Veterinary Anesthesia Nerd Tasha McNerney joins Dr. Andy Roark on the podcast to unravel the intricacies of anesthesia on a full stomach. They explore navigating emergencies when surgeries can’t be postponed, highlight crucial factors in devising meticulous anesthetic plans, and dissect the risks tied to regurgitation during anesthesia.
You can also listen to this episode on Apple Podcasts, Google Podcasts, Amazon Music, Soundcloud, YouTube or wherever you get your podcasts!
LINKS
Veterinary Anesthesia Nerds Symposium 2024
Veterinary Anesthesia Nerds Facebook Page
Canine Cardiology Webinar (Free RACE CE)
REFERENCES
AD Galatos, D Raptopoulos. Gastro-oesophageal reflux during anesthesia in the dog: the effect of age, positioning and type of surgical procedure. Vet Record, 137, 1995: 513-516
DV Wilson, AT Evans, WA Mauer. Influence of metoclopramide on gastroesophageal reflux in anesthetized dogs. AJVR, 67, 2006:26-31
AC Zacuto, et al. The influence of esomeprazole and cisapride on gastroesophageal reflux during anesthesia in dogs. J Vet Intern Med, 26, 2012:518-525
ABOUT OUR GUEST
Tasha McNerney is a Certified Veterinary Technician from Pennsylvania where she works as a educational consultant and relief anesthesia technician. Tasha is the founder of the Veterinary Anesthesia Nerds, while also a Certified Veterinary Pain Practitioner and board member of the International Veterinary Academy of Pain Management (IVAPM) to educate the public about animal pain awareness. In fact, Tasha was the thought leader behind the now celebrated “Animal Pain Awareness Month” within the veterinary industry. Tasha became a veterinary technician specialist in anesthesia in 2015. Tasha loves to lecture on various anesthesia and pain management topics around the globe and was previously named VMX Speaker of the Year.
EPISODE TRANSCRIPT
Dr. Andy Roark:
Welcome everybody to the Cone of Shame Veterinary Podcast. I am your host, Dr. Andy Roark. I’m here with my dear friend, Tasha McNerney. She’s the original anesthesia nerd. Boy, this is a great conversation. Get ready to jot down some notes. I don’t care how much experience you have with surgery and anesthesia, you are going to get some pearls today because Tasha is laying them down thick. This is a great conversation about going to anesthesia when we have a pet with a full belly, and it’s going to happen. It’s just pets don’t always plan to have surgery later in the day when they decide whether or not they’re going to eat. And so this is a thing that we have to deal with. But God, I took so much away from this conversation. It’s a great one, gang. Let’s get into it.
Kelsey Beth Carpenter:
(singing) This is your show. We’re glad you’re here. We want to help you in your veterinary career. Welcome to The Cone of Shame with Dr. Andy Roark.
Dr. Andy Roark:
Welcome to the podcast, Tasha McNerney. How are you my friend?
Tasha McNerney:
I’m good. Thanks for having me again.
Dr. Andy Roark:
Always. I love having you on here. I just be honest. You and I have been talking for like an hour and we finally had to press record and do this episode, but you are a joy. For those of you who are watching on YouTube, it’s Halloween, just so you know. That’s why-
Tasha McNerney:
That’s why I am dressed like this.
Dr. Andy Roark:
Yes, and for those of you who are not watching on YouTube, Tasha is dressed as, do you want to tell ’em what you’re dressed as?
Tasha McNerney:
Yes. So for all of the Swifties out there, if you’ve ever seen the Shake It Off music video, I am the cheerleader section, the cheerleader, Taylor Swift. So shout out to all the Swifties out there. Not going to lie. I am a Reputation girly way more than a 1989 girly. I know that’s controversial. Oh wow. But the reputation costume that I really would want to have, I need some serious time to work on that. So maybe next year we’ll go a Reputation based costume.
