Transcript
Gianluca Bini: All right, so tonight it's Ryan's topic. Oh my God. Boom.
Ryan Bailey: I hope you're all ready. We're going to talk. So I was inspired by the most recent Navis Spring Symposium. Shout out to Bartel.
Annatasha: Thank you.
Ryan Bailey: Something came up and I was like, you know what? We should really talk a little bit more about this from an anesthesiologist perspective. Let's talk about ventilation and how you rough
Gianluca Bini: home
Ryan Bailey: ah you approach it Favorite... ways to do it, when are you doing it, why are you doing it, all the information you can get from it, are you a permissive hypercapnia person, let's get into that, what that really means, if it's worth it, if it's not worth it. So yeah, that's what I want to talk about today. So I guess let's start out with like, how how often are you ventilating?
Ryan Bailey: Like how often are you cranking on the the ventilator?
Gianluca Bini: If they ventilate normal, fine. And, you know, they they're entitled to it's below 60%.
Gianluca Bini: I let them breathe on their own. But the higher side of things is that you know if it's a longer procedure, probably I tend to put them on a vent more. Adelectasis is real, right?
Gianluca Bini: And so don't know. Sometimes I'd rather be a little bit more aggressive with it and and just throw them on a ventilator right away. Of course, there are some cases where ventilation, it's a must, right?
Gianluca Bini: Like your thoracotomies, your your know brain patients, of course, like, you those, you know, we're not even talking about those, I guess, right? Like we're talking about otherwise saldiv.
Ryan Bailey: o We'll talk about those, but...
Gianluca Bini: Okay. Okay.
Annatasha: like, you know,
Ryan Bailey: I want to know if here your average your average case who's getting anesthesia who doesn't specifically require ventilation for some specific disease process or some surgical portion of the procedure.
Ryan Bailey: Like... Yeah. Like, are you cracking it on Like, I'll tell you, I, as a resident, I was like, once they were anesthetized, the minute they started to go apneic following induction, honestly, i usually just crack the switch on the ventilator because it was right there.
Ryan Bailey: And
Annatasha: like you know I supervised you for a year when you were a resident and I don't remember that because I would beaten you sick if I had discovered that.
Ryan Bailey: yeah half a year, half a year, half, half a year.
Annatasha: Half a year, yes. I had to leave because I couldn't take the insane amount of ventilating all the time.
Ryan Bailey: Yes, exactly.
Annatasha: Yeah.
Ryan Bailey: feel like ventilated them a lot more often. um i think partly because it was accessible, partly because of the equipment we had access to And now I'm going to say I'm i'm more in the Bartell camp of I rarely ever break out the ventilator if I don't have to. Like I can get away with a lot of not not starting positive pressure ventilation. and yeah
Ryan Bailey: anyway.
Gianluca Bini: But we are in two different settings, right?
Ryan Bailey: Oh, yes. Yeah, for sure. And like, for me, the ventilator is I have to get the ventilator. I have to connect it because the equipment I have, it's not built into my machine. I would love if it was. I just don't happen to have that type of machine.
Ryan Bailey: When it was there and and readily available, you know, it was like...
Gianluca Bini: Yeah.
Ryan Bailey: So the the decision to do it was much lower.
Gianluca Bini: yeah
Ryan Bailey: Now I want to know, Bartell, where are you at? What's your approach?
Annatasha: i I can barely hold it together right now, gentlemen.
Ryan Bailey: I can tell.
Annatasha: like This is a major source of aggravation for me and in anesthesia in general.
Ryan Bailey: i didn't yeah I didn't know this would cause...
Annatasha: Yeah.
Ryan Bailey: I feel like I have a lot of like really big feelings about ventilation problems.
Annatasha: This is like Bartels sub Q ketamine in Bailey's world. Like this something that I will, I will die on this hill. This is a hill that I would die on is ventilation.
Gianluca Bini: Oh my God.
Annatasha: Yeah. I have some strong opinions for a change about this.
Ryan Bailey: Wow. Okay.
Annatasha: So,
Ryan Bailey: ah
Annatasha: so Now that you guys have said what I think you have to
Annatasha: But here are my thoughts, which are right. So ventilation,
Gianluca Bini: Ha ha ha.
Ryan Bailey: okay
Annatasha: positive pressure ventilation is an aberrant physiological state for the patient. And as a consequence, when we make this exogenous intervention and change the natural physiology of the patient, there are going to be consequences.
Annatasha: I think that flipping the patient on ventilation automatically is either lazy or you don't understand the principles of most of your induction drugs or the fact that your PaCO2 threshold for spontaneous ventilation automatically changes on the inhalation agents.
Annatasha: And therefore you have to let it accumulate a little bit to drive spontaneous ventilation. And people are so busy freaking out about how often the patient breathes even though it's cardiovascularly stable and oxygen saturating appropriately. So it's either lazy or you're too anxious to be able to control your own emotions. In either case, hate.
Annatasha: And I think the one thing that we forget, we focus a lot about on ventilation in terms of, we always talk about like impeded venous return. So changing preload, you know, that is actually only part of the concern.
Annatasha: One of the things like I think people really downplay, and and particularly in patients who are sick and particularly in patients who are going to be hospitalized long-term, is we forget that it promotes an inflammatory process from the sheer forces on the alveoli popping open and closed themselves.
Annatasha: And also the fact that you have to exceed driving pressure like to an extraordinary level to actually reopen alveoli because they're either closed or they're open. They ain't halfway. And I do think that atelectasis is real, but I also, you can't tell me like, know, that ventilation, what what's the difference between ventilating a patient and atelectasis not ventilating a patient in adoletics and unless you are actually doing the specific maneuvers or interventions that are going to help you recruit and maintain open airways.
Ryan Bailey: Right.
Annatasha: So if you're not recruiting, if you're not using bronchodilator, if you're not actually using PEEP, You cannot tell me that ventilation is going to, you know, be your mainstay fight against atelectasis in your average patient. But I mean, the sheer forces on the alveoli, the inflammatory process, and the other thing we forget is it changes intracranial pressures, and not just by driving CO2, but by actually changing central venous pressure. So there's a number of pretty significant consequences.
Annatasha: And my whole point is, is that the body of the patient is smarter than the three of us put together, And in most instances, a healthy patient will compensate appropriately for being unconscious and still, and then make itself physiological stable. And I think we we often ventilate them for no good particular reason and actually cause more problems than we're curing.
Gianluca Bini: I know. I mean, so so
Annatasha: Yeah, so we already skipped over your opinion.
Gianluca Bini: whatever. So, I mean, part of this is, you know, yeah the setting where you're working is different than the setting where I'm working, right? Like, so I have cases that normally go way longer than yours.
Gianluca Bini: Right. So like even a spay.
Annatasha: Okay, sorry, I just wanted to clarify.
Gianluca Bini: Correct.
Annatasha: So the setting comparison is academic versus private, right?
Gianluca Bini: Correct.
Annatasha: i I didn't know if you were trying to like make this something about Oklahoma and I was i was losing the track there. I was like, I don't know what happens in Oklahoma versus Canada.
Gianluca Bini: No, no, there is nothing about, no, the weather has nothing to do with it, but, but you know, in in an academic setting, you you have students that are helping with the procedures or performing the procedures, you of course, that takes way longer than what it does in a private practice, right?
Annatasha: Corn speck.
Gianluca Bini: So like, as pay becomes a three-hour procedure, it's it's normal, right? And so, we administer 100% oxygen to our patients. We scavenge out the nitrogen skeleton that those LVoli have.
Gianluca Bini: Once you put them on their back, if they're hypoventilating, which they do with most of the induction drugs we use, adelectasis does happen, right?
Gianluca Bini: And so even normal ventilator settings with has a little bit of PEEP intrinsic in it, right?
Annatasha: Yeah, but that's only to balance the negative amount of suction being generated by the scavenge.
Gianluca Bini: Right.
Annatasha: So the net total is going to be insignificant physiologically to the patient.
Gianluca Bini: Well, you still have like two or two to four centimeters of water that you do, period.
Annatasha: Yeah, whoop-dee-doo. And that's what's balancing the scavenge, which is usually minus two to minus six. And more importantly, two to four pretty much in the literature has not really shown to do maybe bupkis about atelectus.
Gianluca Bini: Okay, fair. Fair. But then if you if you actually measure any TCO2-PACO2 gap, you will see that you have... have much better values with starting ventilation immediately rather than starting it, you two hours later when your indigents should it's now above threshold you need to start, you know, ventilating it, right?
Gianluca Bini: So being it's 100% the same in a small animal and the same as it is in a human, 100%.
Annatasha: I would give you that in a horse. I'm not sure I'm willing to concede that in a cat or a dog.
Ryan Bailey: Thank you.
Annatasha: No, no, no. If you don't ventilate a horse from the get-go, you are going to get hypoxemia, a relative hypoxemia.
Gianluca Bini: No, no, of course, but the gap, the gap is, you know, that occurs with Small Animal 2.
