Perioperative Anaesthetic Complications and a Spotlight On Inhalational Therapy

This month Dr. Yaiza Gomez-Meijias talks to Dr. Jenny Brown about perioperative
anaesthesia complications. We're also featuring our monthly JFMS clinical spotlight
interview in which Dr. Kelly St Denis discusses inhalational therapy for feline
inflammatory airway disease with Dr. Michael  Barchilon (See More…)

To begin our episode, we sit down with our ISFM 2023 Delegates Choice Award Winner, Dr Jenny Brown, as she shares the results of her abstract entitled 'Perioperative Anaesthetic Complications In Healthy Cats Undergoing Anaesthesia For Neutering In First Opinion Practice'.

We are then joined by Dr Michael  Barchilon, to discuss his latest JFMS article 'Breathe easy: Inhalation therapy for feline inflammatory airway disease'. We learn the differences between asthma and chronic bronchitis as well as the treatment options you can consider for your patients.

For further reading material please visit:

https://go.icatcare.org/AbstractJennyBrownPamelaMurison

https://journals.sagepub.com/doi/epub/10.1177/1098612X231193054

View The Transcript Here

Host:

Nathalie Dowgray, BVSc, MANZCVS, PgDip, MRCVS, PhD, Head of ISFM, International Society of Feline Medicine, International Cat Care, Tisbury, Wiltshire, UK

Speakers:
Yaiza Gomez Mejias, LdaVet MANZCVS (Medicine of Cats) CertAP (SAM-F) Acr AVEPA, ISFM Community Coordinator and small animal clinician

Jenny Brown, BSc BVM&S MRCVS MANZCVS, RCVS advanced practitioner in veterinary anaesthesia and diagnostic imaging, and clinical director of Bracken Veterinary Centre.

Kelly St Denis, MSc, DVM, DABVP (Feline), 2022 ISFM/AAFP Cat Friendly Veterinary Environment Guidelines Co-Chair, St Denis Veterinary Professional Corporation, Powassan, Ontario, Canada

Michael Barchilon, DVM, DACVIM, Clinical Instructor and published JFMS Author

For ISFM members, the full recording of this discussion is available for you to listen to at portal.icatcare.org. To become an ISFM member, or find out more about our Cat Friendly schemes, visit icatcare.org

Creators and Guests

Host

Nathalie Dowgray

What is Chattering with iCatCare?

Welcome to Chattering With iCatCare, the official monthly podcast of International Cat Care, hosted by Yaiza Gomez-Mejias (Veterinary Community Co-ordinator). Each month, we chatter about cats and cat-friendly practices with industry experts and contributors to The Journal of Feline Medicine and Surgery. Each episode contains highlights from our longer discussions and interviews, which are accessible to iCatCare members at portal.icatcare.org. If you would like access to our full episodes, would like to become an iCatCare Veterinary Society Member, or find out more about our Cat-Friendly schemes, visit icatcare.org.

Nathalie Dowgray: Hello welcome
to the September 2023 episode of

Chattering With ISFM. I'm
Nathalie Dowgray head of ISFM

and host of this month's
podcast. First up this month Dr.

Yaiza Gomez-Mejias is speaking
with Dr. Jenny Brown on her ISFM

2023 Delegates Choice
Award-winning abstract,

perioperative anaesthetic
complications and healthy cats

undergoing anaesthesia for
neutering in first opinion

practice. We're also featuring
our monthly JFMS clinical

spotlight interview. This month
Dr. Kelly St Denis discusses

inhalational therapy for feline
inflammatory airway disease with

Dr. Michael Barchilon. We hope
you enjoy this episode.

Yaiza Gomez-Mejias: And at the
ISFM Congress in Dublin, Jenny

presented the results of her
study on perioperative

anesthetic complications in
healthy cats undergoing

anesthesia for nurturing. We
neuter cats on a daily basis.

Would you mind summarising the
main results of your study for

the vets who are listening to
this podcast?