Dr. Andy Roark:
Okay. Well, I mean Taylor has a deep catalog. I think we can just year after year, we can
Tasha McNerney:
Just keep
Dr. Andy Roark:
Going. Just keep going. Alright. I love this. For those who don’t know you, you are Tasha McNerney. You are CVPP which is a certified veterinary pain practitioner. You are a VTS, veterinary technician specialty in anesthesia. You are the founder of the Veterinary Anesthesia Nerds, which was originally a Facebook group, still a Facebook group. However, you have moved way beyond that. You guys have, you’ve had a conference for a number of years. I have heard wonderful things about it. It is all about anesthesia. It has a heavy emphasis on vet techs, which I love, but it’s open to everybody. You guys are doing your next one in San Diego in April, is that correct? April 24?
Tasha McNerney:
That’s correct. Yes. We’re doing April, 2024 and we’re bringing back, we’ve taken a hiatus over the last couple of years with just everything going on and moving in jobs and et cetera. And now we are back and we have some fantastic speakers, not only Darcy and Steven, just wonderful in their own right, but also two great anesthesiologists. Kristen Messenger and Mike Barletta are going to be speaking with us as well. We’re going to get really in depth, really high level anesthesia, new concepts, deep dives into drug pharmacology. But my favorite thing that we do at the conference is the hands-on lab going over head to toe, regional anesthesia, ultrasound guided blocks, different nerve blocks and local anesthetic techniques. So I love that.
Dr. Andy Roark:
I love how you do this. I think the future of learning is this type of really hands-on deep dive when you get together and just really do it. It’s not sitting in a lecture and looking at slides. It is doing the cadaver labs and really doing the skills. Anyway, I love how you guys roll. Also, I love San Diego. It’s a wonderful place to be. You guys are at the Hyatt, which is right on the water and absolutely gorgeous. It’s just, anyway, for anybody who’s looking around and going, man, that sounds amazing. Registration is open. I’ll put a link in.
Tasha McNerney:
Registration is open. Yeah, I can send you the link and we can put it up there. Registration is open. The cool thing about this conference is that we have looked at the data and we know that after a certain amount of time, listen, we all just start to tune out and sitting in a lecture hall for eight hours straight is just a lot. So our lectures are actually from 8:00 AM till 1:00 PM and then our expectation is you’re going to spend the afternoon going out and exploring San Diego. We are really trying to do that work-life balance thing because we want you to actually enjoy your conference and not just see the inside of a conference room. We want you to go outside and explore some stuff. We might be even doing a nerd’s hike where we hike the beach, but also talk about, I don’t know, drug pharmacology as one does.
Dr. Andy Roark:
Totally. So if your boss is like, what will you do in the afternoons? You’re like, I will talk about drug pharmacology. You will while you walk on the beach.
Tasha McNerney:
We will. Sure.
Dr. Andy Roark:
Yeah. Sounds great. Cool. You came to my mind recently because I saw this case and it’s a big dog. I can’t remember exactly what time. It wasn’t a great dane, but I think it was a big shepherd. It was a big shepherd. I remember the hair. I remember hair everywhere. It was definitely a lot of hair. It was a big shepherd. And I saw this dog back after a neuter and it had just blown up. And so this dog had the biggest, most awful scrotal hematoma I had ever seen, like necrotic skin. It was God awful. And I was like, okay, we’ve got to fix this. This dog needs a scrotal ablation. And they brought him in first thing in the morning, and of course I said to them, has he had breakfast? And they were like, oh yeah, he ate everything. And so I thought, you know what?
We need to, we’ll sort this out, but I want to talk to Tasha about anesthesia on a full belly. And also I was like, Thanksgiving’s coming up. I think that’s a good Thanksgiving talk. Is anesthesia on a full belly when I have a full belly, when the patient has a full belly? How does that go? So let me just pause there and we can get into specifics if we want. We can use my one-year-old German Shepherd if we want to, but generally, let me just open the conversation. Tasha, talk to me a bit about putting pets under anesthesia when they have a full belly because it’s going to happen. Ultimately dogs don’t like skip breakfast so they can get hit by a car. That’s not how it works. And so anyway, just start with me a high level. How much of a concern should this be?
