Epidural cath insertion depth ? and poll

[Monty Python]

This weekend I relieved a colleague and inherited a labor epidural. Chart check revealed almost q1h top-ups prior to my arrival. Procedure note indicated pt was 86 kg, LOR at 7.5 cm, and cath taped at 14.5 cm at skin = 7 cm in the epidural space. I retracted the catheter to 11.5 cm at skin when I was called about 45 minutes later, leaving 4 cm in epidural space, gave a few mls of bupiv, and instituted PCEA feature. Never got called back again over the next 8 hours.

How far into the space are others currently inserting labor epidural catheters? I usually do ~3 cm in normal habitus, and 5 cm in those short of ideal body height.

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[ArMed]

How often was the patient hitting the button? How soon after you retracted the catheter did the patient deliver? What is your reasoning for thinking retracting the catheter would have been sufficient to resolve an otherwise inadequate epidural?

 

[psychbender]

I'm mostly the same, 3-5cm in the space. Incidence of asymmetric blocks seems to increase with deeper insertion than that.

 

[deleted162650]

I typically go 6cm (I deal with a fairly fluffy pt population - average LOR about 7cm). I use the soft arrow caths which I think are very forgiving of a little extra insertion depth as they just coil up in place. The stiff braun caths I think need to be limited to about 4cm to prevent tracking off to one side and giving a more unilateral block.

 

[Monty Python]

How often was the patient hitting the button? She did not have PCEA prior to my arrival. I instituted it, and she used it once over the next eight hours, about 30 minutes before actively pushing for delivery.

How soon after you retracted the catheter did the patient deliver?
~8 hours

What is your reasoning for thinking retracting the catheter would have been sufficient to resolve an otherwise inadequate epidural?
Chestnut: "3-5 cm." Personal experience. Seemed like a conservative option to try, before moving to an invasive procedure of replacing the catheter.

 

[Monty Python]

I typically go 6cm (I deal with a fairly fluffy pt population - average LOR about 7cm). I use the soft arrow caths which I think are very forgiving of a little extra insertion depth as they just coil up in place. The stiff braun caths I think need to be limited to about 4cm to prevent tracking off to one side and giving a more unilateral block.

We used to have the Arrows - loved them. Now we have the Brauns which you mentioned. Still prefer the Arrows.

 

[Consigliere]

3-5cm. Anyone inserting them deeper is stupid.

 

[fakin' the funk]

Leave at 4-5 in space, Brauns, also try not to thread a whole lot past that (ideally only threaded a cm past intended leaving depth)

 

[Gas you down]

no more than 3. I used to leave em all at 4-5. I sleep thru the nights once I switched to 3.

 

[Twiggidy]

I go with about 5 cm. As a contrast for them being to deep, I've dealt with/taken over a fair about of epidurals in "healthy" mamas who sweat and then darn thing slides out. Especially if they sweat so much that a pocket forms under the Tegaderm for it to slide into.

I know no one will like it, but I usually go 12 cm for the slender up to 14 cm for the big boned but never at 15 unless i literally had to hub he touey. (he's where SDN will thrash me) I dont tape a window, but instead put the tegaderm on and put silk take all over it to keep it (and the epidural in place). If i have to investigate the sight, then yes, here comes the wax job, but I warn patients and let them know that the gobs of tape is better than it slipping out and me doing it again.

that's just me. my ob anesthesia isn't perfect but it gets the job done

 

[Doctor4Life1769]

5cm.
Paramedian approach.

 

[nap$ter]

This weekend I relieved a colleague and inherited a labor epidural. Chart check revealed almost q1h top-ups prior to my arrival. Procedure note indicated pt was 86 kg, LOR at 7.5 cm, and cath taped at 14.5 cm at skin = 7 cm in the epidural space. I retracted the catheter to 11.5 cm at skin when I was called about 45 minutes later, leaving 4 cm in epidural space, gave a few mls of bupiv, and instituted PCEA feature. Never got called back again over the next 8 hours.

