Baa's and Bleat's - The AASRP Podcast
Baa's and Bleat's - The AASRP Podcast
C-section Survival with Dr. George Elane
Join us for a discussion about doe and kid survival metrics based on different sedation and anesthesia protocols with Dr. George Elane, Assistant Professor of Equine Soft Tissue Surgery at Texas A&M University's College of Veterinary Medicine.
In this episode, Dr. Elane discusses the decision-making process for choosing between sedation and general anesthesia for goat c-sections. He also covers the risks and benefits to does and kids when considering both options. Other topics discussed include analgesia protocol options and post-operative antibiotic selection.
More information about Dr. Elane's work can be found here: https://vetmed.tamu.edu/elane-lab/team/
The article discussed in today's episode is titled "Sedated cesarean sections are associated with increased kid survival compared to general anesthesia in goats: retrospective cohort of 45 cases (2011–2021)" and can be found here: https://avmajournals.avma.org/view/journals/javma/261/3/javma.22.10.0466.xml
If your company or organization would like to sponsor an episode or if you have questions about today's show, please email Office@AASRP.org
Hello, and welcome to this episode of Boz and Bleats, a podcast brought to you by the American Association of Small Ruminant Practitioners. Today we'll be talking to Dr. George Elaine, a brand new faculty member in the surgery department at Tex Texas AM. Welcome, Dr. Elaine.
George:Hi, thank you.
Sarah:So as always, I'd like to start with a little history. Talk to us about where you grew up, your background, the institutions you've been at. Help us get a little idea about who we're talking to today.
George:Absolutely, yeah. So I grew up in Laurel, Maryland, uh originally. Um, and that was where I really fell into basically equine um uh medicine and surgery uh with a great interest in flat track racing uh thoroughbreds because they had their own racetrack in Laurel there. And so that's how I kind of fell into wanting to be a vet. Uh, and then in applying for vet school during high school, I ended up working in a lab at the University of Maryland, um, where we ended up doing a lot of surgeries on sheep and looking at uh turnover of nitrogenous compounds and rumens of sheep. Uh, and so that's where I got my first dose of uh surgery and um uh small ruminants and uh large animals in general, and then ended up going into vet school uh with the interest of becoming a large animal surgeon. Uh and I did my vet school training at Virginia Tech, and then I uh ended up going from Virginia Tech uh to uh Peterson and Smith Equine Hospital in Florida, and then did a second internship at the Mary Ann Dupont-Scott Equine Medical Center in Leesburg, Virginia. Uh, and from there got a combined master's and residency program at uh the University of Florida, which is where we did the uh study that we'll talk about later today. And then uh from there I ended up going to do a PhD at North Carolina State University, uh, and then just finished that uh and moving into a new brand new position at as an equine soft tissue surgeon at Texas AM.
Sarah:Awesome. It sounds like you have really stayed towards the East Coast, haven't you?
George:Absolutely. I like to move around and get as many places as I can for sure.
Sarah:What's your favorite place that you've lived?
George:Oh, North Carolina is beautiful. Uh it's hard to argue with that. Florida was nice too, but it's so hot most of the time.
Sarah:Okay, let's jump in. Today we'll be discussing Dr. Elaine's paper from March of 2023 in JAVMA, entitled Sedated Caesarean Sections Are Associated with Increased Kid Survival Compared to General Anesthesia in GOATs, a retrospective cohort of 45 cases from 2011 to 2021. The reason I absolutely love this paper is because for those of us that do see sections in the field, this is actually how we do them. It just makes me happy when someone like you are like, guess what? You're doing the best you can, even though you're not in a surgery room, nor could we be in a surgery room. This is actually the third podcast I've done about retrospective studies. So I think my listeners pretty much understand how they work. Um I don't know though, could you give us a bit of background on how you decided to do this study, how you got interested, and what the catalyst for the study was for you?
