Asthma- current approach to treatment

Do you realise that asthma is still responsible for one death a day in Australia? It's a condition which we don't hear as much about in the media, but still very important. Today, we're going to discuss asthma. G'day and welcome to Aussie Med Ed, the Australian Medical Education Podcast.

a program born during COVID times to emulate that general chit-chat and banter around the hospital with the idea of educating the medical student and GP alike. I'm Gavin Nyman, an orthopaedic surgeon based in Adelaide, and it's my pleasure to bring Aussie MedEd to you.

And in this series, we've taken a different approach where we ask consultants specialising in their area to address a particular problem and answer the questions on how they would both assess and treat that condition from a medical student or general practitioner's perspective.

Once again, welcome to Aussie Med Ed and I hope you enjoy the podcast. I'd like to start by acknowledging the traditional owners of the land on which this podcast has been produced and pay my respects to the elders both past and present.

G'day and welcome to Aussie Med Ed. Today we're going to discuss asthma and I'm lucky enough to be joined by Dr Jonathan Polachek, Head Respiratory Physician at the Quindersville Hospital, who's going to discuss this condition and how it's changed over the years since I learned about it at medical school.

Asthma remains a very important condition and still responsible for death each day in Australia. He's going to discuss how the new treatments actually reduce the amount of our presentations to the emergency department. Welcome Dr Jonathan Polacek. Look, Gavin, thank you very much. Asthma is a disease which is slowly disappearing. But yes, you are absolutely correct. It does cause deaths, much less than it used to do, although I don't have the statistics in front of me.

because we've got much better at treating it over the last 20, 30 years. It still accounts for about 10% of the population, and girls, women tend to be a little bit more than blokes, and obviously it increases as you get older.

And there's different sort of presentations of it. And we probably think that asthma is a wide range of phenotypes and different asthmas respond to different treatments. However, essentially speaking, the... introduction of inhaled steroids back in the 1980s made a huge difference to the treatment of asthma and more recently in the last two to three years the introduction of biologics.

has really changed the face of asthma or should or will change the face of asthma into the future such that it is probably going to be a disease with very little impact.

It depends on whether you take your medications and I think all the listeners should be aware that one of the reasons that asthma is not well controlled is non-compliant. We have very, very effective treatments for asthma and asthma... treatments are now longer acting and should invoke less non-compliance from people but it still does and the typical case of mortality from asthma.

is the overuse of short-acting beta agonists, such as puffing on your Ventolin 300 times a day, and often in younger people, and then having a catastrophic asthma attack and not being salvageable from that.

So what's the actual underlying cause? Is it all an allergic reaction or some other cause? There's a number of phenotypes. Well, look, I'm not a researcher and I'm going to be able to delve into that in too much detail. But essentially there is indeed allergic asthma. And then there is a whole lot of asthma-type syndromes related to T-cell abnormalities, eosinophils. So we think that, as I said, there are probably a number of different phenotypes of asthma.

Probably in the future, as medicine gets more sophisticated, we're going to be able to work out what those phenotypes and indeed on the genotype is with targeted therapies. which are going to be the way of the future and some of the listeners here will be going into a world when they finish up of targeted therapies and the different phenotypes will be treated in different ways.

and the sort of blunderbuss manner in which we treat a lot of things. Don't worry, Gavin, you'll be all right with the orthopedics, though. That'll remain unchanged. But a lot of medicine is going to be focused particularly on targeted therapies for people. So would the classification be based on those phenotypes, or is there different other types of... So, yeah, look, there's going to be... Look, I don't know. But, I mean, broadly speaking...

We split it up into things like early onset asthma, late onset adult asthma. Yes, there is atopic asthma. And in our current clinical way of... of classifying things, we tend to put them into these broad categories, and we're not anywhere near the stages of being able to be a bit more specific, which is sort of largely true, but...

What is becoming more, the first step of the path to targeted therapies is now the looking at IgE and eosinophils with the idea of trying to reduce both of those with biological agents. which is, as I said, a first step on the way to a more complex targeted therapy. So how would you start off investigating a child or a young adult who you think has got asthma? Well, I suppose you take it on the type of person.