Annatasha: and
Annatasha: But the average gap is five to eight in a dog, so why are we getting upregulated about ventilating? And if we know that's going to happen because of recumbency and sedation anyway. Like that whole my point is that things are going to change. Sure.
Annatasha: But what degree of change is clinically relevant?
Annatasha: one of the other issues I take with ventilation too, is if you do it wrong, either hypoventilate them or hyperventilate them.
Gianluca Bini: Oh, sure.
Annatasha: that can also be catastrophic in and of itself. So, I mean, the number of times I've seen massive kerfuffles with the ventilator, either not driving appropriately or, you know, driving too aggressively,
Annatasha: that that gives me pause to think that it is not benign. and And I think that we are often too quick to jump to it without legitimately good clinical reasons.
Annatasha: Interestingly, also just parlaying a little bit into slightly related topic, which Bailey touched on in his intro is that I just came from the AVA conference in and Vienna lot last month.
Annatasha: And they had a, you know, a human speaker come in and then there were a couple of resident abstracts and they were actually looking at the ventilation modes and whether or not that improved ventilation and whether or not that improved oxygenation. So do you drive pressure? Do you drive volume?
Annatasha: do you cycle it, et cetera? You know, the findings are pretty inconsequential. Like whether you drive pressure, whether you drive volume. um And I thought that was really interesting. Yeah.
Annatasha: Yeah, I thought that was really interesting.
Gianluca Bini: I mean, it makes sense though, right?
Annatasha: And and my my best friend in real life is actually a human cardiothoracic transplant respiratory therapist. And he basically has told me before, he's like, oh, potato, potato. Like people spend way too much time like making like these academic...
Annatasha: you know, assertions about the the mode. And he goes at the end of the day, like, he's like, I drive on, on volume. And he was like, any of these are like, you know, post COVID patients, these are post transplant patients, you know, and he's like, I let the blood gas dictate it So he was like, what ah ah what do you care if you drive volume?
Gianluca Bini: Yeah.
Annatasha: Or what do you care if you drive pressure? Right.
Gianluca Bini: Yeah. No, I mean, I always drive volume do, right? I'd set the pressure limit, right?
Annatasha: hmm.
Gianluca Bini: then you I usually use volume, right? it's Especially like if you have people that are manipulating the abdomen or whatnot and they can put pressure on the diaphragm
Annatasha: Yeah, or they relieve the pressure on the diaphragm and then you're on you know, you have to actually be very careful if you have changes in that extra pleural pressures or those extra thoracic pressures, because if they take pressure on and off the diaphragm, if they open the chest, they close the chest, what you're driving is going to change significantly based on, you know, if you set volume too low, then you're going to achieve a really low pressure after they take diaphragmatic pressure off.
Gianluca Bini: right
Annatasha: So, you know, that that's what I think. I think ventilation gives people a false sense of security and and I you always object to anything that we do where we remove our ability to critically think about what's happening with the patient.
Annatasha: and how what's going on in the procedure is also affecting the patient. In this case, opening abdomen, opening chest, closing, closing, positioning, what have you, obesity, what have you. I think your point about duration, right Because usually duration incurs more hypothermia, hypothermia occurs more hypotension, know positive pressure ventilation, what is their depth?
Annatasha: But you know I see a lot of people just flick the ventilator on and basically tune the fuck out about it. And you're just like, get The critical thinking evaporates, which causes me concern.
Gianluca Bini: Yeah.
Gianluca Bini: You may also be overthinking it a little bit, but it's okay.
Ryan Bailey: Well,.
Annatasha: and luca I mean, I'm not though.
Gianluca Bini: It's okay. All
Annatasha: And that's because, you know why? Because I only see ASA fours and five Es, right? I don't do spays and neuters.
Gianluca Bini: right.
Annatasha: if they call me down from like the lofty offices of upper management,
Annatasha: it's dying on the table, right?
Ryan Bailey: egg yeah
Annatasha: It's dying on the table.
Gianluca Bini: Do you even remember how ventilator looks like nowadays?
Annatasha: Well, a bag and a barrel.
Ryan Bailey: This way, Bartell's going to be like, yeah, it's right here.
Annatasha: The other thing too that I also think that we take away too is one of the things that I've seen a lot of people make like overt mistakes on is patients who have like a chronic acidemia and then people want to bring the PaCO2 between 30 and 45, right?
Annatasha: And that patient has actually you know shifted their pH curve because they've been chronically acideming. And then we get in there we're like fucking gung-ho about ventilating it to 35. And I'm like, you're going to kill it.
Annatasha: And I was just like, you're going to drive the pH absolutely into the toilet if you don't actually let that patient maintain its baseline PaCO2 because now it's in a state of chronic compensation.
Annatasha: Like I said, I just feel that we flip to ventilation literally and metaphorically in a manner that for me is either, like it's very irreverent and oftentimes I find it lazy.
Ryan Bailey: that were
Annatasha: I get why students do it, but even in that case, like it's fine, you know, probably it's probably more fine for ASA ones and ASA twos, but in ASA four and five world, I want that person paying attention and thinking.
Annatasha: So yeah, I told you very strongly about ventilating.
Gianluca Bini: Yeah, no, that's fair.
Ryan Bailey: Well, that was unexpected.
Annatasha: Yes.
Ryan Bailey: the Bit of a shock.
Annatasha: Yeah.
Ryan Bailey: Thought we might struggle to fill the hour, but I think we're going to be just fine. i didn't know you all had such strong feelings. I love it. It makes me feel good because i have a lot of strong feelings.
Ryan Bailey: So, lot Lot to unpack, but let's let's say we've got the average, this a healthy patient, does not require ventilation for a specific reason, but we have chosen to put it on the ventilator.
Ryan Bailey: So what I want you to talk about Like which modes are you using? So volume or pressure, are you going to use a PSV or just like a full control?
Ryan Bailey: And then what's your CO2 targets? Where are you trying to drive CO2 to in your average patient? umm I'm going to get to s sick patients. We can talk all about like all those little and idiosyncrasies, but like, what are you doing for your regular? What's your rate even? What's your inspiratory time? Like, are those all things you're thinking about?
Annatasha: I don't even remember the first question now, but that was a lot.
Gianluca Bini: Thank you.
Ryan Bailey: mean, what are the settings you go to when you start this patient on the vent and your end end goals kind of when you start? Because, like, you're going to take this patient. i don't know. let's say that Let's say it's an average healthy TPLO.
Ryan Bailey: CO2 is 7580, okay? That patient almost requires ventilation.
Annatasha: Sure.
Ryan Bailey: Heavy-handed premed, whatever.
Annatasha: We're speaking to dogs and cats, right?
Ryan Bailey: Okay.
Annatasha: Like for now we can always move to reptiles or horses or whatever.
Ryan Bailey: Yeah, I think probably we'll start with dogs and cats. I mean, I guess the inspiratory time question really is a horse question, but I think we can, yeah, we'll start with dogs and cats and we can go into horses too.
Annatasha: Cause I was like, let me be clear. I mean, reptiles.
Gianluca Bini: Thank you.
Ryan Bailey: going to speak over exotics because it's way too complicated. Ugh.
Annatasha: Oh. Reptiles. Remember Bailey, we were going to write that chapter on reptile anesthesia called, you don't know if it's dead.
Ryan Bailey: Yeah. Let's go down to.
Annatasha: At the time you're like, I don't know, dead, live. I don't know I don't know. Look smart.
Ryan Bailey: I was beating.
Annatasha: Look smart.
Ryan Bailey: Could mean anything.
Annatasha: I guess I, you know, okay. So when I, when I go to set settings, I think the one thing too that I find is under taught for when people learn how to ventilate and, you know, I try to keep things simple. Like I like to always use like base 10 as a number in a lot of my, you know, teachings because people can remember and it they don't get panicked about it.
Annatasha: But one of the things i also teach is that you have to remember to lean weight for lung capacity, right?
Ryan Bailey: Mm-hmm.
Annatasha: so if you're going to drive a tidal volume, you're actually, you know, You have to take into two factors. So for example, if this patient is, you know, being a position in a way where I feel like, you know, its thoracic excursion might be impeded, i'm' I'm inherently going to drive, you know, a higher pressure, for example.
Annatasha: But if I have a patient who is you know quite obese, I'm calculating my tidal volume off of their what I anticipate to be their lean weight, but also remembering that the obesity contributes to increased extra thoracic pressure. And so I'm going to keep my eye very closely on what that driving pressure is and what that then my PA or my end tidal CO2 are and titrate from there.
Annatasha: because what I don't want to do is, you know, drive a volume that is going to cause overexpansion of the alveoli, which is what, like I said, particularly in a patient who might already be in a state of SERS or pro pro-inflammatory. and actually worsen that inflammatory process throughout the body. So I tend to start a little bit more conservatively and then dial up from there.
Annatasha: no my personal record for a PA CO2 in
Annatasha: patient, 147. 147.
Ryan Bailey: Hey,
Gianluca Bini: it's
Annatasha: obviously in that case, you I started ventilation a little bit more aggressively, but like your average healthy pet,
Ryan Bailey: what was that?
