Can They Tolerate an Anaesthetic? The Respiratory Patient Explained

Dr Gavin Nimon: 0:29

Almost every anaesthetic involves a decision about ventilation. Sometimes the patient's intubated and mechanically ventilated. Just as often they're maintaining a spontaneous ventilation through a laryngeal mask airway under procedural sedation or fully awake under a spinal. Whichever technique is chosen, the patient's respiratory status shapes every one of those decisions. The asthmatic requiring an appendicectomy, the COPD patient listed for a knee replacement, the patient with undiagnosed obstructive sleep apnoea whose highest risk period comes in the w-- on the ward two nights post-operatively, and the patients whose record documents a previous difficult intubation. Today, we're unpacking what a doctor needs to know about the respiratory patient presenting for anaesthesia. The lungs themselves, the right heart that depends on them, the upper airways and sleep apnoea, and the difficult airway. And my guest today knows all about this, Dr. Nick Harrington, consultant anaesthetist in South Australia. G'day and welcome to Aussie Med Ed. The Aussie style Medical podcast a pragmatic and relaxed medical podcast designed for medical students and general practitioners where we explore relevant and practical medical topics with expert specialists. Hosted by myself, Gavin Nimon, an orthopaedic surgeon, this podcast provides insightful discussions to enhance your clinical knowledge without unnecessary jargon. I'd like to start the podcast by acknowledging the Kaurna people as the traditional custodians of the land on which this podcast is produced. I'd like to pay my respects to the elders, past, present, and emerging, and recognising their ongoing connection to land, waters, and culture. I'd like to remind you that all the information presented today is just one opinion, and there are numerous ways of treating all medical conditions. It's just general advice and may vary depending upon the region in which you're practising or being treated. The information may not be appropriate for your situation or health condition. And you should always seek the advice from your health professionals in the area in which you live. G'day and welcome to Aussie Med Ed. Well, joining us today is Dr. Nick Harrington. He has taken one of the more adventurous roads into the specialty. Dr. Nick Harrington, an anaesthetist, graduated from the University of Queensland while serving part-time as an infantry soldier in the Australian Army. He then spent some time in the Royal Flying Doctor Service in the Pilbara during the mining boom, retrieving critically ill patients from some of the most remote places in the country. That rural grounding earned him a fellowship of the Australian College of Rural and Remote Medicine before he moved to South Australia to continue his anaesthetic career here in Adelaide at the Queen Elizabeth Hospital, Lyell McEwin, and the Royal Adelaide Hospital. He's now a consultant anaesthetist with a fellowship training in paediatric and trauma anaesthesia and a special interest in regional anaesthesia, and he still teaches emergency skills to rural GPs and remains part of the trauma network at the Royal Adelaide. If anyone knows how to manage an airway when the stakes are high and the resources are thin, it's Nick. Nick, welcome to Aussie Med Ed. Well, it's great to have you on board and to hear about w-- how, how important the respiratory issues are when it comes to doing an anaesthesia. I mean, why does respiratory disease matter so much to an anaesthetist? What actually happens to the lung when we anaesthetise someone, even in a healthy patient?

Dr Nick Harrington: 3:23

Uh, thank you, Gavin. Uh, yeah, that's a special interest of mine. Um, I'm also a examiner for the primary exam for ANZCA, and one of my special interests is, uh, respiratory physiology. Um, so that first part of the question, what happens to the respiratory system during a, just a normal anaesthetic? Um, so as soon as somebody lies down flat on the table, we start to see a thing called atelectasis, which is the small airways closing up, and that's because the abdominal contents and the diaphragm push upwards. But also if there's any weight on the chest, say for a person who's got a high BMI, that's also pushing down on the chest as well. And with that small airways closure we get a thing that we anaesthetists love to talk about, which is shunt, which means that blood is passing past the lungs without getting any oxygen and going all the way over to the left side of the lung and increasing a thing called shunt fraction, which just means non-oxygenated blood going then around the ci-circulation. And we might see it just as a drop in the s-saturations on our sats probe. And in a normal, healthy patient, we don't worry about that at all. They go through their anaesthetic, and they recover from their anaesthetic without any problems at all. It's the, the people who have what we call a large shunt fraction, uh, and that is people who have a very high BMI that we start to get very concerned about

Dr Gavin Nimon: 5:01

Right. So that can cause issues for maintaining oxygenation, or it c- causes a lot more difficulty with ventilation or lots of other factors as well?

Dr Nick Harrington: 5:11

Yes, that's right. Our main aim, uh, as anaesthetists is to take healthy people, get them through their surgery as quick as we can, get them through recovery as quick as we can, and then out of hospital as quick as we can. Because hospitals, unfortunately, can be a bit of a dangerous place, and our job is to get patients home as quick as possible, safely as possible.

Dr Gavin Nimon: 5:34

And how common is it for a patient to arrive on your list with a significant respiratory comorbidity? I mean, is it becoming more common with people's BMI going up and other factors?

Dr Nick Harrington: 5:44

Yeah. So there's c- certain population groups where unfortunately, yes, our population is growing, our BMIs are getting higher, and with that comes a multitude of diseases like diabetes, heart disease, obstructive sleep apnoea, asthma, unfortunately. And so how common is it for us to see it? On one hand, um, with people smoking less and less now I am seeing less and less of the, the really bad COPD patients. I'm seeing less of people who are having to give up smoking around the time of an operation. And with the dawn of medications like Ozempic, Wegovy, Mounjaro, I am seeing BMIs starting to de-decrease, as well as people who have had gastric bypasses and an amazing reduction in their weight, seeing less and less. So I-I'd have to say people with really, really severe respiratory lung disease, I'm seeing less of, which is great.

Dr Gavin Nimon: 6:47

That's fantastic. From an intern's perspective, where they're clerking a patient pre-op, what's the single most valuable thing they can do for you to help you along the way?

Dr Nick Harrington: 6:55

Pl-- I tell, yeah, med students and my anaesthetic trainees, "Please do not put down those stethoscopes." Those stethoscopes are very val-- very valuable. So, for us, an intern junior house officer is our eyes and ears and our sort of early warning system. Also, general practitioners are, are that as well, early, early warning systems. And the mantra that we have as anaesthetists is a good hi-- focused history, physical examination, investigations, consulting with our expert colleagues like respiratory physicians, cardiologists. Then doing any special tests that we need to do for our patients, and then coming up with an anaesthetic plan. That's our sort of go-to stepwise ladder. So as an intern, um, identifying early patients that, uh, have lung disease is very important to us. Actually listening to their chest is very important to us, and any added sound that you hear while you're doing a respiratory exam is very important. Don't just go, "Oh, that's okay." Actually we… you have to do something about it, and you have to let people know. You have to let hopefully the anaesthetist doing the operation know early so that we can assess and optimise the patient, so that we can actually do something about it. And that could be increasing the nebulizers or the inhalational agents they need. It could be chest physio. It could be getting the respiratory physician involved to try and optimise them, putting, putting them on some, um, better respiratory medications. They might have a chest infection, so they may need antibiotics. All of these things doing early, uh, helps us as anaesthetists.