How far into the space are others currently inserting labor epidural catheters? I usually do ~3 cm in normal habitus, and 5 cm in those short of ideal body height.

5-10 cm depending on thickness of fat pad on back. the thicker the fat, the more likely gelatinous shear will pull your epidural out of the space. (also, i secure with an "x" of steri-strips over mastisol under the tegaderm leaving the markings visible - not as many pull-outs).

i would argue that it was your bolus and the institution of the PCEA feature, not your unnecessary retraction of the catheter that gave you 8 hrs free of callbacks in your anecdote.

i never pull catheters back - i either bolus them with a goodly volume or replace the catheter.

can't remember the last time i had to replace my own catheter.

 

[deleted162650]

"Gelatinous Shear" is my new favorite term. Thank you. Would also make a good name for a death metal band.

 

[RK.md]

I get a good LOR to saline, sit the patient straight up, thread 3-5 cm into the epidural space, and then secure the catheter. 🙂

 

[bkell101]

5 cm is what is practiced at our institution. Some do 6-7 in the obese patients and often times I see a unilateral block. I've only retracted the catheter back some if I have a unilateral block and the catheter is greater than 3cm in the space. Retraction of the catheter usually works in these cases.

 

[Twiggidy]

I get a good LOR to saline, sit the patient straight up, thread 3-5 cm into the epidural space, and then secure the catheter. 🙂

I never tried the saline technique as I wasn't taught it in residency, but I tried it the other day on-call. I must say, I kind of liked it. I only did it because I prefer the plastic LOR syringes vs the glass syringe in the kit, but i forgot to open one. So i did saline so the glass syringe would move better. I really liked it.

 

[deleted162650]

I never tried the saline technique as I wasn't taught it in residency

Are any current/recent residents out there still being taught LOR to air? I'm honestly just curious as the only guys I've seen use this technique are the dinosaurs (no offense Twig).

 

[Twiggidy]

Are any current/recent residents out there still being taught LOR to air? I'm honestly just curious as the only guys I've seen use this technique are the dinosaurs (no offense Twig).

None taken. My attendings were/are dinosaurs.

 

[polar403]

I'm in the 3-5 cm camp. 5 cm if there is potential for a lot of shearing from back fat. It's surprising how many epidurals you can salvage after you pull the catheter from 7 cm in the space to 4 cm and bolus it up.

 

[psychbender]

Are any current/recent residents out there still being taught LOR to air? I'm honestly just curious as the only guys I've seen use this technique are the dinosaurs (no offense Twig).

I'm only two years out of residency, and I'm a LOR to air guy. I started with saline, but another youngish attending had me try with air, and that's now my preference.

 

[vector2]

Most in my institution use saline (in the glass syringe) but I use air. I think the tactile feedback from the bounciness of air is more useful than the application of pressure on an incompressible liquid, especially for fatties where saline seems easily pushable into the 7cm of adipose squish that precedes flavum. Also, some pain docs told me that the glass syringe was actually designed for air and that if you're gonna use saline then it should be in the plastic one. Can anyone confirm/deny?

I thread to 4cm in normal habitus. Pull back to 3cm and re-bolus if unilateral. Replace if that doesn't work.

 

[pgg]

I use saline with a bubble of air in the syringe. All the bounciness of just air, but no air gets injected into the epidural space. I imagine/suspect/believe/hypothesize/conject that air in the epidural space might form a bubble around a nerve root, prevent local from getting there (for a while) and perhaps raise the risk of a patchy block.

As for depth, I usually go to 5 cm. If the patient is really obese, I'll bury a bit more catheter under the skin, but not go any further into the epidural space.

 

[Crayola227]

In a different field trolling your threads
Never done a spinal tap in my field, not yet

But I find the idea of inserting a needle into anyone's spine while awake to be one of the more horrifying procedures I can imagine

This all sounds terrible
I'm really worried if I ever get get an epidural
I want to do an unmedicated (or no epidural) childbirth for the freak out factor and other benefits, but I know a breakdown of willpower is likely

How do the patients fare with LOR to air vs saline?