Annatasha: You know, I'm going to want to, what happened is, is that when, was we didn't have an endobronchial blocker and when the surgeon went to take out the like infected tumor lobe,
Ryan Bailey: Was that black house?
Annatasha: and clamped it off, it burst, and then everything dropped dependently into the good lung. And so I just had full, like fulminant barrier. Like the the patient basically aspirated on its own bodily fluids.
Gianluca Bini: That's beautiful.
Annatasha: And I kept it alive for like maybe 45 more minutes, but it was like basically in a constant state of CPR, right?
Ryan Bailey: Oh, yeah.
Gianluca Bini: Nice.
Ryan Bailey: What was the...
Gianluca Bini: Holy.
Ryan Bailey: That was the arterial CO2? What was the untitled at that time?
Annatasha: Unfortunately.
Ryan Bailey: don't
Annatasha: A billion.
Gianluca Bini: Wow.
Ryan Bailey: know.
Ryan Bailey: I just... I wonder if there was a huge gap. like Yeah, don't know.
Annatasha: There was a huge gap, right? Because I was just blood trapping the CO2. And, you know, so like the if the end title was probably like low 40s, which is higher than what you expect.
Annatasha: But if you actually look at that that driving gradient through, like whatever was passing through is inherently going to be high.
Ryan Bailey: Yeah.
Annatasha: But The PACO2, like I definitely lost sphincter control around that point. But anyway, so like my average settings are like, I'm probably going to drive around 10 centimeters of water, know, average dog, you know, 10 to 12 breaths a minute.
Annatasha: And then I just titrate to the individual from there. Right. But that means i have to constantly check back in like, you know, every few minutes while you let those ventilator parameters settle in and that that patient accommodate those changes and then you come and you you titrate around. But those are sort of my baselines for things that are very straightforward.
Ryan Bailey: How about generic gold CO2?
Annatasha: Beanie?
Ryan Bailey: When are you going to start to get itchy to back up? And when are you going to start to get itchy to get more passive?
Annatasha: So in my head...
Ryan Bailey: In this in have average healthy patient, CO2 80 can start.
Annatasha: Right. So in my head, I assume that my average healthy TPLO dog is going to incur a gradient somewhere between five to eight, right? Millimeters of mercury. So in my head, if my end title is 45, then I'm basically imagining that my PaCO2 is 50 to 53, right?
Annatasha: That's the average. So I was like a bare minimum.
Ryan Bailey: Yeah.
Annatasha: That's probably where I'm sitting. I don't get terribly twitchy until I start to... you know, think that probably my PA CO2 is climbing into the mid 60s.
Annatasha: I don't mind a little bit of permissive hypercapnia and not just permissive hypercapnia. So a little bit of built CO2 buildup for our listeners. So it actually helps you with cardiovascular tone because i always teach this. I always say, if you hold your breath for a minute, what happens to your heart rate, right?
Annatasha: Goes up because your body's like, whoa, we should get rid of the CO2. So you get a little bit of cardiovascular tone in a healthy patient. And the other thing you also get to is remember that, like I said earlier, the inhalants sort of dysregulate your normal respiratory drive mechanisms, which is usually high CO2, unless you're really dying, and then it's low oxygen, unless you're a reptile.
Annatasha: But anyway, so, you know, I do know in my head that I got to get up to above 50 or 55 if I want them to breathe on their own, which as per my rant earlier, that's what I'm cutting for.
Gianluca Bini: Yeah.
Annatasha: So, you know, CO2, you know, if it's sitting at 30 from ventilation, I don't fuss too much because I know it's still in the mid thirties. I, you know, if I'm weaning them off the ventilator, I'm going to let it build up until the fifties, but I really don't want to intervene until you're sort of the sixties areas because that little bit of CO2 buildup is beneficial, but I'm not going to start to see that incremental increase in the adverse effects.
Annatasha: So, changes in pH, myocardial depression, changes in intracranial pressure, narcosis, right? So, Yeah, and I know people get really like worked up about 80 and 90, but you can you can coast through that level for a surprising amount of time before the patient is really going to like go off the rails.
Annatasha: Anyway, yeah. So I do the math a little bit in my head, and then it also depends on what my goal is. Am I trying to get them down or am I trying to wake them up? yeah, those are my my two cents.
Ryan Bailey: gro
Gianluca Bini: I don't know. I think my, going back to your initial settings before, i mean, I think usually, so the the nice thing of these new machines we have is that you literally set the weight and it does all the math for you.
Gianluca Bini: So the presets are, you know, you can change them.
Annatasha: Yeah.
Gianluca Bini: But it's the, you know, the the level of laziness that you can have with these machines is like through the roof.
Ryan Bailey: Mm-hmm.
Gianluca Bini: But anyway, so I usually start to like... you know on lean body weight, about like 10 ml per kg usually of tidal volume. I try to start low and then I start with volume control, pressure limited. So like usually I limit it at like 20 centimeters of water.
Gianluca Bini: The respiratory rate, i don't really have a starting setting depending on the breed. I go between eight in eight to in a large breed and two...
Gianluca Bini: 12 to 14 in a small breed. then I go from there. You know, I use CO2 to kind of guide me a little bit. You know, the other thing I look at is like compliance, right? like So I want to make sure that, you know, I'm not for that kind of volume that I'm putting in, I'm not hitting too high of a pressure.
Gianluca Bini: but But yeah, that's that's mostly what i what I really look at. I try to target an entire between 55 and 60, ideally. If I have a block gas, you know i you know I measure the gap and I go from there, really. And that's, again, for for small animal horses, it's a slightly different kind of beast.
Gianluca Bini: is a couple of different train of thoughts on on horses, right? There's some people that prefer to start ventilating immediately, do mundane oxygenation.
Gianluca Bini: And then there is, you know, something more like focused on the cardiovascular side of things and and not starting ventilation right away.
Gianluca Bini: don't know. I think I wanna criticize anything. I care more about oxygenation and put them on the butamine if the cardiovascular sucks.
Gianluca Bini: But, you know, it's kind of hard to catch up on ventilation, I think, one once the lectasis develops really badly in a horse, I think.
Gianluca Bini: I'd rather not...
Annatasha: Oh yeah. It's a nightmare. If your horse is like, if every serial ventilation reading you take your PAO2 is going down and down, like it's time to start telling the surgeon to move.
Ryan Bailey: mean,
Gianluca Bini: Yeah. Yeah.
Gianluca Bini: Yeah. Yeah.
Ryan Bailey: i mean do
Annatasha: you know, so guys, in terms of ventilation, here's, here's something that I've never, never been able to rectify between what is actually published robustly in both human and veterinary literature.
Annatasha: And how i what I actually see clinically, which I understand is anecdotal.
Ryan Bailey: Mm-hmm.
Annatasha: But you know there's there's a lot of papers out there about the high frequency ventilation with the low volume, right? like So you want to ventilate to like six to eight centimeters of water and you just want to have a higher ventilation rate.
Gianluca Bini: Yeah.
Annatasha: I have never clinically done this with a significant... degree of success. and And I, you know, I sit here and I actually, this is how I learned respiratory physiology and ventilation. soll actually sit around doing all these weird breathing patterns because I'm like, well, what happens you breathe like this?
Annatasha: Right? It's basically dead space ventilating. It doesn't go into like a deep, like third component of like, I'm obviously I'm bipedal most of the time, unless Saturday night. But yeah,
Annatasha: and You know, like I'm not ventilating into my deep lung tissue, which means for sure I'm shunting, like shunting like a mofo, right?
Gianluca Bini: Yeah.
Gianluca Bini: yeah
Annatasha: And so, and you know, every time I've, you know, gone in and like, you know, the criticalists and I are chit-chatting and I'm like, how's this patient doing? blah, blah, blah, blah. you know And like you know this could be like when I worked in Singapore, for example, we ventilated a lot of Cobra bite patients and they'd be on the ventilator for three, sometimes four days.
Annatasha: i know it's weird, right? But you know the criticalists are very motivated to drive this sort of low pressure, high frequency ventilation. And then we would pull the blood gas and without fail, you'd have wildly high PaCO2s.
Gianluca Bini: Yeah.
Annatasha: And I was like, you have to drive either a higher pressure or volume.
Ryan Bailey: It's a huge gradient.
Annatasha: In other words, you have to increase minute volume. You have to do it. And the and like like I said, the problem I have with like really rapid positive pressure ventilation is biotrauma, right? Or the sheer stress on on the alveoli that's going to precipitate an inflammatory reaction.
Annatasha: Oftentimes you'll see those patients will start to have signs of like, it looks like they're slowly aspirating. And what they're really doing is they're going into like ARDS. And I just, I have never been able to successfully manage this low pressure, high frequency ventilation so that my patients don't end up being wildly hypoventilated unless you drive the frequency so high that you're basically created a jet ventilator with your normal ventilation.
Annatasha: But like, have you got do you guys do this six to eight shenanigan? And if so, what am I doing wrong?
Gianluca Bini: No.
Annatasha: Like, how is that working? Why am I not aligning with all the literature?
Gianluca Bini: No.
Ryan Bailey: So I think there's a couple things.
