The Science of Decontaminating Subcutaneous Tissue: How Much Lavage is Enough?

Send us a text

Have you ever wondered exactly how much lavage solution is needed to effectively decontaminate a surgical wound? This question, so common in veterinary operating rooms, finally has an evidence-based answer.

Dr. Vanna Dickerson and veterinary student Cody Westmoreland from Texas A&M University join us to discuss their groundbreaking research on subcutaneous tissue lavage. Their study, published in the American Journal of Veterinary Research, reveals that using just 2.5 milliliters of sterile saline per centimeter of incision length can significantly reduce bacterial counts below infection-causing thresholds. This finding challenges previous assumptions and provides surgeons with a practical reference point for clinical decision-making.

The conversation explores the persistent challenge of surgical site infections, which affect 7-10% of patients following GI surgery despite our best preventive efforts. Dr. Dickerson shares her surprise at discovering that relatively modest lavage volumes produced significant bacterial reduction in their silicone model, though she suggests using approximately 10 mL per centimeter in clinical practice to account for the complexities of living tissue. Westmoreland, who brought his experience in surgical infection prevention to this veterinary student research project, discusses plans for future clinical validation studies and potential applications of artificial intelligence in wound management.

Beyond the science, we delve into the researchers' backgrounds, including Westmoreland's journey from operating room technician to veterinary student and Dr. Dickerson's collection of office dinosaurs that "make it impossible to have a bad day." Their work exemplifies how relatively simple interventions can significantly impact patient outcomes and client financial burden in veterinary practice.

Listen now to discover how this easy, inexpensive technique might improve your surgical outcomes, and don't forget to leave us a rating and review on your favorite podcast platform!

Open access article: https://doi.org/10.2460/ajvr.25.01.0030

INTERESTED IN SUBMITTING YOUR MANUSCRIPT TO JAVMA ® OR AJVR ® ?

JAVMA ® : https://avma.org/JAVMAAuthors

AJVR ® : https://avma.org/AJVRAuthors

FOLLOW US:

JAVMA ® :

Facebook: Journal of the American Veterinary Medical Association - JAVMA | Facebook

Instagram: JAVMA (@avma_javma) • Instagram photos and videos

Twitter: JAVMA (@AVMAJAVMA) / Twitter

AJVR ® :

Facebook: American Journal of Veterinary Research - AJVR | Facebook

Instagram: AJVR (@ajvroa) • Instagram photos and videos

Twitter: AJVR (@AJVROA) / Twitter

JAVMA ® and AJVR ® LinkedIn: https://linkedin.com/company/avma-journals

Episode Transcript

Speaker 1 (00:00):
From the makers of vet-recommended Greenies dental
treats comes an easy way tosupport your dog's wellness.
Greenies Smart Essentials dryfood delivers complete, balanced
nutrition with science-backedrecipes.
Greenies Supplements, developedby a team of PhD animal
nutritionists, offers options tohelp support healthy joints,

(00:22):
digestion and more, Whether it'smealtime or mobility support
Greenies helps you care for yourdog from the inside out.
Learn more at Greeniescom.

Speaker 2 (00:35):
You're listening to Veterinary Vertex, a podcast of
the AVMA Journals.
This episode we chat about howlavaging with at least 2.5
milliliters per centimeter ofsterile saline reduces bacterial
load in a subcutaneous tissuemodel, with our guests Vanna
Dickerson and Cody Westmoreland.

Speaker 3 (00:55):
Welcome listeners.
I'm Editor-in-Chief LisaFortier, and I'm joined by
Associate Editor Sarah Wright.
Today we have Cody and repeatguest Vanna, who I got the
opportunity to meet when I wasat Texas A&M a few weeks ago,
joining us.
Vanna and Cody, thank you somuch for taking time out of your
busy schedules to be here withus today.
Yeah, thanks so much for havingus.

Speaker 5 (01:17):
Thank you so much.

Speaker 2 (01:18):
All right, let's dive right in.
So when I was rereading yourarticle this morning, the first
thing that came to mind was thesolution to pollution is
dilution, and I feel like thatcan maybe be the title for our
episode today too.
So your HABR article providessurgeons with a reference point
for deciding what volume oflavage to use for the purposes
of decontaminating asubcutaneous space.

(01:40):
Please share with our listenersthe background on this article.

Speaker 5 (01:44):
Yeah.
So surgical site infections area recurring challenge in
postoperative management, with arelative incidence of about 7
to 10 percent following GIsurgery.
So while there's things we cando to reduce the risk, such as
aseptic skin preparation,prophylactic antibiotics and
peritoneal lavage, thesubcutaneous tissue remains a

(02:05):
potential location ofcontamination during GI surgery.

Speaker 2 (02:09):
Yeah, I think it's going to be really helpful info
for our listeners.
So definitely appreciate youboth submitting this really
important work to AJVR.
So, that being said, what aresome of the important take-home
messages from this AJVR article?

