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Dr. Alberto Neder

Medical Grand Rounds: The Pearls and Pitfalls of Pulmonary Function Tests

Georgia Kersche, MSc Candidate (TMED)

On Thursday, Translational Medicine graduate students had the privilege of hearing from Dr. Neder, an esteemed clinician-scientist of respirology. Using relevant clinical scenarios, Dr. Neder explained how pulmonary function tests (PFTs) help with clinical decision making, highlighting their value and the nuance of individual physiology.
 

PFTs are a valuable clinical tool that guide the diagnosis and care of patients with a possible respiratory pathology. They provide insight into the functioning of the large and small airways and the efficiency of gas exchange in the pulmonary capillary bed (1). Spirometry is the least invasive and most frequently used PFT (1). It involves plotting lung volume over time to show the total air expelled, called the forced vital capacity (FVC), and the forced expiratory volume in the first second (FEV1) (2). The ratio of FEV1/FVC helps identify obstructive or restrictive lung defects. A low FEV1 compared to FVC indicates obstruction, suggesting COPD or asthma, and a reduced FVC indicates restrictive disorders (1,2). In many patients, spirometry allows early detection of COPD so that interventional measures like smoking cessation can be started quickly (2). Another test involving the inhalation of 0.3% carbon monoxide analyzes the diffusing capacity of the lungs, called DLco (3). DLco helps identify emphysema and pulmonary emboli by evaluating the integrity and surface area of the alveolar membrane (3). By assessing how efficiently carbon monoxide can bond hemoglobin we determine if reduced blood flow in the lung parenchyma or thickening of alveolar membranes are contributing to limited respiratory functioning (3, 4). Other tests such as exercise studies assist in identifying and ruling out other conditions (1, 4).
 

Patient context is critical when interpreting PFT. Certain conditions can mask pulmonary pathologies or suggest illness when it is not there (4). For example, severely obese individuals may show a restrictive pattern on PFTs which would resolve with weight loss, but asthma in these individuals could be missed due to the pseudo-normalization of their scores to within normal limits as a result (5). A bronchodilator can help rule out false negatives of asthma in this cohort (5). Another confounding factor is a patient’s blood volume and hemoglobin content, as the Haldane effect can cause higher dissolved CO2 when oxygen saturation is higher which explains the problem of supplemental oxygen in COPD patients (6). But this should also be taken into account in patients with anemia, on hemodialysis, or in shock due to the lower hemoglobin and chloride present to buffer CO2 in the blood (6).

 

Dr. Neder and the class discussed translating these findings into a more comprehensive PFT requisition form to prevent misinterpretation of PFTs. This would give more context to the respirologists to determine gauge normal limits and would remind other physicians of the various factors that affect the performance and results shown on a PFT. We also proposed a more streamlined PFT report that includes only the most necessary information for a treating physician such as FEV1/FVC, adjusted DLCO, and abnormal findings. Finally, recent investigations into how artificial intelligence (AI) can assist in pulmonary dysfunction diagnostics have shown promising evidence for the role of algorithms in this field (7,8). Still, there is no replacing human intuition by specialists like the presenter, but any improvement in the efficiency of diagnosing patients with these minimally invasive techniques is worth further inquiry.

 

During our discussion Dr. Neder took the time to answer each of our questions thoroughly, explaining the science while sprinkling in some of his wisdom along the way. He encouraged the maintenance of a curious mind when conducting research. He also emphasized how vital the role of a clinician-scientist is, in that both the patient-facing role and the concurrent research is necessary to ask relevant questions about patient healthcare. Further, he mentioned the importance of having good mentors throughout our careers. This linked back to our first discussion after Grand Rounds where we heard from Dr. Trier about improving medical education using a coaching mentality. It seems that Dr. Neder embodies the passion and patience Dr. Trier is aiming to cultivate in established physicians, suggesting that he would be an excellent coach for learners.
 

As many of us TMED students have limited backgrounds in respirology, Dr. Neder did an excellent job at creating an in-depth, interesting presentation about respirology’s every-day role in the hospital. I look forward to hearing from my colleagues about their thoughts on the presentation and the potential for innovations around PFTs.

 

