Endotracheal Intubation in Cats

RE: Endotracheal Intubation in Cats

Evelyn Barbour-Hill — Mon, 13 Aug 2018 15:55:12 GMT

[quote user="Chris Milligan"]

[quote user="Evelyn Barbour-Hill"]If you haven't, get your finger a little deeper in.[/quote]

fabulous way to get bitten when the cat sneezes or you didn't give enough induction

[/quote]

Not sure why either of those eventualities is at all likely, but in any case your finger is down the middle so you can't get bitten by anything but incisors. Same as when you are giving a cat a tablet.

RE: Endotracheal Intubation in Cats

Wren — Mon, 13 Aug 2018 15:52:16 GMT

[quote user="David Mills"]I was teaching a student this week and apparently at college they were taught not to pull the tongue too far rostrally. God knows why. I showed how pulling it as far rostrally and ventrally as possible, thereby moving the lower jaw open, allows you to see the larynx easily.[/quote]

Damage to the hyoid apparatus? Pulling on tongues in horses is pretty frowned upon these days for this reason.

RE: Endotracheal Intubation in Cats

Chris Geddes — Mon, 13 Aug 2018 13:43:29 GMT

[quote user="Sarah Keir"]

Apparently humans are very difficult to intubate which is partly why igels are used. Human anaesthetist could not believe how easy it was to intubate a dog!

[/quote]

I asked our MD, human anaesthetist and inventor of i-gel, Dr Nasir about this. He tells me that intubating a human is about the same difficulty as a cat, more difficult than dogs, easier than a rabbit. Certainly not difficult for a trained anaesthetist. He invented i-gels solely for improved safety and comfort, not ease of use.

RE: Endotracheal Intubation in Cats

Lucy Fleming — Mon, 13 Aug 2018 11:27:28 GMT

[quote user="Niall Taylor"]

[quote user="robloxley"]If you're worried about bulbs or batteries, keep spares, or frankly you can buy a whole, disposable laryngoscope (they seem to be single use items in people?) for less than a tenner[/quote]

But why, when it is all unneccesary?

Niall

[/quote]

Because I like them, and I work in the same practice as you?

The light in x-ray is particularly terrible for intubating things...

RE: Endotracheal Intubation in Cats

Chris Geddes — Mon, 13 Aug 2018 10:30:00 GMT

[quote user="Jill Butterworth"]

[quote user="vetbl.locum"]I would like to see a v gel for dogs but that is doubtful any time soon[/quote]

You can already buy laryngeal masks,which are similar but not exactly the same. They are used a lot in humans for short procedures.

[/quote]

Sorry for delayed reaction.

V-gel for dogs will be coming sooner than you think. I can't give a date, but I expect within the next 12 months.

Re your comments about humans Jill...there are two main brands of Supraglottic Airway Device (SGAD) available for humans - the Laryngeal Mask Airway (LMA) and the i-gel - the latter being developed by Dr Muhammed Nasir, who subsequently developed the v-gel. they are used a lot in humans for procedures short and long, and also for resuscitation. Most ambulances in the UK, US and elsewhere have an i-gel for example. A friend who had a heart attack whilst in hospital had an i-gel popped in.

Incidentally, re the terminology - the generic name is SGAD, but "laryngeal mask" is often used as it was the first, much like "Hoover" has for vacuum cleaners! The main difference between an LMA and a i-gel is that the LMA has an inflatable portion whereas an i-gel does not. LMA is more suitable for dogs than human i-gel for this reason, but of course dog v-gel will be vastly superior as specifically designed for dog anatomy.

Anaesthetists I have spoken to so far have particularly excited about the potential for dog v-gel use in recovering brachys.

Chris

RE: Endotracheal Intubation in Cats

Chris Milligan — Mon, 13 Aug 2018 06:45:40 GMT

[quote user="Evelyn Barbour-Hill"]If you haven't, get your finger a little deeper in.[/quote]

fabulous way to get bitten when the cat sneezes or you didn't give enough induction

RE: Endotracheal Intubation in Cats

Evelyn Barbour-Hill — Mon, 13 Aug 2018 02:16:12 GMT

[quote user="Charlotte Marshall"]I seem to recall something about excess traction on the tongue potentially causing nerve damage. Not that it is something I worry about when I am tubing cats.[/quote]

The important word is "excess". Some male veterinary students can be, er, a little heavy-handed.