I'm tall but very very thin, how deep should I let someone go in me? What lubricant is going to be more comfortable? How do I know if it's being done right? what are signs that it's going wrong? Seriously.

 

[dhb]

I'm tall but very very thin, how deep should I let someone go in me? What lubricant is going to be more comfortable? How do I know if it's being done right? what are signs that it's going wrong? Seriously.

as deep as it goes, no lube

 

[fakin' the funk]

Paramedian approach.

Routinely? Interesting.

I always teach (and try to optimize) procedures by eliminating degrees of freedom. Like for epidural, sitting up, no twisting, no leaning.

 

[Doctor4Life1769]

Routinely? Interesting.

I always teach (and try to optimize) procedures by eliminating degrees of freedom. Like for epidural, sitting up, no twisting, no leaning.

Isn't patient positioning key in any instance of epidural or spinal placement? I don't understand the relevancy.
I preferred paramedian approach when I learned it that way as opposed to midline. It always worked, quickly, and I never had to deal with patchy blocks or one sided blocks.

 

[deleted162650]

This all sounds terrible
I'm really worried if I ever get get an epidural
I want to do an unmedicated (or no epidural) childbirth for the freak out factor and other benefits, but I know a breakdown of willpower is likely

How do the patients fare with LOR to air vs saline?

I'm tall but very very thin, how deep should I let someone go in me? What lubricant is going to be more comfortable? How do I know if it's being done right? what are signs that it's going wrong? Seriously.

Oh good Lord. The only thing you need to worry about is writing your acceptance speech for this years "Most Up-Tight Person" award. I get that for the un-initiated, an epidural seems like a big scary procedure, but it's really a simple bread and butter procedure which every BC anesthesiologist has probably performed in excess of 1000 times. If and when you end up in labor, ask to speak to the anesthesiologist early and have them explain everything to you well before you get to the point of feeling like you need one. No need to stress about it now in an online forum.

And asking if pts do better with LOR to air v. saline is like asking if pts do better when their Dr. uses a Littman v. a Welsch Allen stethoscope. It's simply a technique/feel preference and you want your anesthesiologist doing whichever he does on every other epidural he's ever placed. Now take a deep breath, take a shot, or a bong hit, or whatever chills you out, and repeat after me "Everything is gonna be OK"

Now, getting back to technique, I do what PGG does. LOR to saline with a small 1/4 to 1/2 cc air bubble. It gives you that bounce and squish we all like so much, and it also gives a little objective feedback as well. If you can inject fluid without compressing the air bubble, you're in the epidural space. If you can't inject any fluid without that bubble getting compressed first, then you not there yet. This really helps in those fluffy pts or even just those that have soft mushburger ligaments.

With regards to paramedian technique for lumbar epidurals, I find that this is significantly more uncomfortable for the pt as you are going through muscle instead of ligament which is poorly innervated by comparison. In fact, if I'm going for midline, and the pt is experiencing more discomfort than usual, I take this as a good sign that I'm probably not as midline as I thought.

 

[pgg]

Only time I go paramedian approach is for mid-thoracic epidurals. It doesn't make a lot of sense to me to go paramedian in regions of the spine that have nearly horizontal spinous processes. I don't think I've ever tried a paramedian lumbar epidural.

 

[Arch Guillotti]

I preferred paramedian approach when I learned it that way as opposed to midline. It always worked, quickly, and I never had to deal with patchy blocks or one sided blocks.

I think that if you have never dealt with a patchy or one-sided block, then you haven't done enough epidurals.

 

[Arch Guillotti]

Only time I go paramedian approach is for mid-thoracic epidurals. It doesn't make a lot of sense to me to go paramedian in regions of the spine that have nearly horizontal spinous processes. I don't think I've ever tried a paramedian lumbar epidural.

Agree. Sometimes will do a paramedian approach for a spinal though.