Tasha McNerney:
First off, it is a concern. We do know that anytime that our patients do have stomach contents, we are at increased risk for vomiting, but more importantly, regurgitation. And that’s what we really worry about. We definitely don’t want them vomiting. We don’t want ’em feeling nauseous, but we don’t want regurgitation under anesthesia. We know that not only can that cause a problem to the mucosa of the esophagus, but also increases anytime there’s stomach contents, that’s going to increase our chance for a potential of airway, stomach contents, getting into the airway basically. Now you’re mentioning that this patient is going under, is going to go under anesthesia. So let’s just say that when we talk about this from an anesthetic standpoint, the good thing is that we are going to have our airway protected because we’re going to intubate this patient. So having an endotracheal tube in place, having a good seal on that endotracheal tube, testing it to make sure using your capnograph to check to make sure that that seal is appropriate, that is going to help that. If the patient does develop any kind of esophageal reflux under anesthesia, then that airway is going to be protected. So I will say that in this case, if you have a patient come in, whether they be an emergency patient or something like this, where we’re going to do procedure this afternoon and the patient has eaten, then we want to make sure that we are looking at drug choices and setting the patient up for success. There’s nothing we can do to get rid of those stomach contents.
We want to make sure that we are just giving them the safest option possible. And this is why in anesthesia land, we will always advocate for full anesthesia where we can intubate the patient and have control of that airway versus heavy sedation where we might not have control of that airway. And should that patient have esophageal reflux or regurgitation, sorry, that becomes a more dangerous situation.
Dr. Andy Roark:
Let’s just say I’ve got a dog or a cat comes in with some sort of a laceration it, something that needs to be treated, things like that, and you ask the question, when was the last time that your pet ate? And they say, oh, fairly recently. You would actually factor that into is this a heavy sedation case or is this a full anesthesia case? Is that correct?
Tasha McNerney:
That’s correct, yes. And again, that’s going to influence the drugs that we choose. Now, all of our opioids that we are going to utilize and we utilize a lot of opioids, especially if you’re going to surgery with a patient, we know that our full opioids, things like morphine or hydromorphone are going to cause more nausea, more vomiting and more regurgitation, opioids in themselves. Also blunt the protective airway reflexes. There are other drugs that can cause this as well, which are things like anticholinergic. So if you use atropine during your procedure or ace promazine or inhalant anesthetics, and I think sometimes people forget that inhalant anesthetics in themselves can cause nausea, vomiting, blunting that esophageal sphincter tone. So that is something to keep in mind as well. So if you’re going to be utilizing those drugs, absolutely we should have a protected airway and that means intubation of our patient with a good fitting seal that we can verify either with your manometer to check to make sure that your endotracheal tube is holding to the correct pressure or you’re washing your capnograph to make sure you’re getting those nice plateaus. And then we’re not getting any leaking around our airway. We want to make sure that that airway is protected. No stomach contents or regurg can get down into that airway.
Dr. Andy Roark:
I have a RACE CE webinar coming right at you very soon. It is called the Practical Guide to the Mitral Valve Patient. This is with my friend Dr. Natalie Marks. It is on November 29th at 4:00 PM Eastern. That’s 1:00 PM Pacific. It is sponsored by Ceva Animal Health. Guys, I’ve worked with Natalie many times. She’s been on this podcast many times. She’s absolutely great. Super practical, a really wonderful doctor to learn from. This is going to be packed full of pearls, like I said, free hour RACE CE. Jump in and grab it. Link is in the show notes. Get on it fast because this is going to pass us by real quick. Anyway, coming at you. I’d love to see you there. Let’s get back into this episode.