George:Yeah, absolutely. So um it just so happens that when um when you're a surgery resident there, there's always um an inappropriate uh number of um cases that are deposited between each different um resident. So for instance, my resident mate had a lot of other different types of surgery, and I ended up just luck of the draw, got most of the goat c-sections. Um, and so there was actually this one goat that we were doing a C-section on, um, and she was this enormous boredo who ended up having pregnancy toxemia and had five kids actually in her uterus that we pulled out. Um and uh because it was toward the end of the day, the uh anesthesiologist who started the case had decided um she was rather sick. He wanted to put her under general anesthesia, and so we did the surgery. But because it was towards the end of the day, a new anesthesiologist, the on-call anesthesiologist, took over. And of course, it was he and I who had to end up moving this really big boredau when she was back into recovery there, and so we have to lift her off the table, put her on the uh recovery mat, and then she's kind of you know woozy and swinging her head around. Uh, and we're getting knocked around a little bit, and we thought naturally light bulb moment of there kind of has to be a better way uh of doing this. And then we uh ended up having, as we can talk about a little bit, um, we had our internal medicine specialists around that were working on kid resuscitation, and then he came in and said, you know, only two, I think, of those five kids had survived. Um, and so we kind of started talking about it, and you know, why on earth would you bother doing complete general anesthesia? We started talking about the pros and cons of both doing it under general versus doing it sedated. Um, and that's kind of what led us to really want to investigate this further.
Sarah:Yeah, and I like how the intro to the paper talks about comparing it to human medicine. And as I read this, I was thinking we all know that women aren't put under general anesthesia to have c-sections, right? Most women are just giving an epidural and a local block if needed. It was kind of a light bulb moment for me because I always felt like general anesthesia was the gold standard, even understanding that the effect on the kids weren't really great. One question I had while reading this paper was why didn't you include any of the C-sections where the kids had died?
George:Yeah, absolutely. So we were the objective of the paper was really to compare general anesthesia versus sedation in terms of kid survival, and then sort of a secondary objective of looking at um complications in the dough. Uh and so when we really wanted to just look at how and the anesthetic um affects kid survival, uh we considered it kind of inappropriate to include cases where the kids were already dead because they would not have been subjected to either quote unquote treatment, the sedation versus the general anesthesia. Um then there were a few, not many, but still a few where the kids were euthanized, quote unquote, intraoperatively. And for most of them, it was either because they were premature, because it was a pregnancy toxemia case, uh, and the client had decided that the um dough was basically worth more than the kids, and so we were going to uh basically remove the the kids. Or for um, I think one one, maybe two instances, they had things like um carpal contraction and things like that. And obviously that's not something those both both of those conditions are not necessarily related to the actual anesthetic. So we removed those cases um specifically so that we could narrow down and remove extraneous variables uh and really just kind of focus on the anesthetic classification there.
Sarah:Okay, can you briefly go into why someone would choose to do general anesthesia over sedation?
George:Yeah, absolutely. So just kind of um why some of us would choose generally uh general anesthesia versus sedation or something like that. Um the uh most of the time, and when we're in the actual veterinary hospital, we're kind of in the ivory tower, and so we have a whole bunch of help, and you have house officers and students that you're trying to teach. And so there are a lot of people there, so we can afford to do some of the other things that um like you. I've done them out in the field as well, where you basically have, if you're lucky, you have somebody to hold just the one, you know, patient there. Um, and it really does kind of dramatically make a difference when you can, you know, rely rely on other people to do the anesthesia or the sedation and everything like that. But some anesthesiologists believe that you know there's it's better to um generally anesthetize them uh so that you can place the endotracheal tube and therefore theoretically reduce the risk of things like aspiration pneumonia when you have uh especially a young surgeon who's you know mashing on the rumen, um, theoretically that uh can lead to those sort of complications. Um, whereas obviously others prefer the up and about sort of method of just doing sort of recumbent or uh just light sedation to make it easier, and then therefore you don't introduce as much uh potential cardiovascular compromise in the dough. And as you guys can see from the paper itself there, the uh numbers were actually skewed towards the um anesthetic, or excuse me, towards the sedative group, uh just because that is how most of us tend to prefer to do them. Um but there are people out there who still like to um you know protect versus protect the airway and uh basically make it a smoother procedure for the patient, and therefore choose uh general anesthesia.
Sarah:Right. And so what were the most common drugs used for sedation?
George:Yeah, so for sedation here, um basically some of the most common ones were uh midazolam being the um benzodiazepine that we primarily used. Um, and then um all of them will received uh some sort of um either partial or full muagonists, so butorphenol and methadone as preanesthetics. And then the ones that were actually being properly anesthetized were basically anesthetized with either ketamine or propofol. Um and so those were the main ones. Um occasionally the sedative group would get a dose of propofol. Um, and it's one of the things we kind of talked about in our discussion section was that the dose of propofol actually makes quite quite a difference. Um and so the um general anesthetic group got a 0.5 mig per kig dose of the propofol, whereas the sedative group got only a 0.2 mig per kig dose. Um, and that was really to facilitate that sort of twilight analgesia um over the true um sedative or an uh anesthetic dose.