But there's no need to pull it as far ventrally and rostrally as possible. Your one finger that's pulling it forward should also be depressing the dorsum of the tongue and you'll have a clear view. If you haven't, get your finger a little deeper in.

RE: Endotracheal Intubation in Cats

Evelyn Barbour-Hill — Mon, 13 Aug 2018 02:09:13 GMT

[quote user="robloxley"]

[quote user="Evelyn Barbour-Hill"]You do need a light shining into the mouth. If the room light is at the wrong angle, use your operating light.[/quote]

Or use a laryngoscope?

[/quote]

Har har. I knew someone would say that.

But a laryngoscope needs someone to hold it Daylight comes through the window all by itself. The ceiling lights are fixed (probably) on the ceiling.

Just making a point that applies to surgery too, if you find something difficult it may be just that you need more light.

RE: Endotracheal Intubation in Cats

Charlotte Marshall — Mon, 13 Aug 2018 00:24:42 GMT

[quote user="David Mills"]

I was teaching a student this week and apparently at college they were taught not to pull the tongue too far rostrally. God knows why. I showed how pulling it as far rostrally and ventrally as possible, thereby moving the lower jaw open, allows you to see the larynx easily.

[/quote]

I seem to recall something about excess traction on the tongue potentially causing nerve damage. Not that it is something I worry about when I am tubing cats.

RE: Endotracheal Intubation in Cats

Rob Loxley — Sun, 12 Aug 2018 21:05:26 GMT

[quote user="Evelyn Barbour-Hill"]You do need a light shining into the mouth. If the room light is at the wrong angle, use your operating light.[/quote]

Or use a laryngoscope?

RE: Endotracheal Intubation in Cats

Evelyn Barbour-Hill — Sun, 12 Aug 2018 20:53:02 GMT

[quote user="Neil Wheadon"]

[quote user="David Mills"]Just have them put the tube tie behind the upper canines and pull upwards, you can then pull ventrally and rostrally on the tongue and it will appear.[/quote]

Yup, I do that

If you then place your little finger under the larynx - on the skin side (with the hand you are pulling on the tongue) and press gently, this makes the larynx even more obvious

Neil

[/quote]

What's a tube tie? Don't use 'em.

Nurse supports head with one hand, grasps maxilla just behind canines with the other – needs only finger and thumb to do this with a cat. Neck should be comfortably extended. If you are right-handed, head should be pointing to your left. You use your non-dominant hand to lightly grasp cat's chin or lower canines with thumb and index finger, simply to enable you to pull tongue forward with your forefinger alone (easy in a cat because tongue is spiny.) You can then either see the larynx, or palate and ventral surface of epiglottis. If need be, use the nozzle of the Intubeaze to flip the palate up. Do the regulation two squirts. Put the cat down and relax for at least thirty seconds. Repeat the positioning. Now with your best hand you poke the tube in, wiggle it in pharynx to gather plenty of saliva or mucus, use it to flip the palate up; then if you can't see the larynx properly it's because you need to ask the nurse to adjust the angle or straighten the neck a bit more. Usually then the tube slides straight in. But if the larynx stays shut, don't keep poking it. Be patient, it will open eventually.

If you have to do it without assistance, use your non-dominant hand's fingers to both raise the head and open the mouth. Hold an upper canine with finger and thumb and use your ring and little fingers to push mandible down. The cat's head should be hanging on your forefinger by the upper canine: this will get about the desired angle and neck extension. Your index finger is then available to pull the tongue forward.

A lot of words there, but it's really quite simple, and a sight easier to demonstrate than describe.

Oh, one other thing. You do need a light shining into the mouth. If the room light is at the wrong angle, use your operating light.

RE: Endotracheal Intubation in Cats

Michael Woodhouse — Sun, 12 Aug 2018 20:07:00 GMT

[quote user="David Mills"]

It comes around this topic.

Studies are naturally limited by lack of mechanistic cause/effect (like the Brodbelt anaesthetic study which has reached almost Messiah status) and, like surgery studies, by the inherent inability to remove bias of the skill of the operator from the process.