Talk to me a little bit about the approach that some people have of, Hey, this pet’s got a full stomach. We’re just going to use our opioids, we’re going to use morphine, we’re going to use hydromorphine. They’re almost certainly going to throw up, and then we’ll go ahead and do our procedure. You pointed out some things to be concerned about or at least pay attention to with our opioids. Do you hate that approach? Are you okay with that approach? Talk to me a little bit about how you feel about that.
Tasha McNerney:
Yeah, so interestingly enough, my husband, who I should let people know, my husband works in vet med, so when I say I was talking with my husband about something similar to this, he was like, but I would want to give them hydro and dexmed. Then I know they’re going to throw up all their stomach contents.
Dr. Andy Roark:
Yeah.
Tasha McNerney:
Potentially. Yes, potentially that’s true. And this is again, where I have to say every single patient is going to be treated differently because if you said to me, I have a laceration repair on this bulldog, French bulldog, Boston Terrier, boxer, anything, brachycephalic, again, because of their body confirmation, just because of the breed, I know that they are already at a higher risk of vomiting, regurgitation under anesthesia. So if we heavily, heavily sedate them with something like an opioid plus minus dexmedetomidine, even acepromazine, then what I worry about is if my team isn’t on top of it, could they potentially be vomiting but then not be in a position I’m talking about with their body. If they’re on the side, they’re vomiting or if they vomit up and then immediately fall over, we’re not ready with intubation to protect their airway. There is a chance that some stomach contents could get into their airway, and we are at greater risk of aspiration pneumonia. So if this is a brachycephalic breed, I will really try to avoid making them vomit before I am ready because I don’t want them potentially getting anything into their airway.
Dr. Andy Roark:
Yeah, that absolutely makes sense. And as you’re sort of laying this out, I was like, yeah, this is the stuff of nightmares. Yeah, that totally makes sense. So looking at brachiocephalic breeds things like that’s going to specifically or that’s going to increase your concern?
Tasha McNerney:
Yes, 100%. So if this was a shepherd that came in, and again, every patient is an individual. So if you said to me, Tasha, I can’t even get a catheter in without giving this patient some sedation, then again, what we have to look at is what’s the procedure that’s about to be performed? How heavy of analgesia and sedation do I need for this patient? So if I have a shepherd that is in for a scrotal ablation, I know that they have eaten within the past couple of hours, then we have to look at can I get a catheter in? If I can get a catheter in, then we can give our drugs IV. And we know by giving our drugs IV opioids, IV dexmedetomidine IV, we can lessen the overall amount that we’re giving and then that will lessen the side effects. And we usually don’t tend to see if we have given something like hydromorphone or buprenorphine IV, we don’t tend to see the same amount of nausea, vomiting, et cetera, that we will with an IM or subcutaneous injection.
So if I can get IV in, that’s preferred. However, if you say to me, absolutely, this dog is going to need some sedation before we place a catheter because it’s extremely fearful and reactive, then okay, let’s do that. Now, my drug choices might be a little different. Maybe I might choose something like buprenorphine or butorphanol as my opioid plus minus a dexmedetomidine or acepromazine. Again, depending on the patient’s, ASA status health status. So I might give that as an IM injection just to sedate the patient enough to do an IV catheter. And I know there’s people out there saying, Tasha, you just said butorphanol. Butorphanol is not a potent analgesic. I worry if I give butorphanol, then can I still give an opioid? Yes, butorphanol as far as its analgesic properties, pretty short acting. So let’s say you gave that patient butorphanol as a sedative because we don’t want to give it morphine or hydromorphone.
