May 14, 2025 • 18 mins
Ever wondered if you really need to change that needle after drawing up a vaccine? In this eye-opening conversation, Julia Tawil and Dr. Rachael Kreisler challenge a decades-old practice that most of us have never questioned.
Their meticulously designed study measured exactly how much a needle dulls after puncturing a vaccine vial—and the results might surprise you. Using precise force measurements, they discovered that needle sharpness decreases by less than 20% after vial puncture—well below the threshold considered clinically significant. What matters more? The needle's gauge, brand, and how gently you pierce that vial in the first place.
The implications extend far beyond a single needle. With 76% of veterinary professionals routinely changing needles after vaccine aspiration, this small practice change could significantly reduce medical waste, lower needlestick injury risks, and save time across the profession. A follow-up clinical trial with 75 dogs found no difference in patient response between changed and unchanged needles.
This conversation highlights how scientific inquiry can transform everyday veterinary practices, creating safer, more sustainable clinics without compromising patient care. It's a powerful reminder to question even our most fundamental assumptions and seek evidence for everything we do.
JAVMA article: https://doi.org/10.2460/javma.25.01.0025
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
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Wellness Pet Foods (00:01):
Mealtime is more than a bowl of food.
It's the foundation for a longand healthy life.
At Wellness, dry recipes arecrafted with the highest quality
natural ingredients for a tastethat pets love and
scientifically proven throughAFCO feeding trials to ensure
that every complete and balancedmeal supports the five signs of
wellbeing.
With Wellness Pet Foods, petparents can share a life of
(00:25):
well-being together with theirpet.
Sarah Wright (00:31):
This is Veterinary Vertex, a podcast AVMA journals
.
In this episode we chat abouthow needle sharpness is
minimally affected by vaccinevial puncture with our guests
Julia Tawil and Rachel Kreisler.
Lisa Fortier (00:44):
Welcome listeners.
I'm Editor-in-Chief LisaFortier, and I'm joined by
Associate Editor Sarah Wright.
Also, Julia and Rachel, on thisfirst day of spring 2025, on
this nice recording day soexcited to be here with you guys
.
I've had an interest in thistopic for a long time.
My second oldest sister hasbeen an oncology nurse for 40
(01:05):
some years and she's the one whotaught me like never, ever,
ever reuse a needle because ofthe dullness and the pain that
it can cause to your patient.
So, thank you for taking thetime to be with us here today
and to educate us on your reallycool research.
Rachael Kreisler (01:18):
Thank you so much for having us.
Sarah Wright (01:21):
Yeah, thank you.
I definitely echo what Lisasaid.
I was also taught the samething always replace the needle.
Never use the same needle thatyou use to puncture a vial Again
, just to help with pain foryour patients and also
potentially some like microbialconcerns as well.
So glad to see some evidencebehind this and that you guys
actually investigate this.
So, Rachel, your JAVMA articlediscusses how needle sharpness
(01:42):
is minimally affected by vaccinevial puncture.
Please share with our listenersthe background on this article.
Rachael Kreisler (01:49):
Sure.
So in this study we wanted todetermine whether a practice
which, as you guys know, ispretty common that of changing
needles after drawing a vaccineup from a vial was important
from the perspective of needlesharpness.
And we started out by surveyingveterinary professionals and
that includes veterinarians,veterinary technicians, anyone
(02:09):
sort of who might be involved indrawing up or administering
vaccines to get a sense of howcommon the practice of changing
needles actually is and if theychange it, why do they change it
and also which brands they arecommonly purchasing.
We then use three differentbrands in four different gauges
to determine whether passing theneedle once or twice through a
vaccine vial decreases sharpness.
(02:30):
And you can measure sharpnessusing a force gauge.
And this is actually wefollowed the same procedure
that's used to test sharpnessthat needle manufacturers use
when they're demonstrating thesharpness of their needles.
And this force gauge measureshow much force it takes to
penetrate a standardizedmaterial.
The force is measured innewtons and I don't know about
(02:52):
you, I wasn't really familiarwith how much a newton was
before conducting this study,but you can think of it as about
the amount of force that anapple in your hand exerts.
So there's gravity acting onthat apple, it's in your hand
and you can think about sort ofthat's the amount of force of
one newton.
And we also visualize theneedles, we scan them with a
(03:14):
three-dimensional infinite focusmicroscope and then we could
sort of compare before andafters.
So that was sort of ourapproach to taking it.
When we surveyed veterinarians,we found that 76 percent or,
pardon me, veterinaryprofessionals, 76 percent do
routinely change the needlefollowing vaccine aspiration,
and by far their biggest concernwas needle dulling.
