Does Gravity Affect Epidural Spread?

[Noyac]

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So your OB nurse calls and says that the epidural someone else placed earlier is one sided and she had the pt lie on the unaffected side. Is this going to work?

 

[Fastrach]

Works so rarely it's not worth trying, I say. From my troubleshooting, usually a one-sided block will stay that way unless a) the catheter is pulled back slightly or b) you add some narcotic which can diffuse across both sides more readily than the local anesthetic.
And yes, a one-sided block is better than no block at all. If the pt doesn't believe it, turn the damn thing off for a few hours and then ask what they think.

 

[The_Sensei]

So your OB nurse calls and says that the epidural someone else placed earlier is one sided and she had the pt lie on the unaffected side. Is this going to work?

Nope. Educate nurse, replace epidural. I usually skip the educate nurse step since it doesn't seem to work.

 

[dr. mccoy]

The one sided block usually indicates that the epidural catheter has been pushed in too far and has deviated to one side. I agree that the catheter can be pulled out slightly and rebolused to see if the other side can be covered. Otherwise, replace the catheter.

 

[fval28]

I've never seen it work- but try explaining why to the OB nurse😕 - I usually pull back 1-2 cm, aspirate and bolus w/ 5-8 cc's of 1% mpf lido plain and start the gtt again at a slightly higher rate. lido makes the block set up fast and it usually goes away within an hour or so- by giving the patient the immediate relief it gives me some time to talk to her and undo some of the misinformation about epidurals that the OB nurse has planted in her head.
If no relief from the bolus or if it is the 2nd time i've been called for the same thing -I replace the epidural

 

[Noyac]

Very good you guys.

I continue to have OB nurses try to position the pt with regards to gravity. Not just at my present job but everywhere that I have been. I explain to them that the epidural space is under pressure and that gravity has zero effect on the spread of the local. They can't fathom that and therefore don't believe me. I wondered, did they not believe me b/c they have been doing this technique for years and have seen it work? Then my partner tells me that one of the OB nurses called him about a one sided epidural and that she put the pt on the other side and it worked. 😕

Oh well, I guess we should be happy that they are trying to problem solve without just calling us every time.

As far as how to fix it. Pull it back about 2cm and see if it works better. If not, replace it. Narcotics work b/c they are absorbed and therefore systemic. I don't tell them to be happy that at least one side is working. They are paying (hopefully) for a working epidural. Make it work. Replace it if necessary. Only relieving pain of labor on one side is useless. My $.02

 

[The_Sensei]

Very good you guys.

Then my partner tells me that one of the OB nurses called him about a one sided epidural and that she put the pt on the other side and it worked. 😕

Most likely, the repositioning of the patient caused the catheter to move out 1-2 cm thereby providing better coverage.

 

[VolatileAgent]

you guys are talking about unilateral block, which probably does result from the catheter initially positioned on the side where the block is. also, it matters what kind of catheter you use. we use the braun catheters which contain multiple fenestrations at the tip. lastly, there is data that suggests that head down position does affect cephalad spread. so, gravity may play a role in that regard.

 

[achieman]

avg 5 cm to space, i leave it at 10 cm at the skin, that gives 2 cm of "wiggle" room to pull back. I have not pulled it back more than 1 cm fearing that it would come out too far. Honestly, I've turn the patient to the low side and bolused from the bag, and it seems to work 50% of the time. If it fails to improve after 1 hour, I pull back 1 cm, then if it still not working after another hour, I replace.

 

[VolatileAgent]

avg 5 cm to space, i leave it at 10 cm at the skin, that gives 2 cm of "wiggle" room to pull back. I have not pulled it back more than 1 cm fearing that it would come out too far. Honestly, I've turn the patient to the low side and bolused from the bag, and it seems to work 50% of the time. If it fails to improve after 1 hour, I pull back 1 cm, then if it still not working after another hour, I replace.

yeah, pretty much what i do too.

 

[Mman]

If I have a patient complaining of pain on one side with not as much of a sensory level on that side, I turn them so the painful side is down and bolus 10 to 15 cc from the bag and it probably works 2/3 of the time. If they have no level at all, I will pull it back a centimeter and bolus.

FWIW this is with catheters with multiple sideports that are left 4-5 cm in the space.


On a somewhat related note, I've more than a few times seen women that had an epidural that was functioning quite well fall asleep on one side for 2+ hours only to see their block becoming much more one sided.

 

[Laurel123]

It doesn't make any sense to me since the epidural space is a 'potential' space and the solutions are isobaric.

However, clinically, the nurses seem to be right. I have seen patients fall asleep on one side and then that down leg is a lot heavier and they complain that they have discomfort on the other side. I let the nurses have their way and have the patients flip over, and many times, it actually works. For me, it is a lot easier to let the nurses and patients feel proactive about the pain control and whether it is psychological or real, it doesn't really matter. I have tried to test for differential levels after patients are flipped from side to side, and I usually don't see much difference so I can't get much objective data.

