Episode 83: Bronchiectasis – The Overlooked Airway Disease

Hello and welcome back to Med4Day FMC. The podcast, where we simplify complex medical concepts for our listeners. I am your host for the day, Major Hari Krishnan Pee. And in today's episode, we are diving into an often overlooked, yet clinically very significant condition, bronchiectasis. While it may not always be at the forefront of a physician's differential diagnosis, it has profound implication for patient morbidity and management. Joining us today is surgeon left hand commander Srinath, a pulmonologist of highest repute. He works for the Indian Navy. He will help us navigate through the nuances of bronchiectasis from its pathophysiology to diagnosis and management. Together, we will explore why this condition remains underdiagnosed, how to suspect it in clinical practice and the best strategies for optimizing patient care. So, welcome back Srinath. Welcome back to the show again. Thanks Hari. It's good to be back and to talk about one of a very underdiagnosed entity. So, then let's get started. To begin with, could you define this entity of bronchiectasis for our listeners? What exactly does this term encompass? Bronchiectasis is a disease of the airways wherein there is an abnormal, irreversible dilation and thickening of the bronchial walls. So, it's like a end stage of variety of pathological processes that cause destruction of the bronchial wall and its surrounding supportive tissue. Well, then actually, while you are speaking dilatation of the airways, M5CMA also is defined as the dilatation of the airway. Could you differentiate the two for me? M5CMA is a parenchymal disease while bronchiectasis is an airway disease. M5CMA, there is a destruction of the allulah walls. So, there is allulah wall destruction and it is a mostly parenchymal disease, where there is a destruction of allulah wall while bronchiectasis is an airway disease. Where the airway is affected, it gets destroyed and dilated. Alright. So, now moving ahead, what is underlying pathophysiology of bronchiectasis? Could you elaborate on the mechanism leading to airway destruction that you just mentioned? Well, the most widely accepted hypothesis is a cold's vicious cycle hypothesis wherein there is an initial insult to the airway. This initial insult results in a neutrophilic inflammation and this inflammation leads to airway destruction and distortion, which is bronchiectasis. So, once this airway destruction and distortion has set in, there is the mucociliary escalator, the cilia get destroyed leading to impaired mucous clearance. So, whenever there is an impaired mucous clearance in the region of the airway, mucous tend to accumulate in this region, which leads to subsequent bacterial colonization, which leads to a neutrophilic inflammation and further destruction of the airway. So, this cycle, which is called cold's vicious cycle continues. Another pathology is traction bronchiectasis wherein there is a paranchymal and industrial disease, which leads to fibrosis, which causes a dilation of airway by the traction it applies. Right. So, you mentioned that bronchiectasis is the end stage of various pathological process affecting this airway. So, could you walk us through the key condition that can lead to bronchiectasis? There is a wide spectrum of inciting pathology, which if uncontrolled leads to bronchiectasis. In a broad term, any pathology which cause severe airway inflammation or recurrent airway infections or severe airway inflammation can lead to bronchiectasis. So, any disease pathology whether there is a severe airway infection or recurrent airway infection or severe airway inflammation can lead to bronchiectasis. So, these can be in the form of infections like TB, pneumonia, NTM's, obstructions due to a tumor or a form body, impaired mucociliary clearance, as in cystic fibrosis, ciliary dyskinesia, immune divisions is like HIV, A gamma global limeas, excessive immune response like an ABP or a lung transplant rejection. It can be just inflammatory pneumonia, it is like aspiration, toxic form, fumes exposure, ILDs and congenital structure where all these can lead to bronchiectasis. Right. So, then with such a huge list and as we started off by saying that it is a very underdiagnosed entity. So, that means all of us clinicians should have a high index of suspicion about this condition. So, are there any specific red flags or characteristic symptoms of bronchiectasis that should be prompt us to further investigate the patients and think in lines of bronchiectasis? Definitely we should have a high index of suspicion in case of bronchiectasis, it is very much prevalent though under-recognized. Any physician should suspect bronchiectasis when patients present to them with chronic productive of more than 8 weeks duration. There will be persistent production of muco purulent or purulent expectorations, there can be a episodic haemoptysis, there can be history of recurrent chest infections or a poorly controlled airway disease like a poorly controlled asthma, poorly controlled COPD. So, whenever patient has these all symptoms we should suspect bronchiectasis and on examination these patient can have clubbing, there can be coarse crackles on auscultation which does not clear on cuff. Right. So, then moving ahead once a clinician actually has the suspicion of bronchiectasis, how can he confirm the diagnosis? So, what I mean to ask is what role does imaging play and what specific findings should one be looking for? Imaging is a cornerstone for diagnosis, we always need image findings to diagnose bronchiectasis. Whenever we clinically suspect bronchiectasis the first thing we do is a chest x-ray, but chest x-ray is not a very sensitive modality for diagnosis. Dilator and thickened airway can be seen as fan tracks sometimes, there can be mucus plugging in case of conditions like ABPA which can give a finger and glove appearance. The HRCT is a main modality of choice to establish diagnosis of bronchiectasis. Whenever there is one of these three features we can diagnose bronchiectasis which is bronchial and artery ratio of more than one, lack of tapering of the airway when it moves towards periphery or airway visibility within 1 centimeter of the costal pleural surface or airways visible near to the mediasional pleura, in this condition it is a diagnostic of bronchiectasis. Apart from also diagnosing bronchiectasis HRCT also plays an important role in giving us clues regarding the underlying etiology which causes bronchiectasis like if there is a central bronchiectasis points more towards ABPA or structural lung diseases, upper airway it is mostly TB, cystic fibrosis, sarcoidosis, middle lobe mostly NTM's, lower lobe, ciliary dyskinesias, aspirations, CTD related and alpha on antidepressant lotions. Right, so moving ahead to Srinath see, given the nature of chronic, the chronic nature of bronchiectasis, so when we start managing what should be the key principles in our management of such patients and how should