Gianluca Bini: No.
Ryan Bailey: So i I tried this after reading that like Lung Protect or High Low, whatever, Hewlett paper was hot at the time.
Annatasha: Right.
Annatasha: And surviving sepsis tells you to do it too.
Ryan Bailey: and yep
Annatasha: And I'm like, oh.
Ryan Bailey: And I remember my waveform. I've got a little diagram here. was but like this.
Annatasha: For the people who are watching this, Ryan just drew basically like a line of sawtooth triangles.
Ryan Bailey: And I remember...
Ryan Bailey: Yep. And I was like, we're doing high-low, like high-frequency, low-volume. We're going to like do – and we had the fancy ventilator in my residency, and this was like a PDA dog. So it was like relatively compliant on a lot of injectable anesthesia. So like the ventilation was already kind of disturbed by the drugs we were giving.
Ryan Bailey: I was like trying this new strategy for like more cardiovascular stability, and my faculty was like, go pull a blood gas right now. And pulled it, and I swear to God, PaCO2 was like 90%. and They're like, yeah, there's a huge gradient. And like you can see with the sawtooth pattern, you're not and you're not adequately sampling the alveoli. And so the machine is lying to you. So don't monitor the monitor. So that's like stuck with me forever.
Ryan Bailey: i don't know. like I've always wondered if it's just a difference in human physiology versus like dog physiology because that's realistically this high low strategy is what we're trying on dogs and cats we're not trying this on on equine species because you know there's the kind of yeah yeah but like
Annatasha: Oh, the ventilator would explode. Like there's like, we're not sophisticated enough to drive like that. That's why. Right.
Gianluca Bini: yeah
Ryan Bailey: i've never been able to succeed with this strategy in a dog or a cat and i find more often than not you end up not You end up doing more, I guess, dead space ventilation or you're not adequately filling the alveoli. So you're not getting good gas exchange. So your CO2 numbers are like wildly inaccurate. And so when I have actually this, this brings up a point that is like a big pet peeve of mine.
Ryan Bailey: When I walk in the room and the respiratory rates, goddamn like 25, I immediately like freak out and I'm like crazy. crank down the rate, you're way too fast, you're undersampling, it's going to be inaccurate, and then sure enough, I like whip the rate way down, I crank the volume up, you know, instead of these little...
Annatasha: And your first, I bet you your first ETCO2 reading is like 79. you just like, told you.
Ryan Bailey: Yeah, it spikes up like 20 points.
Annatasha: um
Ryan Bailey: And I'm like, yeah, I wonder why the dog was bucking you on the ventilator.
Annatasha: l
Ryan Bailey: Because the CO2 is completely inaccurate and you're chasing your tail because you're not, like, understanding what the screen is telling you. So to Bartel's earlier point about why don't ventilate anything.
Ryan Bailey: Yeah.
Annatasha: No, but I mean, like I said, one of the ways I ah ah genuinely understand like respiratory physiology and ventilation per se is I, I mimic the breathing pattern and and then I actually pay attention to like, do I feel short of breath?
Ryan Bailey: Yeah.
Gianluca Bini: Yeah.
Annatasha: Do I feel lightheaded? What's happening to my heart rate? Right. And obviously like in most cases, my blood pressure is high anyway. because I just ate deep fried pickles. I'm an anesthesiologist. So, but yeah, like I was just like, you know, if you breathe like that, like, you know,
Annatasha: you are not going to the gas exchange surface of the pulmonary tree.
Ryan Bailey: Yeah.
Annatasha: You are sitting in anatomical dead space area. And eventually like, you're just like, your body is like, i don't know what you're doing.
Gianluca Bini: yeah
Annatasha: This is really stupid. And you need to sigh essentially. Like it'll be like oh again. And yeah, I just, like I said, and I've met a couple of people who ventilate and this is like long-term ventilation. Yeah.
Annatasha: In patients, obviously, if you're on long-term ventilation, by definition, you are not doing well. And like, they're not actually checking the blood gas because like, they're they're like, that won't make me feel better. And I'm like, oh, I'm not sure.
Gianluca Bini: okay
Ryan Bailey: Yeah.
Annatasha: But anyway, yeah. And then the other thing too is like, your PCO2 is up there so high, like your pH is going to be super acidemic. And then then you got to start norepinephrine and blah, blah.
Ryan Bailey: Yup. Yup.
Annatasha: And I'm just like, you're fucking everything up. Because this ventilation modality, for me anyway, just doesn't fucking work.
Gianluca Bini: No, no. I mean, we did we did have a jet van at NC State, but that's a totally different story.
Ryan Bailey: Yeah. Oh yeah.
Gianluca Bini: Right? That's a totally different story.
Annatasha: i find I actually find jet ventilation very stressful.
Ryan Bailey: Oh my God, I love it. It's so easy. Yeah. Yeah.
Annatasha: I don't know what it is. I just get so stressed about it. I'm just like, oh, it's...
Gianluca Bini: Yeah. I mean, it's cool, but like, you know, yeah, everything above, i feel like everything about 16 or 18 on a normal ventilator doesn't get you a very efficient ventilation.
Ryan Bailey: yeah yeah
Gianluca Bini: And I do... to Back to your point, Dasha, I actually do really care about eye ratio in small animal and large animal. The ideal, it's you know people say between 1 to 2 or to Usually, I to two and a half
Annatasha: yeah me too
Gianluca Bini: and and and you know sometimes people look at me really weird because i'm getting to this a very precise spot one two and a half right like rather than one point one two two or one two
Annatasha: I would say one to two and a half is my default IDE. And the other thing too is that I do a lot of farting around with the IDE e and not changing the other settings per se.
Gianluca Bini: yeah
Annatasha: I find that conceptually, it's one of the concepts that people really struggle to understand is the IDE e ratio. And i end up drawing like lots of lines out and trying to like teach that. but like If you're in one of those ventilators where you actually set volume by the IDE, e for example, like the Equine Mallard, you know, you do have to wrap your head around it.
Gianluca Bini: Please.
Annatasha: But I will use it to control like that breathing pattern because, you know, ideally you want the ventilation to mimic the natural breathing pattern, which is in pause, out longer pause, right?
Annatasha: Like you nobody breathes like this.
Ryan Bailey: I make people do that.
Annatasha: You'll faint you breathe like that.
Ryan Bailey: When they have the bed at 30 breaths per minute, and I'll be like, please breathe at 30 breaths per minute.
Annatasha: so
Ryan Bailey: That's one second in, one second out. Try it now. And they're like, yeah yeah, you can only do this for like 30 seconds before you're going to faint.
Gianluca Bini: that's Yeah.
Annatasha: you can't even make it to a minute because your body is like uh voluntary control has been overridden due to overt stupidity right
Ryan Bailey: Yeah.
Ryan Bailey: Yeah. It's so unpleasant.
Gianluca Bini: Yeah. Yeah, that's how lion breeds after the fifth hot dog.
Ryan Bailey: Okay.
Ryan Bailey: yes
Annatasha: yeah because his like transabdominal thoracic pressure is like
Gianluca Bini: Okay.
Ryan Bailey: My sonia was just like, roof my body's like, what do I do? I think
Annatasha: it
Gianluca Bini: that's That's the acidosis from
Annatasha: Oh my You must have the worst reflux.
Ryan Bailey: apple high in the hot dogs, it's some sort of combination, like just keeps me regular, you know?
Gianluca Bini: So i went up to to see Ryan and the Giardiniere. So in Italy, we do have this Giardiniere, right? Which is basically...
Gianluca Bini: like pickled vegetables and that's it. But the one that they have in Chicago, it's so fucking hot.
Ryan Bailey: Oh, yeah.
Gianluca Bini: eight
Annatasha: Oh, okay.
Ryan Bailey: It's so good.
Gianluca Bini: i I almost died the first time. And I went on it very easily because I was like, okay, I had this in Italy. you know i love it. you know we We eat it every time. It's totally fine.
Gianluca Bini: I wasn't expecting how hot it was.
Annatasha: So basically, I'm the Chicago spicy version of the normal Italian thing when we talk about ventilation.
Ryan Bailey: Yeah. Oh, yeah, for sure.
Gianluca Bini: Yeah.
Annatasha: I got unexpectedly spicy about a topic you didn't even know. yeah
Ryan Bailey: Actually, this company is a Chicago company and they make a spicy, a hot giardiniera that is my personal favorite. And one of the ways they like to eat some of their hot dog adjacent items, the Polish, which is like a Polish sausage on a bun.
Ryan Bailey: They put giardiniera on the Polish sausage. I've since tried it. It is really fucking good. ah So So a recommendation for your summer grilling, get a Polish sausage, cover it giardiniera.
Ryan Bailey: Dope.
Annatasha: You know, don't know why we haven't picked up a sausage sponsor by now. I mean,
Ryan Bailey: i'm trying I'm trying my goddamn hardest.
Annatasha: I know we are just promoing the absolute like crapola out of these sausage products, specifically, we love Chicago hot dogs.