Dr Gavin Nimon: 8:44

When I was thinking about asking these questions for the, uh, the interview today, I was thinking about really as a, an anaesthetist looking after a patient, really it comes down to two sides, isn't it? Really respiratory and cardiology. Is there any other aspect to anaesthesia that you need to think about, or is it really the bulk of your work down to those two aspects?

Dr Nick Harrington: 9:03

I'd have to say the bulk of our work is those two aspects and other tools, I guess, that has really helped us recently is the echo, the transthoracic echo, and, uh, the reason why we bother our surgical colleagues and our, and your interns and JHOs to get that is that really it's a, it's a great way of unpacking unexplained dyspnoea or breathlessness and just seeing is it the heart that's the problem or is it the lungs that are the problem. So largely, yes. So the answer to the question was cardiac and respiratory are the bulk of our work, but also, you know, we look at the patient as a whole. Diabetes and diabetic management and management of their blood glucose during an operation is very important. Taking care of all of their peripheral limbs, uh, making sure that they don't get a peripheral neuropathy is very important to us as well. Other sys-systems that impact for us are the renal system. It affects drugs that we give. It affects how much anaesthetic we need to give. Liver as well, if that, if that is impaired, that can have a significant impact on the operation itself. And bleeding issues and where we place these patients post-op.

Dr Gavin Nimon: 10:18

Brilliant. Well, let's walk us through your respiratory focus pre-anaesthetic assessment, particularly the history. What questions do you never skip when you assess a patient?

Dr Nick Harrington: 10:27

So things I, I never skip. Identifying early patients that might have postoperative respiratory complications. I'm looking to see whether the patient has any asthma, whether they have restrictive lung disease, pulmonary fibrosis, their smoking history, how much they've actually smoked in their life is important, how bad is their chronic obstructive pulmonary disease is important. I never miss, uh, whether they've got a recent cold or they're coming off a cold or they've just given up smoking. I try to identify if they've had any interaction with a respiratory physician, and I try and get letters from the respiratory physician, the most, most recent letters, and where they're up to with their treatment. There are some really, really good respiratory medications that have come out. One so I won't name names, but there are some really good ones recently, and the patients are telling me, "Oh, I started on this one, and it's just, it's made all the difference." So seeing whether I can optimise the respiratory function at all is what I try to do. Also, functional assessment, that's also important for us are things like can they mobilise around the house? Can they do shopping without becoming short of breath or having to sit down and take a breath? Um, whether they c- they can climb the flight of stairs, that's important to us as well, because that's a bit of… That's a predictor of how they're going to go intraoperatively but also postoperatively, and also guides my decision as to whether they need an HDU or an ICU bed post-op. But it also, uh, guides my decision about how I'm actually going to do this anaesthetic. Uh, it may mean I'm gonna try and avoid a general anaesthetic altogether because that can place, place some serious impact on a respiratory cripple. S- and the advent of really, really good regional anaesthesia now with our, our unbelievably good ultrasounds mean that sometimes I can avoid a general anaesthetic. Which is good for the patient.

Dr Gavin Nimon: 12:35

Well, that's brilliant. Um, you mentioned smoking before. I mean, how does that change your anaesthetic risk assessment?

Dr Nick Harrington: 12:41

We've got this really good professional document from ANZCA which sort of goes through what happens to the patient when they stop smoking, say, three months before, a month before, a week before, or even the night before. And at all those levels, it is act-- they recommend that it is actually beneficial for the patient to stop smoking. And that is because, um, right up until the time of the operation, uh, the nicotine in the smoke can actually increase the patient's sympathetic nervous system, meaning tachycardia and blood pressure, which can put strain on the heart if they've got acute coronary syndrome. You know, stopping smoking right up until the time is beneficial, and the other mantra we advise is ask, advise, refer. So ask them whether they smoke, advise them that giving up smoking is very beneficial to their operation, not, not only sort of wound healing, so the surgical part of the operation, but also anaesthetics wise. Referring, uh, so onto a, uh, you know, a quit line, uh, advising that, you know, we can give you nicotine patches around the time of the operation or nicotine replacement. And I guess going right back to your original question, why smoking and the complications, smoking actually it terrifies me towards the time of the extubation. Not so much during and, the prequel, but, uh, the extubation because, um, smokers, they just have this flood of saliva pouring out as we're waking the patient up and trying to take the tube out. So I actually have to h-- be on high alert at the time of extubation and be prepared to actually re-intubate the patient, uh, because they can suffer things like bronchospasm, laryngospasm, aspiration from all those secretions. So if you see… If you're a surgeon or a med student and you see the, the anaesthetist starting to become very awake, uh, right at the end of the operation, you know that they're looking out for trouble and hopefully preventing trouble before it happens.

Dr Gavin Nimon: 14:49

Very important. I note that the recent cold or chest infection can be an issue as well, not just from smokers, but from extra saliva and that extra production of mucus. Is that the case? And, uh, if a patient turns up for elective surgery with a runny nose or lingering cough, when do you decide to cancel? When is it important between proceeding and not, and not proceeding?

Dr Nick Harrington: 15:10

Yep, that's a great question. And I guess my part-- my final exam training would say patient factors, surgical factors, and anaesthetic factors. Coming off a cold, I find people, uh, have a lot of bronchoreactivity, which is… Which means during an anaesthetic, they can almost behave like an asthmatic with increased mucus production and bronchospasm and wheeze. And they're all very bad things around the time of an operation when you've got a tube down your throat and pulling out that tube, and you could be rubbing against the vocal cords. And our dreaded complication is laryngospasm when the two vocal cords are like that, uh, and not being able to break that. And so for me, if someone's got a cold, um, they're looking terrible, and I look at the operation, is this really elective? And, and we can delay this for a while till you're better. Or is this semi-urgent, like the patient's got cancer? Or is this an emergency? If it's an emergency, I just need to buckle up and do the best I can and probably add sevoflurane, which is, which is a, a bronchodilator, a smooth muscle relaxant. I would tend towards that side of the anaesthetic rather than a propofol total intravenous anaesthetic because it… I, I tell patients sevoflurane is like supercharged Ventolin, so I would use that. And for the semi-urgent, so the cancer patient, it would be a balanced discussion I would discuss with the surgeon, p-perhaps even discuss with ICU for the post-op period, whether the benefits versus the risks of going ahead are such. And, and also look to see whether I can do either a spinal anaesthetic, epidural anaesthetic, or a regional technique to try and minimise general anaesthesia for this patient.