(03:34):
And Julia was the one whoconducted the force meter
analysis, so I'll let her sharethe results of that.
Julia Tawil (03:42):
Yeah.
So we analyzed 330 needles forthe penetration force they
required to pass through astandardized material after
puncturing the vaccine vial zerotimes, one times or two times.
And our thought process wasthat the needles passed through
the vial septum one time wouldsimulate aspirating a vaccine
(04:02):
without a dilutant, and then theneedles passed through the vial
septum twice would simulatevaccines with a dilutant, and
then needles that weren't passedthrough a vaccine vial at all
would simulate changing theneedle after drawing up the
vaccine.
And so what we found is that29-gauge needles required 45%
(04:24):
less force when compared to 20gauge needles, which just
indicates that smaller needlesrequire less force, which is
kind of expected and makes sense.
But then when comparing brands,our brands B and C require an
additional 11% and then 10% offorce respectively percent of
(04:46):
and then 10 percent of forcerespectively.
And what that tells us is thatcareful selection of gauge size
and brands of needles can impactthe force required to puncture
a standardized material.
We also recorded the forcerequired for the needles to pass
through the vaccine vial septum, which we refer to as a vaccine
vial penetration force or VVPF,refer to as a vaccine vial
(05:09):
penetration force or VVPF, andthe VVPF increased the peak
force through the standardizedmaterial by 0.03 newtons for
each additional 0.5 newtonsduring the first penetration,
but was not significant for thesecond penetration, and so for
what that means clinically isthat you should use a gentle
technique when inserting theneedle into the vial septum to
reduce the force needed toadminister the vaccine.
(05:31):
The difference, the forcerequired to penetrate the
standardized material betweenpassage one or two times through
the vaccine vial septum, wasless than 20%, and so therefore
we can assume that it'sinsignificant.
Great.
Rachael Kreisler (05:48):
So, basically force matters when you're
inserting the needle to draw upthe vaccine, but as long as you
have gentle technique.
There was actually I believe itwas 9% difference for that
first penetration and so usuallywe want to say if there's going
to be a difference that'sclinically significant.
(06:10):
If we don't have any goodreason to pick something else,
it's usually they pick a cutoffof about 20%.
So as long as you're carefulwith the penetration, you should
be in good shape.
We did visually examine theneedles also and we saw some
defects.
And of course anything magnified20 times looks pretty scary,
you know, like a dust mite lookslike a big monster on high
(06:32):
magnification.
But when we actually measuredthe magnitude of the hooks, the
biggest hook we could find inthe 52 needles that we imaged
was about 56 micrometers and weknow from human literature that
humans at least can't tell thedifference between hooks of 50
micrometers.
So if you use a new needle or aneedle that's been given a hook
(06:54):
of 50 micrometers, humans can'ttell the difference between the
injections with those twodifferent needles.
It actually takes hooks up to150 micrometers, which is about
three times what we observed inthis study, to detect a small
difference in pain score.
And then the only thing that wecould find associated with
these hooks, that we could seeon the scans, was again this
(07:18):
force used to penetrate thevaccine vial.
Sarah Wright (07:21):
I can add what knowing what a Newton is to my
list of things I learned thisweek, so thank you, and 0.03% of
an apple.
Lisa Fortier (07:29):
Add that into your Newton.
Sarah Wright (07:32):
Exactly.
I'm actually getting ready topromote this article on social,
so maybe I'll add that in aswell.
Learn a fun fact today.
Rachael Kreisler (07:39):
If you're curious, I spent some time last
night looking at what 0.1Newtons would look like, and
that was about two nickels.
So that was about two nickelsdifference that we detected,
again, that sort of the forcethat gravity is exerting on two
nickels in your hand.
To give you a sense of thedifference we found, yeah,
(08:01):
that's a little more standard.
Lisa Fortier (08:02):
You can get some pretty damn big apples these
days, so we have some reallygood information about the
background and study Now, Rachel.
Sarah Wright (08:06):
Yeah, that's a little more standard.
You can get some pretty damnbig apples these days, so we
have some really goodinformation about the background
and study.
Rachael Kreisler (08:13):
Now, Rachel, what are some of the take-home
messages from this JAVMA article?
Ah, so I would say that youknow, if we stop changing
needles routinely, we couldreduce medical waste, lower the
risk of needle stick injuriesthat we incur when we, you know,
recap a needle to remove it andto put a new one on.
But we could do this and stillmaintain the same level of care
for animals.
So, I think it's a small changewe could make that, you know,
across all of the veterinarypractices in the country, could
(08:35):
make a big difference in termsof safety, efficiency and
sustainability, and I guess,even bigger than that, I would
say.