Speaker 4 (02:20):
Yeah.
So I think for me, I think whenwe have a traumatic injury and
there's pus or necrotic debriskind of staring at you in the
face, I think that's a helpfulguide for, okay, I need to
lavage and debride untileverything sort of looks clean
to my eye.
But this kind of study cameabout for me just because I
think when it's an incision youcreated, I had been asked before

(02:44):
, well, if I'm going to lavageit, how much should I use?
And I said, well, I don'treally know.
We have guidelines, you knowsomething like 200 to 300 mils
per keg if it's an abdomenseptic or something like that,
but not so much for wound orsub-Q spaces.
And so for me the take-homemessage was really just kind of
a starting point.
We did find that two and a halfmils per centimeter lavage

(03:08):
decreased it at least below that10 to the fifth per mil CFU
count.
That kind of historically we'vesaid is what we worry about
being at risk for infection.
But we did find even morereduction in bacterial counts
the higher we went, which makessense of course.
But I think for me, clinicallywhat I'll probably use is
something like 10 mils percentimeter, since probably our

(03:31):
real patient has a lot morenuances than our little silicone
model did.

Speaker 3 (03:35):
Really cool that you can model that too, vanna, well
done.
What sparked your interest inSSIs?

Speaker 5 (03:41):
Yeah, so for me.
I'm currently a vet student,but prior to starting my
veterinary education, I workedin the operating room here at
Texas A&M and my entire rolethere was helping the surgeons
to help minimize the surgicalsite infection risk to the best
of our abilities.
And having developed thatrelationship with surgical site
infection prevention and with mycurrent aspirations of pursuing

(04:03):
surgery, it only felt rightthat my project for the
veterinary medical scientistresearch training program that
occurs during the summer monthshere at A&M just had to involve
surgical site infections.

Speaker 3 (04:16):
Glad you mentioned that, Cody.
I forgot you're a vet student.
That's super cool, Well done.
You talked earlier about whatthe maybe some of the most
important findings of thearticle, but always when we do
these things, we're surprised,which then leads to more
articles and more hypotheses.
What were some of the mostsurprising findings from this
article?

Speaker 4 (04:36):
Yeah, I was surprised that the two and a half mil per
centimeter took our bacterialcounts below 10 to the fifth.
I really thought that was goingto be kind of a baby volume
that didn't really quite get itand that we would need higher.
So that was surprising to me.
I think we talk about a lot inthe article and kind of already
mentioned it.

(04:56):
I think bacterial adherence tothese silicone models is not the
same as a live animal sub-Q, sothat's probably part of it.
Same as a live animal subqueue,so that's probably part of it.
And certainly there areprobably more crevices than you
know we had in our model.
So I think still again,probably I would be reaching for
a little bit more, but that didsurprise me.

Speaker 2 (05:16):
So what are the next steps for research in this topic
?

Speaker 5 (05:18):
The next immediate step to this project would be
validating our model to actualclinical cases.
While we believe the trend inreduction with the lavage
volumes used in our model can beused to guide clinical
decisions on lavage, furtherinvestigation is definitely
needed to evaluate for thesedifferences.
We started with the modelbecause, given the relatively

(05:39):
low incidence of surgical siteinfections after GI surgery at
our institution, over 300clinical cases will have to be
required to adequately powersuch a study.

Speaker 3 (05:50):
Sounds like a multicenter study to me.
Cody, I've seen your project inyour future.

Speaker 4 (05:57):
Residency project Right there you go.

Speaker 3 (06:01):
Cody, I don't know if you have this experience in
your experience as a technicianas well, but we have a
manuscript in JAVMA that alsoshows that the vast majority of
people, whoever is doing thescrubbing, don't scrub for the
recommended amount of time.
It's pretty fascinating.
An observer they didn't knowthey were being observed
actually timed it.

(06:22):
You thought you were scrubbingfor the 10 minutes, but it was
five or four or seven or eightor whatever it is.
So that would be an interestingfactor in your next step of
research in this area.

Speaker 5 (06:35):
Yeah, that's a very interesting thought how to
definitely consider that goingforward.

Speaker 2 (06:38):
Yeah, I can send you the article, Cody, after this.
It's definitely reallyinteresting.
Got a lot of attention onsocial media as well, so happy
to pass that along.
So before we start, I was justchatting with Savannah.
Actually, how is volunteeringat the AI Headshot Lounge at
AVMED convention this year?
So AI is definitely at theforefront of my mind, driven
immersing it for the weekend.
So do you see a?