References

  1. Ranu, H., Wilde, M., & Madden, B. (2011). Pulmonary function tests. The Ulster medical journal80(2), 84–90.
  1. Pierce R. (2005). Spirometry: an essential clinical measurement. Australian family physician34(7), 535–539.
  1. Hughes, J., & Dinh-Xuan, A. (2017). The DL NO /DL CO ratio: Physiological significance and clinical implications. Respiratory Physiology & Neurobiology241, 17-22. doi: 10.1016/j.resp.2017.01.002
  1. Culver, B., Graham, B., Coates, A., Wanger, J., Berry, C., & Clarke, P. et al. (2017). Recommendations for a Standardized Pulmonary Function Report. An Official American Thoracic Society Technical Statement. American Journal Of Respiratory And Critical Care Medicine196(11), 1463-1472. doi: 10.1164/rccm.201710-1981st
  1. Pellegrino, R. (2005). Interpretative strategies for lung function tests. European Respiratory Journal26(5), 948-968. doi: 10.1183/09031936.05.00035205
  1. Petersson, J., & Glenny, R. (2014). Gas exchange and ventilation–perfusion relationships in the lung. European Respiratory Journal44(4), 1023-1041. doi: 10.1183/09031936.00037014
  1. Topalovic, M., Laval, S., Aerts, J., Troosters, T., Decramer, M., & Janssens, W. (2017). Automated Interpretation of Pulmonary Function Tests in Adults with Respiratory Complaints. Respiration93(3), 170-178. doi: 10.1159/000454956
  1. Topalovic, M., Das, N., Burgel, P., Daenen, M., Derom, E., & Haenebalcke, C. et al. (2019). Artificial intelligence outperforms pulmonologists in the interpretation of pulmonary function tests. European Respiratory Journal53(4), 1801660. doi: 10.1183/13993003.01660-2018

 

Comments

Name
James King

Mon, 09/27/2021 - 15:14

Hi Georgia,
Thank you for an excellent summary of last week's MGR. You really have done an excellent job of making these topics more accessible and easier to understand.
I wanted to comment on one point that really stuck out to me during the talk, the connection between respiratory issues and inflammatory bowel disease (IBD). As someone whose proposed research is going to work at elucidating mechanisms of pain signalling in IBD, I was shocked to learn that there could be a connection between the two seemingly distinct areas. Dr. Neder proposed that the co-occurrence of respiratory dysfunction with IBD could be related to them originating from a common germ layer (presumably he was referring to the endoderm which forms the endothelium of the gastrointestinal tract and lungs). My original hypothesis would have been that immune dysfunction would account for the co-occurrence of these conditions, for example, an over-active immune cell could cause inflammation in both areas. I'm curious if you, or anyone else, had a different hypothesis for this phenomena? I suspect that because the etiology of IBD has yet to be fully elucidated, the reason for this phenomena is up for debate.
Thanks,
James

Name
James King

Hi James,

First, thank you Georgia for an excellent explanation of pulmonary function tests and their use in the clinic!

I was also very surprised that IBD can be associated respiratory dysfunction, and like you, would have guessed this was from gut inflammation causing more widespread inflammatory effects in the body. Dr. Neder’s hypothesis that these two diseases are associated because the gastrointestinal and respiratory systems develop from the same germ layer was surprising to me. To me, this hypothesis implies more of a genetic basis for IBD, as the pathological changes in the GI and respiratory systems are based their similarities due to developing from the embryonic germ layer. IBD is thought to have some genetic basis, but is also heavily influenced by environmental factors, the immune response, and the gut microbiota (1). Further reading led me to discover various proposed mechanisms for IBD causing respiratory abnormalities. The GI and respiratory epithelia have the same embryonic origin, so both have similar submucosal lymphoid tissue. Both systems are vital to mucosal immune defense. Because the GI and respiratory epithelia are similar, pathogenic changes in the GI epithelium in response to an exposure, like an antigen, may also occur in the respiratory epithelium if it’s also exposed. These changes may then cause inflammation and contribute to IBD and respiratory dysfunction (2). I wonder if this association may create new opportunities to study the pathogenesis of IBD. For example, if differences in the respiratory epithelium between individuals with IBD and respiratory function versus those without IBD may indicate a genetic contribution to IBD.

I look forward to hearing your thoughts,

Samantha

1. Roberts-Thomson, I.C., Bryant, R.V. and Costello, S.P. (2019), Uncovering the cause of ulcerative colitis. JGH Open, 3: 274-276. https://doi.org/10.1002/jgh3.12216

2. Ji, X. Q., Wang, L. X., & Lu, D. G. (2014). Pulmonary manifestations of inflammatory bowel disease. World journal of gastroenterology, 20(37), 13501–13511. https://doi.org/10.3748/wjg.v20.i37.13501

Name
Samantha Ables

Thank you, James and Samantha, for the kind words and excellent contributions! I found the association between different systems interesting as well. So far, these Grand Rounds presentations have proven to me that body systems are not closed systems and interact with one another more than we might anticipate, as we also were shown by Dr. Boyd's discussion on how chronic kidney disease can impact cognition!

Thank you Samantha for the fascinating research you cited about the pathogenesis of both respiratory dysfunction and IBD. It's a great idea that perhaps respiratory studies and PFTs could help us identify and learn more about gastrointestinal diseases. Dr. Neder also recommended that PFTs be used only when IBD flare-ups are controlled and not active, as active IBD can confound the results of the PFTs to prevent the overdiagnosis of COPD. I wonder if similar pathways are contributing to the concurrent improvement of both the IBD and obstruction or restriction in the lungs. If so, do you think that any medications currently used to control IBD could be used to help control pulmonary diseases too, or vice versa, due to their similar epithelial physiology? Further, I am curious to know how pulmonary function is assessed in people with chronic gut issues that are more constant, where there is less opportunity to do a PFT when IBD is controlled.

