Airway obstruction due to decreased airway diameter and increased incidence of mucus plugs has not been directly observed in asthma exacerbation. We studied the changes in the inner diameter of the airway (Din) and the frequency of mucus plugs by airway generation in patients with asthma exacerbation. We compared these patients to those in a stable phase using high-resolution computed tomography (HRCT).P = 0.016), 0.88 (P = 0.002), 0.83 (P = 0.001), 0.80 (P = 0.001), and 0.87 (NS) in the second-, third-, fourth-, fifth-, and sixth-generation bronchi, respectively. The percentages of airway obstruction due to mucus plugs were notably higher in the fourth- and fifth-generation bronchi  than in the other generations of bronchi.Thirteen patients with asthma were studied by HRCT during asthma exacerbation and in a stable period. The HRCT study was performed on patients who could safely hold their breath for a short while in a supine position 1 hour after initial treatment for asthma exacerbation. Using a curved multiplanar reconstruction (MPR) software, we reconstructed the longitudinal airway images and the images exactly perpendicular to the airway axis to measure the Din and mucus plugs from the second-  to sixth-generation bronchi in all segments of the lungs.The ratios of Din (exacerbation/stable) were 0.91(Among the bronchi examined, the fourth- and fifth-generation bronchi were significantly obstructed during asthma exacerbation compared with the stable phase in terms of a decreased airway diameter and mucus plugs. In asthma exacerbation, the Global Initiative for Asthma (GINA) guideline recommends inhalation treatments with a short-acting beta-2 agonist (SABA) and ipratropium bromide in addition to systemic corticosteroids . HoweverRecently, a quantitative image analysis of airway obstruction due to mucus plugs has been explored in severe asthma . QuantitThe purpose of this study is to evaluate the changes in Din and the frequency of airway occlusion by mucus plugs from the segmental bronchus (second generation) to the sixth-generation bronchi by comparing HRCT data during asthma exacerbation with those obtained in the stable phase. The findings might provide a new dimension in quantifying asthma severity and asthma heterogeneity.2 saturation, and accessory muscles being used, for the determination. The patients with asthma exacerbation with life-threatening signs, as assessed by the doctor in charge, were excluded from this study. The CT study was performed 1 hour after initial treatments to evaluate the airway obstruction and screen for other comorbidities that mimic asthma exacerbation, such as bronchopneumonia or heart failure. In the stable phase of asthma, a CT study was performed to assess airway remodeling and airway dimensions. Stable asthma was defined as the absence of clinic visits for asthma exacerbation, unchanged use of asthma medication for maintenance therapy, and the stable use of rescue medication (no more than four puffs per day of a short-acting bronchodilator) during the previous month.The Institutional Review Board of Saitama Cardiovascular and Respiratory Center approved this study (IRB No. 2012 033), and written informed consent was obtained from all study patients. CT scans of the subjects were obtained during asthma exacerbation and in the stable phase during the follow-up period. There was over 6 months between the CT scans in the exacerbation phase and the recovery phase. The asthma severity in the stable phase and exacerbation severity were classified according to the GINA guidelines Reviewers' comments:Reviewer's Responses to QuestionsComments to the Author1. Is the manuscript technically sound, and do the data support the conclusions?The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: YesReviewer #2: YesReviewer #3: Yes**********2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: I Don't KnowReviewer #2: YesReviewer #3: Yes**********3. Have the authors made all data underlying the findings in their manuscript fully available?PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.The Reviewer #1: YesReviewer #2: NoReviewer #3: No**********4. Is the manuscript presented in an intelligible fashion and written in standard English?PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.Reviewer #1: NoReviewer #2: NoReviewer #3: No**********5. Review Comments to the AuthorPlease use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. Reviewer #1: In this paper, Yoshida et al. investigated the utility of using Chest CT scans to evaluate airway diameter and mucus plugs in a small cohort of patients with asthma both during and after an exacerbation. This paper builds on growing evidence from several groups that CT scans provide useful information in quantifying asthma severity, and can possibly provide a new dimension of asthma heterogeneity .Yoshida et al. studied 13 asthmatics one hour after initial presentation for an asthma exacerbation, as long as they were able to lie flat and sustain a breath hold during CT imaging. Asthma diameter was quantified using curved multiplanar reconstruction software, and mucus plugs were identified as areas of airway opacification. The main findings were that multiple airways were narrower and more occluded during an exacerbation, as compared to steady state. Although these findings are predictable and not surprising in and of themselves, they add further support to the idea that CT scans can be useful adjuncts to other measures of asthma severity.The paper is succinctly written with clear figures and results. The manuscript would benefit from careful proofreading and correction for English grammar (starting with the introductory