Sarah:And what were those doses normally?
George:Uh it was basically left up to the anesthesiologist, and so that's why there's quite a bit of a range, but they tended to be things like um incisional line blocks were kind of the most common there. Um, and then we had epidurals, paravertebrals, and intrathecals as kind of the other ones. But a solid, you know, over half of them there were the just the straight incisional line blocks like most of them do. Uh and that was actually one of the things I really um enjoyed when I was writing this paper. It was right before I was studying for boards, and so it was a great review of all the different approaches and methods for um analgesia. Uh, and some people might be able to see that kind of in the introduction section there where it was all included and discussed. Um But the main reason that there's sort of that discrepancy between the general anesthetic group and the um um sedative group is that theoretically, from a uh large uh animal surgeon's perspective, there is a slight increase in um risk of things like incisional infections and things like that, things like that when you're putting in lidocaine or something into your incision. Um and so if you don't have to do it, it's theoretically ideal not to. Uh and therefore um when we have them in an appropriate plane of anesthesia, theoretically they shouldn't feel anything that you're doing anyway. Um, and therefore, there's just kind of those are some of the like the pros and cons and some of the philosophies there. Uh and I won't go so far as to say I think one is better than the other, just that they're they're different.
Sarah:Okay, okay. I find it very difficult to do an epidural in goats. Cows, super easy. Every time I've had a C-section, I try to do an epidural, and I and I'm successful maybe a third of the time. It's just really difficult in goats.
George:It is. Yeah. Epidurals are certainly not my favorite, and that actually led this paper was part of a sort of a sister paper to another one I did looking at spinol in goats because the spinol or subarachnoid is so much easier to hit than the epidural.
Sarah:Oh, okay. Interesting. I'll have to look that paper up next.
George:Yeah.
Sarah:Yeah, absolutely. Just looking over the paper and trying to point out things that are interesting. Can you explain a little bit more about the AESA classification system to us?
George:Yeah, absolutely. So the ASA classification system uh was actually the reason we kind of brought it up was, as I said in the beginning, there, we were talking between myself and the anesthesiologist. Um, and the ASA is the American Society of Anesthesiologists, uh, and they came up with a sort of way to grade or classify every patient from a scale of one to five based off of the amount of risk that you're taking when you anestheti this patient. So, for instance, um, grade one is uh a normal, healthy patient, uh, grade two has a mild systemic disease, grade three has moderate systemic disease, grade four has severe systemic disease, and then a grade five is basically a morabund patient that is really not expected to survive basically 24 hours if it doesn't get whatever surgery that uh you're looking to perform. And so those are kind of the different classifications, and our thought was um in including this in this particular study, was that uh there's obviously a very wide range of reasons to be doing a C-section in a goat. Um you can have pregnancy toxemia, which would you know can correlate with some of the higher end of these um the moderate or severe systemic disease, um, versus something like a dystosia where the goat might be or the doe might be uh more systemically healthy, um, but just have either a malpositioning of the fetus or sort of like a phenomaternal disproportion or even the ring womb or anything like that. And so that was our philosophy for um sort of grading these based on the ASA classification system.
Sarah:Okay, so the ASA is looking at mom to see how healthy she is before surgery.
George:Exactly.
Sarah:That's pretty straightforward. Okay, is there anything else in the materials and methods that you'd like us to go over?
George:Um, not from my perspective. I mean, everything basically was sort of um one of the nice things about having this sort of retrospective design is that you do have so much information and there are so many different variables to um look at. And so we tried to make them into fit them into categories of basically what rescue drugs were given, um, and then um what um uh lidocaine or you know what um uh local regional anesthesia was lose used, uh things like that. And then within the categories started comparing. Um, and so that has some uh effect on the results, obviously.
Sarah:Right. So once you look it over, you ended up with 31 dose in the general anesthesia group and 68 in the sedation group, and that's kind of what you used for your numbers. All right, so let's jump to the results. Um, so go ahead. What did you find? What do we need to pull out?