So if you've got somebody with the typical symptoms of cough and wheeze and perhaps some sputum and the type of story where they are getting sick with a vile infection and then...

being short of breath and wheezy for some times after, or in fact wheezy for most of the time, then in somebody who's young, you'd have to be fairly suspicious of asthma. It gets a bit more... difficult if you've got an adult and particularly an aged adult who may have some underlying cardiac disease because you can indeed get cardiac asthma which is a misnomer.

And our listeners should be well aware that what we're really talking about pulmonary edema, that disguises itself in asthma with a cough and a wheeze. And in fact, they're getting pulmonary edema. So the base level for treating asthma. these days, the introductory way of investigating asthma is obviously demonstrating that there is an improvement in the amount of air.

that is being expelled in one second from pulmonary function tests. And this is the measure called the FEV1. And essentially, we get people to blow out as hard as they can for as long as they can, and then we standardize. a large number of normal people so we've got an idea of what is normal and in this particular laboratory the Queen Elizabeth not only have we done that but now we have a lot of standardized numbers

which are taken from the different races. For instance, Asians tend to have less pulmonary indices than the Westerners, and so that is now adjusted for some racial origins.

And what we're looking for is a 12% improvement in the ability to blow that air out because asthma is an obstructive disease. And we are looking at an improvement of 12% or... greater and which also has to be greater than 200 mils and that is diagnostic essentially of asthma and by giving somebody some salbutamol some short-acting bronchodilator and we get a

an improvement of that, then we would classify that as asthmatic. So from my memory from doing respiratory function tests when I was in RMO, I believe you had a volume, a capacity you had to expel and also the speed at which it came out and also the shape of the...

graph that was produced, are they still the three main figures? Look, absolutely correct. For an orthopod, you're very well informed, Gavin. So, exactly. So what we're looking is a percentage improvement in the amount of air that comes out in one second.

as well as an absolute improvement of greater than 200 mils. And the shape of the curve is important in giving a bit of an idea, but we don't quantify it. And if the curve is scalloped in shape, then that's... suggests a degree of obstruction because the pathophysiology, of course, of asthma is that you get narrowing of the larger airways because you get irritability of the muscles because there's...

underlying airway inflammation. And by treating that and relaxing that muscle, you improve the obstruction and people can blow out better. It has to be remembered that asthma really is an... inflammatory disease and this of course is where the different phenotypes of what actually drives that inflammation is going to be more important. It's always been important but better understood over time.

that inflammation irritates the muscle of the airways, which makes them hyperreactive. And it's almost like, so for instance, if you've got a bit of low-level inflammation, sometimes I tell people who have... an acute viral infection and then get asthma after that it's almost like hitting your thumb with a hammer the virus which is the hammer is long gone but the thumb is still sore and inflamed

And when you knock it against the side of the doorframe accidentally, then it hurts like hell. And so asthma tends to behave in that type of manner. So sometimes the inflammation can be extremely low and people don't have any symptoms. But then something sets it off and there's a low-level inflammation that occurs. And then, for instance, after your viral infection, you breathe a whole lot of smoke, which you might not be normally reactive to.

And like hitting your thumb against the side of a jaw door jam, it creates the discomfort. And in this case, it's going to be sort of spasm of the muscles of the airways.

I'd like to let you know that Aussie MedEd is supported by HealthShare. HealthShare is a digital health company that provides solutions for patients, GPs and specialists across Australia. Two of HealthShare's core products are Better Consult, a pre-consultation questionnaire that allows GPs to know a patient's agenda before the consult begins, with the aim to reduce admin and free up time during a consult, and HealthShare's specialist referral directory.

a specialist and allied health directory integrated into GP practice management software, helping GPs find the right specialist. Excellent. So the diagnosis is based upon the history, the symptoms of wheeze or cough or a bit of production of sputum after perhaps a cold or after exercise.

or in the cold weather, then they're investigated with respiratory function tests. Are there any blood tests you may do as well? You mentioned testing for IgE and things. Are they part of the routine tests? So at the moment, the main... So what you're trying to do... is you're trying to reduce that long-term inflammation. And the long-term inflammation for the first part of that is causing that acute reaction if it gets irritated further.