sentence of the Background).A few additions and modifications would strengthen the impact of the paper.1) Please provide the length of time between the exacerbation phase and the recovery phase CT scans.2) Please explain how their quantification of airway occlusion from mucus plugs distinguished between opacified airways, adjacent blood vessels, or possibly airway collapse.3) How does their method of counting mucus plugs compare or contrast with the “mucus score” reported by Dunican et al (reference 11)?4) Please provide more information about the subjects studied, including: (i) medication use, (ii) timing of lung function tests relative to CT imaging, (iii) other lung function data (e.g. RV/TLC ratio or bronchodilator reversibilty), and (iv) any data on blood eosinophils or FeNO?5) It would be more informative to represent the data using individual data points as well as averages, and not just summary bar graphs.6) Was there any correlation between their CT indices of airway narrowing, or mucus plugs, with lung function measurements, or severity of the asthma exacerbation?Reviewer #2: Yoshida et al. present a study of airway obstruction measured by two different indices on CT, in patients with asthma at time of exacerbation and at stable follow-up. The first main finding of the paper is that internal diameters (Din) of the 2nd to 6th generation airways are smaller during asthma exacerbation than at follow-up and that these differences are greater in progressively smaller airways up to the 5th generation. The second main finding of the paper is that mucus plugs were more frequent on CT scan up to the 5th generation in patients during asthma exacerbation than at follow-up . The authors conclude that the greatest obstruction at time of exacerbation was seen in the 4-5th generations and that this obstruction was seen in both decreased Din  and increased mucus plugging. There is a lack of published data in the literature comparing patients longitudinally during exacerbation and at stability, which this paper goes some way to address, though in small numbers.Major commentsBy way of background in the abstract, the authors state that “decreased airway diameter and increased mucus plugs … influence the effectiveness of inhaled drugs”. The reviewer is not aware of data supporting this statement. In the introduction, the authors present a good unbiased review of the literature in this area. At the conclusion of the introduction, the authors refer to “the pitfall of inhalation therapy at asthma exacerbation” which needs to be supported by a reference. The conclusion in the abstract accurately reflect and do not overstate the findings of the paper and do notIn the methodology, the authors describe an automated airway tree segmentation using a spanning tree algorithm. I think this needs to be more descriptive. Is this fully automated or is there any manual component to the measurement as there is with many segmenting algorithms? Are the mucus plug measured or counted manually on the segmented CT scans? Counting is alluded to in a figure legend but not in the methods text. How are the same airways/plugs compared longitudinally across scans? How did the authors handle multiple mucus plugs in the same segment? A more detailed description in the on the algorithm for generating the CT measurements and mucus measurements would be welcome in the main text or supplementary data.In the statistics section there is no reference to adjusting for any confounding variables.In the results, the authors claim that the decrease in Din and presence of mucus plugs contribute to airway obstruction during an asthma exacerbation but, although pulmonary function was described in the methods, no PFT data is reported in the results. This is likely because it is not standard practice to perform PFT;s during exacerbation, but it would be nice to show a correlation between FEV1 or FEV1/FVC and 4-5th airway obstruction by DIN, by plugs and by a combination of both. In this way, the authors claim that these CT findings are particularly important for airway obstruction would be supported by the data. There is not data in this study to support the hypothesis that the changes in Din and mucus plugs are influencing the pharmacodynamics of inhalation therapy.In the discussion, the authors report that mucus plugs were less frequently observed in the more distal airways but this is not reflected in their data. The authors discuss the possible role of surfactant in the aetiology of mucus plugging in the small airway but most airways analysed in this study were not considered small airways (<2 mm).Minor comments:The text would benefit from review by a native English speaker. In general, it was well written and there were only a few places in the text where minor changes should be made to the language.Please clarify what is meant by “The exacerbation severity … classified according to GINA guideline”. Authors should clarify whether they mean severity based on symptoms, peak flow, vital signs on presentation etc.Number of patients recruited should be reported at the beginning of the results section. A consort diagram showing the number of patients screened, excluded, did not consent etc., could be included.Asthma control is referred to in the results  but not defined in the methods.How was bronchiectasis measured? It is referred to in the results but not the methods.The authors overstate the importance of these finding in suggesting that patients should be made aware that the limited effectiveness of their inhalers during an acute exacerbation and that they should use a systemic corticosteroid instead. This goes agains current guidelines and is