Dr Gavin Nimon: 17:08

Excellent. On examination, when you assess the patient too, are there any things that might change your plan either for post-cold or other factors from the general health of the patient?

Dr Nick Harrington: 17:18

Definitely, and especially for paediatric anaesthesia, a, a physical exam for-- of the patient's very, very important. So listening to the lungs, listening to added sounds, are wheeze, crackles, murmurs, any of those things are very, very significant. Looking, obviously looking in the patient's airway and their nose. Are they… Have they got snot running down their nose? You know, have they got enlarged tonsils or mucus running down the postnasal space, posterior pharyngeal wall? Any of those things are significant. Looking for temperature, and I would be very reluctant to go ahead with any of those things, uh, in an elective operation.

Dr Gavin Nimon: 17:59

Well, what investigations are also useful? You mentioned echocardiogram. Yes. Uh, are there any other tests that you might wanna perform or get organised prior to surgery?

Dr Nick Harrington: 18:08

Yes. So pulmonary function testing, we actually look at as anaesthetist. We see whether the patient has an obstructive lung pattern or a restrictive lung pattern or a mixed, which is a combination of both. Uh, how and how bad that is, uh, and whether it's reversible with bronchodilators, and also see changes over time. Perhaps they've had pulmonary function tests four years ago and then another set maybe a year ago, and then we get it pre-op, and we see changes over time. Uh, so they're very important to us. Chest X-rays are important. We look at them. The echo we've already mentioned. We're especially concerned about pulmonary hypertension and right ventricular failure, so we look to that because that is a dreaded thing under anaesthesia is the acute right heart failure or pulmonary hypertension as you know, the pressure's really high. That, that also means a very rocky anaesthetic for us. Other lung tests. A CT chest is also important. It can show atelectasis or, uh, oedema or consolidation. Those are important. I'm just trying to think of the trauma scenario. So if patient has rib fractures, um, or a chest drain in, or needs a chest drain in 'cause they've got a pneumothorax or a haemopneumothorax, uh, that's also very, very important. Ultrasound as well. So the ult-- the advent of ultrasound, we can look to the lungs to see whether there's sliding lungs, uh, whether there's a pneumothorax, and even s-- you know, the ultrasound gurus are now looking at the lung parenchyma itself and seeing consolidation, effusions, those sort of things.

Dr Gavin Nimon: 19:57

So you talked about transthoracic echo. Are there any anaesthetists that do those themselves given that you're so… you're pretty good with the ultrasound machine and nowadays for doing blocks?

Dr Nick Harrington: 20:06

Yeah. There, there's a rise actually. We-- The, the anaesthetic community has recognised how important assessing the heart is, and you will find more and more anaesthetists that are competent with a transthoracic echo. Um, and sometimes we're practising it under the drapes while you guys are doing your surgery, uh, because the more you do, the better you get. There's lots and lots of courses out there, and I recommend to the interns and med students that are coming through now please do those courses and practice on each other because I think it will become just commonplace having a bit of a look at the heart before an anaesthetic and, you know, as I said before, the e-- the ultrasounds are getting better and better. The images are getting better and better, and we can really diagnose a lot of things preoperatively with that. Not just the heart, but also looking in the stomach contents to see whether the patient's properly fasted before theatre. It's also very important, uh, especially in the day of Ozempic, Wegovy, Mounjaro, where we're seeing very delayed gastric emptying.

Dr Gavin Nimon: 21:41

But if we move on to like specific lung conditions, I mean, asthma is obviously a really important one for anaesthesia. What do you want to optimise for an asthmatic patient before they come to theatre, and, and what happens if they do bronchospasm on the table?

Dr Nick Harrington: 21:55

We want to, yeah, we want to a-optimise them before theatre, and that can mean things like a period of steroids. It can mean ensuring that they're n-not only taking their broncho preventers, but also their relievers. Chest physio is also important. Any mucus there, expectorating any mucus. We s-- We, I guess we categorise the asthmatics into mild, moderate, and severe, and the, you know, moderate to… and severe, we want to ensure that the respiratory physicians have seen them preoperatively and that we've cha-- we've talked to them. If they bronchospasm on the table, then we have a, a specific set of drills that we do, and that includes in… as I said before, sevoflurane is a great, um, bronchodilator, so we would increase our percentage that of sevoflurane that we're giving them. We might need to deepen them further using perhaps propofol and some opioids. If it's extubated them and, um, we are now holding the mask over them, then we would increase our level of PEEP and myself, I just hold the bag and wait for that spasm to relieve itself. So they need positive pulmonary ventilation. At worst case scenario, you may have to re-intubate them and perhaps send them to ICU fully anaesthetised, um, so that they can be ex-- uh, extubated at a later time.

Dr Gavin Nimon: 23:25

Okay. What about those patients that think they've got asthma, they've actually got COPD? How does your approach differ? I mean, obviously some of them might be retaining carbon dioxide as well.

Dr Nick Harrington: 23:34

Yeah.

Dr Gavin Nimon: 23:34

Yeah. Um, what's your approach as a severe COPD patient?

Dr Nick Harrington: 23:37

Is to avoid a general anaesthetic at all. And that can even mean can we do the surgery just under local anaesthetic, which we oftentimes forget, but which c-c-can be done. Going back to the pulmonary function test, if that we do the bronchodilator part of that, and we can see whether there's a reversible component, then that lends credence to the fact that they've got asthma, and they may need to be started or, or actually take their asthma medications. That does scare us, the re-- the really, really bad COPD patients where they've got very little respiratory function left. And for those patients, if they've got a fractured neck of femur, for instance, I would advocate a spinal anaesthetic and perhaps little, if any, sedation And also, sorry, I have-- I failed to mention another area of our practice that has really, uh, helped us recently is the high flow nasal oxygen. So I would probably use high flow nasal oxygen on those patients as well. That has been a real game changer for our specialty.

Dr Gavin Nimon: 24:42

I note that anaesthesia has changed a lot. You've mentioned the high flow nasal oxygen.

Dr Nick Harrington: 24:46

Yeah.

Dr Gavin Nimon: 24:46

Other things that have really changed your practice?

