85 e-Letters

published between 2017 and 2020

  • The importance of experimental conditions in the assessment of products relevant to human consumption

    Although electronic cigarettes (ECs) are a much less harmful alternative to tobacco cigarettes, there is concern as to whether long-term ECs use may cause risks to human health. There are reasonable concerns and should be elucidated as soon as possible to learn how to best employ these products, causing the least possible damage to users.
    Scott and colleagues aimed at define whether e-cig vapors have a negative impact on human alveolar macrophages (AMs) viability and function (1). They tested human AMs from lung resection specimens from healthy donors by exposing these cells to the electronic cigarette vapour condensate (ECVC).
    First of all, the authors dedicated a detailed explanation to the method used to condensate the vapour, but the protocol used to generate vapour is quite ambiguous, omitting to indicate puff volume, puff number, and in particular if the pump used to aspirate the vapors were able to generate the correct puff profile (2). This is a crucial step in the validation process of an exposure method, because if the vapours are generated with incorrect regimes, they can lead to the production of inaccurate ECVC and thus to distorted results invalidating all the conclusions of the study. We think the author could detail the regimen employed for vapour generation.
    Furthermore, airway macrophages are resident in the connective tissue and not exposed directly to the liquid-air interface, therefore the method used for the exposition of these cells...

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  • Additional differentitation

    The differentiation between an empyema and a peripheral lung abscess is really difficult. The authors have summarized most points on differentiation. We had of a similar case, which looked like an Abscess on Chest Xray and had Acute angulation with lungs on Chest Ct, but due to the smooth inner walls and enhancement of pleura, we treated the case like an Empyema. Interestingly the initial CT showed some volume loss with ribs appearing crowded and this feature was more pronounced in the subsequent CT done after 2 weeks. Thus, associated volume loss with rib crowding could also be an additional point in the differentiation favoring Empyema and this volume loss might appear fairly early as well.

    ****can provide CT films of the same****

  • Cost-effectiveness and tuberculosis elimination: never the twain shall meet

    The National Institute for Health and Care Excellence (NICE) 2016 Tuberculosis (TB) guidelines no longer recommend screening contacts of adults with extra-pulmonary TB (ETB). However, no new evidence since the previous published guidelines was provided to support this policy change. Moreover, despite the guidance, some regional TB multidisciplinary teams and services continue to screen ETB contacts.(1)

    In their original article in Thorax, Cavany et al estimated the cost-effectiveness of screening ETB contacts in London.(2) The authors’ findings suggest that screening of such contacts is unlikely to be cost-effective at the threshold of £30,000/QALY - the “willingness to pay” threshold commonly used by NICE.(3) The authors’ findings are tempered by the data being London-specific and not generalizable to the rest of England, and the lack of robust available evidence on either transmission rates or index cases’ pre-diagnosis symptom duration. Nevertheless, the authors recognise these limitations and their sensitivity analysis suggests that, even with assumptions of higher rates of transmission or prolonged symptom duration, their principal findings would not change.

    The findings of this strong, well-designed study are important and provide much needed evidence for national debate around strategies for TB contact screening. Resources for TB services across England, especially those allocated to tracing contacts of TB patients, are becoming increasingly constrain...

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  • Impact of electronic cigarette on our health

    According to recent study published by Sebastian et al., (1) electronic cigarette vapor impairs the activity of alveolar macrophages, which engulf and remove dust particles, bacteria, and allergens that have evaded the other mechanical defenses of the respiratory tract. This study finding is important and it shows that the long term health impact of e-cigarettes use may be more harmful than we know (2).

    Meanwhile, industry, tobacco research community and the online information are promoting electronic cigarette as a less harmful tobacco cessation tool. However, before more leeway to advertise the harm-reduction benefits of vaping products, we believe that the first step would be to establish whether vaping products are indeed safer tobacco cessation device or harm reduction tool (3). Moreover, currently available evidence (including clinical guidelines and position statements of credible medical organizations) based information need to ensure that people are protected from commercial interests and are able to make informed decisions based on current best evidence on electronic cigarette and its long term health effects (3). It is our moral obligation that we should not be promoted electronic cigarette to our children and people those who never wanted to smoke tobacco. At the same time, it is important to promote the proven non-tobacco nicotine products such as Nicotine Replacement Therapy (gum or inhalators) to smokers those who are sincerely wanted to quit.