not a message we would want to emphasise at this stage. Rewording should be considered.Reviewer #3: The manuscript titled “Changes in Airway Diameter and Mucus Plugs in Patients with Asthma Exacerbation” by Yoshida et al. is focused on identifying airway diameter changes and presence of mucus plugs immediately following an asthma exacerbation. To do this, the authors followed a small cohort of stable and unstable asthmatics. High resolution CT (HRCT) images were acquired at baseline and one-hour following the exacerbation. In addition, spirometry tests were collected at baseline. While the study is unique, mainly because of the imaging performed immediately following an exacerbation, there are a few points that should be addressed prior to publication:My main concern lies in the identification of mucus plugs during the exacerbation phase. How are mucus plus distinguished from airway closure due to hyper-constricted airways? Specifically, why would there be more mucus plugs during an exacerbation than during the stable phase?Why were the PFTs taking two weeks after the HRCT scans were acquired during the stable phase? Should they have been collected at the same time? Were PFTs attempted during or immediately following the exacerbation?The sentence on line 193 is confusing: “This study clearly showed that small airway shifted toward proximal at asthma exacerbation.” Is this because the small airways are solely defined based on their diameter and the diameters become smaller because of airway constriction? Should classification of which airways are considered small should be done at baseline to allow for direct comparison?The CT scans were collected at the end of inspiration – which I assume is FRC + TV? Were the lung volumes verified? Specifically, did the authors verify that the images were acquired at the same lung volume during both the baseline and exacerbation scans?While the manuscript is clear, and it is easy to understand the data collection and interpretation of the results, I believe that the manuscript could benefit from a careful grammar analysis. For example, the first sentence of the abstract should read something like: “Airway obstruction, due to decreased airway diameters and an increased incidence of mucus plugs, are two structural variables that influences the effectiveness of inhaled drugs during an asthma exacerbation.”**********what does this mean?). If published, this will include your full peer review and any attached files.6. PLOS authors have the option to publish the peer review history of their article  digital diagnostic tool,  20 Dec 2019Response to the reviewers’ commentsReviewer #11) Please provide the length of time between the exacerbation phase and the recovery phase CT scans.Answer: Materials and Methods section, Study design and participants in revised text. (lines 76-77) Thank you for your comment. We added the following:　 “There was over 6 months between the CT scans in the exacerbation phase and the recovery phase.” 2) Please explain how their quantification of airway occlusion from mucus plugs distinguished between opacified airways, adjacent blood vessels, or possibly airway collapse.Answer: Materials and Methods section, CT data acquisition and image analyses in revised text. (lines 118-121)Thank you for the comment. We added the following sentence in the text.“Mucus plugs were distinguished from focal opacified airways, such as airway collapse or adjacent blood vessels, identifying no focal decrease of outer airway caliber and recognizing adjacent blood vessels between opened proximal and distal airways from the mucous area.” 3) How does their method of counting mucus plugs compare or contrast with the “mucus score” reported by Dunican et al. (reference 11)?Answer: Discussion section in revised text. (lines 286-291)Thank you for the comment. We added the following sentence in the text.“The definition of mucus plugs by CT image was the same as that of the report by Dunican et al. [11]. However, a plugged airway in a cross section and longitudinal section could not necessarily be seen by conventional HRCT images. In this study, precise cross-sectional and longitudinal-sectional images could be obtained by MPR for each bronchial segment. Also, we analyzed the peripheral airway to the sixth-generation bronchi.” 4) Please provide more information about the subjects studied, including (i) medication use, (ii) timing of lung function tests relative to CT imaging, (iii) other lung function data , and (iv) any data on blood eosinophils or FeNO.Answer: Table 1 and Materials and Methods section in revised text. (lines 139-140)Thank you for the comment. The matters that you pointed out about (i) medication use, (iii) other lung function data on bronchodilator reversibility, and (iv) any data on blood eosinophils are now included in Table 1. The matter that you pointed out about (ii) timing of lung function tests relative to CT imaging is now addressed in the revised text as follows: “Pulmonary function tests (PFTs) were performed within two weeks of obtaining the HRCT scans in the stable phase.”5) It would be more informative to represent the data using individual data points as well as averages, and not just summary bar graphs.Answer: Figures 3, 4, 5, and S1 as well as Figure Legend in revised text.Thank you for the comment. We changed the figures by using summary bar graphs and individual data points as well as averages. Each point represents the mean Din ratio of each segment or the percentage of mucus plugs in each segment of 13 subjects.6) Was there any correlation between their CT indices of airway narrowing, or mucus plugs, with lung function measurements, or