 

[VolatileAgent]

I let the nurses have their way and have the patients flip over, and many times, it actually works.

just curious about your opinion on this then...

many ob nurses also believe that epidurals increase the rate of cesarian section too. so, do you allow them to "have their way" and delay placement, especially since many of them are supposedly "advocating" for that mom?

 

[meddog1]

Nope. Educate nurse, replace epidural. I usually skip the educate nurse step since it doesn't seem to work.

 

[meddog1]

just curious about your opinion on this then...

many ob nurses also believe that epidurals increase the rate of cesarian section too. so, do you allow them to "have their way" and delay placement, especially since many of them are supposedly "advocating" for that mom?

Funny, where I work the nurses request them early (I am convinced) as a chemical earplug.

 

[Laurel123]

just curious about your opinion on this then...

many ob nurses also believe that epidurals increase the rate of cesarian section too. so, do you allow them to "have their way" and delay placement, especially since many of them are supposedly "advocating" for that mom?

It's called picking my battles. In my explanation of an epidural I tell them that the rate of c/s is not increased. I'm just stating the facts and I tell that to all the patients and nurses. However, if the nurse wants to flip the patient from side to side, I have found that letting them do that leads to happy nurses, happy patients, and less pages for me. Besides, like someone mentioned earlier, educating them on baricity and negative pressure will not convince them of anything.

We know what we know. But I don't know what it is like in your practice, but in mine, we don't put an epidural in until the OB 'orders' the epidural. So sometimes it is the OB that is delaying the epidural and I could give them study after study but it is still their patient and if they don't want an epidural yet, the patient isn't getting one.

 

[VolatileAgent]

It's called picking my battles.

this may be part of the problem, namely your perception that you have to "battle" nurses on any level.

I don't know what it is like in your practice, but in mine, we don't put an epidural in until the OB 'orders' the epidural. So sometimes it is the OB that is delaying the epidural and I could give them study after study but it is still their patient and if they don't want an epidural yet, the patient isn't getting one.

this is an excellent opportunity for you to educate them (OBs and patients). at our institution, this starts well before mommy shows up with her water broken. there has been a real change in the mindset here over the past 2-3 years about this topic, especially since we have one of the world opinion-leaders in OB anesthesia concerning this issue at our institution.

so, maybe this will catch-on elsewhere. until then, i can only wait until someone comes out with a study that shows pain results in longer labor. because, i can't tell you how many "therapeutic epidurals" i put in before our L&D team (OBs and nurses) finally wised up.

 

[VolatileAgent]

Funny, where I work the nurses request them early (I am convinced) as a chemical earplug.

if it's earplug time, it's already too late. now, when we get 8-9cm, +1 station, 100% effaced "requests" for epidurals, they are usually subsequently met by an attending-attending discussion. no excuse to make a mom suffer like that... unless she wants to. if you are truly acting as a consultant when you assess that mom, you'll "advocate" for her as well, not based on your feelings or what you think is right, but by what is the best evidence base. you should pick that battle, unless you're content being nothing more than a technician and someone else's order filler.

 

[thegasman]

If I get a one sided block the patient is already laying with painful side down (from nurses instruction - they all seem to believe in this) when I come in the room. I bolus with 10 cc or so of 0.125 bupiv and about half the time this works. If not I replace. I don't know if gravity plays a role, but I definitely think volume of local does. I place my catheters +4 or so. If the catheter is directed to one side, it makes sense that it would take a higher volume to get adequate spread to the other side.

 

[VolatileAgent]

there is a great japanese study where they looked at the changes of the epidural space during pregnancy. somehow, these guys (leave it to the japanese) figured out a way to get a fiberoptic camera through the tuohy needle - "epiduroscopy". their findings are breathtaking (and help to more rationally explain a lot of what we observe on a day-to-day basis)...

for those who can link it:

http://www.springerlink.com/content/rdhuw1ep8c9m1ywu/

 

[The_Sensei]

Funny, where I work the nurses request them early (I am convinced) as a chemical earplug.

Same here, dude. As soon as the patient hits the door they get the epidural spiel from the fat, lazy (90% of them here are - seriously) nurse who doesn't want to deal with the patient. 😡

 

[Laurel123]

this may be part of the problem, namely your perception that you have to "battle" nurses on any level.



this is an excellent opportunity for you to educate them (OBs and patients). at our institution, this starts well before mommy shows up with her water broken. there has been a real change in the mindset here over the past 2-3 years about this topic, especially since we have one of the world opinion-leaders in OB anesthesia concerning this issue at our institution.

so, maybe this will catch-on elsewhere. until then, i can only wait until someone comes out with a study that shows pain results in longer labor. because, i can't tell you how many "therapeutic epidurals" i put in before our L&D team (OBs and nurses) finally wised up.

Your's is a good attitude and its something I miss about residency - most people seemed interested in hearing a thought out explanation. But while everyone at my institution is nice and does provide good patient care - I am a newbie working with OB's that have been around for 20-30 years and the reality is that it is an uphill battle for me. So again, I stand my ground when I believe patient care is at stake.