Dr Nick Harrington: 24:48

Yes. Yeah, sorry. We-- I forgot to mention with the the asthmatic, sometimes, uh, avoiding putting a tube down i-is the way to go, and, um, uh, we've got really fantastic laryngeal mask airways now. The one I tend to use a lot is the i-gel, which I find anybody can put down . Ambulance officers, med students, even the lay public, if you give them a couple of goes could put a, an i-gel down, and they really do tend to give a good seal around the laryngeal inlet and al- and also minimise the disturbance to structures further down, like the vocal cords, the subglottic space, the trachea. So I'd say about eighty to ninety percent of my anaesthetics is done under laryngeal mask airway, and I find the i-gel to be the one of my preference. Uh, so yeah, that's been the advent I, I spoke about the high-flow nasal oxygen where we can deliver humidified, uh, and warmed air or oxygen in through the nose or mouth up to seventy to eighty litres per minute, which is unbelievable to think about when you think we use nasal prongs, and we use two to four litres per minute. So the high-flow nasal oxygen, and I found it has crept a lot into my practice in that it keeps those small airways open for longer. It helps me with the morbidly obese patient at induction, where I tilt the table up to give them the best functional residual capacity that I can, which is the oxygen store. And using the high-flow nasal oxygen in that-- in the, the lead-up and the period of time when I give the patient the anaesthetic medicine that puts them off to sleep, but also muscle relaxes them. If I c-continue using that high-flow nasal oxygen and just do jaw thrust to keep the airwa- to keep the oxygen trap all the way down to the small airways open I hardly ever see any more a desaturation, which for those of you being in the, in theatre, and you start hearing sats going down from ninety-two to eighty-eight to seventy, you'll know what a disturbing noise that is.

Dr Gavin Nimon: 27:07

Yes. Yes. What about the interstitial lung disease or bronchiectasis or pulmonary fibrosis? Are there any special traps for those?

Dr Nick Harrington: 27:14

I don't see them very often anymore. Uh, I must say bronchiectasis, interstitial lung disease, the fibrosis I, I see now and then, especially when they've got syndromes, rheumatoid arthritis, Sjögren's syndrome, any of the sort of pulmonary fibrosis syndromes. I must say that they don't disturb the anaesthetic too much as long as you get your ventilation strategy right, and I guess that leads on to a lung protective ventilation strategy. And in the old days, we used to give them huge tidal volumes, such like ten mils per kilo. So we were seeing tidal volumes of six hundred mils to seven hundred mils, which we found was stretching out the small airways and, and giving the small airways the trauma, which we've now come to realise we shouldn't be doing. So we're doing smaller tidal volumes, say six to eight mils per kilo, and perhaps increasing the respiratory rate somewhat, making sure that we've got PEEP, which is positive end expiratory pressure, which helps keep those small airways open and, and trying to minimise the, the driving pressures that we're using to get to force the air down into the lungs. So I guess we're being gentler to our patients' lungs.

Dr Gavin Nimon: 29:00

Excellent. We've already touched upon the use of regional anaesthesia and, and blocks for the use of the difficult patients. But a thought comes to mind about those, those patients, particularly in my area of shoulder surgery where we are often-- they often do an interscalene block, but the patients have the worst respiratory disease. Often they're keen to avoid it because of the risk of phrenic nerve palsy. Is that a common scenario, and is there any other scenarios that we can think about in that situation where a regional block isn't the most useful thing?

Dr Nick Harrington: 29:28

Uh, yeah it's actually quite common. I do quite a few interscalene blocks, and unfortunately, yes, the phrenic nerve is layered down over the anterior scalene, and the brachial plexus through that area is through the anterior and middle scalene. So unfortunately, even though we, we make the shoulder really nice and numb so that we reduce pain both intraoperative and post-operatively, uh, we can see unfortunately that hemidiaphragm raised for, you know, as long as the block is working. And in most people that's fine. They can breathe fine without, you know, one diaphragm working that well. But in the respiratory cripple, the very severe COPD, that can be very, very bad. So in, in those instances, we can try and do perhaps a shoulder block that is further away from the neck, further away from that phrenic nerve, a lower down nerve block, even a supraclavicular nerve block. But it may not give as good a regional anaesthesia, but it-- but we do try and avoid that, um, phrenic nerve block. So other… You also asked whether we avoid regional anaesthesia in other areas. We should always, as anaesthetists, discuss with our surgeon whether we want to do a block, whether the surgeon feels like they don't want us to do a block. Sometimes our blocks are so good that they can mask things like compartment syndrome. Um, so I, I try and always ask the surgeon, you know, will this impact in any way for that? And I, I think the one that comes to mind is the tibial plateau fracture. And the surgeon says, "You know, I'm really worried that it may mask that," then I, I will try and not do a nerve block. And as long as the surgeon, uh, is happy to put local anaesthetic in and around the area, then I'm f-- I'm fine with that. And the patient will probably need more medication such as fentanyl or morphine or oxycodone. And I may add, may add other things like opioid-sparing drugs like ketamine, make sure they have Panadol, tramadol, things like that. So yeah, there are some-- sometimes when unfortunately we can't do the nerve blocks.

Dr Gavin Nimon: 31:39

Well, I think you explained at the start when we talked about the heart and lungs- Mm … being the, the main issue, and you mentioned there were all these other factors which all interact. Generally, I think you can't think about lungs in isolation. You've got to think about the heart. Perhaps you can talk us through why that's important in the scenario of like, uh, right heart failure and cor pulmonale. Why is this so important to you?

Dr Nick Harrington: 32:00

When I think of cor pulmonale, the, the thing that comes to mind is very morbid obese patient with the obstructive sleep apnoea and, and it's a bit like hypertension. They don't really know it it's happening, but over a period of time of all that hypoxia overnight from the multitude of, of, uh, apnoeas that they undergo, poor old right heart is having to drive blood against all of its restriction through their lungs so that their heart starts to become I guess it's, it starts to turn into the left ventricle in terms of the thickened wall and needing to really drive that pressure through. Uh, and the right heart doesn't like doing that, and it can lead to ischaemia with that thickened muscle wall of the heart. And I guess pulmonary hypertension for us, you know, experienced anaesthetists have seen the right heart failure, uh, and it can be unrecoverable for some patients. That can be the terminal life event. So we do, we try and identify those patients early. We ha-- we can use special techniques for the pulmonary hypertension patient, things like nitric oxide, milrinone, sildenafil, uh, just to try and open up the, you know, the pulmonary arteries. So yeah, identifying those patients early, very important. We may need to involve our cardiothoracic fellows, uh, because they have expertise in that area. They can guide us on, you know, best way of doing the anaesthetic and drugs to use, drugs both pre-op, intra-op, and post-op. And they're also very good at saying,"You shouldn't do that anaesthetic."