Jenny Brown: Yeah, sure. So we
looked at, it was a

retrospective chart analysis.
So we looked at anesthetic

charts from, just over a
thousand cats and looked at a

few different things. So the
first thing looked at obviously,

was that was the mortality rate.
And sadly, we did have one cat

in the study who did die. It
wasn't really a big enough

numbers in the study to really
come to conclusions about that,

but it was consistent with
previous studies in similar

populations. Next sort of
thing, we looked at the most

common complications that have
been identified in these cats,

and our top three were
hypotension, so low blood

pressure, bradycardia, so low
heart rate, and hypothermia, so

cold temperature. And we made
the definitions by doing like a

literature review first, so we
knew what we were looking for.

And then our final bit was
looking at any factors that were

associated with an increased
instance of these complications.

And so really the most stunning
one was that a longer anesthetic

duration was associated with
increased likelihood of all

three of our top complications.
And we had a few other things.

So the drugs the animals
received, because it was a

retrospective study, they'd just
received whatever the vets and

nurse had had chosen to give
them. So hypotension was

associated with an acepromazine
pre-med, whereas bradycardia was

associated with medetomidine,
which is probably unsurprising

for people who know how the
drugs work. So there were some

interesting sort of drug effects
as well.

Yaiza Gomez-Mejias: As an
advanced practitioner in

anesthesia, would you like to
share any recommendations or

tips regarding the use of
isoflurane and medetomidine?

Jenny Brown: So think in terms
of isoflurane, that definitely

was potentially linked with an
increased risk of hypothermia if

they had a higher maximum
percent of isoflurane. So across

quite a lot of complications, we
were seeing that the higher

isoflurane, the more likely we
were to see these complications.

So I think it is important to
think about how we can minimise

the isofluorine dose. So using
multimodal analgesia, making

sure that when we do see these
things like low blood pressures,

we're turning the vaporizer down
and looking at other ways to

provide analgesia for them.
Medetomidine, other than being

associated with bradycardia,
didn't seem to be a risk factor

for any of the complications.
And I think when we look at

bradycardia, we looked at the
literature definition. It

probably wasn't in a population
of cats who were receiving Alpha

Twos because quite a lot of
literature is when we were back,

when we were using acepromazine.
So I would say don't be worried

about using it

Yaiza Gomez-Mejias: Thank you. I
think that's going to be very

helpful for many people. Thank
you so much.

Jenny Brown: Oh, thank you very
much.

Nathalie Dowgray: And now over
to Dr. Kelly St Denis. She's

speaking with Dr. Michael
Berchilon about his JFMS

clinical spotlight article.
Breathe Easy. A review of

inhalational medications for
feline inflammatory airway

disease. Don't forget JFMS is an
open access journal now and the

link to read the full article is
in the show notes.

Kelly St Denis: What's the
difference between asthma and

chronic bronchitis and what's so
important about knowing why it's

different?

Michael Barchilon: I think
there's a couple reasons. I

think practically probably the
most important thing is that

they don't tend to have airway
collapse, which is one of the

hallmarks of cats with asthma.
So they should be treated

differently, because they don't
have airway collapse. I think

that's probably the most
practical difference. The other

thing I think, that's a little
bit tangential, but I think is

important is that if we diagnose
a patient with asthma, one of

the hallmarks of asthma is that
they have eosinophilic airway

disease. And if we can prove
that, then we know that there

are other things that cause
eosinophilia, like heartworms,

lung worms, even just knowing
that it's eosinophilic versus

neutrophilic, which is typical
of bronchitis patients, then we

still can further pursue
additional diagnostics to make

sure the patient truly has
asthma, and not heartworm

disease, for example.

Kelly St Denis: Yep. Thinking
about steroids, probably a lot

of cats we were talking about
earlier end up on oral steroids.

And of course, that delivers
steroids to the entire system,

whereas we have the option to
deliver steroids directly to the

lungs, which is probably more
ideal. But there is a lot of

pushback, it can be really
difficult to get caregivers

interested in this. I think it
can be quite extensive in time,

but certainly worth the while.
And as you say, if people are

clicker training or working with
their cats at home, that's just

something you could start
working towards should they ever

need it. What's your sense of
how long it would take to train

a cat if you were just cold
turkey, starting to train them?

Michael Barchilon: Yeah, so my
conversations with owner is

typically about a month. My
conversations with caregivers

tends to be somewhere in the
range of, it's gonna take time.