I don’t want it to be vomiting all over. So let’s give it a little butorphanol, less likely to vomit and then say the time goes by, you can always top off with IV hydromorphone or IV buprenorphine. Okay, yes, some of the receptors are going to be taken up with the butorphanol, however, not all of them are. So layer in your other opioids, once you get that IV catheter in place, our other opioids like hydro are going to be fast acting. If you have fentanyl at your practice, you could consider that as well of the opioids. Morphine is going to be the one that causes the most vomiting and of the pure MU opioids, methadone is going to be the one that causes the least amount of vomiting. If you have access to methadone, again, for a GI case or something, that’s usually what I’m going to go towards. However, if you’re at a practice that doesn’t have any MU opioids, then you have to use what you have on the shelf, and that’s when I start to look at things like butorphanol and then follow it up with longer lasting, higher level analgesia with buprenorphine.
Dr. Andy Roark:
Okay. No, that totally makes sense. And yeah, I’ve got to tell you, starting off with a buprenorphine or sort of a partial agonist and then adding in more of a pure agonist, that’s not a tool I really have in my toolbox. I have to sit with that. So is that a fairly common procedure? Are there things that you should be concerned about? Do you see, I don’t know. When you start with something that’s sedative and then you add an IV pure opioid on top of it, so start with buprenorphine and then add in some hydromorphone IV. Again, I just don’t have a lot of experience with that combination in my hands. Is there anything I should be looking out for or anything that I want to pay attention to?
Tasha McNerney:
Yeah, no problem. So I’ll just clarify that. If I was going to do this where I needed a sedative at first, I would be using butorphanol, not necessarily buprenorphine. Buprenorphine in itself of the opioids is not going to cause a lot of good sedation. So if I’m looking at a patient where I just need some sedation to get me through to get a catheter in place butorphanol is where, that’s where you want to go. Again, if I’ve used butorphanol say 45 minutes to an hour beforehand, and now I’m about to induce anesthesia and I need some analgesia and I’m about to give hydromorphone, yes, you potentially could not see as strong effects with your hydromorphone. However, as with any anesthetic or any analgesic protocol, it’s not all about the opioids. We want to make sure that we’re using a multimodal protocol so that way if there are some receptors that aren’t able to be taken up with the hydro and those MU receptors aren’t able to be fully agonized with our hydro, well that’s okay because guess what?
We’re also adding in things like maybe a Lidocaine CRI. We’re using regional anesthesia to our fullest extent. We’re adding in dexmedetomidine together with opioids, a really wonderful sedative analgesic combination. I think, again, if anybody’s ever heard me speak how much I love dexmedetomidine, and even the addition of half a mic to one mic per KG IV dexmedetomidine is going to provide additional synergistic analgesia. So I think that if you are at all worried that maybe my hydro is not going to work as well because an hour ago I gave butorphanol, that’s fine. Again, you’re going to do a multimodal protocol. We’re not always just going to rely on our opioids, and if we look at some of the evidences from human medicine, it really is about playing with and being very careful with or targeting our opioids, maybe even reducing our opioids and increasing some of these adjuncts like dexmedetomidine lidocaine, regional blocks, et cetera.
Dr. Andy Roark:
Is there any chance that you’re going to see a bounce phenomenon? So you use Butorphanol, which has got a pretty short half-life, and I give my hydromorphone, am I going to see increased effects from the hydromorphone after the butorphanol wears off, or is that not going to happen?
Tasha McNerney:
No, not usually, or at least we don’t seem to appreciate that again, because usually these patients are now under the effects of inhalant anesthesia.
Dr. Andy Roark:
Okay, so we’ve talked about choosing our opioids and what that looks like. Talk to me a little bit about GI protectants, things like that.
Tasha McNerney:
Yes, excellent. Because again, if I have a patient that came in and they needed an emergency surgery, let’s say they have a fracture or whatever, they have the laceration repair, they have eaten. I’ve chosen the most appropriate opioid. We have a catheter in. Now, another thing that’s going to be important, again, because we know that these drugs that we’re using like opioids, like inhaling anesthetics, are going to blunt those reflexes and they are going to decrease the sphincter tone or esophageal sphincter tone. Then we want to make sure that we are putting GI protectants in, and this is things like pantoprazole, omeprazole, metoclopramide, not only the bolus of metoclopramide, but also then a CRI of metoclopramide. So things like this, if I know that patient is going to surgery and they’re going to get opioids and inhaling anesthetics, I know that they’ve eaten in the last four hours, I’m going to my clinician and I’m saying, okay, also before we get started with inhalant anesthesia, once we get that catheter in, how do you feel about pantoprazole?