Dr Gavin Nimon: 33:45

Right. The right heart and the left heart failure, they can also be affected by positive pressure ventilation- Mm as well. Is that correct?

Dr Nick Harrington: 33:53

Yeah. I guess the chest wall and the heart are a series of, I guess, pressure areas, and putting greater pressure on the outside of one can affect the other. It's, I guess it's a careful balance in that we need to ventilate the patient, and we try and keep those small airways open so that they don't get shunt and hypoxia. But we also need to realise with positive pressure ventilation and PEEP, we are affecting the, the heart as well and its ability to drive blood out, not only into the lung circulation but into the systemic circulation. So like all things, it's a careful balance. Um, it's perhaps trialling to see how you're going in one area, realising that you might be affecting the other. And I, I guess it leads back also back to that transthoracic echo and the skills there, and being able to look inside the patient's chest and seeing what their right heart's doing, what their left heart's doing, and catering for those needs.

Dr Gavin Nimon: 34:52

Okay. And does it cause issues if you've got both a patient with COPD and ischaemic heart disease, or was that… does that make it even more difficult to balance the competing aspects?

Dr Nick Harrington: 35:01

So when I think of ischaemic heart disease, I think of supply and demand and the coronary arteries and ensuring that we try and reduce demand, which might mean a slower heart rate, more diastolic filling time and supply, so ensuring that they've got a full left ventricle, that they're well filled preoperatively, they're not dehydrated, making sure that they're not in rapid AF things like that and also ensuring, you know, if they've got ischaemic heart disease it's a whole different set of questions and making sure you've talked to the cardiologist, seeing whether they've had stents or coronary artery bypass grafts, ensuring that we may even need to do a angiogram pre-op to make sure that their coronary arteries are the best that we can get them. If they've got that and COPD, they're the ones that I would really try and do a neuraxial or a regional technique, um, try and avoid the full general anaesthetic. But if you have to do the general anaesthetic, just ensuring that you've got an ICU bed post-op is very important. Talking to the ICU colleagues pre-op or or even there's also a thing called prehab where we-- it's not common, but if we're lucky enough to having them go to ICU pre-op to be optimised is excellent, and then coming to theatre and then going back to ICU can be the patient's best management.

Dr Gavin Nimon: 36:28

Brilliant. What should a medical student listen out for the hints of respiratory disease that affect the heart?

Dr Nick Harrington: 36:33

I very much, uh, advocate to the med student, and I wish I knew then what I know now is really that, that sort of a history, physical exam, investigations, talking to expert colleagues, and then coming up with a plan. That sort of four-tier program is not only important at the med student level, but also at my level as well. And history-wise, just you really need to try and identify early who's gonna be trouble in the anaesthetic and surgery and who will be trouble in recovery and who will need an ICU bed. So identifying the respiratory cripples, the COPD, the ones who are, um, CO2 retainers, the ones who are on home oxygen, they're all trouble. Uh, the ones who c-continue to smoke despite everything they can be trouble as well. And as a med student and a junior house officer, that's your, that's your opportunity to do the full respiratory exams over and over and over again because that is how you're going to get good at it. And that will then lead to, as you get more experience, being able to take shortcuts with your exams, uh, and I guess really honing in on what's important. But I do advocate doing the full respiratory exam on your patients. And yeah, just anything that you hear on your chest exam is important, like crackles, wheezes, creps, any of those things. Doing a, a spirometry on the ward is also quite helpful and useful, so I advocate that as well. And it's not hard. It's, it's not invasive. You just pull out a spirometer. Yeah, just I g- I guess also, um, vital signs are very important, the respiratory rate for the patient, the saturations, blood pressures. Look at all those things.

Dr Gavin Nimon: 38:24

Obstructive sleep apnoea. Why is it such a big deal perioperatively, and what actually can play up with it?

Dr Nick Harrington: 38:30

The big deal with obstructive sleep apnoea is that unfortunately anaesthetics can make it worse. Putting them through an anaesthetic with all of the medications that we use, especially opioids, can tip someone who's on a knife edge over. So identifying early people with obstructive sleep apnoea and the STOP-Bang criteria that we use is important. Identifying whether a patient has a CPAP mask and ensuring them, ensuring that they bring it in with them to hospital is very important. Even if it's a day case, it may turn into an overnight case. But you can just… You can-- Most of the time you can very much pick the obstructive sleep apnoea patient. It's the person who's, you know, quite round. They've got a thick neck. They might have a beard and hiding a small lower jaw. They have a big tongue, and they've got high blood pressure. They're usually male, and they're the ones that you ask, "Oh, has your wife or your partner ever heard you snore or told that you snore?" And they say, "Oh yeah, you know, they have to sleep several rooms down from me 'cause of my snoring." And they're the ones that we try to get in a sleep test to see, you know, how often they are having hypopnoeas during the night or apnoeas and identifying, uh, that they do need a CPAP mask. A lot of times I ask patients about sleep apnoea, and they say, "Oh yeah, I've had a sleep test. They said I'm bad, but I… And they said… Oh, they gave me a CPAP mask, but I never wear it 'cause I, I hate it." They're ones also that I see quite commonly. A-and what do I do about it? So they're the ones that I then need to organise that night for a high dependency unit bed because they need sats monitoring overnight. They need their… If they're using their CPAP, they need it on overnight, uh, and they need a nurse to check on them regularly, and, um, they may need oxygen overnight as well. So they're ones that we need to organise early, HDU or ICU, and it may influence my anaesthetic in terms of trying for a neuraxial or regional technique rather than a general anaesthetic.

Dr Gavin Nimon: 40:44

Excellent. And if you've got the obese patient and the obstructive sleep apnoea, uh, how does that affect your positioning and pre-oxygenation both prior to surgery and during recovery? Is there anything particular you might do during the actual operation itself?