I think it's always importantto critically examine the
practices we follow and makesure they're backed by solid
evidence and stay up to datewith the literature through
resources like JAVMA.
Lisa Fortier (08:53):
Yeah, thanks for that pitch.
I would say the same.
You know, I just expected thatthis was told to us because
there was literature to supportit.
But you know, you have to golook, I guess.
So thank you for bringing thatto us report it.
But you have to go look, Iguess.
So thank you for bringing thatto us.
Rachael Kreisler (09:11):
What sparked your interest in this topic of
needle dulling through diaphragmpuncture, right?
So I participated as avaccinator under the PrEP Act,
which that was the act thatenabled veterinarians to
administer COVID-19 vaccines topeople, and so I had to be
trained, and as part of thetraining I received, there was
materials from the CDC thatspecifically mentioned that the
needle did not need to bechanged after a vaccine was
drawn up, and I was like, well,that's hot, so we don't do it
(09:34):
for people.
And so of course now I'm likewell, why do we do it for
animals?
Provided, but that's of course.
When I turned to literature andI couldn't find anything, there
was stuff about maybe reusingneedles for folks who have
(09:54):
diabetes.
There's quite a lot of study onthat but there really wasn't
anything in veterinaryliterature.
I teach the public healthcourse at Midwestern University
and so I teach about the risksof needle stick injuries and
regulated medical waste disposal, so I was pretty familiar with
the potential risks and thecosts associated with changing
needle.
So I really wanted to just getthis done and add something to
(10:18):
the literature so people who arecurious or want to promote best
practices can actually havesome evidence.
Lisa Fortier (10:27):
Yeah, I always say to people too you know, it's
not just the cost of that needle, somebody has to order that
needle, somebody has to stockthat needle, somebody has to
throw out your medical waste.
So you're really doing a hugeservice to hospitals if they can
convince people that you don'tneed to change a needle two or
three times.
As Julia said earlier, wants topull up the diluent.
I put the emphasis on adifferent syllable.
(10:48):
Julia Wanted to drop thediluent.
So it's a great study and,rachel, you and Julia both said
some of the most important ortake-home messages.
But every time we do a studywe're surprised by some finding.
What surprised you and Juliafrom your results in this
article.
Rachael Kreisler (11:07):
I had no idea that the vial puncture
technique was going to matter somuch and, I'll be honest, I had
no idea that brand would make adifference.
I'd never thought about either.
I just stick the needle in thevial and I order the cheapest
syringes.
Julia Tawil (11:23):
Yeah, I agree, when you're working in a hospital
setting you're typically notpaying attention to how gentle
or aggressive you're kind ofpuncturing that vaccine vial.
But our studies showed thatthat does make a difference.
Sarah Wright (11:38):
It's fascinating.
So often with studies, we'releft with more questions than
answers.
So what are the next steps forresearch in this topic?
Rachael Kreisler (11:46):
Well, I'm actually very excited to you're
going to hear it here.
First, we just wrapped up adouble-blind, randomized
controlled trial of 75 dogs todetermine whether there's a
clinical difference.
Because of course it's allgreat, you know we have these
force meters and newtons andthat, but I mean, I think what
we all care about is what is theanimal experience?
(12:09):
And so we used an objectivemeasure of the heart rate.
We also did a blindedsubjective reaction rating to
videos of the dogs getting theinjections, and then we also
asked the person who gave theinjection whether they could
guess which needle had beenreplaced and which one had been
used to puncture the vaccinevial.
(12:29):
And we didn't find anydifference by any of these
measures.
So there was a very smallincrease in heart rate between
the DHPP and the rabies vaccine.
My suspicion is that's thelocation, because we did use the
typical locations for the frontright shoulder for the DHPP and
the rear right rear for therabies.
(12:51):
And then there was also a smallincrease in heart rate for the
second as compared to the firstvaccine.
I think we can kind of you know, maybe the animal knows what's
coming.
And we also did see the heartrates on average were correlated
with the fear, anxiety or FASscore, but we didn't see any
difference whatsoever with thechanged or the replaced needles.
(13:15):
So I'm very excited we'rewriting up the manuscript now
and we're excited to share thenext steps.
Sarah Wright (13:25):
Very cool.
It's always nice to hear whenyou guys have something actually
set up for next steps, soawesome.
Can't wait to see that out.
So this week we actuallypublished our first AJVR
Artificial IntelligenceSupplemental Issue, which we're
super proud of and very excitedabout, and our listeners can
find that on our website.
So for this particular topic,Rachel, do you see a role for?