Thank you both for your insights!

Name
Georgia Kersche

Name
Sophia Linton

Mon, 09/27/2021 - 16:52

Great job Georgia!

Dr. Neder talked a lot about his career path and how it has contributed to his success and research.

What were some of the main takeaways you all took from this portion of our talk?

Sophia

Name
Sophia Linton

Hi Sophia,
The biggest thing I took away regarding the career section of our discussion was that Dr. Neder viewed being a physician as a career that helped the individual, and a researcher/scientist as a career that helped society. I've always had a hard time trying to figure out which aspect I would like to focus my life's work on. TMED is definitely opening my eyes more and more to the importance of physician-scientists, and increasingly I think that is the right path for me. I'm very curious to hear what others thought about the career path discussion.
Best,
James

Name
James King

Hi Sophia,

A great question. The main takeaways I had from this portion of Dr. Neder's talk were how his international training contributes to his practice and his research philosophy.

When discussing his international training, he talked about cultural differences between Brazil, Europe and Canada. He said that the British were rather pragmatic with their approach to clinical care and research. He said that the most challenging thing about coming to Canada was leaving the research institute that he was the head of and starting from scratch. Despite the smaller size of Canada, he said we had good funding for research and good healthcare organization. It is evident by the impact he has made on his Canadian patients that this endeavour was worthwhile. He also shared with the group "not to lose your drive to go ahead, don't betray your dreams" and "to be open to moving around." These sentiments somewhat remind me of points Dr. Trier had around the importance of having a growth mindset.

When asked why he loves research so much, Dr. Neder shared that in research, you help every doctor's patient while in practice you only help a patient on the individual level, both are very rewarding and have their pros and cons. He also said it is vital to protect your research time for clinical things can begin to 'snowball.'

Overall, Dr. Neder's insights were beneficial to our group of inspiring clinical scientists and researchers. I would be interested in hearing what other takeaways my peers had.

-Alyssa

Name
Alyssa Burrows

Thanks for the great summary Georgia, what a fascinating discussion we had last week! It was invaluable to learn about how various aspects of Dr. Neder's career have enriched his approach to research and patient care. In response to Sophia's question, I learned two important lessons from Dr. Neder on the topic of career development.

To start, his emphasis on the importance to see medicine as an art resonated with many of us. Despite how deeply mathematical and systematic the field of Respirology proves itself to be, Dr. Neder convinced us that it is just as equally an art. He mentioned that this perspective allows him to treat patients to his fullest potential, and to maintain curiosity in his successful research each day.

The second lesson that I learned from Dr. Neder in terms of career development is the power of working and learning across the globe. Dr. Neder's career spans multiple continents, and he attributes much of his wisdom to his experiences of living and working around the world. We learned that significant growth can happen when you become immersed and challenged in new places with unfamiliar customs and rich history. Thank you again to Dr. Neder, Georgia and class for the great learning opportunity!

Name
Katie Lindale

Hey Georgia,

Great work putting together this very insightful write up about a complex topic.

I really liked what Katie pointed out from the lecture, in that he viewed his work as an art. Often we can get pulled into the “day-to-day” routine and lose track of what drew us there in the first place. This was something I took away from Dr. Neder’s talk. It was amazing to see his love and passion for Respirology, even after many years in the field. This shows if you follow your passion in your educational journey, the end will be just as exciting as the path that took you there.

The main thing I found so fascinating was his confidence to state “no this doesn’t make sense” [testing metrics], even when the world of Respirology is saying it does. I am sure he faced challenges along the way having this view, but in your opinion, do you think we should all challenge things we feel aren’t correct? And if so, what would be your biggest optical?
Amazing job Georgia!
Kyla

Name
Kyla

Name
Emmanuel Fagbola

Wed, 09/29/2021 - 08:34

In reply to by Kyla Tozer (not verified)

Hey Kyla,

I would love to provide my thoughts and personal insights on this question.

First, I wanted to thank Georgia for a job well done in summarizing the key points from Dr. Neder’s MGR presentation in an effective manner.

As Queen’s Translational Medicine Graduate Students, each one of us is honing our research skills. The basis of our education is looking to develop our ability to ask the right questions, develop and test hypotheses, draw conclusions, and repeat this process. In doing this, we hope to advance the field of Medicine in our area of interest with a focus on improving patient care.

With this in mind, I believe we should be eager to challenge things that we feel are incorrect or can be improved. Moreover, being a physician-scientist puts an individual in the optimal position to do this. For example, Dr. Neder may have reflected on the efficacy of PFTs throughout his early career as a respirologist. As a researcher, he would be able to take this inquiry to the lab, formulate a hypothesis based on current research and his clinical background, and test it. This process can only benefit the field of respirology, Medicine, and mainly, patients and the care they receive. His research may find that PFTs are effective, which would help create a greater body of evidence to support them as an optimal clinical tool. On the other hand, he may also find that PFTs have some flaws, which would encourage more research to support the optimization of the test or the development of a new test altogether.