Ryan Bailey: All these very local chupons. Oh
Annatasha: And i just feel like we really need to start, you know, getting that message out there to the guys that like, you know, they they really have an audience capture in the veterinary anesthesia community, which is an uncoffed market for them.
Ryan Bailey: my gosh.
Ryan Bailey: I will say someone came back and they said our podcast on fluid therapy, they were at an anesthesia conference this last week, and they said our topic on fluid therapy was referenced in one of the presentations and that fluids are a drug. And I was like, oh, my little heart is so happy.
Gianluca Bini: Oh, my God.
Annatasha: I was told at the Vienna conference that my tagline, which is let's all learn to walk before we learn how to fly, has just taken off in anesthesia schooling in Europe. Everyone in Switzerland apparently is saying it.
Annatasha: And I was like, hooray.
Ryan Bailey: Wow.
Annatasha: Pretty sure I didn't make that up, but I'll take the credit. and
Gianluca Bini: Bye.
Annatasha: Yeah, no. So yeah, no, we' i although i don't want to be formally referenced because like disclaimer, if you follow her advice and something goes badly, i don't want any liability. Yeah.
Ryan Bailey: All right. I feel like we're, I have, i have a list of topics here and we're definitely not going to get through them all. We're not even going to come close. And this is just a quick handwritten note, but I do want to talk about equine ventilation because it gets into one of my personal favorite ventilator things, inspiratory time and how we can adjust inspiratory time, which also then gets at like inspiratory flow.
Annatasha: it's not.
Ryan Bailey: Do we rampantly ramp up or do we slow push up? yeah What's your approach to equine ventilation? i I'll start first just because I haven't done much talking about what I do. I don't do a lot of equine anymore.
Ryan Bailey: when I did, i was a... I think I tried once or twice to not ventilate, to try... Let's see how they do. He's on his side. it's gonna be It's going to be just fine.
Ryan Bailey: Spoiler alert.
Annatasha: no it's not
Ryan Bailey: It was...
Annatasha: and and 1,000% not.
Ryan Bailey: It was not just fine. The horse did, i think he desaturated. We had to get him on the vent. It was a whole big rigmarole. And, you know, this was back in the day where we did not have the fancy ventilators. So we had the bag in the barrel situation. and that thing was like.
Annatasha: I hope I wasn't the chief supervising you on the case where you were like, not going play this horse, because I definitely would have, like, wrapped your knuckles for that.
Ryan Bailey: No, I'm sure i'm sure you weren't.
Ryan Bailey: Oh, yeah, I'm sure you weren't. But yeah, it did not. I mean, I think some of the faculty there were a little bit lenient on like the the like laterally recumbent horse that they could be OK ventilating.
Ryan Bailey: But yeah, this horse was definitely not. And we had to like get the ventilator and do all the rigmarole, which is fine. But I was a I ventilate. pretty much everything. um Obviously, slow rates, long inspiratory times, you know, two to four seconds, depending. i think I started on the low end, like the two second inspiratory time.
Ryan Bailey: And then when I had trouble, you know, started to
Annatasha: You need that inspiratory time to fill that volume of lung. like
Ryan Bailey: Oh yeah, I totally agree. I just wasn't always on the like, you know, if my, if I, you know, waveform analysis is obviously so much more important on the ventilators, you know, if you're getting those nice plateaus, I was generally okay with it.
Ryan Bailey: where if I wasn't getting the plateau phase, I was not trusting my CO2 and would definitely slow down my inspiratory time or increase my volume, uh, to try and get, you know, that better, better waveform. So I could trust the numbers.
Annatasha: I mean, I certainly don't crank my flow rate like a jackass from zero to hero either.
Ryan Bailey: Well, I mean, like some ventilators you can actually control the way the, I i don't know how many of the anesthesia ventilators, but know the, the.
Annatasha: There are small animal ones where you can do that too. But if you notice, if you really drive the the flow rate, like the liters per minute to the ventilator,
Ryan Bailey: Yeah.
Ryan Bailey: I got the end. Oh no. What?
Annatasha: actually drive the PIP in the patient up and you'll see see it on the waveform because they'll be like, it's almost like the, it's like, like the opposite of a curare cleft.
Ryan Bailey: Yeah.
Annatasha: You see like an early days, like spike.
Ryan Bailey: Oh.
Gianluca Bini: Yeah.
Annatasha: And that usually tells me like, woo flow is too high. And again, I don't think that's good for like this delicate, sometimes irritable inflammatory prone lung tissue.
Ryan Bailey: No.
Annatasha: So
Ryan Bailey: Yeah, no, that's not, I wasn't saying to adjust my oxygen flow rate more than like in those really nice ventilators where you can actually say like rapid inspiratory flow versus a slower, i I don't know it well enough to know like how they set the parameters by knowing the critical care ventilators, you can actually change the way the breath is firing into the lungs
Annatasha: No, that's what I'm talking about, Bailey. If you change it so that rate of the flow, right?
Ryan Bailey: oh
Annatasha: So you're actually driving like a high velocity inspiratory flow from the ventilator, not not your oxygen flow meter.
Ryan Bailey: Yeah. Yeah.
Ryan Bailey: Yeah. Okay. As you were saying.
Annatasha: You will drive an increase in pressure and you will see that spank on your tracing.
Ryan Bailey: Oh yeah.
Annatasha: Yeah.
Ryan Bailey: I think that's not.
Annatasha: And that's from the ventilator control and like, you can adjust your oxygen as much as you want. but yeah, no, that's from the ventilator flow. But like I said, like rapidly moving, air, which cold, is, can cause, you know, sheer stress on, on the, on the tissue.
Ryan Bailey: Yep.
Annatasha: So I generally, unless I'm in a, you know, grave pickle, tend to err on the side of being more judicious in that capacity.
Ryan Bailey: Yep.
Gianluca Bini: Yeah. Yeah. I mean, I don't have an oxygen-driven ventilator for horses, so we have two taphoniuses. so, like, they're pissed on there.
Annatasha: Okay. You have non-pneumatic. Yeah.
Gianluca Bini: Yeah, they're piston driven. So, but, you know, you you have different ventilator modalities, right? Like there is this new like flex ventilation and whatnot that they developed at UPenn, I think.
Gianluca Bini: You know, yeah, if I can, I try not to have that blast off, you super fast.
Ryan Bailey: Oh yeah.
Annatasha: she just shoot the like Just shoot the patient right off the end of the circuit.
Annatasha: right
Gianluca Bini: Right, right.
Ryan Bailey: Just literally walking into the chest.
Gianluca Bini: I try to do that. Yeah.
Gianluca Bini: Yeah, right?
Ryan Bailey: One breath and we're off to the bases.
Annatasha: Let's go in forest, but guaranteed you could like rocket fire a budgie across the room with that kind of behavior. Yeah.
Gianluca Bini: Oh, yeah.
Gianluca Bini: Yeah, no, I try not to do that.
Ryan Bailey: i this
Gianluca Bini: But, I mean, the other thing that people need to, and I think that a lot of people forget, is like, you know, how all the physiology about, like, you know, the time constants of the different alveolites, right?
Gianluca Bini: And in different areas of, you know, the lung and, you know, how they... So, I mean, that's something that, you know, people sometimes forget and, like, you know, they don't...
Gianluca Bini: And that goes back to your comment, Asha, that these machines can be dangerous, right? you know You need to know how to set it up. And you know some of them have more fail-safe than others.
Annatasha: Yep.
Gianluca Bini: Unfortunately, the ones that we have in VATMAD, especially the holder stuff out there, it's kind of on the sketchy side. yeah so
Annatasha: Just as cross-reference, like the time i was on Large Animal at Davis and Christine exploded the bag in the barrel and it sounded like someone had fired ah bazooka ah bazooka in the clinic.
Gianluca Bini: Nice.
Annatasha: And I swear to God, my heart stopped beating for at least four seconds. Like I had zero perfusion.
Gianluca Bini: nice
Ryan Bailey: I will say, like, I know there's a lot of hate on the bag and the barrel. That thing a ah fucking fucking workhorse that thing you ah ah like if this you knew when the pao2 got down below a certain level the only reason was because the ventilator was fucking broken i remember like one time i think i had a po2 in a horse of like 60 or 80 and like i immediately recognized it was because the ventilator wasn't working correctly and i was like thank god it's not this horse is dying in front of me it's because the equipment is dying in front of me
Ryan Bailey: And you know what?
Annatasha: And yet, why do you all work together?
Ryan Bailey: It happened another time and I was right. It was also an equipment related issue and it was not the horse dying. So, you know, fix the equipment, fix the problem. It was like instantaneous.
Gianluca Bini: Sure.
Ryan Bailey: Once you, once you resolve that, it was like off to the races.
Annatasha: Yeah, I mean, I could drive a car or I could have 50 people pull me in a cart to work, but guess which one I'm going to pick? Great.
Ryan Bailey: Yeah.
Annatasha: like the great
Ryan Bailey: So what are you doing with your equine patients? How are you, you're ventilating everyone at this point? Are you on the, are you ah allowing them to to do it on their own? Are you, uh,
Gianluca Bini: No, fuck no.