and causing that bronchospasm. The second part of this problem is that over a long term, and you have inflammation that is continuing to... brew along in the airways is you get the formation of scar tissue and it's called remodeling of the airways and over an extended period of time that means that reconstructs or remodels the airways so that you get

chronic, irreversible obstruction. So it doesn't happen with everybody, but there is a risk and that to then chronic obstructive airways disease. So that's one of the things that we want to try and avoid. So we have...

two main ways of treating that inflammation. And the one that is most well known is obviously the preventer inhalers. So the Ventolin that we just talked about is an acute... adrenaline-like inhaler, and of course adrenaline was used in the old days in asthma, but salbutamol is a selective adrenaline-like inhaler, a beta agonist, and it basically affects the...

smooth muscle and dilates the smooth muscle, relaxes the smooth muscle, dilates the airway, should I say. The better option is to try and reduce the inflammation in the airways and obviously prevent irritable muscle that will cause asthma or... a long-term remodeling of the airways. And the way it was done in the old days was giving people prednisolone or another type of steroid. And this would be fine for the airways and improve the airways terrifically.

Steroids, long term, are a very nasty drug for the body. And apart from osteoporosis and cataracts and diabetes, they're in fact extremely toxic. So at some point in the 70s and 80s, people worked out or probably before.

for that how to deliver that directly topically to the airway we deliver steroids topically to the skin so at some point someone said okay well let's put this in the inhaler and see if we can dump it directly onto the airways and ever since then there's been an arms race between the drug companies to see who can produce the better inhaler that would deposit the most steroid directly into the airways, particle styles, etc.

So the mainstay since the 1980s, and if you ask some of my older consultants, they will say that the whole world changed for asthma in the 1980s. And the respiratory physicians before that would all have their spirometers. And they'd be measuring people with their asthma on a semi-daily basis or every time they saw them. And we don't do that now because we simply don't have any great need to continue to look at the FEV1 from day to day.

So the entity of inhaler has made a huge difference to asthma and has been the mainstay that we've had for many years now. The newer agents are targeted at Omolumazab.

What's the other one? No, it's gone out of my head. But these antibodies or monoclonal antibodies are now designed to bind various receptors and or to try, in the case of IgE... to try and reduce the IgE level, and the bendrolizumab is designed to bind to the eosinophils and reduce the eosinophil count, and that has had immense change.

the lives of people who have asthma that has been very hard to control. And somewhat in the early days of treating that, but people who have very difficult and very brittle asthma, it can have an extraordinary improvement in there. So these biologics are designed to try and reduce the mast cell response that occurs in asthma, and therefore this mast cell releases the toxins that damage... Yes. Look, I forget the exact mechanism now, I'm afraid.

But it is designed to reduce the inflammatory responses related to IgEs and in the case of Malumazab, the inosinophil in the way of the other two. So how often would someone present with an acute asthma attack to a hospital nowadays compared to previously? Well, I think that probably a young person is unlikely to, really. I mean, she will have the odd person that will turn up. You know, it's rare nowadays. What we see most of is a complex mix of, as you quite...

rightly identified cardiac, smoking-related lung disease or chronic obstructive airways disease with probably some asthma thrown in on top. So it's not that common anymore. And the other things that we try and do, obviously, if there are some other causes that are worth considering, so for instance, reflux and getting acid down the wrong way will worsen or can certainly...

present like asthma but can also exacerbate asthma. If you've got very bad sinus disease then the mucosa is sort of continuous all the way up and down and that can certainly make asthma worse if it's uncontrolled. And things like desynthesization aren't really proven to be effective in asthma, but obviously they are useful in allergic rhinitis. And if you have bad allergic rhinitis, then perhaps getting them desensitized would be a good.

thing to try. Although desensitisation is often only really useful if you've got one or two things that you can specifically desensitise to. You mentioned the asthma associated with smoking. The COAD or the obstructive airways disease you get with smoking can be restrictive or obstructive, I believe. I presume the asthma is just a small, minor exacerbation of that chronic disease that's caused by a secondary inhaled factor.