When challenging what we feel to be incorrect or inadequate, I believe the biggest challenge is our propensity to worry about what others think and the fear of change. I believe that it is essential to remember in these scenarios that the field of Medicine is where it is today because of individuals that challenged previous standards of care. Similarly, to advance the body of knowledge in the field of Medicine, researchers need to continue asking questions and challenging current practices.

Name
Emmanuel Fagbola

Hi Katie,

I loved reading your comments on what resonated with you most about Dr. Neder's career development. Reading our other classmates' posts, it is interesting to see the correlation between impact and individual perspectives. I think personal perspective contributed to my agreement with your idea that Dr. Neder's global approach to respirology was especially notable. I recently had the privilege of working in a mobile clinic in Tanzania. Before this experience, I would consider myself sheltered and unexposed to healthcare systems outside Canada. Being immersed in another healthcare system, specifically in a third world country, made me greatly appreciate our healthcare in Canada. With his international experience, Dr. Neder also expressed during the discussion just how lucky we are to have access to such excellent healthcare. He also mentioned how although we have an exemplary healthcare system, there is always things we can learn from other countries and healthcare structures. For this reason, I believe global health courses are essential in a comprehensive medical education and can help create a philosophy of universal values. Globalization is advancing at a fast pace. Global health courses can help address inequities and prevent challenges that arise as patients and coworkers become increasingly ethnically diverse. I like this quote from a paper called Opening our eyes to Global Health, “Responding to globalization lies not only in knowledge but embraces human rights, justice and, most important, self-awareness.” I have attached the link to the paper below if anyone is interested. I would be curious to see if Dr. Neder supports adding global health courses to the medical curriculum and if any of our classmates would be interested in taking a global health course!

Thank you, Georgia, for the excellent summary and to Dr. Neder for his enthusiastic and educational presentation!

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4673063/

Best,
Bethany

Name
Bethany Wilken

Dear Sophia,
It is interesting to hear about how many different paths can be taken in medicine and research. Dr. Neder highlighted the bidirectional relationship between the two, as they both shaped his career in different ways. It can be overwhelming to consider that when choosing a specialty that one must think of patient population, work-life balance, research opportunities, the job market, the culture of the specialty/hospital, etc. I took from Dr. Neder's discussion that it is vital to be open to new opportunities and pathways guided by your individual goals and interests, recognizing that medicine and research are a journey of lifelong learning!
Kiera

Name
Kiera Liblik

Name
Georgia Kersche

Wed, 09/29/2021 - 12:35

In reply to by Anonymous (not verified)

Hi Kiera!

The bidirectional relationship of research and medicine was a highlight for me, too. Dr. Neder seems to have struck a special balance between being an excellent clinician for the patients at KHSC, while also contributing leaps and bounds to world-wide research, including publishing a leading textbook in Portuguese.

You're absolutely right, the vast amount of options you will have as a researcher and physician must be overwhelming. The sheer number of possible paths also excited me, though, as with all those considerations that you mentioned there seems to be the opportunity to carve out a career ideally suited to you as an individual. I know your journey of life-long learning will be a highly successful one!

Thank you so much for your insights on this topic.

Name
Georgia Kersche

Hi Sophia & all,

Chiming in on the career path sentiments: both clinical and research-oriented work are of course vital to the progress and effectiveness of a healthcare system, and I think it's really important to factor in the kind of impact you want to have in choosing either path.

To an extent, I agree with Dr. Neder's thought that, as a researcher, you're helping all of science and the medical community, whereas work in the clinic "only" helps one person at a time. But I'm sure he'd agree that there's much more nuance to the equation. A single study can very easily take in excess of a year or two to complete, and there's no guarantee that each will produce material differences in the way care is delivered. One's entire career might culminate in a new method of treatment that benefits many patients, but this is a large "might" and is inherently a long time in the making. I think the beauty in research comes in having an unfailing drive to push the limits of human understanding. Without people who value this, societal progress is left to chance. Ultimately, I think research pushes the boundaries of what we can do, although not all of this new ground is of equal value to improving the lives of patients.

Alternatively, on-the-ground clinical work functions within our existing realm of knowledge and primarily offers high-intensity care for one patient at a time. This lends itself more to those who value directly seeing the impacts of their efforts and the human side of medicine as opposed to the abstract. Depending on one's specialty, there's much lower risk in whether or not your work actually improves someone's quality of life.