George:Yeah, absolutely. So as uh is probably true for most retrospectives, uh anytime you analyze a lot of data, there's obviously a lot of results. And so uh I think some of the biggest results were the fact that um we did notice an increased uh rate of kid survival when with the C-section was performed under sedation compared to general anesthesia. Um so for instance, that rate there is listed as um, I think it's uh 96 or 97 percent of the um uh goats survived, or excuse me, of the kids survived in the sedation group versus about 66% or so uh of the kids in the general anesthesia group. And that was kind of the primary goal of this paper was to see what the difference between in kid survival rate was between these two sort of methodologies there. Um and then basically there's uh we looked at each of the different sort of categories or types of variables that we saw. Uh so for instance, the um uh I think it was the in the ASA status there, um we tried to separate them into quote unquote healthy doughs, which were an ASA status of one and two, so normal or mild systemic disease, uh, versus uh dose that were either moderately or severely systemically affected. Um we did find that the uh does who uh ended up being in the general anesthetic group tended to be an ASA status of three or higher, but that ended up not being, that was more of a trend, not a true statistically significant result. Um moving towards the actual statistical findings that were significant. Um we talked about the presence of multiple kids. So if you have only one um kid that you're doing a C-section on, uh that tends to be associated with a better um outcome of survival for the kid. Um and then similarly, uh the use of preoperative opioids uh was associated with a decrease in uh survival to discharge for the kids.
Sarah:Yes, and that really surprised me.
George:Yeah, yeah. I mean it ends up um being that yeah, you know, you end up with all of these different potentials and uh for uh mechanisms for providing analgesia both for the dough or for using it for uh sedative purposes and combining it in your anesthetic protocol. Um, but uh it's I think one of those things that, you know, uh just because we can do it and it makes us feel better, um, should we really be doing it? Uh and that opens up kind of a big, big can of worms, as it were, to start talking about um opioids and whether or not we should or should not be giving them and uh what mechanisms to to use for them.
Sarah:Yeah, for sure.
George:Yeah. Uh and those were the three biggest sort of findings in the study were the um C-section uh survival uh under the sedative group, the presence of the multiple kids, and the pre-operative opioids. Um we did have some other sort of um variables that we looked at. They ended up not being quite as significant though.
Sarah:Right. I mean, it's always nice when the math justifies that you're doing the correct thing.
George:Yeah, it is nice to actually see a result. I feel like a lot of these retrospective studies, you set out to answer a question and then statistically you find that there's no result, you know, no difference or anything like that.
Sarah:Yeah, sure.
George:And it was nice to be able to kind of demonstrate a difference in this case.
Sarah:Yeah, yeah. And when we know more, we can do better. Absolutely. Okay, let's see. So moving into the discussion, if there's anything specific we want to point out and report besides what we've already talked about.
George:Yeah, so we kind of talked about the opioids there, um, and we just know that from all of the human literature that uh they tend to cause a respiratory depression and especially in a dose-dependent manner, there. Um and so that was one of the questions that we were interested in in identifying. One of the um things we had, you know, been interested in was our secondary objective, which was uh, you know, identifying complications in the dough between the different um types of uh general anesthesia versus sedation there. Um but uh on a uh as I guess a good note, the Rate of complications was so low they ended up not being able to identify any real statistical significance. And so it's good that you know we had few does that had those complications, but if we had had more complications, maybe we would have been able to identify a statistically significant difference there. And that was based off of our discussion with the anesthesiologists in talking about between or looking at general anesthesia and protecting that airway versus sedation and leaving that airway unintebated and unprotected, whether or not we would really reduce that risk. And like I said, we couldn't really determine that based off of our low number number of postoperative and perioperative complications.
Sarah:Okay, remind me, and maybe it wasn't in the paper. Did most of the does get antibiotics?
George:Oh yeah, most of them did. I don't think that we specifically looked at um antibiotic uh use or specific um which types they were. Uh this was mostly focused on basically the surgery and the anesthetic portion of it. Okay. Certainly all of the does got postoperative antibiotics there.
Sarah:Okay. You know, I'm always looking for tips and tricks to help um the animals survive. On almost all of my cow C-sections, um, the cows do great and they survive, but you know, not so much with the goats. Um, the more I learn about aftercare and the better, the better survival I had, even like giving fluids before starting this d-section. I'm always wondering about which antibiotic is the most helpful post-surgery. You know, um, do you do a few days of oxy tet and flu nixin? Um, it's just hard to know for sure how to help them. And I do feel like if all of these can help them survive, um, in my mind, if they feel good and they can focus on their baby, it just gives them another reason to live.