[/quote]

David, I agree. That said most of us won't do 80,000 anesthetics in our careers. Small factors and selective memory may mean that we miss small details that can have a big effect. We are talking about death of owned animals here, each one is very significant to the owner.

My take from the paper is that tubing cats adds unnecessary extra risk and should only be use when required. I don't tube cats for short procedures. I'm sure all the vets in the study that had maybe a single animal die could tell you how they safely tube cats......

We need more big pieces of research like this in vet medicine. We also need to take heed of them and stop going down the "it will never happen to me with my perfect technique" denial.

RE: Endotracheal Intubation in Cats

Neil Wheadon — Sun, 12 Aug 2018 18:03:40 GMT

[quote user="David Mills"]Just have them put the tube tie behind the upper canines and pull upwards, you can then pull ventrally and rostrally on the tongue and it will appear.[/quote]

Yup, I do that

If you then place your little finger under the larynx - on the skin side (with the hand you are pulling on the tongue) and press gently, this makes the larynx even more obvious

Neil

RE: Endotracheal Intubation in Cats

David Mills — Sun, 12 Aug 2018 17:24:09 GMT

[quote user="Jill Butterworth"]o visualise the larynx in a cat easily, I need it to be almost suspended by the upper canines.[/quote]

Just have them put the tube tie behind the upper canines and pull upwards, you can then pull ventrally and rostrally on the tongue and it will appear.

Never seen the point of pulling the skin forward on the neck personally.

RE: Endotracheal Intubation in Cats

Jill Butterworth — Sun, 12 Aug 2018 16:50:32 GMT

[quote user="Niall Taylor"]Not using a laryngoscope isn't 'tubing blind'[/quote]

I agree, but it can be dependent on the nurse assisting. To visualise the larynx in a cat easily, I need it to be almost suspended by the upper canines. In a difficult case, it also can help if they use their free hand to pull the skin of the ventral neck forward. I only began to have difficulty intubating cats when I needed glasses, I didn't realise immediately.

There is also a technique of suspending a cat's head by placing the forefinger of your non dominant hand behind the canines order that you can intubate a cat alone. I'm of the old school which thinks that it is very useful to be able to know how to do things on your own, so you are not floored if two emergencies come in at once or your nurse has to leave the room unexpectedly.

https://www.youtube.com/watch?v=H0gvM1yGVeg

RE: Endotracheal Intubation in Cats

Niall Taylor — Sun, 12 Aug 2018 07:28:00 GMT

Not using a laryngoscope isn't 'tubing blind', it is perfectly possile to visualise the larynx etc without the need for technology. Human anaesthetists need laryngoscopes because our larynxes have shot down our necks over the last few hundred thousand years of evolution. Our anatomy is different to that of cats and dogs.

Niall

RE: Endotracheal Intubation in Cats

Virginia Campbell — Sun, 12 Aug 2018 00:48:07 GMT

I don't find blind intubation very easy in cats. I like being able to see the larynx to aim with the lignocaine spray and then to sit with the laryngoscope watching the closed ones waiting to pounce with my tube when they open briefly, or to gently prise open the stubborn ones using a K wire down the tube as a stylet. I wouldn't like to do that blind as the more you touch them the more you annoy them.

Agree about tubing brachys - a big blocky head for the nurse to lift and no maxilla to speak of for her to get hold of, tacky froth everywhere down the back if it has been even mildly worked up at any stage beforehand, fat slippy tongue to pull forward, redundant blobby pharyngeal tissue that becomes odematous at the drop of a hat, long soft palate flopping around in the way and even getting aspirated into the trachea sometimes, a tiny trachea and a crappy little hypoplastic larynx with utterly feeble lateral movement of the pathetic excuses for arytenoids. All while it's going from preoxygenated pink to horrible blue.

I do occasionally tube blind on the easy ones to try to keep my hand in a bit but I much prefer the scope. I reckon if you usually tube blind you should occasionally use the scope, to get used to assessing the length of normal soft palates and the shape and movement of normal larynxes, the better to judge whether a soft palate resection or tieback is likely to do the next abnormal creature any good.