How do you feel about maybe some cisapride omeprazole? Do you want me to start a reglan CRI? Things like that. We do have some evidence that doing these things is going to decrease the amount of esophageal reflux under anesthesia. Then another thing that I want people to know is if you as the anesthesia technician are with a patient and they’re under anesthesia and you notice that they do have regurgitation either coming out of their mouth, coming out of their nose, et cetera, that’s really important to note. You want to let your clinician know that because that pH of those gastric contents that are coming up, that’s acidic. So we risk damaging the mucosal layer of the esophagus. So not only do we want to make sure we alert our clinician, write it down on our anesthetic record, but also it’s going to be important to not only have your suction ready, but you’re going to want to lavage that.
Now, there was a study looking at whether or not just plain saline versus saline with diluted bicarbonate was better to reduce that pH in the mucosa, and they did find that if you’re going to lavage the esophagus, then you want to make sure that you’re using saline with diluted bicarbonate in it to neutralize that pH, and then you have your suction ready, suctioning all of that out. Also, one thing that you want to note is, again, on your anesthetic record, we want to make sure that we know that this patient did have some regurgitation intraoperatively, because then I might want to talk to my clinician about whether or not this patient should be started on something like sucralfate once they have their swallow reflex back.
Dr. Andy Roark:
Yeah. Alright. That totally makes sense. Great. I feel good about this. Is there any other things I need to look out for? Any words of wisdom, pieces of advice?
Tasha McNerney:
No. Well, interestingly enough, the patients that do have the highest amount of regurgitation under anesthesia are orthopedic patients. So again, if your patient is a orthopedic fracture repair, then they actually already have a higher incidence of having that regurgitation, so be prepared with your GI protectants.
Dr. Andy Roark:
Why do you think that is?
Tasha McNerney:
I don’t know, but it was a really interesting study. I can send you the paper if you want to put it in the show notes. Yeah, sure. Send. But they look like they saw that orthopedic patients actually had a 25% chance greater incidence of esophageal reflux and regurgitation than the other patient populations. It’s very strange. Oh,
Dr. Andy Roark:
That’s fascinating. Cool.
Tasha McNerney:
And again, again, so brachycephalic already have an increased risk of regurgitation under anesthesia, so make sure you are protecting their airway at all costs.
Dr. Andy Roark:
Yes, I love it. Awesome. Thank you so much for talking through this with me. I have a page and a half of notes from a 15 minute conversation, absolutely enjoyable. I really appreciate your time. I will put links to the anesthesia nerds conference up. Tasha, where can people find you online?
Tasha McNerney:
Yeah, we are on the veterinary anesthesia nerd, so veterinary anesthesia nerds.com is the website for all of our information where you can find all of us speaking. And if you really want to get involved in the chat where our chat is mainly going over cases still as a Facebook group, but a very active Facebook group. We are looking to move off of Facebook in the near future and just be located on our website. But for now, you can find us on Facebook, you can find us on Instagram, and come see us in person in San Diego.
Dr. Andy Roark:
That sounds awesome. Awesome. Thanks so much for being here, guys. Thanks for tuning in. I hope you learned something. I hope you took something in the way. Take care of yourselves, everybody.
Tasha McNerney:
Bye.
Dr. Andy Roark:
And that’s it. That’s our episode. That’s what I got for you. Thanks, Tasha, for being here. Guys, thanks to you for tuning in and listening. Take care of yourselves, everybody. We’ll talk to you soon.