak of that dome just to the medial side of it. I enter here, through the fascia lata, and then through the fascia iliacus. I run the needle right down that muscle edge on the medial side. I begin to inject. If the injectate dissects and goes above the artery, you still have one more fascial plane to go through most likely. If the injectate disects and goes under the artery, you are golden.

This is how I do it. I run anesthesia for an orthopedic asc and spend most of my days doing blocks. I've had good results with the above. Hope it helps.

 

[excalibur]

Too funny, Jet. On several levels.

Seeing how you converted, when you used to be so reluctant. I cannot persuade some of my partners to make the jump. They don't see what you now know. Ultrasound makes it easier.

Next funny thing...

I agree! WHO IS THIS HOLDING NURSE?!?!

Has the Jet man been converted to Ultrasound and then gone on to hire a team to do his prep, sedation, and maybe charting too?? THAT'S NIIIIIIIICE!! LIFE IS GOOD, NO?

I am also envious of the amounts of blocks you guys are doing a week. I sadly only do I would say 3-4 PNB a week. Most are ISB and I do them all in the span of 1-2 days in the week. Would LOVE to bang out 4-5 a day. Why? Because I love achieving 0 pain for 24 hours in about 5 mins. But more importantly, if I did 4-5/day, I could hire the PNB nursing team...

"Nurse #3 be sure to include in your documentation that we used a 22 g 2 inch needle. Leave all the records by the bin. I will sign them after I've had my coffee. Text me when the next one is ready."

On a more seious note, I have encountered same problem, Jet, with USG femorals. U see the fascia AND the nerve clearly and get the needle there in 5 seconds. Then I spend some 2 minutes trying to get the classic patellar twitch as I only see medial twitch. Sometimes I have had to settle for the medial just because I try to get patellar but no go, I see the nerve right by the needle tip, and I already repositioned all around the nerve looking for patellar. I end the block laughing in my head, that this is the easiest blind block, but I am having difficulties with the US. I don't really have a good explanation on why or how to achieve patellar. My technique is to try and still obtain patellar twitch though. If the clock is running out in my head, then I just settle for the medial twitch, but use the US screen to view local spread and reposition needle to surround the nerve in local.

 

[Oggg]

My partners are learning Fnb and CFNB from me and they flub it all the time. A lot of the time, they lose the "perfect frame" due to hand fatigue or sloppy technique or needle/probe misalignment. I used to Teach blocking the nerve above the femoral artery bifurcation, but there is a lot of variation and anatomy, so now I teach that the best place to block is where your best picture is. You really need a picture where you can see the fascia iliaca dive under the artery, and you should be able to see the huge femoral nerve under it, distinct from the muscle. I get really close to the nerve and make sure my local spread is pushing into the nerve or surrounding it. I usually see a little sheath around it For training, I recommend injecting above and below the nerve. If its not obvious, sometimes you can see great spread proximal or distal. And don't fall for the mushy decoy stuff that is above the fascia iliaca but often just lateral to the artery (sometimes labelled femoral component of genitofemoral nerve).

 

[seinfeld]

I tend to find best results of FNB using US and stim. I stay high in inguinal crease to ensure i am get the femoral nerve before it starts to fan out too much. I do the block out of plane and only see tissue deflections. I use the stim to confirm/ID the nerve, as some others have pointed out, it is not reliable. I usually find it adjacent to a tissue plane.I then ensure i "donut" spread as i am injecting. I do not use nurses for other than pannus control. I am right handed. Left hand on US probe and never letting go and the right hand alternates between needle movement and injection. Also remember to de-bubble as bubbles in your injection make US harder to interpret.

Good luck and dont give up

 

[sevoflurane]

Good to see you on here man. 😎

Sounds like you are getting a sartorious twitch, which means you are anterior and too medial. Come out and move a little more lateral and you should get that patellar snap we are always after. FWIW, I find no need to be right on the nerve. If you are visualizing it pretty good, let the hydrodissection do the work for you and "lift" the fem. nerve from the fascia from underneath. Doughnuts are nice, but not necessary. Cheers.

 

[BLADEMDA]

Good to see you on here man. 😎

Sounds like you are getting a sartorious twitch, which means you are anterior and too medial. Come out and move a little more lateral and you should get that patellar snap we are always after. FWIW, I find no need to be right on the nerve. If you are visualizing it pretty good, let the hydrodissection do the work for you and "lift" the fem. nerve from the fascia from underneath. Doughnuts are nice, but not necessary. Cheers.

U/S guided blocks DO NOT require the nerve stimulator. Use the Stimulator as an additional device for nerve localization. After about a hundred Femoral Nerve blocks using U/S you will easily be able to hydrodissect the nerve from the Fascia Iliaca. I usually inject inject 10-12 mls above the nerve but below the Fascia Iliaca. You will clearly see the nerve move away from the fascia iliaca after just a few mls.

Then, I inject 10-12 mls undernearth the nerve. Again, this fairly easy to do with U/S. You won't need the stimulator at all once the nerve is located (see paragraph above) so I only keep it on at times to ensure my needle is below the nerve or just touching the posterior portion.

If you keep it up U/S becomes as easy as Nerve Stimulator guided blocks. Plus, you are certain that your blocks will work and that the needle didn't enter the nerve.

In short, forget the Patella snap and focus on getting local around the entire nerve. If you are having any difficulty visualizing the needle or the nerve only place local where you are certain the needle isn't entering the nerve. In these circumstances forget about any doughnut sign or encasing the entire nerve.

Until you get good with U/S The Nerve Stimulator is your best friend. I recommend you keep the stimulator in place with U/S assistance for Femoral Blocks for the first 100 blocks.