Rachael Kreisler (13:43):
AI.
Well, you know AI is great forpattern recognition and you know
, I think that you know, forsomething like rating the dog's
reaction to the injection.
It would be something thatwould be much more repeatable
and reliable, potentially, thanour human raters.
We did use three raters to tryto increase our reliability and,
(14:07):
you know, we, we sort oftrained, uh, you know, to sort
of be congruent and we stillonly got moderate agreement.
So, uh, you know, I'd be veryexcited, and I think the, the
folks who watched all the videoswould be very excited to have a
, a tool that was faster andbetter, uh than and again, that
we could, you know, rely onscientifically.
Sarah Wright (14:27):
Love those answers .
We've said the C4, but we'reactually compiling them and
going to be sharing them See.
So, some cool research ideasand, for those of you just
joining us, we're discussing howneedle sharpness is minimally
affected by vaccine vialpuncture with our guests Rachel
and Julia affected by vaccinevial puncture with our guests
Rachel and Julia.
Lisa Fortier (14:49):
Julia, as a veterinary student, how did your
training and previous work notonly help you to do the study
design, get the work done, getthe manuscript written like
really cross the finish line.
That's impressive, and how didyour work, previous experiences,
prepare you for that?
Julia Tawil (14:59):
Yeah, thank you.
So as part of the veterinarymedicine curriculum here at
Midwestern University, we'reenrolled in a course called
Principles of VeterinaryScholarship, which is actually
organized by Dr Kreisler, andthe class is structured to
enhance students' skills increating scientific questions
and solutions surroundingveterinary medicine, and so I
(15:21):
specifically believe that itcontributed to my ability to
kind of assess scientificevidence when reviewing previous
peer-reviewed literature, youknow, for this project and just
kind of going through asystematic approach on how to
approach a problem.
Sarah Wright (15:37):
Very cool.
I'm actually presenting at theSAVMA Symposium at Davis
tomorrow morning, so excited toinspire students to get excited
about scholarly publishing.
This next set of questions isgoing to be very important for
our listeners, and the first onedeals with the veterinarian's
perspective.
So, Rachel, what is one pieceof information the veterinarian
should know about?
Needle sharpness and vaccinevial puncture.
Rachael Kreisler (15:58):
I would say the bottom line is it's okay not
to change the needle if you usegentle vaccine vial puncture
technique.
Very well said.
Sarah Wright (16:06):
And on the other side of the relationship, Julia,
what's one thing clients shouldknow about this topic.
Julia Tawil (16:11):
I think they should know that, as veterinarians, we
are regularly assessing optimalvaccination protocols that can
contribute to environmentalsustainability while reducing
medical waste.
Lisa Fortier (16:27):
But also ensuring that the welfare of our patients
remain uncompromised.
I wonder if they would evennotice.
Do you think they'd notice thatwe change needles or we don't
change needles?
Rachael Kreisler (16:37):
I never did.
I'm a second-careerveterinarian so I had over 10
years as a sort of civilian petowner and I will guarantee you I
had no idea.
Lisa Fortier (16:45):
Yeah, I don't think I would watch.
Rachael Kreisler (16:49):
I probably didn't.
Lisa Fortier (16:51):
Yeah, I'm trying to think of like when my kids
get vaccinated.
Anyway, thank you guys again.
Really fantastic and suchpractical information for our
practitioners.
We really appreciate it.
As we wind down, we like to asksome fun facts.
So, Julia, what is yourfavorite animal fact?
Julia Tawil (17:12):
My favorite animal fact is that sea otters use
really hard shells or rocks tocrack open their prey, such as
sea urchins open their prey,such as sea urchins.
Lisa Fortier (17:23):
Wow, interesting, did not know that.
And, Rachel, for you, what isthe oldest or the most
interesting item on your desk orin your desk drawer?
If you have it, you can show ittoo.
Rachael Kreisler (17:32):
Oh, yeah, well.
Okay, here we go.
I have a prayer candle, so Ihave a prayer for useful data,
right?
That's too funny.
Actually, it's a prayer candleuseful data.
Sarah Wright (17:42):
Right, that's too funny.
Actually, seeing your prayercandles, I saw on my vet school
classmates Instagram storyyesterday she had a prayer for
paying off student loans, soyou're not alone with some of
our day-related prayer candles.
And Julia love the aquaticanimal.
Fact.
I have a very soft spot for seaotters, so they're awesome.
Well, thank you so much, racheland Julia.
We really appreciate you beinghere today and sharing your
(18:04):
research with us too.
Rachael Kreisler (18:07):
Great.
Thank you so much for having us.