So certainly, both are necessary. We need the tools that clinician scientists produce as well as enough hands to ensure that these tools are sufficiently and expertly used. What resonated with me the most in this MGR was Dr. Neder's infectiously enthusiastic attitude towards his work. He's clearly taken many risks in moving between systems and abandoning his established position where he grew up, which only reveals his commitment to having as great an impact as he can. I have the utmost respect for him for pursuing his dreams and maintaining his passion for as long as he has.

Name
Nolan Breault

Name
Alyssa Burrows

Mon, 09/27/2021 - 20:57

Hi Georgia,

Fantastic job facilitating the discussion and summarizing our talk in your post. A question/topic I had for the second part of the discussion – was “What are the impacts of air pollution on your patients and their diseases?” This question was prompted by a newspaper story published on the death of a 9-year-old girl who died of acute respiratory failure, severe asthma and air pollution exposure which further acerbated her asthma, as confirmed by a corner. The air and nitrogen dioxide emissions well exceeded the legal limits by both the EU, national and WHO guidelines. The conclusion of her death is a “landmark moment,” i.e. never having been done before and called pollution a “public health crisis.” (1). Dr. Neder briefly mentioned air pollution by living close to busy roads as a known concern for his patients.

A review paper on Asthma and Air Pollution suggested several molecular pathways, including oxidative stress and Th2/Th17 immune dysregulation, as to how air pollution can exacerbate the disease. Young children with asthma, especially in economically disadvantaged neighbourhoods, are at increased risk of adverse effects from air pollution exposure. Improved air quality prevents exacerbations but requires strong governmental efforts to move away from fossil fuel for transportation and energy production; this approach is also needed to mitigate climate change (2).

Some questions to consider: is air pollution a concern in other diseases? Is there anything that clinicians, clinician-scientists, and scientists can do to approach/ address these problems?

(1) https://www.theguardian.com/environment/2020/dec/16/girls-death-contrib…
(2) Guarnieri M, Balmes JR. Outdoor air pollution and asthma. The Lancet. 2014 May 3;383(9928):1581-92.

Name
Alyssa Burrows

This is really neat Alyssa.

Can someone remind me what Dr. Neder said about the health consequences of living next to highways?

Sophia

Name
Sophia Linton

This is a really interesting discussion, Alyssa!

Sophia, I believe Dr. Neder mentioned that lung function decreases by ~1% a year for those who live close to a highway.

Georgia, I really enjoyed your summary! We sometimes underestimate the significance of the lungs in the human body. It plays such a central and fundamental role, combined with almost every other system of the body. Lifestyle choices have such a big impact on health. Researchers have reported that patients living close to highways had increased risk of neutrophilic bronchitis and an elevated risk of developing asthma. Asthma exacerbation and lower lung function was reported, particularly in women (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3071007/).

I wonder whether, or in what ways, health considerations play a role in urban planning - any thoughts?

Lubnaa

Name
Lubnaa Hossenbaccus

Hi Lubnaa, very interesting thought!

As I'm sure we've all hear about in the media, the growing population combined with an increasing wealth gap between the wealthy and the working class is causing more and more people to flock to cities for access to jobs and accessible housing. Like you pointed out, this must have some consequences for public respiratory health.

A brief search showed me that urban planning can play a significant role in the health of its pedestrians, but there are pros and cons to different solutions. For example, trees, vegetation, and green spaces in cities improve surrounding air quality, lower the incidence of wheezing, and stress levels in the population (1). However, a high volume of vegetation risks obstructing views of vehicles, and even trapping pollution and particulate rather than absorbing it (1). To me, it seems like an urban planner should try to promote a balance between green space and concrete infrastructure. I am concerned that as the climate crisis and overpopulation progresses this will become more of an issue.

References
van Dorn, A. (2017). Urban planning and respiratory health. The Lancet Respiratory Medicine, 5(10), 781-782. doi: 10.1016/s2213-2600(17)30340-5

Name
Georgia Kersche

Dear Sophia,
If I remember correctly, Dr. Neder mentioned that research has shown that living near a highway is bad for respiratory health, and antioxidants can help prevent and reverse the damage that inhaling polluted air can cause. I could not find a citation from Dr. Neder himself on this topic (still could be out there, if anyone else can find one!) but I did find another paper that confirms his statement. In a review published in 2008, the authors confirmed that oxidant pollution exacerbates cardiopulmonary disease by oxidizing genetic material, promoting carcinogenesis and inflammatory disorders, and causing lung damage (1). You're right, this is equally neat and concerning!
Best,
Georgia

References
Ciencewicki, J., Trivedi, S., & Kleeberger, S. R. (2008). Oxidants and the pathogenesis of lung diseases. The Journal of allergy and clinical immunology, 122(3), 456–470. https://doi.org/10.1016/j.jaci.2008.08.004