Annatasha: Thank
Gianluca Bini: Now, I've ventilated them all, start from the get-go, usually six to eight breaths per minute, aeration of one to two and a half. Tidal volume, depending on size, of course.
Ryan Bailey: Right.
Gianluca Bini: you know Pressure limited, usually...
Gianluca Bini: 40-ish, 45, like as a as a starting point. And of course, depends on you know if it's a colic or the abdomen is bloated, we may need to go in a different direction there.
Ryan Bailey: Right.
Gianluca Bini: But usually that's that's my starting point and we ventilate from the second it's intubated, hoisting the table, connect it, press start, boom.
Ryan Bailey: Yep. Yeah.
Ryan Bailey: yeah
Annatasha: Beanie and I have now realigned. like i basically I think you will die more quickly of hypoxemia than you will of hypotension.
Ryan Bailey: Absolutely.
Annatasha: So I also ventilate from the get go because i ventilate from the get-go because, just like Beanie said, like I have more rapid and more reliable interventions to address cardiovascular status than I do equine hypoxemia.
Gianluca Bini: Yeah, of course.
Ryan Bailey: Oh yeah.
Annatasha: like
Gianluca Bini: Yeah.
Annatasha: There's actually only a finite number of things you can do, and if they ain't working, it's going to die. So, you know, I don't want to be behind the curve on oxygenating the equine patient.
Annatasha: So I am going to ventilate from the get go. I might not be crazily aggressive on that first two breaths you know while you're trying get the art line in and see what its pressures is and what have you but at the end of the day like you know I've had colics at the tables you know systolics of 40 and you know you can get them back from that from but like trying to get a horse out of a PAO2 of 45 like fuck I wish you well like by then the guts are blue and the surgeons are losing it and it's just it's never going to stand up
Ryan Bailey: Oh my god, yeah.
Gianluca Bini: Good
Ryan Bailey: Yep. Yep.
Annatasha: I'm more tolerant of the hypotension than I am of the hypoxemia. And like I said, I can fix it more reliably than I can if I get behind with atelectasis in a horse. Because, i mean, first of all, performing a recruitment maneuver in a horse, like, yeah good fucking luck.
Ryan Bailey: yeah
Gianluca Bini: luck. like
Ryan Bailey: yeah
Annatasha: And, um you know, it's already on 100% oxygen. I can't give it more, you know? So it's just like your ability to address it is extremely limited and mostly inefficacious.
Annatasha: So it becomes a time game to how long you can tolerate this relative hypoxemia before it's going to impede recovery, tissue healing, like viability on the table.
Ryan Bailey: Yeah.
Annatasha: So yeah, I ventilate from the get-go. My parameters are very similar to what John Lucas said. Yeah. Yeah.
Ryan Bailey: I feel like the only thing you can like in the the hypoxemic horse or the horse whose oxygen tension is maybe they're not hypoxemic yet, but they're, they're dropping like a stone. The only thing you can pray for is like that your CO2 gradient is so high that you're like, Oh crap. I can like, you know, expand the lung a little bit more and like get more alveoli to participate. Cause I'm under ventilating a little bit. And like, that's all you can hope for. And like,
Ryan Bailey: Otherwise, just like shit, like batten down the hatches. It's about to get real, everyone.
Gianluca Bini: but
Annatasha: usually when I sort of come a little closer to the end of the surgery table and I'll be like, things are not going as well as I would like. So anything we can do to expedite this portion of the procedure would be in the patient's best interest.
Gianluca Bini: Yeah.
Ryan Bailey: Are you a, i I remember reading this as a resident and I don't think it ever really became in vogue, but there was some literature about peep in horses from the jump.
Annatasha: Yes. I remember that that was a big deal when I was a resident.
Ryan Bailey: like
Ryan Bailey: And I think they were going up to 20 centimeters of water peep to, and that's where they really achieved a difference, which is wild.
Annatasha: Well, basically like you can take your five CM PEEP, you know, insertion and just throw it in the garbage, right?
Ryan Bailey: Yeah. Oh yeah.
Ryan Bailey: Yeah. oh yeah
Annatasha: like Like, especially for equine.
Ryan Bailey: Yeah.
Annatasha: you, yeah, no, the, the papers that came out where you they looked at the recruitment mover and the recruitment maneuver timing and driving pressures, and then the amount of PEEP you had to set to maintain like open lung capacities.
Ryan Bailey: Right.
Ryan Bailey: Yeah.
Ryan Bailey: Yeah.
Annatasha: were, would kill a cat, right? Like it would kill, right?
Ryan Bailey: Yeah. Oh, yeah.
Annatasha: But yeah, no, you have to drive like up like 20, uh, of, uh, peep, 20 centimeters of water peep and your recruitment maneuver pressures, you know, you're going up to 40, 50, they drove up to 70, I think.
Gianluca Bini: Oh yeah. yeah
Ryan Bailey: Yep.
Ryan Bailey: Yep. I think so.
Annatasha: and I was like, somebody has very large gonads, but, yeah, I, they drove like in like parameters that when I think the paper first came out, everybody was like, this is insane.
Ryan Bailey: Yeah.
Annatasha: you know, and like I said, would kill a person, kill a horse, but sorry, kill a person, kill a cat, kill a dog, kill a cat. you know, horse is horse of a different shade. So, yeah, like it's, like I said, this is my whole point about hypoxemia. Like it is incredibly difficult to address.
Gianluca Bini: Yeah,
Annatasha: You have a very limited number of things you can do. And most of the time, unless you are going to do it with balls to the wall aggression, are just going to watch PAO2 slowly go, eh.
Ryan Bailey: Mm-hmm.
Gianluca Bini: yeah you're fucked.
Annatasha: name a man and it and and
Ryan Bailey: Yep. Yep.
Gianluca Bini: Yeah, you're fucked. At that point, you're fucked.
Annatasha: And most colics don't start, like most colics are not going to the ground on the first three breaths with like a PAO2 of 600. So if you go down to 400 over the next 45 minutes, who cares?
Ryan Bailey: Oh, yeah.
Annatasha: Most of my colics hit the table. I'm like excited if it's 220, right?
Ryan Bailey: Yeah.
Gianluca Bini: Oh, yeah.
Annatasha: Right.
Ryan Bailey: Yeah.
Gianluca Bini: Yeah. Yeah.
Annatasha: because then I'm like, cool, I have about an hour before it's going to hit around the hundred mark and I'm going to start to get clenchy.
Gianluca Bini: Yeah.
Gianluca Bini: Yeah.
Annatasha: But yeah, so I think, yeah, those are, equines are, yes, they're significantly more challenging from a ventilation point of view, which means I tend to be more assertive in that capacity.
Ryan Bailey: Let's talk about cats.
Annatasha: Okay.
Gianluca Bini: Fucking Ryan.
Ryan Bailey: I mean, i feel like they're also different. Like, Abe.
Annatasha: Yes.
Ryan Bailey: a they They don't hypoventilate, so it's rare that we need to ventilate them. They fucking hate ventilation. Like, they they do not take to it well at all, like, unless you're paralyzing them. And then, you know, tough shit. They got to eat it.
Ryan Bailey: And like, they are just immediate blood pressure in the toilet. Like the lowest pressures you've ever seen. Like, and and I don't, this is a another thing I don't understand. And I'm going to ask you all.
Ryan Bailey: Cause like, I've had to deal with this. I'm like, what the fuck's wrong with this fucking cat? Why are cats this way? Cat, open chest, they're breathing. Spontaneous. And I'm like, how?
Ryan Bailey: How are you doing this?
Gianluca Bini: is
Ryan Bailey: How are your lungs still open? Like, what is going on?
Annatasha: It's just the sheer nature that cats not want to be told what to do and their lungs are just like, I'm the last.
Gianluca Bini: Yeah. They can't die. They can't. and They are allergic to death.
Ryan Bailey: thick but yeah yet they can't.
Gianluca Bini: No.
Ryan Bailey: Like, what do you do? How do you approach cat ventilation? Cat with the P, you know, you've got, classic example for me from residency, you've got the uremic acidotic cat.
Ryan Bailey: They're on the table. Their pH is like 7.0. Their potassium is creeping up and you want to take that pH and start to drive it up and you know you've got to get that CO2 down because it's like 60, 65.
Ryan Bailey: sixty sixty five
Gianluca Bini: You know, I'm. Yeah.
Annatasha: Well, if that's a chronic metabolic acidemia, then you probably shouldn't be dicking around of ventilation. You should be giving high harm.
Ryan Bailey: But it's not because these cats are are obstructed and they're like in AKI.
Annatasha: Oh, right. Sorry. Sorry. I forgot it was an obstruction.
Ryan Bailey: Yeah.
Annatasha: Yeah. My bad.
Ryan Bailey: yeah
Annatasha: Yeah. Um, I mean, my bad. Sorry. It was an acute. Yeah. But I was like, don't fucking do that in a chronic CKD patient bill. You'd kill it.