Yeah, thank you for having us.
Sarah Wright (18:11):
And to our listeners.
You can read Rachel and Julia'sarticle in JAVMA.
I'm Sarah Wright with 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.
Mealtime is more than a bowl of food.
It's the foundation for a longand healthy life.
At Wellness, dry recipes arecrafted with the highest quality
natural ingredients for a tastethat pets love and
scientifically proven throughAFCO feeding trials to ensure
that every complete and balancedmeal supports the five signs of
wellbeing.
With Wellness Pet Foods, petparents can share a life of
(00:25):
well-being together with theirpet.
Sarah Wright (00:31):
This is Veterinary Vertex, a podcast AVMA journals
.
In this episode we chat abouthow needle sharpness is
minimally affected by vaccinevial puncture with our guests
Julia Tawil and Rachel Kreisler.
Lisa Fortier (00:44):
Welcome listeners.
I'm Editor-in-Chief LisaFortier, and I'm joined by
Associate Editor Sarah Wright.
Also, Julia and Rachel, on thisfirst day of spring 2025, on
this nice recording day soexcited to be here with you guys
.
I've had an interest in thistopic for a long time.
My second oldest sister hasbeen an oncology nurse for 40
(01:05):
some years and she's the one whotaught me like never, ever,
ever reuse a needle because ofthe dullness and the pain that
it can cause to your patient.
So, thank you for taking thetime to be with us here today
and to educate us on your reallycool research.
Rachael Kreisler (01:18):
Thank you so much for having us.
Sarah Wright (01:21):
Yeah, thank you.
I definitely echo what Lisasaid.
I was also taught the samething always replace the needle.
Never use the same needle thatyou use to puncture a vial Again
, just to help with pain foryour patients and also
potentially some like microbialconcerns as well.
So glad to see some evidencebehind this and that you guys
actually investigate this.
So, Rachel, your JAVMA articlediscusses how needle sharpness
(01:42):
is minimally affected by vaccinevial puncture.
Please share with our listenersthe background on this article.
Rachael Kreisler (01:49):
Sure.
So in this study we wanted todetermine whether a practice
which, as you guys know, ispretty common that of changing
needles after drawing a vaccineup from a vial was important
from the perspective of needlesharpness.
And we started out by surveyingveterinary professionals and
that includes veterinarians,veterinary technicians, anyone
(02:09):
sort of who might be involved indrawing up or administering
vaccines to get a sense of howcommon the practice of changing
needles actually is and if theychange it, why do they change it
and also which brands they arecommonly purchasing.
We then use three differentbrands in four different gauges
to determine whether passing theneedle once or twice through a
vaccine vial decreases sharpness.
(02:30):
And you can measure sharpnessusing a force gauge.
And this is actually wefollowed the same procedure
that's used to test sharpnessthat needle manufacturers use
when they're demonstrating thesharpness of their needles.
And this force gauge measureshow much force it takes to
penetrate a standardizedmaterial.
The force is measured innewtons and I don't know about
(02:52):
you, I wasn't really familiarwith how much a newton was
before conducting this study,but you can think of it as about
the amount of force that anapple in your hand exerts.
So there's gravity acting onthat apple, it's in your hand
and you can think about sort ofthat's the amount of force of
one newton.
And we also visualize theneedles, we scan them with a
(03:14):
three-dimensional infinite focusmicroscope and then we could
sort of compare before andafters.
So that was sort of ourapproach to taking it.
When we surveyed veterinarians,we found that 76 percent or,
pardon me, veterinaryprofessionals, 76 percent do
routinely change the needlefollowing vaccine aspiration,
and by far their biggest concernwas needle dulling.
(03:34):
And Julia was the one whoconducted the force meter
analysis, so I'll let her sharethe results of that.
Julia Tawil (03:42):
Yeah.
So we analyzed 330 needles forthe penetration force they
required to pass through astandardized material after
puncturing the vaccine vial zerotimes, one times or two times.
And our thought process wasthat the needles passed through
the vial septum one time wouldsimulate aspirating a vaccine
(04:02):
without a dilutant, and then theneedles passed through the vial
septum twice would simulatevaccines with a dilutant, and
then needles that weren't passedthrough a vaccine vial at all
would simulate changing theneedle after drawing up the
vaccine.
And so what we found is that29-gauge needles required 45%
(04:24):
less force when compared to 20gauge needles, which just
indicates that smaller needlesrequire less force, which is
kind of expected and makes sense.
But then when comparing brands,our brands B and C require an
additional 11% and then 10% offorce respectively percent of
(04:46):
and then 10 percent of forcerespectively.