Dr Nick Harrington: 40:57

Um, I'll, I'll go back to the induction time, so getting the patient off to sleep. If they're morbidly obese, they've got sleep apnoea. Uh, what I do is they're almost sitting like a beach chair. They're in a relaxed sort of beach chair position. I would have my high flow nasal prong oxygen on I would have at least one good drip in and giving them fluid, and I would also make sure they've probably got a hover mat underneath them as well. I ensure that their airway, as when I say the airway, their head and their neck are in the optimal position for me for when I need to look inside with a laryngoscope. And oftentimes once you've done all that, uh, the airway itself is not very difficult. Usually, they've got good mou-mouth opening, and you sweep that huge tongue aside, and you can, you can see the larynx quite easily. But the thing we try and guard against is that really sharp desaturation once we've given them the anaesthetic agent and the opioid and the muscle relaxant. It used to take me by surprise how quickly they would desaturate. Uh, and that goes to that when I was talking about that shunt. The healthy patient has a shunt perhaps of about five percent. These patients can have a shunt up to forty-five to fifty percent, which is sig… extremely significant. But in the day of the high flow ni-nasal oxygen, we're seeing less and less of that. I guess also that leads on to discussion about difficult airways and sometimes we need to do a, an intubation where it's awake, and that means that the patient is sitting up awake, and we put local anaesthetic maybe all through the nose and the back of the nose and the mouth and the larynx itself And we use these fantastic little endoscopes with a tube railroaded over it to get the endoscope in through the nose and then down the back of the mouth and then into the trachea. And we use a series of steps to enable that to happen. And the morbidly obese patient, it may be that we need to do that.

Dr Gavin Nimon: 43:04

And that'd be more common in a sleep apnoea patient because they usually are overweight.

Dr Nick Harrington: 43:09

I have to say in this day and age, with the advent also of the amazing video laryngoscopes we have, I would say that if they've got good mouth opening and you know that the back of the, the tongue is okay, that first anaesthetic I described where they were ramped up and then, and the nasal flow oxygen, most times we do that with the video laryngoscope so that we can see. When they don't have good mouth opening or they've had head and neck surgery or radiation or some, some anatomical problems with the upper airway, then you'll see the anaesthetist doing the awake fibreoptic. We might give them very minimal sedation, but the, the reason why we're doing that is, is we do-- we don't want to induce the patient, give them muscle relaxant and find that we can't open the mouth properly. We don't want to find that we're suddenly having to do a nasal intubation. We try and guard against that situation.

Dr Gavin Nimon: 44:06

Brilliant. I mean, you've already said about the size of the neck and mouth opening. What other bedside assessments do you use to assess how easy it is going to be to intubate them?

Dr Nick Harrington: 44:15

Yes, you'll see the anaesthetist using a series of, of examination techniques, which means that there's no one good test. And, um, and sometimes we unfortunately are surprised when we look down with our laryngoscope and we can't even see the larynx. And you'll see the anaesthetist starting to get very alert in that situation. And so yes, we use a series of tests which includes mouth opening. Getting them to poke their tongue out and seeing whether I can see their uvula and their posterior pharyngeal wall, which is the Mallampati score. That can be one little aid. Seeing their distance between their mentum, which is the little chin, and the thyroid cartilage. Assessing how flexible their neck is, extension and, and flexion. Other things that, that we use is whether they can protrude their jaw. So just meaning that they can bring their jaw forward. And that sort of identifies also the patient who's got micrognathia, which is a small lower jaw, and that, that's a little, uh, red flag for me. It brings my antenna up. Whether they've had a, uh, a syndrome like Goldenhar or Pierre Robin syndromes. They can also be difficult airways as well. Whether they've had, as I said before, any head and neck surgery and radiation therapy and making their neck very stiff. Whether they've had a tr-a tracheostomy put in is also important or any subglottic stenosis. So they're all things that I look for. But even, you know, doing all those bedside tests it can give me a bit of an idea this patient might be difficult, but it's by no means, uh, a hundred percent guaranteed.

Dr Gavin Nimon: 45:58

I presume a, a patient who says they've had trouble previously, would you take pretty seriously as well?

Dr Nick Harrington: 46:03

That's it. You might have- Exactly right. Then that's where we try and gather for, uh, anaesthetic records from previous hospitals, previous anaesthesia, whether they've got a difficult alert bracelet on, whether they're on the difficult airway registry. Yeah. Ch- any- anything that's airway or difficult airway related is significant. This is where med students, GPs are our eyes and ears and our forewarning radars. Uh, so yeah, taking that history, get… Uh, any history of difficult airway important, gathering all the documents from the various hospitals, which can be quite a laborious task. Commonly, what's done is a pre-health questionnaire done by nurses to screen out patients that are boringly normal versus ones that we need to see. And yeah, those, um, sort of pre-health questionnaires are really important to identify the, the high-risk patients and, and those one I, I really try and see pre-op. Uh, even if it's uh, a video telehealth, I try and see them and try and, um, work out what I'm going to do on the actual day. I like to be forewarned. But even on the day, us as anaesthetists, we do that airway exam. I try and encourage my registrars to make sure you do a, a good cardiorespiratory exam because the more you listen, the more you'll identify, oh, that's normal, that's not normal. So looking in the airway and gaining informed consent from the patient, the benefits, the risks of all, all of the things that we do, uh, and making sure that they're fully informed and they know what they're getting into.

Dr Gavin Nimon: 47:41

Yeah. Well, I think you've gone through the broad steps of, of progress for a difficult airway. What are your stepwise fashion for difficu- dealing with a difficult airway?

Dr Nick Harrington: 47:49

In a… When I'm in a teaching hospital I'm h- I'm trying to be a guard against the s- the sort of losing art of the awake fibreoptic. So I try and encourage the f- the awake fibreoptic whenever we can Because there are times where, especially if you're a private anaesthetist or if you're in rural and remote settings, uh, you, you could be the first word and the last word on anaesthesia. S- so you need to be up to date with your skills and up to date with your courses and your CME. And I would advocate, if you're thinking about doing an awake fibreoptic on someone, then you should go ahead and do it. It does take a bit of time, a bit of pre-planning. Okay. So it starts right out in the holding bay, and that's where I put a- an oxygen mask on and a nebulizer, and I start nebulising some lidocaine in through, through the patient's upper airways and respiratory tract, and I tell them to breathe in and out through their nose and in and out through their mouth. As well, I give, I give them glycopyrrolate, and that dries up the secretions of their, of their tongue and, um, and lower down a little bit. Because for topical local anaesthetic, you want a dry mucous membrane which will, which will encourage passage of the lidocaine across the mucous membrane to where it needs to go. And I start thinking about what nerves I need to cater for, for an awake fibreoptic, and that starts with the… Up the top is the trigeminal nerve. Further down is the glossopharyngeal nerve, and then down here is the vagus nerve. So I try to start breaking it up, uh, and I use things like Co-Phenylcaine and five or four percent lidocaine sprays in the nose, uh, in the, in the back of the mouth, the tongue itself, and then down in the trachea. I use a spray as I go technique, which means as I'm putting in the scope, I'm also delivering some local anaesthetic. I have seen some anaesthetist, and I have been trained for some who do a tracheal puncture or a cricotracheal puncture, uh, pop a little cannula in there and then squirt some local anaesthetic in to try and anaesthetise from the below the vocal cords all the way down to the carina and below.