Name
Georgia Kersche

Name
Kiera Liblik

Mon, 09/27/2021 - 21:24

Dear Georgia,
Thank you for your comprehensive and well-written summary of MGR last week! It was a pleasure to hear from Dr. Neder.
What struck me about your commentary was your emphasis on the importance of physicians in a world of technological advancement. I think that sometimes there is a misconception that machine learning, robotics, etc. will replace the expertise of an MD or scientist. In fact, I think that these technologies serve to amplify the skillset and creativity of clinicians/researchers. For example, a tool like a PFT interpretation software can help increase efficiency and, accordingly, amount of time spent on research and with patients. Of course, these technologies take a long time to develop, train, and validate. It is exciting to see how innovation bridges research and medicine!
Kiera

Name
Kiera Liblik

Dear Kiera,
You raise an interesting point, and I agree that there is often an overarching misconception about technological advances and the need for clinicians.
As Dr. Neder emphasized in his talk, diagnostic tests should not be used alone to diagnose patients, but rather in synergy with observations to confirm impressions the physician has. For this reason I think that advances may improve diagnostic accuracy and efficiency etc. but will still always require a clinician to interpret and confirm such tests.

I also think another invaluable aspect of a clinicians role is having first hand experience with their patients to further inspire their research. After all, this is one of the key pillars of translational medicine/research! This first-hand inspiration is something that I believe technology could never replace.

Cassie

Name
Cassie Brand

Hi Cassie, thank you for your comment!

I agree with your point that technological advances should complement a physician's mind, not the other way around. One thing that stuck with me from Dr. Neder's talk was that when he assesses a patient, he first uses his own intuition to draw hypotheses about what is likely going on with their respiratory function. By doing so, he takes into account their medical history and their current situation, and his instinct that has been honed from years of clinical experience. Only then does he review the results of the PFTs looking to confirm his hypothesis or point him in a different direction. This ensures that he is looking for relevant factors of their pulmonary functioning, and not being distracted by the nuances my initial post discussed. I thought it was interesting that he uses his intuition first, then the tests to confirm. To me, this speaks to how invaluable a human set of eyes and an experienced physician are compared to a machine. No doubt there is a role for technological advances to improve patient care, but I don't believe you could replace a physician like Dr. Neder.

Thanks Cassie!

Name
Georgia Kersche

Name
Trinity Vey

Tue, 09/28/2021 - 12:39

Hi Georgia,

Thank you for a fantastic summary of Dr. Neder’s talk and our TMED discussion. Something that stood out to me from the lay-press-focused portion of our discussion with Dr. Neder was the risk that smoking marijuana poses for developing COPD and other respiratory diseases. With the recent legalization of cannabis in Canada, I couldn’t help but wonder if we will begin to see increased levels of COPD in the coming years as a result?

There seems to be conflicting literature on the subject - A 2016 review concluded that there is an association between inhalational marijuana and COPD, spontaneous pneumothorax, and bullous emphysema (as well inhalational marijuana being a risk factor for lung cancer) (1). However, another study I looked at noted that smoking only marijuana was not associated with an increased risk of COPD, while smoking both tobacco and marijuana synergistically did increase one’s risk (2). Interestingly, while I was researching this topic, I came across several lay-press articles suggesting that marijuana (mainly when consumed in methods other than smoking) may potentially alleviate symptoms of COPD by helping with sleep, reducing inflammation/phlegm, and reducing pain (https://copdnewstoday.com/2017/06/12/cannabis-benefit-copd-patients/).

Dr. Neder highlighted the fact that often COPD patients are unwilling to cease tobacco smoking despite being diagnosed with pulmonary disease, and I’d imagine this might be the same for long-time marijuana smokers. From a healthcare perspective, I wonder what can be done to bring further attention to the potential respiratory health complications of marijuana smoking? How might the conflicting research on this subject impact patient’s decisions?

I look forward to hearing your thoughts!

Best,

Trinity

1. Martinasek, M. P., McGrogan, J. B., & Maysonet, A. (2016). A Systematic Review of the Respiratory Effects of Inhalational Marijuana. Respiratory care, 61(11), 1543–1551. https://doi.org/10.4187/respcare.04846

2. Tan, W. C., Lo, C., Jong, A., Xing, L., Fitzgerald, M. J., Vollmer, W. M., Buist, S. A., Sin, D. D., & Vancouver Burden of Obstructive Lung Disease (BOLD) Research Group (2009). Marijuana and chronic obstructive lung disease: a population-based study. CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, 180(8), 814–820. https://doi.org/10.1503/cmaj.081040