Ryan Bailey: Right. yeah
Annatasha: I was like, were you not listening to me rant before? anyway, no,
Ryan Bailey: We just are like, ah, this cat, this is a chronic CKD cat. We won't be ventilating him. He'll be just fine. And and somehow he will anyway.
Annatasha: I mean, you know, the, ah the other thing that's weird about cats and like respiratory physiology is how markedly they are like intolerant to aspirating right oh if a cat aspirates you you toast yeah you're you are at the cat is in serious trouble and you look like the world's biggest ding whereas you know dogs have you know they're they're like second almost to like cows like cows aspirate and they're like yo what's your point
Ryan Bailey: Oh my god.
Gianluca Bini: You're fucked.
Ryan Bailey: Yeah.
Ryan Bailey: But dogs also, like, their larynx is just like, here comes the fluid and the larynx is like... Give it to them!
Annatasha: Yeah, no, I agree. there's There's some nuances to cat anatomy and physiology. Like, why are they so hyper prone to laryngospasm over like, a let's not forget laryngeal edema. And then my personal favorite, where they do that weird mucosal blistering, like that comes up through their gums and their tongues and like occludes everything. And you're just like, drinking the cat.
Gianluca Bini: yeah
Annatasha: and They're also intolerant of trachs. Like, yeah, no, I just, I don't know.
Ryan Bailey: Let's have way more asthma than we recognize, too.
Annatasha: Yeah.
Ryan Bailey: There's way more feline asthma than we...
Annatasha: I'm not sure have any clever answers here.
Gianluca Bini: oh yeah
Annatasha: I mean, I know the lung ratio in cats and dogs is a little bit different. know, like the actual anatomy of the lung and its ratio to like body surface area body weight, whichever way you want to correlate it is different to a dog.
Gianluca Bini: Yeah.
Annatasha: but for whatever, and cats are just, they are designed to become inflammatory, right?
Ryan Bailey: Yeah.
Annatasha: Like everything makes a cat inflammatory, right? Like, but you just you just look at a, you put the catheter in the wrong way and they're like, I think I'm going to die of sepsis. You know, like, like they're just hyper, you know, pro-inflammatory little guys. And I'm not sure i have a clever answer, but my approach in terms of like cat ventilation, honestly, it's not going to be terribly different.
Annatasha: know, similar parameters and,
Annatasha: You know, I don't paralyze as much as I used to When I trained as a resident, we paralyzed a lot of cases.
Ryan Bailey: Yeah. Yep. Yep.
Annatasha: that was but largely related to the fact that Cornell churns out a lot of the paralytic papers. But, and of course, in human medicine, they basically, you you know, everything gets rocuronium right at induction, right?
Ryan Bailey: yeah yeah
Annatasha: Yeah. it's like It's like the default basis of care is that everything is paralytic.
Gianluca Bini: Yeah.
Ryan Bailey: yep
Annatasha: It's like you have an ingrown toenail and they're like, get the raccaronium. And I'm like, oh my God, calm down. The only reason I don't paralyze, I think as much as I used to is because the access to the paralytics has become significantly more restricted than when I was a resident, right?
Annatasha: Like you cannot get atricurium anymore. Like cis-atricurium is basically off the market here.
Ryan Bailey: Yeah. Yep. Yeah. yep
Annatasha: everything else has become now caught like Vecuronium, like a box of Vecuronium is like exorbitant. So it's become cost prohibitive to do that. But I don't really remember, like it's not ringing a bell that I like disproportionately paralyze cats to control ventilation versus dogs.
Annatasha: I don't know. I don't think I have a cat specific strategy. Beanie? Beanie?
Ryan Bailey: yeah
Gianluca Bini: I, to be honest with you, cats, again, they're really, really rarely ventilated. They they rarely require ventilation. ones where tend to try to get more control is like deformatic carnias.
Ryan Bailey: yeah
Gianluca Bini: Those are the ones where, you know, I tend to, if they don't, if I can't overcome their ventilatory drive, I just paralyze them.
Ryan Bailey: yeah
Gianluca Bini: yeah We use Rokuronium at the moment and it works pretty well.
Annatasha: It
Gianluca Bini: You know, it's cheap enough, to be honest.
Ryan Bailey: yeah
Gianluca Bini: The Adrakoorium, like, it seems like, you know, once you pierce the bottle once or twice, like, it stops working somehow. Like, I don't know.
Annatasha: becomes wildly unpredictable, right?
Gianluca Bini: It
Annatasha: Like you're talking up either every 20 minutes or every four and you're like, i don't understand what's happening.
Gianluca Bini: It is.
Ryan Bailey: Yeah.
Gianluca Bini: Yeah, it's crazy. It's crazy. Rokuronium, I think it's way more, you know, reliable, so don't quote.
Annatasha: Bailey, do you have this like cat? I know you have a lot of cat theories out there.
Ryan Bailey: yeah
Annatasha: But do you have a cat ventilation strategy you'd like to eliminate us with?
Ryan Bailey: No, I i don't. i I will say I've been really... front like it is a When I have to ventilate a cat, it is a big source of frustration because it they just they don't take the ventilation well. Their pressure is just like completely tank. It can be really hard to get them to stop breathing. You end up having to drive their CO2 so fucking low that like you're just absolutely hammering the lungs, hammering the cardiovascular system, hammering like Venus return. It's just like...
Ryan Bailey: And at the end of the day, I just sit there and I wonder like, okay, yes, this is like what the textbook says would be the smart thing to do and would like... approach this the best but like this patient in front of me is like screaming that this is not a good idea but like it makes no sense because like by every standard if i didn't do this this cat should be like dead as a stone you know and like how do you reconcile those two things like i'll never forget
Annatasha: I hear you.
Ryan Bailey: i'm I'm sure I had ah ah case as a resident where, you know, it's a uremic acidosis cap because it has a ureteral obstruction. It's creatinine is like fucking infinite.
Ryan Bailey: It's potassium is also infinite. And i can control CO2 to try and bring down, you know, that potassium a little bit while we start the, you know, bicarb and calcium gluconate and all that other stuff.
Ryan Bailey: And like, somehow CO2 3035 and the cat and PA CO2 to match and the cat is still ventilating. Like it's still fucking ventilating.
Ryan Bailey: And it's like Yeah.
Annatasha: I don't know. I'm not sure any of us understand cats. My my biggest thing with cats is like, you'll have like a like an undetectable Doppler pressure and they'll be awake.
Ryan Bailey: yeah
Annatasha: And I'm like, most things with blood pressure or a systolic blood pressure of 30 or 40 would be unconscious anyway. Like that kind of hypotension anesthetizes you from back of cerebral perfusion.
Annatasha: Not a cat. A cat is leaving.
Ryan Bailey: Yeah.
Annatasha: A cat is leaving with a pressure of 30 and you're like, I don't understand. And you're like, I don't understand what's happening.
Ryan Bailey: Yep.
Annatasha: Like, You're hypoxemic, you're hypercapnic, you're hypothermic, you're hypotensive, you're bradycardic, you're acidemic. Oh, but you're awake and trying to live, right?
Ryan Bailey: Yes.
Ryan Bailey: Yeah.
Annatasha: And you're like, I don't, I don't, I don't think cracked the Pandora's box open for secret cat physiology completely, but.
Ryan Bailey: He's like,
Ryan Bailey: Ooh, I do. Your comment on Doppler did make me want to say something. we had a case the other day. but Healthy dog, for a spay.
Gianluca Bini: Amen.
Ryan Bailey: It was an employee pet. We were spaying the dog. Map, 40. Dog got, I don't remember the anesthetic plan, but it wasn't anything crazy. Map was 40. I was like, get the Doppler.
Ryan Bailey: Doppler pressure, 120. 120. one twenty I was like, well, I'm done farting around here. We're going to go ahead and put our line in this dog. Systematic pressure, 120.
Annatasha: I had today exactly the same thing, but the reason oscillometric was being unreliable is because it was a Sharpay.
Ryan Bailey: i
Annatasha: And when you put a cuff around 92 wrinkles of skin, it's not going to read accurately.
Ryan Bailey: Right.
Annatasha: No, I'm not disparaging the Doppler as ever being accurate, but I will point out even a blind squirrel can find a nut occasionally.
Ryan Bailey: This was a Dalmatian.
Ryan Bailey: This was a Dalmatian.
Ryan Bailey: I was like, had we put the Doppler on the entire time, we would not be farting around with the art line. We would just have moved on with our lives.
Annatasha: Okay, congrats on your statistical outlier.
Gianluca Bini: Okay, Ryan.
Ryan Bailey: Yeah.
Annatasha: That's not going to change the way we practice.
Ryan Bailey: Yeah. So Doppler for the win.
Gianluca Bini: Also, maybe buy better equipment for your non-invasive blood pressure.
Annatasha: oh
Ryan Bailey: I have not had issues. This is the first. It was very weird. It was on multiple machines. I don't, I still do not understand. With different cuffs, different, yeah. I don't. I was baffled. I was very baffled.
Annatasha: Listen, Bailey, sometimes there are days where even my art line, I'm like, that's not real, right?
Ryan Bailey: Oh, I know.
Annatasha: Yep.