And what that tells us is thatcareful selection of gauge size
and brands of needles can impactthe force required to puncture
a standardized material.
We also recorded the forcerequired for the needles to pass
through the vaccine vial septum, which we refer to as a vaccine
vial penetration force or VVPF,refer to as a vaccine vial
(05:09):
penetration force or VVPF, andthe VVPF increased the peak
force through the standardizedmaterial by 0.03 newtons for
each additional 0.5 newtonsduring the first penetration,
but was not significant for thesecond penetration, and so for
what that means clinically isthat you should use a gentle
technique when inserting theneedle into the vial septum to
reduce the force needed toadminister the vaccine.
(05:31):
The difference, the forcerequired to penetrate the
standardized material betweenpassage one or two times through
the vaccine vial septum, wasless than 20%, and so therefore
we can assume that it'sinsignificant.
Great.
Rachael Kreisler (05:48):
So, basically force matters when you're
inserting the needle to draw upthe vaccine, but as long as you
have gentle technique.
There was actually I believe itwas 9% difference for that
first penetration and so usuallywe want to say if there's going
to be a difference that'sclinically significant.
(06:10):
If we don't have any goodreason to pick something else,
it's usually they pick a cutoffof about 20%.
So as long as you're carefulwith the penetration, you should
be in good shape.
We did visually examine theneedles also and we saw some
defects.
And of course anything magnified20 times looks pretty scary,
you know, like a dust mite lookslike a big monster on high
(06:32):
magnification.
But when we actually measuredthe magnitude of the hooks, the
biggest hook we could find inthe 52 needles that we imaged
was about 56 micrometers and weknow from human literature that
humans at least can't tell thedifference between hooks of 50
micrometers.
So if you use a new needle or aneedle that's been given a hook
(06:54):
of 50 micrometers, humans can'ttell the difference between the
injections with those twodifferent needles.
It actually takes hooks up to150 micrometers, which is about
three times what we observed inthis study, to detect a small
difference in pain score.
And then the only thing that wecould find associated with
these hooks, that we could seeon the scans, was again this
(07:18):
force used to penetrate thevaccine vial.
Sarah Wright (07:21):
I can add what knowing what a Newton is to my
list of things I learned thisweek, so thank you, and 0.03% of
an apple.
Lisa Fortier (07:29):
Add that into your Newton.
Sarah Wright (07:32):
Exactly.
I'm actually getting ready topromote this article on social,
so maybe I'll add that in aswell.
Learn a fun fact today.
Rachael Kreisler (07:39):
If you're curious, I spent some time last
night looking at what 0.1Newtons would look like, and
that was about two nickels.
So that was about two nickelsdifference that we detected,
again, that sort of the forcethat gravity is exerting on two
nickels in your hand.
To give you a sense of thedifference we found, yeah,
(08:01):
that's a little more standard.
Lisa Fortier (08:02):
You can get some pretty damn big apples these
days, so we have some reallygood information about the
background and study Now, Rachel.
Sarah Wright (08:06):
Yeah, that's a little more standard.
You can get some pretty damnbig apples these days, so we
have some really goodinformation about the background
and study.
Rachael Kreisler (08:13):
Now, Rachel, what are some of the take-home
messages from this JAVMA article?
Ah, so I would say that youknow, if we stop changing
needles routinely, we couldreduce medical waste, lower the
risk of needle stick injuriesthat we incur when we, you know,
recap a needle to remove it andto put a new one on.
But we could do this and stillmaintain the same level of care
for animals.
So, I think it's a small changewe could make that, you know,
across all of the veterinarypractices in the country, could
(08:35):
make a big difference in termsof safety, efficiency and
sustainability, and I guess,even bigger than that, I would
say.
I think it's always importantto critically examine the
practices we follow and makesure they're backed by solid
evidence and stay up to datewith the literature through
resources like JAVMA.
Lisa Fortier (08:53):
Yeah, thanks for that pitch.
I would say the same.
You know, I just expected thatthis was told to us because
there was literature to supportit.
But you know, you have to golook, I guess.
So thank you for bringing thatto us report it.
But you have to go look, Iguess.
So thank you for bringing thatto us.
Rachael Kreisler (09:11):
What sparked your interest in this topic of
needle dulling through diaphragmpuncture, right?
So I participated as avaccinator under the PrEP Act,
which that was the act thatenabled veterinarians to
administer COVID-19 vaccines topeople, and so I had to be
trained, and as part of thetraining I received, there was
materials from the CDC thatspecifically mentioned that the
needle did not need to bechanged after a vaccine was
drawn up, and I was like, well,that's hot, so we don't do it
(09:34):
for people.