Name
Trinity Vey

Hi Trinity,

I think this is actually a really interesting and topical angle for public health going forward. As you've noted, the jury is still out with respect to causation between marijuana usage and certain illnesses (lung cancer, COPD), but there are some commonalities between marijuana smoke and that of the more heavily-studied tobacco. Comparative investigations of the compounds in either smoke has shown that many of the carcinogenic and inflammatory molecules (such as aromatic amines and nitrogen oxides, respectively) that are found in tobacco smoke are also present in marijuana at 3 to 5-fold concentration, while also retaining qualities in an aerosol form that allow them to accumulate on and diffuse into lung tissue (1, 2). However, differences in the way the two substances are typically used may account for why we don't have as concrete conclusions with respect to disease onset. The half-life of nicotine in circulation is ~2 hours, while that of THC and CBD is ~30 and 31 hours, respectively (3). This manifests behaviourally by multiple tobacco cigarettes being consumed by users on a daily basis compared to a few inhalations from a single marijuana cigarette. This is compounded by the differences in propensities for addiction that we see between the two drugs. Thus, "usage" of either drug results in a massive disparity in the amount of smoke particles that one's lungs are exposed to. Marijuana usage has been been shown to provoke inflammation of the respiratory tract and aggravate asthma, but it may be likely that the pathologies encountered by average tobacco and marijuana users differ massively because of how the substances are used.

My personal take is that yes, it's likely that increased marijuana usage will positively correlate with the incidence of COPD and other respiratory illnesses because of the high concentrations of mutagenic and inflammatory compounds present in the smoke, but this will moreso affect heavy users. It'll be very interesting to see how the legalization of marijuana affects safety regulations around its consumption (will we see filtered joints as exists for tobacco cigarettes?). I think this is a really cool topic!

Best,

Nolan

References
1. Moir, D., Rickert, W., Levasseur, G., Larose, Y., Maertens, R., White, P., and Desjardins, S. (2008) A Comparison of Mainstream and Sidestream Marijuana and Tobacco Cigarette Smoke Produced under Two Machine Smoking Conditions. Chem Res. Toxicol. 21: 494-502. https://doi.org/10.1021/tx700275p
2. Graves, B., Johnson, T., Nishida, R., Dias, R., Savareear, B., Harynuk, J., Kazemimanesh, M., Olfert, J., and Boies, A. (2020) Comprehensive characterization of mainstream marijuana and tobacco smoke. Sci Rep 10: 7160. https://doi.org/10.1038/s41598-020-63120-6
3. Smith-Kielland, A., Skuterud, B., Morland, J. (1999) Urinary excretion of 11-nor-9-carboxy-delta9-tetrahydrocannabinol and cannabinoids in frequent and infrequent drug users. J. Anal. Toxicol. 23: 323-332. DOI: 10.1093/jat/23.5.323

Name
Nolan Breault

Hi Trinity, thank you for your comment! Good job expanding on what we briefly touched on during the discussion.

I do think that there is a risk of increased COPD cases as more people take up smoking legal cannabis, especially in combination with the huge increase in nicotine use in youth with the rise of e-cigarettes. I like that you cited some conflicting sources, as I have found that cannabis research has a tendency to rarely come to a strong conclusion without numerous confounding factors. For example, it is difficult to elucidate the effects of cannabis alone on one's physiology, because it is so often used concurrently with tobacco, nicotine alone, alcohol, or other recreational drugs. I feel that more research into the effects of cannabis alone is warranted.

To answer your questions, I think that you are absolutely right that the conflicting information is unlikely to prompt users to take the respiratory risks of smoking cannabis seriously. This is similar to how unreliable information is spread with regard to cannabis and pregnancy, for example, websites like CannaMommy.org make it easy for people to confirm their biases. To combat this, I feel that providing unbiased, accurate information in schools about the risks and benefits of using cannabis would be beneficial. Perhaps instead of teaching the "abstinence-only" approach, it would be valuable to accept that many people will try cannabis in their lifetime and to instead educate about harm-reduction, like eating or vaporizing cannabis rather than smoking it. Lastly, I think that the benefits of cannabinoids that you mentioned are worth looking into for COPD patients! The various ways to consume cannabis may prevent the impact of further smoke inhalation and could encourage smokers to try a method that is less damaging to their respiratory health. This way, COPD patients could enjoy the anti-inflammatory and pain-reductive effects of cannabis.

Thanks, Trinity, for a thought-provoking comment!

Name
Georgia Kersche

Name
Pierce Colpman

Wed, 09/29/2021 - 14:17

Hi Georgia, firstly I would like to say thank you for an amazing summary of Dr. Neder’s wonderful talk! I think you touched on all the key points beautifully and adding a nice part at the end about some of his wise words to all of us was much appreciated!

My question had to do with the last article which you referenced which speaks to the use of artificial intelligence to outperform pulmonologists in interpretation of PFT’s (1). You mentioned that “there is no replacing human intuition by specialists such as Dr. Neder” however, the paper by Topalovic et al., 2019 contradicts this. The study collected over 120 pulmonologists from 16 hospitals in various European countries and got them to independently examine different patient cases according to a pre established protocol. The same patient files were examined by AI-based software for PFT interpretation, and the results were run through statistics software. It was found that the AI based software outperformed the pulmonologists in both interpretation (34% improved) and in pointing to the correct diagnostic category (84% improved) and they stated that their results indicate that individual pulmonologists do not sufficiently capture the information available in PFT’s. All this accounted for, this is however only one study, and Dr. Neder’s experience is vast in comparison. I am wondering your opinion on why you think/ Dr. Neder thinks that pulmonologists are invaluable? If these tools were to be better (as was the case with the Kinarm robot, and the AI diagnostics in this paper), why not use them instead of paying a specialist or do you think the human connection and personality of a physician is too valuable to lose?