Let's try Prednisolone for a
month, and then slowly

transition over to that 'cause I
think the worst thing to do is

to accelerate or try to
accelerate it and force a cat to

to do inhalation when it doesn't
want it. And then you've totally

broken the trust. I typically
give them a couple weeks to a

month, for that slow
progression.

Kelly St Denis: Yeah, and it
seems like it's, it just takes

patience. In the article it says
inhaled glucocorticoids are not

immediate acting, so it's
recommended to overlap treatment

with oral glucocorticoids
anyway, so as you say, that kind

of gives them time. We're
talking about inhalational

therapy and one thing that I'm
not very familiar with is

nebulizers. so they, I don't
know if it's because they're not

readily accessible or well
promoted or just that we get

what we need for asthma out of
the inhalational therapy through

the inhalers and masks. Did you
wanna tell us a little bit about

nebulizers and what kinds are
available and what role they

would have for us in practice?

Michael Barchilon: Yeah, so
there are, a couple different

kinds of nebulizers and they all
have, just like everything, I

guess, pros and cons. Probably
the most common one that would

be used for vet med would be the
jet nebulizers. They tend to be

the cheapest nebulizers. But
what nebulizers do is they

basically aerosolize whatever
medication you, you're doing,

versus something like a puffer
like you, you described, it's

already aerosolized and you're
just delivering it. So a

nebulizer changes the
composition of whatever you're

giving. So jet nebulizers, can
be used, they tend to be a

little bit loud, which obviously
has its downsides but they tend

to be relatively cheap and so
contrast that with, something

like mesh nebulizers, which,
aerosolize things through a

mesh. And those tend to be more
expensive. But are much more

quieter. And there are studies
looking at different types of

nebulizers, and there's also
like piezoelectric, Which is in,

in the middle, if you will.
There are no studies really

comparing the efficacy of these
things in cats and there's a

surprisingly little amount of
information comparing the

efficacy of them in humans.
Different nebulizers can or

can't be used with certain
medications just because of the

way they nebulize things. So if
you do decide to get a

nebulizer, you have to make sure
that whatever drug you're

nebulizing can be used with that
type of nebulizer. I think that

nebulizers could represent a
really good way to, to

aerosolize medications. and one
of the things that I think,

potentially could be, in the
future is trying to nebulize

molecules that are even smaller
to try and get down to the lower

airways 'cause if you think
about a cat, their airways are

already so small. Most of what
is available, there, there are

obviously some veterinary
products, but not uncommonly

people will buy human nebulizers
which will aerosolize the

medications for human airways. I
think that there are going to be

some smaller molecules that,
that will be available. But as

far as I'm aware, they're not
currently available for Vet Med.

And the other big problem here
is price and so nebulizers, you

have to buy the machine. It's,
it can be loud. It can be

expensive, but I think
nebulizers potentially can offer

a very good way for us to get
medications to our patients, but

I think we're really just in the
infancy of inhalational medicine

to begin with. But I think that
they're promising. I think that

they're promising.

Kelly St Denis: Yeah, I hadn't
really given it any thought

before. I was reading the
article. I'm like, wait a

second. I haven't really thought
about nebulizers before, because

we do focus so much with asthma
and inhalational therapy with

the chambers.

Michael Barchilon: I think the
chambers are, are relatively

easy, and they're relatively
cheap compared to the

nebulizers. Whether they're
better or worse than nebulizers.

I still think I think we need to
figure that out.

Kelly St Denis: Yeah. And it may
be just like you said, what

applications each has that may
be different. So at least for

now, we're, we're doing well
with what we have.

Nathalie Dowgray: If you are an
ISFM member, don't forget, you

can listen to the full version
of this podcast and all the

other ISFM member benefits,
including congress recordings,

monthly webinars, the clinical
club, the discussion forum, and

much much more at
portal.icatcare.org. If you're

looking for more free CPD, we do
have two open access webinars in

October from IDEXX and Purina we
have diagnosing and managing

feline multiple morbidities,
simple answers for complex

cases. And that's with Rebekah
Mack-Gertig and Marge Chandler

on the third of October. From
Dechra, on the 10th of October,

we have uraemic toxins, why we
should be concerned? And that's

with Dr. Jessica Quimby. We'll
be back again next month. If you

don't want to miss out, do make
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