intrathecal catheters

[Idiopathic]

so never had a wet tap as a resident (300+ epidurals) and was only an observer when incidental ones occurred on L+D and we placed IT catheters. I understand the reasoning and dont want to debate that necessarily.

However, last night i atttended TWO wet taps. The first one we threaded an IT catheter and there were no other issues. The second one, however, we couldnt inject through the catheter (I assume a micro clot was occluding the lumen), and so, grudgingly, I pulled it and after the second catheter was intravascular, I placed the third one myself and got a good block. Fine, moving on.

However, would you have left the non functioning IT catheter in on the second patient, and placed another epidural for analgesia, with plans to pull the IT catheter 24 hours later? I know that we are pretty much guaranteeing a blood patch for this patient (i told the resident on to just do it when they pull the epidural catheter to avoid another touhy placement) but if I had left both catheters in would that have been a better choice?

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[proman]

I don't think prophylactic blood patches prevent post dural puncture headaches. I'd pull the intrathecal catheter, remind the patient about how we discussed headache as a possible complication and follow her daily. If she developed a PDPH then I'd move to blood patch earlier rather than later (would still try caffeine briefly). I also hope to never practice OB.

 

[SleepIsGood]

My personal preference is to not use IT caths, for multiple reasons, and also since you have to trust someone else (RN) to not accidentally thnk it's an epidural and run an infusion rate on that basis. But we arent talking about that on this thread.

Secondly, I would do what you did and take out the IT cath. I know that keeping the IT cath in would increase fibroblastic activity and possible help with healing of the hole, blah blah blah. However, if your intention is to place an epidural cath anyways, 1) you are increasing the chance of an infection by placing and keeping two lines in a patient's back. 2) Again, the RN or someone may run the epidural infusion rate into the IT cath that you were not using.

If you have to do a blood patch, you have to do it.

 

[Idiopathic]

Well we do enough IT catheters that the nurses know how to manage them, and also I would have capped the end off and taped it down so that nobody could have infused through it.

I also do not like them for one reason or another, but we see almost 100% PDPH with our wet taps and so the risks of a blood patch versus an IT catheter have to be weighed, since our headache rate is probably <10% with IT catheters

 

[Idiopathic]

oh and also our team makes all changes and management decisions with epidurals, it may be because we have a relatively small delivery service (<4000 a year) compared to other big academic centers

 

[Licoricestick]

Are you still seeing a 100% PDPH rate even when you place an IT catheter? What gauge touhy are you using?

I would leave the catheter (with a knot tied in it) and either place another epidural or go with a remifentanyl PCA (if she doesn't want you to have another go).

 

[rsgillmd]

so never had a wet tap as a resident (300+ epidurals) and was only an observer when incidental ones occurred on L+D and we placed IT catheters. I understand the reasoning and dont want to debate that necessarily.

However, last night i atttended TWO wet taps. The first one we threaded an IT catheter and there were no other issues. The second one, however, we couldnt inject through the catheter (I assume a micro clot was occluding the lumen), and so, grudgingly, I pulled it and after the second catheter was intravascular, I placed the third one myself and got a good block. Fine, moving on.

However, would you have left the non functioning IT catheter in on the second patient, and placed another epidural for analgesia, with plans to pull the IT catheter 24 hours later? I know that we are pretty much guaranteeing a blood patch for this patient (i told the resident on to just do it when they pull the epidural catheter to avoid another touhy placement) but if I had left both catheters in would that have been a better choice?

As helpful as I find intrathecal catheters to be, if you can't inject through it/aspirate from it, in my opinion you are better off just pulling it. You did the right thing repeating the epidural yourself.

I can't quote you any literature off the top of my head. I'm sure if you really want to, you can Google/PubMed it anyways. But prophylactic blood patches have basically been shown to be totally useless at worst, or slightly delay the onset of the headache at best.

I'm sure you already discuss the possibility of a PDPH as part of your consent. My approach to the patient after a wet tap is along the lines of: "As we discussed earlier, in about 1% of the patients the needle goes a little too far. This happened with you. Don't worry, you are not in any danger. You will still get good pain relief. About half of the patients in whom this happens may get a headache 1-2 days later. This headache is treatable. After your baby is delivered we can talk about things you can do to possibly reduce this risk of developing a headache, and how to manage it if it does occur."

The patients usually take this approach well. They are usually just happy that they will still get pain relief from their labor.

 

[Bertelman]

"As we discussed earlier, in about 1% of the patients the needle goes a little too far. This happened with you.

I hope your wet tap rate isn't really 1%.

 

[rsgillmd]

I hope your wet tap rate isn't really 1%.

No. Lower than that, but I'm not sure of the exact rate for our institution. I personally haven't had one in about 3 years now, but I've been mainly supervising this past year.

Apparently nationally the range is somewhere along the lines of 0.8% to 2-3%. It's going to vary a little depending on which article you look at (1 of them gave a higher upper range). I have some household chores to take care of, but if you are interested I can probably send you some articles either this evening or tomorrow.