 

[BLADEMDA]

The depth of catheter insertion is also related to whether you dilate the space with saline and/or local prior to insertion of catheter. For example, if you only bolus with 5 mls of volume prior to catheter insertion then limiting the depth to 4-5 cm seems prudent; if, however, you dilate the space with 10 mls of volume through the needle the catheter can be inserted 6-8 cm without any problems whatsoever. In morbidly obese patients I highly recommend the latter approach.

FYI, the air vs saline debate has been going on since 1990. The reason most use SALINE with a small air bubble is to decrease the chance that the air will create a pocket in the epidural space and block the local. If you are using the air technique try to limit the volume to less than 3-5 mls of air; this may seem easy to do but in the real world with a 350+ pound patient the volume of air can really add up if you attempt the procedure a few times.

 

[Doctor4Life1769]

I think that if you have never dealt with a patchy or one-sided block, then you haven't done enough epidurals.

Nah, I had enough patchy and one sided blocks.
That changed when I went paramedian. Never had patient complaints going paramedian anymore than I did when attempting midline (with regards to pain or discomfort).

 

[Crayola227]

Thanks guys this debate has been enlightening. I feel better hearing how you do this.

And I'm not excessively uptight thinking this is scary. I don't know much about it. I've never had a PARQ on this. I always see patients do this little involuntary jump, not fron the penetration of the needle but when it goes deeper.

Are you guys hitting the cord? How do you keep from doing that? I'm just ignorant on this so I'm curious. That's my fear that my cord's gonna get stabbed. That's reasonable fear not knowing more about the procedure. Inquiring minds want to know.

 

[urge]

as deep as it goes, no lube

LOL

 

[Arch Guillotti]

If you are using the air technique try to limit the volume to less than 3-5 mls of air; this may seem easy to do but in the real world with a 350+ pound patient the volume of air can really add up if you attempt the procedure a few times.

It is easy to do. I barely inject any air at all. The vast majority of the time I know when I am on the ligamentum flavum so that when the loss comes I really don't inject much air at all.

 

[Twiggidy]

This is hilarious.....

I always see patients do this little involuntary jump, not fron the penetration of the needle but when it goes deeper.

If you're seeing all these epidurals being performed and are curious, why don't you ask questions to the person performing the procedure? You have first hand opportunity to get insight right there

Are you guys hitting the cord? How do you keep from doing that? I'm just ignorant on this so I'm curious. That's my fear that my cord's gonna get stabbed. That's reasonable fear not knowing more about the procedure. Inquiring minds want to know.

Simple anatomy. The spinal cord ends at about L1. Labor epidurals are done at L3-4. Take @SaltyDog advice. Take a bong hit and chill...

 

[Ronin2258]

+5cm from loss of resistance (usually 5-7, depending how generous the BMI.) +3cm is minimum.

I personally like the Braun kit. The kit I use currently has a 17ga Touhy, compared to the 18ga in the Braun. That one gauge difference in the needle seems to be enough to make getting into the interspace a bit harder, especially with the geriatric population I deal with now for total joints, much to my surprise. Noticed a bit of a difference when it came to older patients/smaller spaces compared to the patients from the obstetric population.

Just out of curiosity, what is the record for LOR for everyone? Mine was ~10cm, which gave me a catheter distance of 15cm at the skin for a labor epidural. Shocked the OB doctor who thought I couldn't do it, but it got the woman through a trial of labor and a C-section when things went bad.

 

[Urzuz]

Simple anatomy. The spinal cord ends at about L1. Labor epidurals are done at L3-4. Take @SaltyDog advice. Take a bong hit and chill...

And we don't penetrate the dura (the sac in which the spinal cord resides), but rather stop right outside of it. Rarely during epidural placement the needle can puncture the dura, but as Twiggidy mentioned, we are below the level of the spinal cord, so your spinal cord will be intact regardless.