Speaker 4 (07:02):
role for AI in this area of research at all in the
future.
Yeah, I think I thought a lotabout this.
I've been always letting mystudent or house officer pick
which questions they want toanswer and they always give me
this one.
I don't know why, but I thinktwo areas.
I mean I'm actually workingwith our biomedical engineering
group here at A&M right now onwhat they're ultimately hoping

(07:24):
will be a machine learningsystem where you can image, for
example, a wound and use datafrom that to have this machine
tell you I think this wound isgoing to heal in two weeks, or I
think X is wrong with the phaseof wound healing.
So I think that's one area thatwe potentially could see this.
And I think the other thingthat could be useful is,

(07:46):
especially for a particularpractice.
It probably would be relativelysimple to set up a system where
you, you know, kind of say,okay, I had a surgical site
infection in these 10 cases thisyear and use sort of an AI
system to look at all of thekind of different variables, to
look for patterns.
I think those are kind of twoareas that I could see it

(08:07):
becoming useful for infections.

Speaker 2 (08:09):
For those of you just joining us, we're discussing
decontaminating subcutaneoustissues and linear surgical
wounds with our guests Vanna andCody.

Speaker 3 (08:17):
Hey, cody, even though you're a veterinary
student, you have a lot oftraining, and how did that help
you to prepare to write thisarticle?

Speaker 5 (08:24):
Yeah, so my undergraduate degree was in
biomedical sciences, but also,like I mentioned, for this
project, I participated in theVeterinary Medical Scientist
Research Training Program, whichis a 13-week-long program
during the summer here at A&M,and this program held weekly
seminars and topics likescientific writing and
statistics, which really aidedme when I was first writing this

(08:47):
article, and, of course, Icouldn't have done it without my
mentor, dr Dickerson.

Speaker 4 (08:53):
Yeah, I'll add.
I think most of the vet schoolsrun a VMS RTT, so if there's
anybody listening that you knowmaybe is a vet student and
potentially interested inresearch, it's a great
opportunity, very cool.

Speaker 2 (09:05):
We love to see veterinary students' names in
our journals.
And, Cody, have you heard ofour journal awards?
I know I think Vanna has.

Speaker 5 (09:12):
I have yes.

Speaker 2 (09:13):
Awesome, very cool, very cool, great.
See, the word is spreading.
So for those of you listenersthat maybe don't know, we do
give awards to students andhouse officers as well for
articles that are published inour journals.
So we take rolling nominationsthey close in March every year
and then our judging panel looksat the articles and then we
select winners.
So very cool.
So now we got to move on to thefun part, I think, of this

(09:36):
episode.

Speaker 4 (09:58):
As you know, van, I get this question a lot.
This is a very importantquestion for our listeners.
What for things like packingoff the GI before you cut into
it, changing gloves, changinginstruments for closure?
But at least for me it makes mefeel a lot better that it's
kind of one more step that wecan do to hopefully prevent
surgical site infections that'snot giving systemic antibiotics.
So I think that's my takeawayfrom this.

(10:20):
That I think is important isthis is an easy thing that you
can do.
It's cheap, quick, so somethingyou can add to a repertoire to
hopefully decrease your surgicalsite incidents.

Speaker 2 (10:30):
And on the other side of the relationship, what's one
thing clients should know aboutthis topic.

Speaker 5 (10:36):
Yeah.
So while we cannot cannotpredict or prevent the risk of
surgical site infectionsentirely, our hope is that
utilizing lavage on thesubcutaneous tissues will help
mitigate this risk further.
Not only can this improveoutcomes for our post-operative
patients, but it should alsoease the financial burden these
complications can have on ourclients.

Speaker 3 (10:56):
Hey, cody, while we have you and this will date you,
maybe we're always surprised.
What was the first concert youattended?

Speaker 5 (11:02):
In 2008,.
I went to the Houston Life'sLock Show and Rodeo and I was
forced to go to this concertwith my sister, but it was the
Hannah Montana concert.

Speaker 3 (11:14):
I don't think we've gotten that answer?

Speaker 2 (11:15):
Have we Sarah?
No, we haven't.
But, cody, mine was JustinBieber, like baby JD, like just
starting out, like middle school, yeah, so that's a fun one.

Speaker 3 (11:26):
That's awesome.
And Vanna, for you.
What's the oldest or the mostinteresting item on your desk or
in your desk drawer?

Speaker 4 (11:33):
Yeah, so I have a lot of random things in my office
and on my desk, but I thinkprobably the most interesting
are my bajillion dinosaurs,because you just like can't have
a bad day if you look up andsee a dinosaur, you've got to
smile.
So I have probably like five orsix or more in my office.

Speaker 3 (11:53):
That's awesome.
We haven't gotten that answereither.

Speaker 2 (11:57):
See, these are fun.
So you know we can do the videoand we can actually see, like,
what's on your desk.
I think that's really cool forour listeners and viewers.
Well, just thank you both somuch for being here today and
for also contributing your workto AJBR.

Speaker 4 (12:10):
Yeah, thanks for having us again.

Speaker 5 (12:13):
Yeah, thank you so much.

Speaker 2 (12:14):
And to our listeners.
You can read Vanette Cody'sarticle on AJBR.
I'm Sarah Wright at LisaFortier.
Be on the lookout for nextweek's episode and don't forget
to leave us a rating and reviewon Apple Podcasts or whatever
platform you listen to.