But there's almost a tendency for the smoker, the chronic smoker, to call it asthma when really they've got what would in the olden days be called emphysema. Yeah, so we're slightly getting away from asthma here. So chronic obstructive airways disease will be... an irreversible obstruction, whereas asthma is by definition a reversible obstruction. And it can have some asthma as a superimposed problem, or it can be related to asthma in the first place.

is actually quite different. With the obstruction, look, it's difficult to know because obviously they are short of breath and have chronic sputum reduction, etc. Emphysema is... what happens when you destroy the small airways and the alveolar sacs because the lung trying to remove essentially the products of smoking starts attacking itself.

essentially, and causes those areas to be destroyed. And you generally see that with smoking, but you will then see a reduction in the ability to get oxygen in from the outside world. and CO2 out. And that's what we can then measure on some of the full pulmonary function tests that you were indicating a little earlier. So we can do lung volumes and we can also do gas transfer. If you have something that's

obstructed over a long period of time, you will get trapping behind that obstruction. So if you have a very bad asthma over a long period of time and the air doesn't get out and you overstretch... these airways and damage these small airways and the sacs you will get a lot of extra volume an extra residual volume in those lungs which becomes then hard to do physical activity

particularly if you have something called gas trapping. But I think we're getting a little bit away from the basis there, Gavin. So asthma can lead to some... COAD conditions with the chronic obstruction and chronic smoking can have some asthma mild flare-ups associated with it.

And what about the acute attack? What's the mainstay of treatment if you get someone comes in who's non-responsive to a puffer? Sure. The acute attack of asthma can be very, very frightening.

The intensive care management of very severe asthma can be very, very frightening. Now I'm talking for the doctor as much as for the patient because they can be very unstable. I think the first thing that the listeners should realize... is if they have a young person who is really having trouble breathing, they need to be aware that they are compensating very, very hard and there is always a risk of becoming tired.

do a blood gas on somebody who is young and their CO2 is beginning to go up and their O2 is beginning to come down, then you really need to be very worried and have somebody who can intubate somebody fairly quickly. It's rare, but it does happen. And the last thing, the classic one, is some young person who is very short of breath and who is really struggling and hyper-expanded. So you can see them at the end of the bed. They're sweaty.

They're sort of breathing at the top of their range. Their lungs are very hyperexpanded and they can't get that breath in. You have to be very, very worried. What they will eventually do is they will simply stop breathing on you and then... all hell breaks loose. When all hell breaks loose, you do not want to have sent them around to radiology for a chest x-ray. You want to keep them in the department where you can see them. So...

The treatment has generally been lots and lots of Ventolin and getting them to breathe lots and lots of Ventolin in. You get some IV hydrocortisone into them and you could try, I mean, we don't do it.

But in the past, we would have tried even a little bit of adrenaline to try and improve things. And perhaps they still do that in emergency. I haven't really had to deal with that for quite some time. Other treatments in the intensive care setting would be infused magnesium and putting them onto a...

Boyle's machine, although I don't think anybody does that nowadays, which was the idea of giving them an anaesthetic through the airways to try and relax the airways. But sometimes you simply can't ventilate these people if they are that bad. everybody should realize that a very sick asthmatic, particularly a young, well, any very sick person is a problem, but a very sick, young asthmatic, you want to be very, very careful.

And they shouldn't be going to a general ward. You should have them in a high dependency or in an ICU ward where they can be well seen. However, if we get back well before that level of management, where all I can suggest is caution. The general emergency plan that we give people is aimed at reducing an exacerbation, which we assume is increasing airway inflammation, and it might be viral and it might be bacterial.

So the standard way we educate our patients is to have a written emergency plan where they will, for instance, have their preventer, let's just say serotide in this case. exactly how much and then at the next level if they're getting a bit wheezy they will have a bit of ventolin on their emergency plan and then if they're really getting sick and wheezy and coughing and sputum then we'll give them a reducing course of

prednisolone plus an antibiotic. And in that type of plan, in an effort to ward off serious decompensation, and if a patient is intelligent enough to then follow it, it can be extremely successful. and can avoid any acute presentation. However, there will always be very brittle asthma out there and there will always be people who actually were non-compliant and they're the ones obviously to be worried about.

Now with those emergency scenarios, which are obviously very rare, the other drug that came to mind when I was thinking about asthma was theophylline. Theophylline's sort of gone a bit out of favour because you don't want to fill up a whole, you know, somebody who is older.

with underlying cardiac disease with theophyllum. But I think, you know, if you were struggling with somebody and you were trying not to have them intubated, then you could try a theophyllum infusion. I think it's gone very much out of it. I think that's back from... In my days, I was down in emergency, Gavin. I haven't seen anybody using that for a long time.