I feel like it's totally normal to be a scared of having an epidural. I do them on patients all the time, and the thought of someone placing an epidural in me freaks me out. That being said, as other have mentioned, talk to your anesthesiologist and they will (should) allay your fears. Think about how many millions of babies are delivered, and how so many women these days get epidurals. If we were paralyzing mothers left and right you would think we would have stopped doing it a while back 🙂

 

[ph8]

Just out of curiosity, what is the record for LOR for everyone? Mine was ~10cm, which gave me a catheter distance of 15cm at the skin for a labor epidural. Shocked the OB doctor who thought I couldn't do it, but it got the woman through a trial of labor and a C-section when things went bad.

Used what we affectionately called the "harpoon" ---- 13+ cm tuohy. LOR @ 13cm + some skin tenting....left the catheter at 18-19cm at skin. epidural worked like a charm.

I'm curious to hear others....

 

[Crayola227]

This is hilarious.....

If you're seeing all these epidurals being performed and are curious, why don't you ask questions to the person performing the procedure? You have first hand opportunity to get insight right there

Most of my exposure was as a med student in the OR... I was mostly trying not to get in the way while people stampeded around me, I always wanted to ask more questions
1) Rather than spending all of the surgery rotation scrubbed in at the bed... if there's enough hands, maybe students should be encouraged to spend time behind the curtain with the anesthesiologists.... the 15 total minutes I ever got to spend yakking with them taught me more than the whole surgery rotation (hyperbole but yeah). They could build that in. Rather then a mere few students taking a whole elective on anesthesia, maybe all students doing surg could get a little time with you guys. I always thought it was bull**** we didn't learn more from y'all

Simple anatomy. The spinal cord ends at about L1. Labor epidurals are done at L3-4. Take @SaltyDog advice. Take a bong hit and chill...

I will take it from you guys that the bong hit isn't going to interact unfavorably with the anesthesia, and go with that. It's funny I don't think docs pass out enough Valium to scared patients before certain procedures

Yeah, the anatomy thing was pretty dumb*ss on my part. Irrational fear brain hijack. Thanks for the education guys

Plus I was being a troll with my question dripping innuendo... we need more humor on the boards that isn't at someone's else's expense

 

[pgg]

Used what we affectionately called the "harpoon" ---- 13+ cm tuohy. LOR @ 13cm + some skin tenting....left the catheter at 18-19cm at skin. epidural worked like a charm.

I'm curious to hear others....

If I think the harpoon will be needed for a lumbar labor epidural, I will move up a couple spaces. Low thoracic epidurals (T10-12) are effective for labor pain, and there's usually a shelf of sorts above the buttocks so that deep layer of lumbar fat is avoided and insertion depth isn't as great. I haven't needed the long Tuohy since I started doing this.

 

[BLADEMDA]

If I think the harpoon will be needed for a lumbar labor epidural, I will move up a couple spaces. Low thoracic epidurals (T10-12) are effective for labor pain, and there's usually a shelf of sorts above the buttocks so that deep layer of lumbar fat is avoided and insertion depth isn't as great. I haven't needed the long Tuohy since I started doing this.

That's my trick for 2+ decades but I prefer L1-L2 over lower thoracic whenever possible.

 

[pgg]

That's my trick for 2+ decades but I prefer L1-L2 over lower thoracic whenever possible.

Agree, lower is better. You can get some sacral sparing sometimes, if you have to get up too high.

 

[CodeBlu]

In a different field trolling your threads
Never done a spinal tap in my field, not yet

But I find the idea of inserting a needle into anyone's spine while awake to be one of the more horrifying procedures I can imagine

This all sounds terrible
I'm really worried if I ever get get an epidural
I want to do an unmedicated (or no epidural) childbirth for the freak out factor and other benefits, but I know a breakdown of willpower is likely

How do the patients fare with LOR to air vs saline?

I'm tall but very very thin, how deep should I let someone go in me? What lubricant is going to be more comfortable? How do I know if it's being done right? what are signs that it's going wrong? Seriously.

Try multiple ones? See what works best. It's like spaghetti, whatever sticks...

In all seriousness though, epidurals are not THAT bad.