severity of the asthma exacerbation?Answer: Table 2, Result, Discussion section in revised text.Thank you very much for this important comment.Lung function and CT indices were analyzed in the stable phase and added to Table 2, the results (second paragraph from the last: lines 240-245), and the discussion section (third paragraph: lines 301-305). The results of the CT indices and severity of asthma exacerbation are presented in the last paragraph of the results section (lines 259-265).Response to the reviewers’ commentsReviewer #2Major commentsBy way of background in the abstract, the authors state that “decreased airway diameter and increased mucus plugs … influence the effectiveness of inhaled drugs”. The reviewer is not aware of data supporting this statement. In the introduction, the authors present a good unbiased review of the literature in this area. At the conclusion of the introduction, the authors refer to “the pitfall of inhalation therapy at asthma exacerbation” which needs to be supported by a reference. The conclusion in the abstract accurately reflect and do not overstate the findings of the paper and do notAnswer: Abstract, Introduction section in revised text.Thank you for this comment.We changed the background section in the abstract as follows: (line 19)“Airway obstruction, due to decreased airway diameter and increased incidence of mucus plugs, has not been directly observed at asthma exacerbation.”We also changed the introduction section as follows: (lines: 54-55)“Thus, the airway dimeter and mucus plug are two critical factors to limit the effectiveness of inhaled corticosteroids (ICS) and bronchodilators at asthma exacerbations. The mucus plugs, as well as narrowed airways, could be the target of inhaled corticosteroids and bronchodilators during asthma exacerbation.”In the methodology, the authors describe an automated airway tree segmentation using a spanning tree algorithm. I think this needs to be more descriptive. Is this fully automated or is there any manual component to the measurement as there is with many segmenting algorithms? Are the mucus plug measured or counted manually on the segmented CT scans? Counting is alluded to in a figure legend but not in the methods text. How are the same airways/plugs compared longitudinally across scans? How did the authors handle multiple mucus plugs in the same segment? A more detailed description in the on the algorithm for generating the CT measurements and mucus measurements would be welcome in the main text or supplementary data.Answer: Materials and methods section, CT data acquisition and image analyses in revised text.Thank you for the comment.The trace of bronchial trees was half manually. As described in the text, one　bronchus was selected on the principle that it should be more centered and well recognized in one segment in the stable and acute phase. If the bronchus was obstructed by a mucus plug before the sixth-generation bronchus, we traced the bronchus manually to the sixth-generation bronchus. We recorded the mucus plugs as “yes” or “no” from the second- to the sixth-generation bronchial compartments in a single segment. We then calculated the percentage of mucus plugs among the 13 subjects in a given bronchial generation in a given lung segment.In the statistics section there is no reference to adjusting for any confounding variables.　Answer: Materials and methods section, CT data acquisition and image analyses in 　　revised text. (lines: 122-125)We added the following comments in materials and methods section to show how we evaluated the Din and mucus plug.“We noted the presence of mucus plugs as “yes” or “no” from the second- to sixth-generation bronchial compartments in one selected airway in one segment. We could then calculate the percentage of mucus plug among the 13 subjects in a given bronchial generation in a given lung segment.” In the results, the authors claim that the decrease in Din and presence of mucus plugs contribute to airway obstruction during an asthma exacerbation but, although pulmonary function was described in the methods, no PFT data is reported in the results. This is likely because it is not standard practice to perform PFT;s during exacerbation, but it would be nice to show a correlation between FEV1 or FEV1/FVC and 4-5th airway obstruction by DIN, by plugs and by a combination of both. In this way, the authors claim that these CT findings are particularly important for airway obstruction would be supported by the data. There is not data in this study to support the hypothesis that the changes in Din and mucus plugs are influencing the pharmacodynamics of inhalation therapy.　Answer: Results and Discussion section in revised text.Thank you for the comment.We did not perform a PFT in patients with acute asthma. We performed PFT in patients in the stable phase, and the data were used only for patient characteristics, Table 1. It is well known that Din correlates with PFT data, but we did not analyze the correlation in this study because the size of the study was too small.In the revised manuscript, we analyzed the relationship between PFT data and CT image data. To our surprise, the mean Din of all bronchial compartments nor the mean Din of the second to the sixth airway was not correlated with the predicted percentage FEV1 or FEV1/FVC, however, the total number of mucus-plug-positive bronchial compartments were correlated with the predicted percentage FEV1 and FEV1/FVC (Table 2 was added). The data further supports the results of Dunican’s paper (reference 11).In the discussion, the authors report that mucus plugs were less frequently observed in the more distal airways but this is not