I have resisted chatting about this marmite topic, simply because of the sheer volumes of worms that come out of this particular can. Let’s open that can and here we go.
Performing any kind of ventilation for an unconscious or anaesthetised patient requires a Cuffed Endotracheal tube (ETT) We need a seal around the tube and the trachea otherwise when we give the patient a breath, we will lose that back around the ETT. There are other positives to cuffing a tube, anaesthetic gas leakage and reducing the risk of foreign material entering the airway. Especially important during a dental for example. Fundamentally we cannot perform intermittent positive pressure ventilation (IPPV) without a cuffed tube.
During a crash ventilation is still indicated in vetmed and so IPPV will be necessary.
Yet many of the practices I visit are horrified by the suggestion of using a cuffed ETT. Sadly, cats are overrepresented for tracheal injury, and this was backed up by a VDS article. Before we go into that though I want you think about how you used to cuff the ETTs of cats.
How we’ve always done it…..
I tell you my version which is set around 14 years ago mind. The vet would place the orange cuffed ETT into the cat’s trachea. Then using a 5ml syringe we would put a little bit of air into the pilot balloon. Give that balloon a little squeeze. Fold over the tubing between the balloon and the tube which would then be secured with the cap of a syringe. For those who are slightly fresher to the profession those pesky rubber tubes were a total PITA. You could never just pop the end in and hope it would stay there. It would always pop out.
Then cuff inflated I would carry the cat into theatre. Once done I’d probably pop it over my shoulder as I went back to recover area whilst carrying the patient and the paperwork. I’m not sure we ever disconnected when moving the patient….
I spent the majority of my subsequent years in referral setting where things were very different in anaesthesia land. We cuffed the silicone tube whilst giving the bag a gentle squeeze, allowing us to stop when we stopped hearing the air escaping, still not perfect though! We also never ever carried an intubated patient. They were on a table or trolley. Their airways straight and without flopping around.
We never had an issue. Why do I mention silicone and rubber? Well high-volume low-pressure vs low volume high pressure cuffs. Check out this post for more about that.
Cuffing Safely
Great I hear you say, but where’s the evidence. Well, below are some papers to read and peruse at your leisure. Demonstrating that when done safely cuffing an ETT is reasonable. But caution should be taken and tools used to ensure we do not over-inflate that cuff. So, manometer syringes like these or this handy little device from ACE.
Am I telling you that you must use a cuffed ETT for every cat?
Absolutely not, that’s the team’s decision after having a conversation and looking the evidence.
But you will have to replace your uncuffed ETT for a cuffed one should you need to do IPPV. I don’t know about you but that’s the last thing I want to do in a crash…….
Feeling unsure about what to do in crash? Get in touch to book us in for some fun in-house training.
Further Reading about using Cuffed ETT:
https://www.scvetspecialists.co.uk/about-us/news/december-2017/airway-management-part-1
https://www.theveterinarynurse.com/content/practical/endotracheal-intubation-of-the-dog-and-cat