At our site on occassion we will be asked to instill xylocaine into the cuff of our endotracheal tubes. Generally speaking for patients whose tube is in good placement but have that incessant irritated cough. Per protocol the Intensivists have asked us to use 5cc Xylo(4%) and 1 cc HCO3(8%) and top up with air to no leak. This has prompted many discussion regarding VAP as the cuff has to be emptied to do this. How often should it be replaced? Should we not replace and just top it up from time to time. Mostly we have settled on just topping up the level. How does it change the dynamic of the cuff using a liquid rather than a gas? Mostly we have determined it to be acceptable as long as we use minimal fluid and top with air for MOP. This isn't something we do on a regular basis but occassionally it does occur.

Recently we have had cuffs rupture. Why did this happen was it the pH deteriorating the cuff or was it irresponibility in monitoring how much fluid was going into the cuff. We're not sure. Ok so heres my question? Does anybody else do this? Is there any evidence this is a good or bad idea? Have there been studies regarding the integrity of cuffs using media other than air to fill a cuff?

Thanks

I am not sure I understand. Here is what I think you said. You inflate the ETT cuff with xylocaine/HCO3. This is done for the incessant coughers. If I understand correctly... my question is what is the expected effect of the xylocaine inside the cuff? I have seen viscous lidocaine instilled into the airway for these patients with varying success, but not in the cuff. I hope there is someone with some data on this, I haven't seen any that I recall. Your question on dynamics of fluid rather that air in the cuff is very relevant. I have seen H20 used for cuff inflation in cuffs that were all silicone, supposedly this may work better as the air molecules manage to find their way out through an all silicone cuff. My biggest worry with using the H2O or any thing other than air is what if the cuff blows. What ever has been sitting in that cuff is in the airway. Seems like it might get to growing something if it sits in that cuff at 37 degrees long enough. I guess you had to deal with similar.
As to deflation and VAP, another great point. Unless you have a tube with an above the cuff suction lumen, you will be dropping some above the cuff gunk into the airway on your way to VAP city.

When you said you had cuffs rupture, it reminded me of the reason I never use anesthetic agents for lubrication any more. If you have access to the insert from a Portex trach it states: "The use of topical aerosol anesthetic agents has been associated with the formation of pin holes in PVC cuffs. Anesthetic jellies and lubricants have been associated with complete or partial occlusion of tracheal tubes. I saw this years ago and have just avoided all topical anesthetic agents coming in contact with my airways since. I realize this is from the trach insert, but aren't the trachs and ETT cuffs made of the same material? I have an insert from a Shiley Perc. it mentions nothing about this that I can see, but the Bivona insert I have states: "Use only water soluable lubricants with this tube. Use of petroleum based lubricants or topical anesthetics can damage this tube". I am wondering if you got a little more than a pinhole due to a reaction of the xylocaine with the PVC. Not something I have ever been a witness to, just something that makes me wonder.

Hi Gary:

Sorry I tend to be a little verbose. Yeah simple question have you any evidence that xylocaine will degrade the integrity of a cuff?

Most of the evidence is Anaesthesiology based of use for xylocaine in a cuff. Same reason for using it as a viscous fluid I suggest. My rational, weak as it is, was for those who are simply bucking the tube. Seems to be effective in most cases in providing a small amount of local anaesthesia.

One of our Intensivists who doubles as and Anaesthetist brought this to us a few years ago and since we have adopted a policy to use xylocaine safely. He had some papers to back up his logic. The use of bicarb was to change the pKa of the xylo making it more permiable to the membrane providing a more rapid onset of action.

The question has existed right from the beginning. What will this do to the integrity of the cuff. First of all its a low pressure high volume cuff. They are meant for air. Logically air should fill it. Fill it with a fluid this changes the pressure of the cuff and defeats the purpose of it in my opinion. Second, is the notion that since xylocaine is neither air nor water the pH of the fluid may have negative effects on the silicone thus resulting in possible rupture. This is purely speculation on my part, but we have had two cuffs rupture for no good reason. In both instances the cuffs contained xylocaine and bicarb.

I appreciate what you mentioned about not using xylo as a lube. I did not know this. Thank you very much. It would stand to reason not to use petroleum based products due to the chemical volatility involved when mixing oxygen and petroleum. If pin wholes develope from using xylo on the outside of a cuff it would stand to reason that xylo on the inside of the cuff(especially in a 4% concentration) would generate just a likely a result.

Here are some papers on the use of xylo in cuffs:

Can J Anaesth. 1999 Jan;46(1):82-6.
Can J Anaesth. 2000 May;47(5):412-4
Anesth Analg. 2005 Nov;101(5):1536-41
Eur J Pharm Sci. 2001 Jun;13(3):319-23
J Clin Anesth. 1997 Aug;9(5):394-7
Reg Anesth. 1990 Jan-Feb;15(1):37-40


On the other hand little research has been done on the effects of long term use of xylo in a cuff:

Masui. 1997 Nov;46(11):1508-14



And one paper I found demonstrates that xylo use can actually cause permanent nerve damage however it is slightly out of context:

Exp Neurol. 1986 Oct;94(1):166-73



As far as VAPs are concerned this should be of utmost concern. In most cases the xylocaine is added as an after thought and thus presents the possibility of macro aspiration even under the most sincere circumstances. I appreciate your comments here and have suggested this for further discussion with my collegues.

So I guess my question remains has anyone found evidence that xylocaine is bad for endotracheal tube cuffs. I would concur however that as a current practice it seems like a bad idea.
Thanks

Fin,
thanks for the references, very enlightening. I am very curious, is the use of lidocaine in airway cuffs being done in any other facilities? Any cuff probs if so? Thanks

HI Gary
To be honest I have not had the opportunity to inquire of other facilities. I have recieved patients from other places who have had water in the cuff for flight. I no that a near by larger center hospital has also seen this method used.
Aside from that Im not certain.