Salvaging the subarchnoid "epidural" catheter

[ecCA1]

If you got a wet tap when you placed the epidural catheter (needle had regular LOR, no CSF), would you just use as a single-shot spinal and re-dose as needed, run as a very low-rate infusion, or pull and try again?

---

Members don't see this ad.

 

[SleepIsGood]

If you got a wet tap when you placed the epidural catheter (needle had regular LOR, no CSF), would you just use as a single-shot spinal and re-dose as needed, run as a very low-rate infusion, or pull and try again?

Pull and try again...

I just remember there was a discussion about this during grand rounds. Back in the day ppl woud keep the epidural caths in the subarachnoid space. However, no one does that because of the supposed risk of cauda equina syndrome if I recall correctly.

 

[rsgillmd]

Pull and try again...

I just remember there be a discussion about this during grand rounds. Back in the day ppl woud keep the epidural caths in the subarachnoid space. However, no one does that because of the supposed risk of cauda equina syndrome if I recall correctly.

We do it a lot. To my knowledge this risk of cauda equina syndrome that has been documented has been with the spinal microcatheters not epidural catheters. I have had good results in preventing PDPH with intrathecal catheters left in place for 24 hrs.

 

[goodoc]

Keep it dose it pull it 24 hrs later, less pdph. The risk is for small bore continuous infusion.

 

[Arch Guillotti]

Usually we put another one in at a different level. Sometimes we will leave the catheter in and dose hourly or so w/ bupi/fent/epi or very rarely run an infusion sans demand dose.

 

[SleepIsGood]

oops...just read over my previous reply...lol...totally messed up my grammar there .."there be". No I idea what I was writing.


Are you guys saying that if you wet tapped someone, you would then thread the epidural cath through the Toughy? Presumbly, that epidural cath is now in subarachnoid space right? You're right it was microcaths that historically caused Cauda Equina Syndrome..but I think they were infusing Lido or something. At any rate, that's a microcath they threaded causing this...why would someone think that threading a epidural cath (which I presume is larger) wouldnt have a disastrous outcome?

 

[SleepIsGood]

If you got a wet tap when you placed the epidural catheter (needle had regular LOR, no CSF), would you just use as a single-shot spinal and re-dose as needed, run as a very low-rate infusion, or pull and try again?

If there's no CSF, how would you know you had a wet tap?

 

[Trisomy13]

thread it, dose it, single shot with repeats later if necessary, or low rate infusion with no demand dose if the OB nurse looks smarter than the average bear and you trust her. tell mom she might have a headache but she's done feeling anything resembling contraction pain. pull after 24 hrs.

 

[Pooh & Annie]

I was also wondering how it was a wet tap if you saw no CSF.

We once intentionally placed a subarachnoid epidural catheter in a patient with an EF of around 15%. It was for a large inguinal hernia. We held off dosing until we got in the OR, then dosed with 20mg 2-chloroprocaine before the incision. Dosed another 20mg when the first one started wearing off. It worked great. If the hernia was smaller, we probably could have just done an ilioinguinal iliohypogastric and some incision site local.

An epidural catheter dosed properly shouldn't lead to the same symptoms in theory, since it's thought the problems were due to high concentration local exposed to a very small area of nerve, causing local neurotoxicity.

 

[ecCA1]

It was noticed that CSF leaked from the catheter once it was placed. The wording was poor, I admit.

 

[cchoukal]

Keep it dose it pull it 24 hrs later, less pdph. The risk is for small bore continuous infusion.

In my board/ITE prep, Hall and Chantigian say the following:

pooling of local anesthetics in dependent areas of the spine within the SA space has been identified as the causative factor in cases of cauda equina syndrome. Microlumen catheters may enhance the nonuniform distribution within the IT space, but cauda equina syndrome has been associated with large catheters as well.

And they cite stoelting basics, p 176.

There was recently a trial in Anesthesiology of spinal microcatheters in laboring women, so it seems there is a faction trying to bring these catheters back into use.

There IS evidence, as someone pointed out, that leaving an IT catheter in, whether you use it or not, might decrease PDPH in laboring women...

That said, our attgs seem split about 50/50 between leaving it (dose intermittently or on a pump) and pulling it.

 

[jetproppilot]

WE DO IT ALOT.. To my knowledge this risk of cauda equina syndrome that has been documented has been with the spinal microcatheters not epidural catheters. I have had good results in preventing PDPH with intrathecal catheters left in place for 24 hrs.

If you're really doing it ALOT, dude,

you need some deft dudes at your university to show you how to make a wet tap an extremely rare occurrence.

LIKE ONCE A YEAR.