1. Topalovic, M., Das, N., Burgel, P., Daenen, M., Derom, E., & Haenebalcke, C. et al. (2019). Artificial intelligence outperforms pulmonologists in the interpretation of pulmonary function tests. European Respiratory Journal, 53(4), 1801660. doi: 10.1183/13993003.01660-2018

Name
Pierce Colpman

Hi Pierce, great question! And thank you for participating remotely during the discussion, I admire your commitment to learning even when not feeling 100%!

Your question carries a lot of nuance, but yes, I do believe that there will be some role for physicians for the foreseeable future that cannot be totally replaced by technology. Machines will likely have differing amounts of responsibility in different areas of medicine. For example with new microscopic surgical techniques, there is an opportunity for surgeries to remove cataracts or oropharyngeal cancers to be performed by robots under the supervision of a physician. To draw from personal experience, a family friend recently underwent Transoral Robotic Surgery (TORS) which was robotically assisted to get the best possible margins of a tumor removed, and she had a very positive experience. TORS involved the use of robotic microscopic lasers to be minimally invasive and highly effective at removing cancer, and is associated with improved quality-of-life for 1 year after surgery (1). On the other side of the spectrum, I think in some specialties it would be difficult to replace humans, like psychiatry or when interacting with conscious pediatric patients. Ultimately, I do not believe that the question is humans vs. tech in terms of who is better, but rather how technological innovations could complement humans in how quickly and how well they can perform their jobs. For example, Dr. Neder mentioned that when he consults on a patient, he first lays eyes on them and forms a hypothesis for what could be going on, then uses various tests to determine whether or not he was correct. As you mentioned, AI may be very helpful for interpreting those PFTs that we discussed, but ultimately a final treatment plan will come from the physician, who should take into account the incredible technology we have available to us.

Thanks!

Dziegielewski PT, Teknos TN, Durmus K, et al. Transoral Robotic Surgery for Oropharyngeal Cancer: Long-term Quality of Life and Functional Outcomes. JAMA Otolaryngol Head Neck Surg. 2013;139(11):1099–1108. doi:10.1001/jamaoto.2013.2747

Name
Georgia Kersche

Name
Dilakshan

Thu, 09/30/2021 - 17:06

Dear Georgia,
Thank you so much for this wonderful summary and your thoughts on the talk delivered by Dr. Neder. You raised some very interesting points regarding technology and its’ integration in the role of a physician from Dr. Neder’s talk. Furthermore, some of our colleagues have also commented on the role of technology in the future – with some taking the position that technology can replace physicians while others taking the position that it will supplement the role of a physician. Although only time will tell how policies and advancements in research will influence the role of technology in medicine, we can certainly discuss the research barriers in place that prevent the advancement of technology in pulmonary functional tests (PFT).
A recent paper by Giri et al (2021) in Frontier in Physiology beautifully outlines the current state and application of machine learning in PFTs. Similar to other fields of medicine, one of the largest hurdles that prevent large scale commercialization of applied AI in PFTs is the need for high quality representative data. While a large dataset is required in order to train and test the accuracy of machine learning algorithms, it also needs to be representative with annotations of historical biases in data collection. Furthermore, given the longevity in the use of PFTs, the existence of different formats for data acquisition and sharing by PFT software is also a large barrier to progression. Finally, there needs to be a consensus and collaboration among a wide range of personnel which consists of clinicians, biomedical engineers, and information technologists. However, despite the hurdles, the new developments in AI represents significant advances that could be the future of PFT, regardless of its role in relation to the role of a physician.

Name
Dilakshan

Hi Dilakshan! Thank you for your comment about the hurdles between now and 'the future'.

Certainly, as translational medicine students, it is our job to assess the current limitations of technology and formulate a plan to overcome them. You mentioned that large datasets are necessary to make algorithms accurate and representative of as wide a section of the population as possible. Since this is such a daunting task, I feel it may be worthwhile for a group of clinicians, biomedical engineers, and information technologists to focus on one system or one diagnostic test as a prototype that could then be extended to other specialties. Perhaps PFTs are a good candidate to be that trial, whereby extensive long-term research strongly reduces the need for clinician decision making. Have you found any of these trials in progress? I wonder if this could be helpful for providing specialized care in more remote areas, such as Northern Canada and economically underdeveloped countries. For example, we discussed the increasing burden of pulmonary pathologies in communities where air pollution is severe. As a more advanced country research-wise, innovations created here could be applied to many populations around the world where getting a live pulmonologist to do a physical exam might be difficult.

Thank you for your insights!
Georgia

Name
Georgia Kersche

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