we tailor the treatment to address both symptoms of the patient and I believe we should always attempt to shunt the disease progression in such cases. What we should remember is that in bronchiectasis and irreversible disease, once there is an airway destruction and it cannot be reversed but what we can prevent is further destruction of the airway, further exacerbations which leads to ongoing destruction. So when we clinically suspect bronchiectasis, we need a CT to confirm diagnosis of bronchiectasis and once the diagnosis is established, first we should look is, is there an ongoing pathology, ongoing pathology which can lead to progress of this airway disease. So as per guidelines, any freshly diagnosed case of bronchiectasis should be screened for ABPA, CTDs, primary ciliary dyskinesias, alpha on antidepressant deficiency, cystic fibrosis and immunodeficiencies. So as per the clinical setting, ideally patients should be screened but based on the physician description, they should be screened at least for ABPA connected tissue disorders and based on imaging modality, if they have a high clinical suspicion, they should be screened for alpha on antidepressant deficiency and ciliary dyskinesias. So once that is established, we have a subwise management of bronchiectasis as laid by the BTS guidelines. Then step one is to treat the underlying cause, of course we should look for any ongoing pathology which leads to bronchiectasis, any airway infections which is their active infection is there, has to be treated and airway clearance techniques forms a major part of the step one therapy. They should be sent to a physiotherapist for secretion clearance excise pulmonary rehabilitations. The patient should be vaccinated and in case they have any exacerbation, it should be promptly treated. So if in this step one, the patient has three or more exacerbations a year, then we progress to step two wherein we intensify the physiotherapy effort and we add a mucolytics like an acetyl cysteine and despite the step two, that is adding a mucolytic intensifying the physiotherapy. Patient has three or more exacerbations in a year. We go to step three wherein we work the patient up for airway colonization. So bronchiectasis patients are at risk of airway colonization. These organisms can form a biofilm in the airway making them much resistant to antibiotic therapy. So all these patients in step three should be screened for at least three airway colonizers. One is pseudomonas, second is aspergillus and third is endium. So they should be screened for these three colonizers and if found, it should be eradicated and despite eradication therapy and intensified physiotherapy mucolytic agents is a patient still has three or more exacerbation a year. We progress to step four where we can add a long-term acolyte and despite this, if the patient has five or more exacerbations, we can go to intravenous antibiotic therapy every two to three months. Well I believe the treatment part is a little tricky for us general physicians and you happen to mention that this is a condition which is often overlooked and mismanaged by general physicians. So what are some common pitfalls that you have observed in its diagnosis and treatment? What I have observed is first is bronchiectasis is often underdiagnosed. When a patient presents with cough and chronic sputum production, the most common diagnosis which is made is COPD. They go for a primary chest x-ray, x-ray often comes out normal if there is no much significant bronchiectasis. So it is under diagnosed in that way. This leads to an ongoing airway destruction and by the time someone goes for a CT, a significant part of lung is destroyed. And second thing which I have noticed is there is a tendency in India to label bronchiectasis as mostly post-TV sequelae, even if the patient does not give out a history of TB. So this leads to underdiagnosed of conditions like NTM, ABPA, primary ciliary dyskinesias which leads to ongoing airway destructions. So physicians should always remember that if the patient does not give a history of TB or if there is a bilateral bronchiectasis or bronchiectasis with prominent lower or middle low involvement, they should be screened for pathologies other than TB, apart from TB or about TB. Thirdly is people are not routinely worked up for airway colonization. These bronchiectasis patients are at risk of airway colonization. So if we are not working them up for airway colonization, there can be a persistent airway infection, neutrophilic inflammation leading to progression of this bronchiectasis wherein starting from a small part of a lobe, it progresses to an entire lobe. So all these patients should be screened for at least seromonas, aspergillus and NTM. Fourth is lack of knowledge regarding secretion clearance exercise and chest physiotherapy. Most of the physicians consider bronchial dilators as the treatment of choice for bronchiectasis, wherein in reality there is no much evidence regarding the use of bronchial dilators in bronchiectasis. The cornerstone of treatment is secretion clearance exercise and pulmonary rehabilitation. So all patients with bronchiectasis should be reviewed by a good physiotherapy team. And fifth is the overuse of inhaled corticosteroids, which is prescribed for bronchiectasis patients. Ideally inhaled corticosteroids should be restricted to only patients with asthma bronchiectasis overlap and those who have ABPM. All other patients should not be given. Well that has really made us really wiser when it comes to management of bronchiectasis. So finally, before we take a leave, I request you to give us few take home message for our listeners regarding the identification and management of bronchiectasis that we just mentioned. Out of what we have discussed, I would like you to give a few take home message for our listeners. And my take home points will be to give a high index of suspicion for bronchiectasis in patients who presents with persistent product of recurrent lower respiratory tract infection or uncontrolled airway disease like uncontrolled asthma, uncontrolled COPD, do a CT and look for bronchiectasis. Not all bronchiectasis is post TB, even though it is the most common cause in India, but not all patients are post TB bronchiectasis. Always clean the patients for an ongoing cause which can lead to progression of this bronchiectasis. Evaluate all patients of bronchiectasis for airway colonisation and if found do eradication therapy. Approach bronchiectasis in a stepwise manner with emphasise on physio therapy, chest physiotherapy and secretion clearance. That's it from my side. A very big thank you, Srinath for sharing these insightful episode and all these details about bronchiectasis with us. And we request you to join us for further episodes with such insightful discussions. And thank you, all our listeners for tuning in. Stay connected with us on MedPod AFMC for more expert discussions on key medical topics like this. Until next time, stay informed, keep learning.