Okay, yeah, just the depth of my knowledge there, so obviously well out of touch. It sounds like the research has come on a fair bit over the years with the way it's attacked now and the actual control of it, and it sounds like it's great to hear that the numbers are coming down. significantly. Has it been flared up by the COVID scenario? Has that made a big difference at all to asthma? I mean, we've had a very relaxed COVID experience in comparison to other countries like the Italians.

2000. So, I mean, asthma is obviously going to be an ear and ear very inflammation and COVID is going to make that worse. And, you know, if you end up by having an asthma attack. or you are severely ill with COVID, then there are antivirals that are now available to treat that. And if you were a brittle asthmatic, then you'd want to get vaccinated and be ready to go to a COVID care centre.

to be treated if needed. But I think the latter variants of COVID have had less of an ARDS, adult respiratory distress syndrome, that was... most of the rest of the world in the earlier phases of COVID. So I think basically you treat asthma with COVID like asthma with any other viral infection.

And finally, the last time asthma made the news was with the thunderstorm cases they had, particularly in Victoria. Is that a big thing, and how does that actually cause asthma? I must say, in my time here, we haven't had... significant thunderstorm asthma. As I understand it, what you're seeing with thunderstorm asthma in quite rural communities where there's lots of grains and pollens and in an appropriate environment where thunderstorms can...

before the rain, large numbers of pollens and put them into the clouds where they get wet and then burst into spores and then come back down with the winds before the thunderstorm. And I think that's... obviously causing a lot of allergens out there, which ends up by being inhaled and causing thunderstorm asthma, really. So I think under those circumstances, people just have to be aware that thunderstorms are coming.

on the Bureau of Meteorology and treat themselves with meteor agonists as needed and or call emergencies if they really are struggling.

And do you think asthma will end up being like a, you've probably implied it probably is actually, a genetic type condition? Some families are more prone to it than others? Look, it's hard to know, isn't it? I mean, there's obviously going to be genetic... predispositions to a certain type of phenotype and then there might be something that you've been exposed to for whatever it does to the immune cascade.

or in the environment that you happen to be living in has mould or something that exacerbates it. I think it's always going to be a sort of combination of those type of things and we will have... probably different types of inflammatory pathways that eventually trigger a similar type of response, which we call asthma, but there'll be a wide range of paths to get to that. And I'm assuming that...

Over time, we will delineate it. And I think there's enormous change in how we treat a huge number of medical conditions with these monoclonal antibodies.

sort of changing the way we're going to do medicine. The other thing that's going to change the way we do medicine, and I can't talk to you about the research, and that is the RNA has been pioneered with the COVID vaccine as a way of delivering different... therapeutic options to cells and I can only see this type of thing accelerate not slowing down and I think we're going to be seeing in 50 years time very different medicine than what we've ever seen.

Yeah, like any war, there's always advances in medicine, and this has been a war on a virus, so the mRNA vaccines are going to be brilliant, aren't they? Yeah, well, I think this is all going to accelerate. I think, you know, you're going to be... Medicine for you and me, Matt, is going to be quite unrecognizable. So there's always going to be broken bones, Gavin, so you'll be right.

Look, it's fantastic having you on Aussie Med Ed and taking your time to speak to us about asthma and learn a bit more about it. I actually didn't realise the numbers had come down so much, so it's great to hear about it because obviously what brought it to my attention was watching a few old movies and thinking of some actors or actors.

who had passed away from asthma and made me think of it. So it's good to hear that it's getting better, better controlled. We certainly see much, much less. Respiratory outpatients, you know, 20 years ago was all asthma, badly controlled asthma. with limited ability to treat it. Excellent. Well, thank you very much again for coming on Aussie Media. It's great to have your time. And once again, thank you very much. Jonathan Polacek.

Thank you very much, mate. I'd like to thank you very much for listening to our podcast. I'd like to remind you that the information provided today is just for general medical advice and does not pertain to one particular medical condition or one way of treating a particular condition.

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