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  • Absence of evidence is not evidence of absence! Lessons from recent trials of adjunctive IMT in COPD and recommendations for further research: careful selection of candidates, controlling interventions and choosing the most adequate outcomes.

    We support the view of Drs. Polkey and Ambrosino that recommendations for clinical practice should not be based on either positive or negative preoccupation concerning the potential effectiveness of a treatment but rather on an impartial evaluation of the available data. In their editorial entitled ‘Inspiratory Muscle Training in COPD: can data finally beat emotion’ they unfortunately provide a fairly one-sided evaluation of this treatment, based on an incomplete and largely outdated review of the available evidence1. It is unfortunate that they neglect a major part of available data, which could contribute to a more balanced and fair discussion about this intervention. We therefore deemed it necessary to add this missing evidence along with our own interpretation of recent findings to the discussion.
    Complexity of studying add-on interventions to pulmonary rehabilitation
    Based on the results from three recent multicentre trials2-4, Polkey and Ambrosino exclude a role for adjunctive IMT in the rehabilitation of patients with COPD. As emphasized in a previous opinion piece by Dr. Ambrosino5, it is important to distinguish between studies that evaluate the effects of inspiratory muscle training (IMT) as a standalone intervention (i.e. in comparison to no intervention or a sham control intervention) and studies on the effects of IMT added to a pulmonary rehabilitation program (PRP).
    Concerning the first comparison, there is a large amount of data available s...

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  • The effect of living at high altitude and living in urban settings on lung function decline

    We read with interest the findings of Miele et al. on the relationship between environmental exposures and decline in lung function (1). The authors reported that living in urban settings and living at high altitude were associated with accelerated decline in pre-bronchodilator FEV1 and FVC. Investigating the effects at area level is important from a public health perspective and extra analysis on this valuable dataset as suggested below will help to untangle these links further.
    Study participants were recruited from four settings in Peru: Lima, Tumbles, urban Puno and rural Puno (1). Urban living and high-altitude dwelling (as binary variables) were defined based on these four settings. The authors compared the effect of urban living (Lima and urban Puno) with rural living (Tumbes and rural Puno); and the effect of high-altitude dwelling (urban Puno and rural Puno) with low-altitude dwelling (Lima and Tumbes). It is possible that the observed independent effects found by the authors of urban living and high-altitude dwelling may be driven by the urban Puno group (high altitude and urban living). In other words, there may be an interaction between urban living and high-altitude dwelling and investigating this potential interaction would be informative.
    As discussed by the authors, the adverse effect of high-altitude dwelling on lung function decline may partly be related to hypoxia and adverse effects from living in urban settings may be related to outdoor air...

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  • Lung volumes measurement for risk stratification in smokers without COPD

    We appreciate the points raised by the commentator about our study (Zeng et al.)[1] published in June 2018 issue of Thorax that (1) the prevalence of abnormal residual volume to total lung capacity ratio (RV:TLC) in our study of ever-smokers with preserved spirometry is substantially higher than that observed in the commentator’s past studies,[2-4] and (2) an assumption by the commentator that stringent exclusion of those with abnormally low TLC and those with diagnosis codes of interstitial lung diseases (ILD) in their electronic health records (EHR) may have resulted in overestimation of the prevalence of abnormally high RV:TLC among smokers with preserved spirometry.

    We would like to draw the attention of commentator and readers to the following points:

    1- The studies referenced by the commentator used pulmonary function tests (PFT) data collected from 708 patients in 2013 across 5 clinical sites associated with University of Minnesota Medical Center with inclusion criteria of patients 18 years of age or older with or without history of smoking.[2] They included about 50% women and 3 African Americans. Our study was performed on PFT data obtained from 1985 through 2017 through the United States Veterans Affairs (VA) nationwide EHR from 7,479 patients across 37 VA medical centers in the United States with inclusion criteria of patients 40 years of age or older with an EHR diagnosis code of smoking, which likely suggests heavy smoking for VA patients. Our st...