Dr Gavin Nimon: 50:02

Right.

Dr Nick Harrington: 50:03

And, and also some people do regional nerve blocks of the superior laryngeal nerve, the interior na- laryngeal nerves. That's quite a thing because they're walking needles off the hyoid bone. That's amazing. But I, I found I get a lot of success just from Co-Phenylcaine spray, lidocaine spray, and spraying as I go and, um, having a, an expert assistant with me who can do perhaps a, a bit of gentle sedation, and that means things like midazolam, maybe dexmedetomidine, those, uh, those sort of things. The sedation where you can… where you're not burning your bridge, which you can reverse and come back out again. As well, I should say I'm doing this with, um, high flow nasal oxygen again, and you can even use that high flow nasal oxygen to deliver lidocaine in as well. You can see now why I'm saying it's such a game changer, this high flow nasal oxygen.

Dr Gavin Nimon: 51:29

Yeah. Excellent.

Dr Nick Harrington: 51:31

Yeah The actual, uh, intubation itself. So I've got a, a very small endoscope, and I've got a, a smallish tube, like a size six endotra-- nasotracheal tube on, and I'm going in along the, uh, below the inferior turbinate of the nose, and I'm looking all the way back to the postnasal space where the adenoids live. And then I'm diving down with the scope, and then I can see the trachea, hopefully. I have to bring the tongue forward then so that I can see the laryngeal inlet, spray a bit more local anaesthetic over the cords. The patient coughs a bit there. That's… I apologise to the patient for that. Uh, and then and then once I'm satisfied, I then dive down through the vocal cords and get that scope all the way down till I can see the carina, which is the division of the, I guess, the first division into the right and left lungs. And then when I'm there, then we, uh, railroad the, the small tube over. And then once we're satisfied we're in the right space, we can quickly get the patient off to sleep, and away they go

Dr Gavin Nimon: 52:31

Brilliant.

Dr Nick Harrington: 52:32

Mm.

Dr Gavin Nimon: 52:32

So you've got a whole system. And how often would you do that then?

Dr Nick Harrington: 52:35

Fortunately, these video laryngoscopes are getting better and better. So unfortunately, I… perhaps once a year I'd get to do an awake fibreoptic. I did a lot more when I was a, a fellow at the Royal Adelaide Hospital because oftentimes I'd be there at the middle of the night and, um, patients would come in with unfortunately dental disease, and they would have these, this huge collection of, of pus below the jaw. And they'd also have spasm of their masseter muscles, so they had no, very little mouth opening. So I would find myself together with maxillofacial surgeons at two or three AM, uh, doing awake fibreoptics. Um, so it was great training for me and the poor oral surgeons having to operate at that time.

Dr Gavin Nimon: 53:19

Excellent. One of the thoughts that always comes to mind with anaesthesia and difficult issues is a poster I saw on a wall once where there was a… would've taken a half an hour to read it, and it said, "Malignant hyperpyrexia, you've got seconds to act." Apart from malignant hyperpyrexia, what other types of conditions can occur that you need to watch out for, and how do we identify that?

Dr Nick Harrington: 53:38

I think you alluded to the anaphylaxis, which is a, a very scary complication that can happen not only during anaesthetic but also on the wards, giving giving a- any medications, can happen in the community thanks to bees and, uh, and other, other things. We can't predict the patient who's going to have an anaphylactic reaction very well. So it's sometimes a, a… you know, a- an extremely life-threatening condition that just can happen without warning. Obviously, we… I guess we, we go through from the pa- time the patient starts in hospital, we ask them, "Do you have any allergies?" And then they get asked, "Do you have any allergies?" probably about a hundred more times. Uh, even before theatre we do that, and it, it really is to try and negate, uh, the potential for giving a patient something that they're allergic to and causing an anaphylactic reaction. The best thing that we can do is be very well trained, know those cognitive aids inside, outside, and upside down, do anaphylactic CME once a year. And I find that those cognitive aids are, are really, really helpful. So not only anaphylaxis, but the malignant hyperthermia are the cognitive aids. The good old ALS, so shockable and non-shockable pathways are very, very important because if you're the team leader in those scenarios, you've got about a thousand things coming into your brain at once, and cog- cognitively offloading some of those things that you should never forget is very, very helpful.

Dr Gavin Nimon: 55:07

What about the malignant hyperpyrexic patient or the family history of that? Is that common?

Dr Nick Harrington: 55:11

It's not that common. There are clusters of families who, who do have that. We really advocate testing for any re… for relatives of malignant hyperthermia. And cognitive aid for that is really, really good. Especially, I really like the one by the AAGBI, which breaks it down into recognition. What you should do is your immediate management, which is dantrolene, further management, and then follow-up. I've never seen a case myself, but we all as anaesthetists train for it, and we do workshops on it. And I guess if you do identify a malignant hyperthermia patient, then i-- uh, avoiding all of the triggers, which is suxamethonium and the volatiles. So we prepare the theatre to not have any of those things in it, and we also prepare the machine to make sure it doesn't have any of the volatiles left in it. So we preempt and prevent.

Dr Gavin Nimon: 56:09

Brilliant. Once a respiratory patient's asleep-

Dr Nick Harrington: 56:12

Mm.- Dr Gavin Nimon: what's lung Yeah. Uh, I, I said it a little bit before. It's the, it's the lower tidal volumes. Perhaps we increase the, the respiratory rate a little bit, which means, you know, twelve to fourteen respiratory resps per minute. Really try and minimise the plateau pressures, the driving pressures that we're giving to the patient, adding PEEP. If they have an obstructive picture, what I tend to do is lower the respiratory rate a-and also increase the inspiratory-expiratory ratio. So for example, instead of inspiratory time being one and the expiratory time being two, I would increase the expiratory time to be, say, one is to three or one is to four, just to give them a chance to breathe out. Because with the obstructive picture, that is the pathology, is that they're having difficulty expiring the oxygen, uh, and we try and avoid breath stacking. So… And I can sort of c-- I can tell the obstructive patient when I look at our CO2 monitor just to see how that CO2 is going out. Uh, normally in a normal healthy patient, the CO2 trace looks like a square. Um, but w- for an obstructive patient it might look more like a shark fin.

Dr Gavin Nimon: 57:27

Yeah.

Dr Nick Harrington: 57:27

And so I increase that expiratory time and so that the shark fin gets to the top of the fin.