And so of course now I'm likewell, why do we do it for
animals?
Provided, but that's of course.
When I turned to literature andI couldn't find anything, there
was stuff about maybe reusingneedles for folks who have
(09:54):
diabetes.
There's quite a lot of study onthat but there really wasn't
anything in veterinaryliterature.
I teach the public healthcourse at Midwestern University
and so I teach about the risksof needle stick injuries and
regulated medical waste disposal, so I was pretty familiar with
the potential risks and thecosts associated with changing
needle.
So I really wanted to just getthis done and add something to
(10:18):
the literature so people who arecurious or want to promote best
practices can actually havesome evidence.
Lisa Fortier (10:27):
Yeah, I always say to people too you know, it's
not just the cost of that needle, somebody has to order that
needle, somebody has to stockthat needle, somebody has to
throw out your medical waste.
So you're really doing a hugeservice to hospitals if they can
convince people that you don'tneed to change a needle two or
three times.
As Julia said earlier, wants topull up the diluent.
I put the emphasis on adifferent syllable.
(10:48):
Julia Wanted to drop thediluent.
So it's a great study and,rachel, you and Julia both said
some of the most important ortake-home messages.
But every time we do a studywe're surprised by some finding.
What surprised you and Juliafrom your results in this
article.
Rachael Kreisler (11:07):
I had no idea that the vial puncture
technique was going to matter somuch and, I'll be honest, I had
no idea that brand would make adifference.
I'd never thought about either.
I just stick the needle in thevial and I order the cheapest
syringes.
Julia Tawil (11:23):
Yeah, I agree, when you're working in a hospital
setting you're typically notpaying attention to how gentle
or aggressive you're kind ofpuncturing that vaccine vial.
But our studies showed thatthat does make a difference.
Sarah Wright (11:38):
It's fascinating.
So often with studies, we'releft with more questions than
answers.
So what are the next steps forresearch in this topic?
Rachael Kreisler (11:46):
Well, I'm actually very excited to you're
going to hear it here.
First, we just wrapped up adouble-blind, randomized
controlled trial of 75 dogs todetermine whether there's a
clinical difference.
Because of course it's allgreat, you know we have these
force meters and newtons andthat, but I mean, I think what
we all care about is what is theanimal experience?
(12:09):
And so we used an objectivemeasure of the heart rate.
We also did a blindedsubjective reaction rating to
videos of the dogs getting theinjections, and then we also
asked the person who gave theinjection whether they could
guess which needle had beenreplaced and which one had been
used to puncture the vaccinevial.
(12:29):
And we didn't find anydifference by any of these
measures.
So there was a very smallincrease in heart rate between
the DHPP and the rabies vaccine.
My suspicion is that's thelocation, because we did use the
typical locations for the frontright shoulder for the DHPP and
the rear right rear for therabies.
(12:51):
And then there was also a smallincrease in heart rate for the
second as compared to the firstvaccine.
I think we can kind of you know, maybe the animal knows what's
coming.
And we also did see the heartrates on average were correlated
with the fear, anxiety or FASscore, but we didn't see any
difference whatsoever with thechanged or the replaced needles.
(13:15):
So I'm very excited we'rewriting up the manuscript now
and we're excited to share thenext steps.
Sarah Wright (13:25):
Very cool.
It's always nice to hear whenyou guys have something actually
set up for next steps, soawesome.
Can't wait to see that out.
So this week we actuallypublished our first AJVR
Artificial IntelligenceSupplemental Issue, which we're
super proud of and very excitedabout, and our listeners can
find that on our website.
So for this particular topic,Rachel, do you see a role for?
Rachael Kreisler (13:43):
AI.
Well, you know AI is great forpattern recognition and you know
, I think that you know, forsomething like rating the dog's
reaction to the injection.
It would be something thatwould be much more repeatable
and reliable, potentially, thanour human raters.
We did use three raters to tryto increase our reliability and,
(14:07):
you know, we, we sort oftrained, uh, you know, to sort
of be congruent and we stillonly got moderate agreement.
So, uh, you know, I'd be veryexcited, and I think the, the
folks who watched all the videoswould be very excited to have a
, a tool that was faster andbetter, uh than and again, that
we could, you know, rely onscientifically.
Sarah Wright (14:27):
Love those answers .
We've said the C4, but we'reactually compiling them and
going to be sharing them See.
So, some cool research ideasand, for those of you just
joining us, we're discussing howneedle sharpness is minimally
affected by vaccine vialpuncture with our guests Rachel
and Julia affected by vaccinevial puncture with our guests
Rachel and Julia.