That being said, I still feel that turning and bolusing is worth a try because I have seen it work. It probably has to do with volume.

 

[VolatileAgent]

But while everyone at my institution is nice and does provide good patient care - I am a newbie working with OB's that have been around for 20-30 years and the reality is that it is an uphill battle for me. So again, I stand my ground when I believe patient care is at stake.

try offering a "dry catheter" next time, laurel. tell them it's "cutting edge", which it sort of is, and see what happens. the answer you'll get - acceptance or not - will tell you all you need to know about what "unseen" forces are really at play. that's how we started the culture change at our institution.

you are the consultant. the expert in pain management in the soon-to-be parturient. you're not mandating how they should do their job in delivering the baby. they shouldn't be mandating how you do yours. too often i don't think residency programs adequately stress this, to our profession's discredit. or, maybe you just haven't yet hit the point (if you indeed haven't already) of being sick of sitting behind some contracting woman and trying to hit a moving target.

 

[Noyac]

or, maybe you just haven't yet hit the point (if you indeed haven't already) of being sick of sitting behind some contracting woman and trying to hit a moving target.

If this is the situation I am thrown in, I just do a spinal, straight up. 25g Pencan with Bupiv and fent.

If they are going to be in labor for more than 1 hr, I put the epidural in after the spinal while they are comfy. Then start them on the PCEA.

I don't fight a severely laboring woman with a 18g Touhy.

 

[VolatileAgent]

I don't fight a severely laboring woman with a 18g Touhy.

funny.

yeah, and CSE's are nice too. one of my fellow seniors recently was called to the floor to place an epidural, and the woman practically delivered while he was behind her trying to get the damn thing in. the OB nurse who was there (and is also extremely cool) told me later that i would have crapped myself if i'd seen the look on his face. i could only imagine him trying to swing her legs back from the edge of the bed as the baby's head was popping out...

 

[militarymd]

Just remember, that every place does things differently.

Every patient population is different....and therefore their expectations are different.

What's right one place is wrong at another.

The former Chair and Section head of OB anesthesia from University of Miami is now one of my partners...and we have discussed variations in practices and beliefs across the country....

and it varies.....

Just remember........they came to have a baby with their OB....if there was no anesthesia department....they're still going to have that baby with that OB.

 

[Mman]

they came to have a baby with their OB

And they are going to have a baby with whichever of 14 MDs/DOs is covering for their OBs group today.🙂

 

[VolatileAgent]

And they are going to have a baby with whichever of 14 MDs/DOs is covering for their OBs group today.🙂

yeah, kinda hard to change the culture when you don't even know the culture... which, as the general sentiment in my post, is why a lot of personal preference persists in medicine. it's worthwhile to make relationships - positive relationships - with the OB staff as well. in the end, you won't be that nameless, faceless "anesthesia" who shows up for five minutes and puts the epidural in. and, about six months ago i actually had a mom stop me in the mall and thank me, by name, for making her comfortable during her labor and talking to her afterwards. (of course, i wasn't going to admit to her then that i couldn't remember who the hell she was... ).

 

[TIVA]

With regards to the original question: does gravity influence epidural spread?

The answer is yes. The epidural is not a potential space as someone mentioned before. It's an actual space, filled with fat, lympatics, engorged blood vessels, and traversing nerves. That's why the Japanese were able to do those "epiduroscopies."

I typically explain to my patients and to the nurses that the epidural space is like a sponge. This catheter goes into the sponge. And through the catheter we inject numbing medicine. And like any wet sponge, water will gravitate towards the dependent parts of the sponge. That's why one-sided blocks can be improved (although not always for reasons already mentioned above) by simply turning the patient.

Otherwise agree with most other contributions above.

 

[meddog1]

if it's earplug time, it's already too late. now, when we get 8-9cm, +1 station, 100% effaced "requests" for epidurals, they are usually subsequently met by an attending-attending discussion. no excuse to make a mom suffer like that... unless she wants to. if you are truly acting as a consultant when you assess that mom, you'll "advocate" for her as well, not based on your feelings or what you think is right, but by what is the best evidence base. you should pick that battle, unless you're content being nothing more than a technician and someone else's order filler.

Perhaps, but they are not "my" patients at the onset of admission. They belong to the OB docs and I function as a consultant when I am called upon by the OB service. I think it may not be the best thing for me to just walk on into a patient's room and start talking about doing a procedure that has not been requested by their primary first. On that same note, I do indeed get upset when I am called by some nurse who tells me she has a G6P5 who is currently at 7cm and they want to rush an epidural in before she delivers. This is ludicrous and happens frequently. What is the rationale here - "If we atleast get the CLE in the last 5 minutes before delivery, we can demonstrate that we gave the patient standard of care" (??). I mean, the woman is squeezing out the kid effortlessly like a greased bratwurst.