Ryan Bailey: That's the fucking, when that happens, I'm just like, well, I'm going home for the day.
Annatasha: Yeah, like sometimes when I look at the art line, I'm like, this is absolute bullshit. Like what is going on
Ryan Bailey: Yeah.
Annatasha: know, and it'll be like a perfect place.
Ryan Bailey: Yeah.
Annatasha: of boom And it's still rinky dinky. But like I said, once in a while, a blind squirrel will find a nut. And maybe your today was the day your Doppler actually read the pressure correctly. And I'm happy for you.
Ryan Bailey: so
Annatasha: I'm happy for you.
Ryan Bailey: and yeah was
Gianluca Bini: We're very happy for you, Ryan.
Ryan Bailey: so I was overjoyed. knew you'd all appreciate it. I knew you'd love it.
Annatasha: Are you trying to build back like the rapport and the respect from the earlier Doppler desert island comment? Cause.
Ryan Bailey: no Oh, i this is this is me shouting out all my colleagues who reached out to me, Christine, for one.
Annatasha: Oh, one of them.
Ryan Bailey: was so glad said Doppler.
Annatasha: Oh, one of them.
Ryan Bailey: I was so glad you said Doppler.
Annatasha: Okay. Well, all of you need to be reexamined by the regulatory board.
Ryan Bailey: that
Annatasha: It's an outrage.
Gianluca Bini: and
Annatasha: Okay.
Gianluca Bini: Are they all from Davis?
Annatasha: Yes, of course.
Gianluca Bini: Yeah, of course.
Ryan Bailey: Yes.
Annatasha: Those are Ryan's resident mates who reached out and were like, it's okay, Bailey, Dopplers are cool.
Gianluca Bini: Of course.
Gianluca Bini: Oh,
Ryan Bailey: Hey, you know, yeahall we all have our own, you know, idiosyncrasies and ours is just Doppler and that's just, that's who we are.
Gianluca Bini: it's funny.
Annatasha: Yeah, no, the entire faculty of Florida was like, what the hell is Bailey on?
Gianluca Bini: Yeah.
Ryan Bailey: I'm sure.
Annatasha: yeah Team Italy slash Florida was like, no.
Gianluca Bini: So much of the Nieren.
Ryan Bailey: I can't imagine the entire faculty team of Florida is listening to this because I feel like they're really, they they've got better things to do than to listen to us pontificate about our feelings on anesthesia.
Annatasha: How dare you? They listen all the time. They have to because they're all my president mates.
Ryan Bailey: I mean, they do. Yeah, I guess that's true. They are your resident mates.
Annatasha: Yeah, they have to.
Gianluca Bini: Oh.
Ryan Bailey: I was like, they're much smarter than me, so they they can't be listening to what I have to say.
Annatasha: Actually, it'd be surprising to think about how many veterinary anesthesiologists listen to us. And I think a large part of it is because we say things that don't necessarily get said because we're less worried about the diplomacy and the politics of it. And I actually think that's what gives a little bit of credence and merit to our podcast because these things need to be discussed, but nobody actually wants to say it, right? Like nobody actually wants to say that Dobbler is trash.
Annatasha: Yeah.
Ryan Bailey: but got the greatest adventure of all time.
Annatasha: Right. But like, I think like I've got, you know, the people who I know who who tune in, who are not just here for the hilarity and the hot dogs, they're saying, you know, like, I'm so glad that you said that about fluids or I'm so glad that you guys talked about the dexamide because that's what I think, but I never say it.
Annatasha: Right. And I always feel like if I try to bring it up, like I just get bullied back down into like status quo. And I'm like, well, nothing improves and nothing changes if we don't have like the spectrum of opinion, right?
Annatasha: Because that's what pushes us to actually like think and and be better. So yeah, I mean, you'd be surprised how many veterinary anesthesiologists listen because they just want to have one other person just say the thing that they've never said, you know, and happy, you know, we're happy to be those people for you guys.
Gianluca Bini: Yeah.
Ryan Bailey: mean
Ryan Bailey: The only reason I agreed to do this is so I could have a platform to just scream about Kat's sympathetic tone and why so dysregulated under anesthesia and why we need to do more about it.
Annatasha: Okay.
Ryan Bailey: So, you know...
Annatasha: Yeah, and apparently I've been just biding my time until the ventilation talk came up. like
Ryan Bailey: I had so many other things to talk about and now we like,
Annatasha: Yeah, but I spiraled right there because I was like, look, guys, second ventilation irks me to no extent.
Ryan Bailey: yeah. yes
Gianluca Bini: Yes. i
Ryan Bailey: So, Crystal's not buying any ventilators.
Annatasha: Wait, quickly, what's on the rest of your list?
Ryan Bailey: She's just like, oh, let's see.
Annatasha: Just so like I'm curious.
Ryan Bailey: I wanted to talk about like, what is your, like, where are you sitting for permissive hypercapnia? How permissive are you? And when do you think that's appropriate, inappropriate?
Ryan Bailey: are you actually doing anything about PPV, SPV in real time? Like when I know, i know the human papers are all based on very low tidal volumes and very low peak inspiratory pressures.
Gianluca Bini: yeah
Ryan Bailey: But in a real time case, when you got an A-line in and you can see like pulse pressure variations, the stock pressure variation, whatever number you want to choose, are you actually doing something about it? are you like, I'm hammering, you know,
Ryan Bailey: There are certain cases where you've got to hammer those lungs. You're at you know high peak inspiratory pressure, high tidal volume. You're probably not going to do anything about it, but on those lower ones, do you actually assess that knowing that it's not really what the papers say?
Annatasha: Maybe we need to have a ventilation part two discussion.
Ryan Bailey: Yeah.
Ryan Bailey: Sure. And then I wanted to talk, i mean, these are just topics I came up with off the top of my head, but I also want to talk about when do you want to, how do you approach discontinuing ventilation?
Annatasha: Beanie looks jazzed.
Ryan Bailey: and then going to do a whole thing on like, for those cases where we think ventilation is important, you know, recent onset acidosis, sepsis kind of cases, uremic acid cases, they're not common, but we see them, you know, the patients that you're going to kill by letting their CO2 climb up because the pH is so deranged that if you let it climb even further, you're going to set it to like, you know, the death spiral essentially.
Ryan Bailey: You know, how do you approach intracranial pressure cases?
Annatasha: I think we should have a part two and keep this list.
Gianluca Bini: We should have a part two.
Annatasha: Yeah, this list is excellent. And i think I think people would want to hear about, like, especially the intracranial pressure, because I also have feelings about that. But, you know, these are great questions, like how to discontinue ventilation, like permissive hypercapnia.
Gianluca Bini: Yeah. Yeah.
Annatasha: We did take a bit, but, you know,
Gianluca Bini: Part two.
Ryan Bailey: I genuinely cannot believe the I just thought it's just me over here fussing and like perseverating over little ventilator idiosyncrasies. also want to talk about like when you have a patient who like clearly isn't taking to your like inspiratory time and flow rate, how do you make adjustments?
Ryan Bailey: Do you think it really matters? Or do you think that patient has some other disease process? Anyway, I've got a lot of feelings about ventilation. I think about it a lot, even though I don't ever do it.
Annatasha: One of my mostest favorites is to come into a case and like the ventilation is just a hot mess and I just go like this, boop, and I just turn it off.
Ryan Bailey: Oh my God. Oh, and then I also, I got a,
Annatasha: And I'm like, enough of this bullshit. And then I start to take a little like handbagging and like, I just sort of bring everything back to where it actually feel
Ryan Bailey: oh and then i also
Annatasha: running off the ventilator, i because I get so mad about bad ventilating and I'm like, fuck this. And I just, you know, like it's bucking, it's bucking. And I'm like, well, i don't know if you've noticed this, but every time it bucks against a breath, the airway pressures go up to about 42. So before we actually pop the lung,
Annatasha: let's stop this insanity. And then, yeah. And then insanity. And then, you know, let's just go, a little let's just come back to like step one. Let's walk before we can fly.
Annatasha: and like, think about what's happening. Is it depth? Is it pain? Is it position? Is it pulmonary physiology? Like what? Like blood gas, like use your brain. and This is my whole point about ventilation. You have to critically think now.
Ryan Bailey: I also want to talk about handbagging. Is it all strapped up to the ears?
Annatasha: Yes, yes, okay.
Ryan Bailey: Anyway, well, I'll leave it there for now.
Annatasha: Part two, I think part two would be great.
Gianluca Bini: right, part two, guys. All right, we came up to the the hour.
Ryan Bailey: Oh my God.
Gianluca Bini: Thank you so much for listening. Remember, you can watch this on Apple Podcasts and YouTube. See you next time.
Annatasha: And if you're a hot dog company, we are looking for a sponsor.
Gianluca Bini: Yeah, yeah.
Ryan Bailey: Yeah. I will eat all the hot dogs you give
Annatasha: Sausages, no sorry, hot dogs and sausages, both welcome. We would also accept buns.
Annatasha: Yeah. Yeah.
Gianluca Bini: but Nice to be continued.
Annatasha: and