Dr Gavin Nimon: 57:33

And you've talked about the difficulty with extubation when we're talking about the smoking patients. Are there any other aspects that you wanna mention about that? Because I can believe it can actually be worse than actually putting the patient to sleep.

Dr Nick Harrington: 57:43

Yeah. Uh, they're the ones where I, I say to the surgeon, "Please hang around for a bit until the tube is fully out," and even after that ensure that I've got at least one anaesthetic nurse, maybe two. It's helpful in a teaching hospital that you have a, a registrar with you. And you've almost got to put them back into the same position that they were f- on induction so that they… we maximise their functional residual capacity, uh, which is their oxygen store. We… If… So sitting up surgery for the obese patient, it just gets that abdo- those abdominal contents away and down. Uh, and even the, you know, if they've got breast tissue, just getting that down and away so you're not completely supine. Uh, I find that I'm awakening patients with high flow again as a measure. I also, extubation wise I tend to downgrade the patient. So I go from a tube to an oropharyngeal airway to their own airway with a mask on, and I'm giving some positive pressure to them being able to breathe for themselves. And if I find that they are winning with all those step-down approaches, then I say, yes, this patient's ready for recovery.

Dr Gavin Nimon: 59:03

Well, when they leave the theatre, your job doesn't end there. I believe postoperative analgesia is also important, and often the anaesthetist will write up a little medication for that.

Dr Nick Harrington: 59:12

Mm.

Dr Gavin Nimon: 59:13

How do you balance the, the type of analgesia you use versus the, their condition?

Dr Nick Harrington: 59:17

And that's where the, the regional anaesthesia has transformed us, and also the spinal anaesthetics have, have really helped. If you can get a patient out to recovery who's in not too much pain, that you're already winning. What I try to do is we have protocols, so pain protocols out in recovery. And so that-- I guess that's the first line is the fentanyl pain protocols. I try and maximise the non-opioid medication, so I make sure that they've had Panadol. I make sure that if their kidneys and their gastrointestinal linings are okay, that, um, that they've had some nonsteroidal anti-inflammatory. Things like tramadol, which is a weak mu opioid, I try to give that as well. And, uh, and then judicious doses of the short-acting opioids like fentanyl or oxycodone I tend to give in recovery. And especially if I'm doing orthopaedics, hopefully they've at least had either had a nerve block from me or local anaesthetic from the surgeon or LIA so that, you know, it's all part of a balanced anaesthetic. And, and yeah, we're really trying to minimise those opioids, which can cause respiratory des-depression, can cause sedation, ca-can cause CO2 buildup, can cause pe-perioperative respiratory complications, desaturations, slow the patient down from getting out of hospital, which are, are all things I'm trying to avoid.

Dr Gavin Nimon: 1:00:50

And what about the role of a postoperative respiratory physiotherapy?

Dr Nick Harrington: 1:00:53

I try and identify either before or during the anaesthetic or even after the anaesthetic respiratory physio. Uh, with, again, with orthopaedics, the, the patients get the benefit of early physiotherapy to try and get them up and mobilising as soon as we can. And sometimes I, I advocate for the physio to do their chest as well because, you know, if they're smokers and they've got reduced mucociliary clearance, they've got mucus everywhere, then we, we wanna try and expectorate all that. So chest physio is good, getting them to breathe. The tri-f- the little balls that go up, getting them to do that as well is good. We're guarding against atelectasis, which is collapse of those lower airways, 'cause sometimes people don't breathe very well after the operation. Oh, that leads me to another discussion, which is I ensure that we have reversed all our neuromuscular blocking drugs before going out to recovery because Yeah, research has shown that, you know, patients that ha-have residual, uh, neuromuscular block are more likely to have postoperative pulmonary complications, pneumonias, aspirations, further time in hospital, needing to go to ICU, things like that. But yeah, chest physio when it's needed can be amazingly good.

Dr Gavin Nimon: 1:02:13

Well, if you could think about three main messages to take home from this episode, and we've discussed so much. Yeah. Uh, what would be the three key points you'd want to pass on to a junior doctor or medical student- Yeah … when they're seeing a patient that's got respiratory issues and coming to anaesthesia?

Dr Nick Harrington: 1:02:29

I think my message would be we, as med students, when were you a med student, Gavin?

Dr Gavin Nimon: 1:02:34

A long time ago nine-nineteen eighties. Yeah. Dr Nick Harrington: There's a reason that history and physical exam, and it's-- and, you know, at the time you think, "Oh, this is boring." It's so important, and we learnt from a book called Talley and O'Connor, and doing a p-- a good history physical exam on patients, uh, is, is so beneficial. It helps your colleagues like me, the anaesthetist, and Gavin, the orthopod, identifying early. So like that malignant hyperthermia cognitive aid, the recognition, immediate management, further management, and follow-up. A recognition of patients that are gonna cause trouble, uh, during an operation is really, really important. And if you've got time as a GP to try and optimise them, get them seen by the right people, that can make all the difference. It can make the difference that they have a, a smooth perioperative journey and, and an excellent rehab. So identifying them early, getting them seen by the correct people or doing it yourself, like starting them on some bronchodilators, preventers, antibiotics, really, really important. Chest physio, getting them to exercise before an operation is really important. Just, you know, even walking, deep breathing exercises, really important. So yeah, phys-- history, physical exam, and appropriate investigations, please, I highlight that. Other take home messages is also identifying, uh, the difficult airway patient is important for us. And come and join us in theatre. See what anaesthetists do, pick our brains, ask us lots of questions, and you might even find that anaesthesia is for you. And, you know, hopefully every anaesthetist that you see in theatre will encourage you and explain how to try and do anaesthetics as a career and, and the training pathway and things to do to get on the training program. And one day you might even end up seeing me because I'm a primary examiner. So you might even get the opportunity to sit over the other side of a table from me while I ask you gentle questions about respiratory physiology. Yeah. Certainly a good encouragement and a good endpoint for our talk today about e-e-excitement of doing anaesthesia. I understand it's actually, uh, so many different areas of anaesthesia to go into. It's a wide and broad spectrum, and there's so many different areas that people will enjoy doing it. So it's great to hear what it involves. I really love hearing what my colleagues do and learning more about it. So look, thank you very much for coming on Aussie Med Ed today, Nick. It's been fantastic to have you on board, and I really appreciate the words of wisdom.

Dr Nick Harrington: 1:05:10

Thank you, Gavin, and I'll see you in theatre soon.

Dr Gavin Nimon: 1:05:13

Thanks again for listening to the podcast and please subscribe to the podcast for the next episode. Until then, please stay safe.