RE: Endotracheal Intubation in Cats

Rob Loxley — Sat, 11 Aug 2018 17:51:49 GMT

[quote user="Anthony Todd"]

[quote user="vetbl.locum"]Dogs have larger airways so effect of cuff not as important[/quote]

The cuffed tube [which hasn't been grossly over-inflated before!] is not much bigger than uncuffed, certainly not significantly.

[/quote]

The internal diameter of an uncuffed tube is higher than the internal diameter of a cuffed tube; the resistance to flow down a tube (i.e. the main reason for not using a tiny tube) is proportional to the 4th power of the radius, so increasing the internal diameter by only a small amount (maybe half to 1 mm) makes a big difference when using tubes with small internal diameters (2-5mm) to start with. [Before someone points out, yes airflow down an ET tube isn't a perfect non-compressible medium with perfect laminar flow, but you get the idea]

[quote user="Anthony Todd"]Human laryngoscopes were too big and obstructive[/quote]

They do come in different sizes; premature babies, for example, do get intubated... I like the miller size 1 for most things but have a couple of other sizes.

RE: Endotracheal Intubation in Cats

Jill Butterworth — Sat, 11 Aug 2018 11:23:17 GMT

[quote user="vetbl.locum"]I would like to see a v gel for dogs but that is doubtful any time soon[/quote]

You can already buy laryngeal masks,which are similar but not exactly the same. They are used a lot in humans for short procedures. They are easy to use because they can be placed blind, so good to have in an emergency box so that nurses who may be less experienced at ET placement can use them or for those difficult moments in an animal losing consciousness, and much better than a mask as the tongue can be pulled forward from the larynx.

RE: Endotracheal Intubation in Cats

Anthony Todd — Sat, 11 Aug 2018 11:07:44 GMT

[quote user="vetbl.locum"]Dogs have larger airways so effect of cuff not as important[/quote]

Are you sure a 3 kg dog has a larger diameter trachea than a 3 Kg cat?

The cuffed tube [which hasn't been grossly over-inflated before!] is not much bigger than uncuffed, certainly not significantly.

Have a look at your tubes in the rack. If the small ones have a crumpled saggy cuff they have been grossly overinflated because they were too small for the trachea and a much larger size should have been chosen.

BTW the pointy twinlite attachment [clear plastic thingy that lit up] I found helpful when tubing small animals, Human laryngoscopes were too big and obstructive.

RE: Endotracheal Intubation in Cats

vetbl.locum — Sat, 11 Aug 2018 08:08:23 GMT

[quote user="Anthony Todd"]

Why un-cuffed in cats but cuffed in dogs, which seems like an elephant in the room?

[/quote]

I believe due to small airway diameter in cats and ratio of cuff versus tube ie use of cuffed limits tube diameter

Dogs have larger airways so effect of cuff not as important

Rgds

RE: Endotracheal Intubation in Cats

Anthony Todd — Fri, 10 Aug 2018 23:27:46 GMT

Why un-cuffed in cats but cuffed in dogs, which seems like an elephant in the room?

Back in the day cats were seldom tubed and never for routine surgery or dentals.

I've saved one or more cats with mouth-to-mouth.

RE: Endotracheal Intubation in Cats

David Mills — Fri, 10 Aug 2018 22:11:16 GMT

One of our hospitals has a cool laryngoscope, LED with plastic transmission tubing for the light, lasts ages.

The use/not for me entirely depends on the lighting of the room or the conformation. Some brachys can be bastards to tube.

RE: Endotracheal Intubation in Cats

Niall Taylor — Fri, 10 Aug 2018 21:35:59 GMT

But why, when it is all unneccesary?

Niall

RE: Endotracheal Intubation in Cats

Rob Loxley — Fri, 10 Aug 2018 21:31:39 GMT

[quote user="Niall Taylor"]But if it is perfectly possible and very easy to tube cats and dogs wthout a laryngoscope why would anyone want to do so WITH one - it simply introduces an extra, unnecessary complication. And what happens when the batteries are flat or the bulb has blown?[/quote]

You could say the same of many bits of equipment that may be considered 'luxuries' - pulse ox, capnograph, oscillating saw, ultrasound, laparoscopy, diathermy etc.
If you're worried about bulbs or batteries, keep spares, or frankly you can buy a whole, disposable laryngoscope (they seem to be single use items in people?) for less than a tenner