 

[sevoflurane]

I stimulate most all of my blocks along with USD. The exception would be those patients who have a broken bone (don't want to hurt them even when stimulating @ .5 MA).

Otherwise, I see no downside and hooking up the stimulator takes a mere 5 seconds or less.

Furthermore, the femoral nerve isn't always easy to find on the big individuals (bmi's>45) and those who have less desireable tissue with lymphadenopathy or fat lymph nodes pretending to be nerves. We've all seen it.

Another issue are those individuals whose fem. nerve divides (sometimes extensively) just above the inguinal ligament. I particularly like seeing a patellar snap with those individuals.

I rarely need the stimulator, but again, I see no downside to it's use and the feedback I get from both techniques simultaneously may be slightly better than USD alone in the patients where the anatomy isn't perfect. Scrambling around to find a stimulator would just waste my time, so I just hook it up from the beginning and quietly smile under my surgical mask when I see a patellar snap or a bouncy deltoid followed by some nice looking hydrodissection.

However, I will say that I was trained during the transition of landmark to USD based blocks, so I've done more than my fair share both ways and I've been trained to look for and identify particular twitches.

Our group is an ortho heavy group and we do a ton of blocks. This has been the type of regional anesthesia I have chosen to adapt to in my practice. I don't think I'll go to USD only... although I easily could if I thought it was better. My 2 cents.

 

[Oggg]

nerve stim becomes a liability when you do CFNB. the stim Tuohy and stim catheters are more expensive.

 

[sevoflurane]

:Explain to me how usd + stimulation is a "liability" for a cFNB.
CFNBs are so dang easy to place. I don't buy the liability card for one nano second. Not even for a new-b @ catheters. 🙂
That being said, if you are doing a catheter and you have a good picture of the nerve, going without stim. is totally legit and proven. I have no beef there.

You don't need a stimulating catheter to place a CFNB, I dont know of anyone still doing this. An epidural catheter is far superior and is blunt and cheap.

 

[EdPierce]

the downside of the stimulator is the exact situation the OP is describing. i.e. what do you do if yous US image looks great but no twitch? Ive been trained to take it without twitch, never had an issues with failed blocks, it happens so often that you have a good image and no twitch that you end up just abandoning the twitch - makes the block take longer, doesnt really add anything

 

[BLADEMDA]

the downside of the stimulator is the exact situation the OP is describing. i.e. what do you do if yous US image looks great but no twitch? Ive been trained to take it without twitch, never had an issues with failed blocks, it happens so often that you have a good image and no twitch that you end up just abandoning the twitch - makes the block take longer, doesnt really add anything

Ed, I agree with you and have almost abandoned the nerve stimulator except for one block: Femoral.

I still like getting a twitch from time to time for the difficult to see Femoral nerve. My N with Nerve Stimulator guided Femoral blocks is multiple thousands vs just a few hundred U/S guided Femoral blocks.

I've gotten quite good at FICB and Femoral Blocks with U/S and can easily locate and block in under 3 minutes. Still, I use the NS from time to time as a tool to facilitate nerve location prior to injection. Once the nerve has been confirmed I then use U/S for the actual block (usually I end up moving the needle away from the Femoral nerve by a few mm prior to injection).

I've never seen the Femoral nerve not twitch at 1.5 or 2.0. I've seen it not twitch at 0.5, 0.8 and even 1.0 but never 1.5. Since I'm not using the "twitch" per se but rather just confimation of nerve I'm not worried about getting a twitch below 1.0, 0.8 or 0.5.

I do like making sure there is NO TWITCH present at under 0.5 for my initial injection as I prefer my first 1-2 mls to hyrodissect the nerve off the fascia iliaca so I have a clear image of the nerve for my block.

 

[BLADEMDA]

nerve stim becomes a liability when you do CFNB. the stim Tuohy and stim catheters are more expensive.

Ogg,

I had one patient with a difficult to locate Femoral nerve requiring a catheter. So, I used my Braun Stimulating needle (echogenic), Nerve stimulator and U/S to locate and block the upper portion of the nerve (hydrodissect off the Fascia Iliaca). Then, I used an Epidural kit with Tuohy needle and catheter to block the bottom of the Femoral nerve. I left the catheter in place under the Femoral nerve.

While this may not be your preference in terms of technique it works quite well and maintains patient safety.

 

[sevoflurane]

...i.e. what do you do if yous US image looks great but no twitch? Ive been trained to take it without twitch, never had an issues with failed blocks, it happens so often that you have a good image and no twitch that you end up just abandoning the twitch - makes the block take longer, doesnt really add anything

I get a no twitch scenario once in a while. Maybe .5% of the time. 1:200 blocks. If I know I'm looking @ the nerve I inject the local and move on w/o a twitch. No time in my practice to do a 10 minute block. Push on and go. They wake up comfy. It adds quite a bit when you are not sure what you are looking at under USD... A patellar snap looking back at you is your friend in those situations.

 

[Oggg]

Blade, I think I will agree with you that in the rare case that you can't get a good US image, using a stim needle as a finder can be a useful tool. I vaguely remember co-blocking someone that way a while ago, but since then no problems with US only. It takes a couple failures to really understand the imaging for the US fem block, then it really becomes consistent. I'm trying to teach my partners how to image the FN better; it takes a lot of practice cuz the anatomy is variable

 

[jetproppilot]

Good to see you on here man. 😎

Sounds like you are getting a sartorious twitch, which means you are anterior and too medial. Come out and move a little more lateral and you should get that patellar snap we are always after. FWIW, I find no need to be right on the nerve. If you are visualizing it pretty good, let the hydrodissection do the work for you and "lift" the fem. nerve from the fascia from underneath. Doughnuts are nice, but not necessary. Cheers.

Beautiful.
Thanks G!!!
Good thread.
Thanks for all the responses!