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  • Should lung volumes measurement accompany every spirometry?

    Should lung volumes measurement accompany every spirometry?
    Spyridon Fortis MD1
    1Division of Pulmonary, Critical Care and Occupational Medicine, University of Iowa Hospital and Clinics, Iowa City, IA, USA

    Corresponding Author:
    Spyridon Fortis, MD
    UIHC – Internal Medicine
    200 Hawkins Drive – C33 GH
    Iowa City, IA 52242
    Email: spyridon-fortis@uiowa.edu
    Word Count:
    Author Disclosures: Authors declare that there is no conflict of interest regarding the publication of this paper.
    Running Head: Lung volumes with every spirometry
    Key Words: COPD, diagnosis, lung volumes, RV/TLC, preserved lung function.

    In their study published in the June 2018 issue of Thorax, Zeng et al showed that RV/TLC ratio in smokers with preserved lung function is associated with clinical diagnosis of COPD, higher rates of respiratory medications prescriptions, emergency room visits, hospitalizations, and all cause-mortality[1]. The findings strongly support that patients with respiratory symptoms and normal spirometry who have air trapping in lung volume measurements have worse outcomes than those with no air trapping. Those patients at risk for COPD may suffer early obstructive lung disease which has not yet met the spirometric criteria for COPD diagnosis.
    I congratulate the authors for their study as they address a very clinically relevant topic. Further studies are neede...

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  • Response to “Prospective randomised controlled trial: fixed 1-year screening interval group versus a tailored intervals group,” letter response by Silva et al

    We thank the authors of the letter in response to our paper for their interest and positive appraisal of our model. Likewise, we appreciate the design of the Multicenter Italian Lung Detection (MILD) trial which, despite its small sample size, demonstrates that annual intervals are unnecessary for the majority of screenees. Once more European data is available to perform cost-effectiveness analyses, we hypothesize that personalised screening intervals will prove to be the preferred design. Furthermore, it is estimated that most inclusion criteria used to select high-risk participants encompass only 70% of all lung cancer cases in the population; reassessing risk and tailoring interval groups after the baseline scan may enable the inclusion of persons of lower risk. As Silva et al mentioned, there is no reason to set the upper limit of follow-up intervals at 2-years. We also agree that volumetric nodule measurements are better suited for determining follow-up procedures than (perpendicular) diameter, and hope to be able to implement this into a future model. Moreover, risk scores may be calculated autonomously by computers in the future, with only a select few dubious cases requiring radiologist attention.

  • The EPICC trial, is it possible to perform intensive rehabilitation in the current framework of intensive care?

    The EPICC trial addresses the rarely investigated topic of rehabilitation in the critical care setting [1]. We note with interest that no improvement was found in outcomes in the rehabilitation group compared to the standard treatment group. Some of the reasons are clearly highlighted by Schaller et al. in their response to the paper including the time to starting intervention, therapy times and also sample size. Only 41% of the participants in the intervention group and 35% of the standard treatment group contributed data throughout the study period. In addition to this, only 8% of the intervention group managed over half the target therapy time and the EPICC trial showed that ‘an extra 10 minutes of physical therapy per day does not make a difference [2]’
    This study triggered an audit within our own 16 bedded mixed surgical and medical intensive care department assessing the number of sessions carried out over a 2 week period compared to those attempted. We investigated the actual duration of sessions achieved as compared to a target of 45 minutes rehabilitation each day during the working week (Monday-Friday). On average, 23.3 (standard deviation 20.19 minutes) minutes of rehabilitation per day was achieved and only 35% of attempted physical therapy sessions were completed. These figures are similar to those cited within the EPICC trial and highlight some of the difficulties of achieving longer therapy times within a busy intensive care department. Some of the fac...

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