MAYBE.

 

[ecCA1]

Jet,

What's your view of the spinal infusion technique, though? Would you just single-shot the lady every hour or so, or throw a pump at her set for a cc an hour (or whatever)?

 

[rsgillmd]

If you're really doing it ALOT, dude,

you need some deft dudes at your university to show you how to make a wet tap an extremely rare occurrence.

LIKE ONCE A YEAR.

MAYBE.

OK, you win. Bad choice of words. Dural puncture itself is low in my institution, but when we do get one (usually once every couple of months) most of the people I know insert the catheter intrathecally and run at 2 ml/hr (bolused only by us if necessary -- usually not) until delivery. We leave it in place for 24 hrs and pull it the next day. I'm in a teaching institution, so July/August is probably our highest wet-tap rate.

I've had 5 so far in 3 years, of which 2 were classics. On 1 I didn't realize it until I took my syringe off -- the syringe didn't fill up but CSF was dripping out. On another the lady moved in response to a contraction as I was threading the epidural catheter.

My last wet-tap unfortunately was yesterday. It was also the weirdest. I got into the epidural space and passed the spinal needle to give the intrathecal dose (as part of CSE). But when I went to thread the catheter it wouldn't go despite rotation of the needle. Since I was still confident I was in the epidural space (I placed the stylet in to clear the needle and injected saline easily x 2) I decided to try a Portex catheter. The Portex went easily. When I went to aspirate I had free flow of CSF. This is despite the fact that there was nothing dripping from the Tuohy when I was trying to insert the catheter.

Of the previous 4 patients, my first wet-tap patient needed a blood patch. But on that one my attending was with me, and he pulled the needle back until the CSF stopped flowing and threaded the catheter into the epidural space. I was a scared CA-1 at the time (October) that I didn't bother to question him.

While my case series is too small to draw a conclusion from, anecdotally the blood-patch rate is higher in those residents/attendings that go at a different level.

 

[SleepIsGood]

Its funny...

I really didnt realize how 'big' the epidural space is until I've been on pain. When we're using the fluoro machine to see the 'spread' of contrast before injecting the steroids you can get an appreciation of the epidural space. Obviously the space 'opens' up more when you push contrast. But tht almost makes me feel like instead of doing loss of resistance, it's better to use saline to open up the space. I wonder if there's a smller chance of a 'wet' tap.

 

[Gaseous Clay]

Its funny...

I really didnt realize how 'big' the epidural space is until I've been on pain. When we're using the fluoro machine to see the 'spread' of contrast before injecting the steroids you can get an appreciation of the epidural space. Obviously the space 'opens' up more when you push contrast. But tht almost makes me feel like instead of doing loss of resistance, it's better to use saline to open up the space. I wonder if there's a smller chance of a 'wet' tap.

What do you mean in your last statement? Do you use air for your LOR? I typically like to use at least 4-5 ml NS for LOR (though some Attendings will tell me to stop at around 2 ml). Like you said, adding that extra volume seems to open the space up more allowing for more spread of medication, plus the intravascular rate is lower with NS vs air.

 

[coprolalia]

Like you said, adding that extra volume seems to open the space up more allowing for more spread of medication, plus the intravascular rate is lower with NS vs air.

Didn't we have this argument already?

-copro

 

[Planktonmd]

Its funny...

I really didnt realize how 'big' the epidural space is until I've been on pain. When we're using the fluoro machine to see the 'spread' of contrast before injecting the steroids you can get an appreciation of the epidural space. Obviously the space 'opens' up more when you push contrast. But tht almost makes me feel like instead of doing loss of resistance, it's better to use saline to open up the space. I wonder if there's a smller chance of a 'wet' tap.

The choice of air versus saline for LOR is strictly based on personal preference and once you are used to one of them you should not change.
I have been doing this business for a long time (relatively), and I have done thousands of epidurals all of them using air for LOR because this is how I was trained and this is how I can accurately appreciate loss of Resistance, my wet tap rate is very very low (maybe 1 every 2-3 years).

 

[jetproppilot]

Jet,

What's your view of the spinal infusion technique, though? Would you just single-shot the lady every hour or so, or throw a pump at her set for a cc an hour (or whatever)?

I wouldnt do it for labor, Dude.

If I got a wet tap on a parturient during placement of a labor analgesia catheter I'd go to another level and try again.

For a knee replacement/other ortho-lower extremity case, a C section on an Orca, or similar case under epidural I'd thread the catheter intrathecally and dose with spinal-HB bupiv, and redose if needed.

I'd never put a pump on an intrathecal catheter regardless of clinical situation.