1% is an easy number for patients to understand and remember.

 

[deleted126335]

For those who decide to leave an intrathecal catheter in, what cocktail do you use for infusion for labor analgesia?

 

[Idiopathic]

So, i operate under the following assumptions. Our wet tap rate is about 1:100-1:150, but we train SRNA and junior residents. Wet taps with 18g tuohy seem to reliably result in 80-90% PDPH. We usually patch the people whom we know were wet tapped and have a headache ASAP, since it delays discharge.

So, we place IT catheters when we can, with the nurses knowing that they do not get pulled for 24 hours.

We will use the same cocktail as we do for epidurals, but at about 30-40% of the dose - 2-3 cc/hour of 0.1%bupiv/2mcg per cc fentanyl with a low PCEA bolus of like 0.5-1cc q 30minutes

 

[Idiopathic]

I hope your wet tap rate isn't really 1%.

Most studies quote about a 1% rate of incidental dural puncture with routine epidural placement. Seems to be reasonable to quote that number

 

[pgg]

I would leave the catheter (with a knot tied in it)

Our epidural catheters are surprisingly kink-resistant and remain patent despite knots. A CRNA here wet tapped someone a few months ago, put in an IT catheter, used it during labor, tied a knot postpartum intending to leave it in x24 hours, and discovered that she could still withdraw CSF from it.

If you haven't already, you might want to take one, tie a knot or 3 in it, and see if you can push fluid through. Just for grins.


Super-aggressive tape and labeling might be better than trusting a knot.

 

[rsgillmd]

Our epidural catheters are surprisingly kink-resistant and remain patent despite knots. A CRNA here wet tapped someone a few months ago, put in an IT catheter, used it during labor, tied a knot postpartum intending to leave it in x24 hours, and discovered that she could still withdraw CSF from it.

If you haven't already, you might want to take one, tie a knot or 3 in it, and see if you can push fluid through. Just for grins.


Super-aggressive tape and labeling might be better than trusting a knot.

PGG, I like the idea. I'm on call in OB tomorrow. Will definitely try it.

 

[rsgillmd]

For those who decide to leave an intrathecal catheter in, what cocktail do you use for infusion for labor analgesia?

I tend to run the same infusion as epidural, but at 2 ml/hr. When I was learning about using intrathecal catheters during residency, I tried 1 ml/hr because I was running the epidural infusions at 10 ml/hr. But quickly found this to be ineffective. 2 ml/hr definitely works better.

We don't really have many PCEA buttons here, so we bolus the catheters manually -- usually Bupivacaine 2.5 mg (1 ml).

 

[PinchandBurn]

For those using IT caths, you guys arent allowing patients to give themselves 'demand' doses are you? I'd assume something like 1/4 ml every 20min would be almost impossible to program

 

[SexPanther]

For those using IT caths, you guys arent allowing patients to give themselves 'demand' doses are you? I'd assume something like 1/4 ml every 20min would be almost impossible to program

We do program a demand dose, but it is usually something like 1cc q30 min.

 

[dhb]

Most studies quote about a 1% rate of incidental dural puncture with routine epidural placement. Seems to be reasonable to quote that number

Most studies are done at academic centers. I highly doubt you can apply this number to a PP setting. I would guess PP to be at 0.1% or lower.
Maybe jwk can give us some numbers from i high volume practice.

 

[pgg]

Our epidural catheters are surprisingly kink-resistant and remain patent despite knots.

Today I took an Arrow 19 g FlexTip Plus epidural catheter from one of our epidural kits and tried to knot it closed. Multiple knots did not alter the resistance to injection at all. Pushing fluid through it was easy and smooth.

The knots were as tight as I could make them without snapping the tubing (which I did once and is why the pic shows a broken catheter).

 

[Idiopathic]

Most studies are done at academic centers. I highly doubt you can apply this number to a PP setting. I would guess PP to be at 0.1% or lower.
Maybe jwk can give us some numbers from i high volume practice.

as ive previously stated, im at an academic center and we have junior residents and srna's doing our epidurals so it seems pretty reasonable to quote >1%

 

[dhb]

as ive previously stated, im at an academic center and we have junior residents and srna's doing our epidurals so it seems pretty reasonable to quote >1%

I don't disagree with you, i'm just saying that this number can't be applied to the majority of practices.

 

[pjl]

Although my personal rate is <1%, I still quote the higher number (actually I say 1-2% chance of headache), just like I give the most conservative estimate with regards to other regional procedure complications. It is extremely rare that you are going to alter someone's decision because of a headache change that is 1% versus 0.1%, and it makes me feel better. If they are really squirmy I will sometimes let them know that if they are unable to sit still their risk is substantially higher, depending on if I think this will alter their behavior.
I agree that in the real world the rate is likely much lower, probably the 0.1-0.2 range, but who in private practice is going to design a study to show their rate of wet tap, or even do a retrospective review?

 

[Idiopathic]

but who in private practice is going to do a study

fixed