George:Yeah, and the analgesia was only briefly touched on in the, at least in the paper there. But um, we did do, you know, creatinine values just to double check and make sure if we were going to give them flunics and that they weren't gonna have any kidney issues. Um, and most of them uh ended up going on maloxicam anyway. Um, and that was really just kind of uh uh case kind of dependent. And um the way we managed these at the University of Florida there was that medicine often took uh the patients, the doughs back if the kids survived, um, versus surgeons tended to the surgery service tended to keep the doughs if none of the kids survived, and then we were just managing the surgical site um for the dough there. And so that opened up a lot of, as you can imagine, a lot of differences in sort of case management, uh, which was uh why we didn't necessarily analyze them. I certainly agree with you with the analgesia too. I s we saw it with some frequency where you'd have the doughs that, especially if they were the pregtox doughs, but they were close enough to parturition that the kids uh could survive there. Um if they burnt feeling great or laid down a lot, then you notice the kids kind of start trying to wander away and look for you know milk or whatever it was that they were sort of uh roaming about a lot more, versus the doughs that uh ended up being systemically more healthy, uh, you know, they interacted, they bonded with their kids more. Um, and so keeping the dough comfortable was all postoperatively was always one of the best things that I could think of, whether that's you know increased um opioids or increased um uh analgesia with NSAIDs and things like that for sure. And then um we uh we, I mean, I suppose we could talk for for ages about how to do it in cattle there, but um a lot here there's a lot of um back and forth talk and about the pros and cons versus doing the standard flank incision um that we did here versus the para um uh inguinal sort of approach or the paracaustal approach, uh especially in cattle. We don't do that as much in the goats, obviously. Um but um there's you know a lot of a lot of different methods that have been good, which usually means there's no one great one. Um but for in this case, you know, we had a hundred goats, almost a hundred goats, and they were all um done with that left uh peringuinal fossa approach, and I think that works, you know, just great. As long as you maintain good aseptic technique and everything, it's always good.
Sarah:Right, right, yeah. Let's see. I feel like we've kind of touched on a lot of it. All right, I think that was pretty much all the questions that I had written down. Anything else you want to add?
George:Nope. Um, other than um uh I think that uh I'm very you know pleased and thankful to have been invited here. And um I think that uh I hope that this is useful. One of my uh professional goals is always to write a paper that I think will show up on surgery boards, and so I hope that uh eventually some some uh good or use comes out of this particular paper.
Sarah:Yeah, I'm always looking for papers for the podcast that talk to a broad swath of the AASRP membership. Okay, so I always end with this final question. What do you think is the next big problem that researchers need to think about in the world of small ruminant medicine?
George:Yeah, so um one of the things I think would be really interesting that's coming out now, um, it may not be true for you know general um small ruminant medicine, but specifically related to C-sections, and because so many of the doughs that we cut in this paper uh were related to pregnancy toxemia, um, the use of um uh some newer techniques, things like chemoperfusion that we're looking at doing. And while this is definitely right now a um an ivory tower academic uh principle, uh the use of something like hemoperfusion would be really, really good to pull out a lot of those inflammatory cytokines. And we're starting to wonder now if we could improve our um success rate uh if we were to remove a lot of those um inflammatory cytokines and improve the systemic health of the dough.
Sarah:I love it. I love it. It's so specific. Most people are like parasites, but that's something this is something that people can really focus in on.
George:Yeah, absolutely. No, that's um it kind of lends itself a little bit closer to my research is mostly in um ischemic uh horse intestine now. Um, and as kind of a side branch, we're looking at this hemoperfusion and how it might help in horses as well. Um, and then when we were started thinking back up to this paper, it's like, oh, I wonder if it would help in the goats as well. And so would be interested to try it, but uh there's some baseline things I think we have to find out first, um, specifically in terms of um uh because we have to systemically um uh anticoagulate them, place in a uh place them in a status of uh anticoagulation. Uh, can we actually do that safely? And so there's a lot of groundwork to be done before we can actually start applying it to clinical cases. But I think it would be an exciting thing to kind of move on in in future directions there.
Sarah:Sure. All right. Well, thank you so much for joining us. Thank you for doing small ruminant research. And if you haven't heard, AASRP has started a research grant that's awarded about every other year right now. So look out for those proposals and requests if AM will let you keep doing research on small ruminants.
George:Oh, absolutely. No, we're we're already looking into them there for sure.
Sarah:Perfect. Well, we'll leave it here with you and good luck in your new position.
George:You too. Thank you so much for having me.