Lisa Fortier (14:49):
Julia, as a veterinary student, how did your
training and previous work notonly help you to do the study
design, get the work done, getthe manuscript written like
really cross the finish line.
That's impressive, and how didyour work, previous experiences,
prepare you for that?
Julia Tawil (14:59):
Yeah, thank you.
So as part of the veterinarymedicine curriculum here at
Midwestern University, we'reenrolled in a course called
Principles of VeterinaryScholarship, which is actually
organized by Dr Kreisler, andthe class is structured to
enhance students' skills increating scientific questions
and solutions surroundingveterinary medicine, and so I
(15:21):
specifically believe that itcontributed to my ability to
kind of assess scientificevidence when reviewing previous
peer-reviewed literature, youknow, for this project and just
kind of going through asystematic approach on how to
approach a problem.
Sarah Wright (15:37):
Very cool.
I'm actually presenting at theSAVMA Symposium at Davis
tomorrow morning, so excited toinspire students to get excited
about scholarly publishing.
This next set of questions isgoing to be very important for
our listeners, and the first onedeals with the veterinarian's
perspective.
So, Rachel, what is one pieceof information the veterinarian
should know about?
Needle sharpness and vaccinevial puncture.
Rachael Kreisler (15:58):
I would say the bottom line is it's okay not
to change the needle if you usegentle vaccine vial puncture
technique.
Very well said.
Sarah Wright (16:06):
And on the other side of the relationship, Julia,
what's one thing clients shouldknow about this topic.
Julia Tawil (16:11):
I think they should know that, as veterinarians, we
are regularly assessing optimalvaccination protocols that can
contribute to environmentalsustainability while reducing
medical waste.
Lisa Fortier (16:27):
But also ensuring that the welfare of our patients
remain uncompromised.
I wonder if they would evennotice.
Do you think they'd notice thatwe change needles or we don't
change needles?
Rachael Kreisler (16:37):
I never did.
I'm a second-careerveterinarian so I had over 10
years as a sort of civilian petowner and I will guarantee you I
had no idea.
Lisa Fortier (16:45):
Yeah, I don't think I would watch.
Rachael Kreisler (16:49):
I probably didn't.
Lisa Fortier (16:51):
Yeah, I'm trying to think of like when my kids
get vaccinated.
Anyway, thank you guys again.
Really fantastic and suchpractical information for our
practitioners.
We really appreciate it.
As we wind down, we like to asksome fun facts.
So, Julia, what is yourfavorite animal fact?
Julia Tawil (17:12):
My favorite animal fact is that sea otters use
really hard shells or rocks tocrack open their prey, such as
sea urchins open their prey,such as sea urchins.
Lisa Fortier (17:23):
Wow, interesting, did not know that.
And, Rachel, for you, what isthe oldest or the most
interesting item on your desk orin your desk drawer?
If you have it, you can show ittoo.
Rachael Kreisler (17:32):
Oh, yeah, well.
Okay, here we go.
I have a prayer candle, so Ihave a prayer for useful data,
right?
That's too funny.
Actually, it's a prayer candleuseful data.
Sarah Wright (17:42):
Right, that's too funny.
Actually, seeing your prayercandles, I saw on my vet school
classmates Instagram storyyesterday she had a prayer for
paying off student loans, soyou're not alone with some of
our day-related prayer candles.
And Julia love the aquaticanimal.
Fact.
I have a very soft spot for seaotters, so they're awesome.
Well, thank you so much, racheland Julia.
We really appreciate you beinghere today and sharing your
(18:04):
research with us too.
Rachael Kreisler (18:07):
Great.
Thank you so much for having us.
Yeah, thank you for having us.
Sarah Wright (18:11):
And to our listeners.
You can read Rachel and Julia'sarticle in JAVMA.
I'm Sarah Wright with 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.
Popular Podcasts
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
24/7 News: The Latest
The latest news in 4 minutes updated every hour, every day.
Crime Junkie
Does hearing about a true crime case always leave you scouring the internet for the truth behind the story? Dive into your next mystery with Crime Junkie. Every Monday, join your host Ashley Flowers as she unravels all the details of infamous and underreported true crime cases with her best friend Brit Prawat. From cold cases to missing persons and heroes in our community who seek justice, Crime Junkie is your destination for theories and stories you won’t hear anywhere else. Whether you're a seasoned true crime enthusiast or new to the genre, you'll find yourself on the edge of your seat awaiting a new episode every Monday. If you can never get enough true crime... Congratulations, you’ve found your people. Follow to join a community of Crime Junkies! Crime Junkie is presented by audiochuck Media Company.