reflected in their data. The authors discuss the possible role of surfactant in the aetiology of mucus plugging in the small airway but most airways analysed in this study were not considered small airways (<2 mm).Answer: Results and Discussion section in revised text. (line: 323-325)Thank you for the comment.We discussed the surfactant to explain the results of Figs. 4 and S2. We changed the section in the discussion as follows: 　“Therefore, the airway surfactant from the alveolus might partly explain why there are more mucus plugs in the fourth- and fifth-generation bronchi than in sixth-generation bronchi.”Minor comments:The text would benefit from review by a native English speaker. In general, it was well written and there were only a few places in the text where minor changes should be made to the language.Answer:Thank you for the comment.The revised text was reviewed by a native English speaker.Please clarify what is meant by “The exacerbation severity … classified according to GINA guideline”. Authors should clarify whether they mean severity based on symptoms, peak flow, vital signs on presentation etc.Answer: Materials and methods section, Study design and participants in revised text.(lines: 81-86)Thank you for the comment. We added the text as follows:“The severity of asthma exacerbation in this study’s patients was determined according to the descriptions in the section “Management of asthma exacerbations in the emergency department” in the GINA guidelines. We used objective assessment and other measurements, such as respiratory rate, pulse rate, O2 saturation, and accessory muscles being used, for the determination.”Number of patients recruited should be reported at the beginning of the results section. A consort diagram showing the number of patients screened, excluded, did not consent etc., could be included.Answer: Result section in revised text. (lines: 161-163)Thank you for the comment. We added the following sentence to the result section:“Seventeen patients who had emergency visits to our center with asthma attacks were included. Of these, three were excluded because of their life-threatening condition. One did not consent, and the remaining 13 patients were enrolled.”Asthma control is referred to in the results  but not defined in the methods.Answer: Materials and methods section, Study design and participants in revised text.(lines: 78-79)Thank you for the comment. We added the following sentence in the methods section,“We evaluated asthma control according to the consensus-based GINA symptom control tool.”How was bronchiectasis measured? It is referred to in the results but not the methods.Answer: Materials and methods section, CT data acquisition and image analyses in revised text. (lines: 121-122)Thank you for the comment.We added the following sentence in the materials and methods section, CT data acquisition and image analysis.“We checked whether mucus plugs were associated with bronchiectasis, defined as a bronchoarterial ratio of greater than 1.5.” The authors overstate the importance of these finding in suggesting that patients should be made aware that the limited effectiveness of their inhalers during an acute exacerbation and that they should use a systemic corticosteroid instead. This goes agains current guidelines and is not a message we would want to emphasise at this stage. Rewording should be considered.Answer: Discussion section in revised text.Thank you very much for the important comment.“Nonetheless, it should be important to note that the first-line treatment for asthma exacerbation is the use of inhalers [1], and they act directly on obstructed airways. This study shows considerable mucus plugs in acute asthma, but all the patients in this study were successfully relieved by inhaled bronchodilators and systemic corticosteroids. It might be that even partial responses to the inhalers were effective to relieve dyspnea in asthmatics.”We changed the first paragraph of the introduction and added the above comment to the conclusion part of the discussion (lines: 351-357).Response to the reviewers’ commentsReviewer #3My main concern lies in the identification of mucus plugs during the exacerbation phase. How are mucus plus distinguished from airway closure due to hyper-constricted airways? Specifically, why would there be more mucus plugs during an exacerbation than during the stable phase?Answer: Materials and methods section, CT data acquisition and image analyses in revised text. Thank you for the comment.We added the following sentence to distinguish mucus plugs from airway closure.“Mucus plugs were distinguished from focal opacified airways, such as airway collapse or adjacent blood vessels, identifying no focal decrease of outer airway caliber and recognizing adjacent blood vessels between opened proximal and distal airways from the mucous area.” (lines: 118-121)Increased mucus plugs were reported in fatal asthma , and its mechanisms are considered as type 2 inflammation, as noted in the discussion [11].Why were the PFTs taking two weeks after the HRCT scans were acquired during the stable phase? Should they have been collected at the same time? Were PFTs attempted during or immediately following the exacerbation?Answer:Thank you very much for the comment.It is desirable to test CT and PFTs on the same day, and they were done on the same day in five patients. However, we also considered it acceptable if they were done within two weeks.The sentence on line 193 is confusing: “This study clearly showed that small airway shifted toward proximal at asthma exacerbation.” Is this because the small airways are solely defined based on their diameter and the diameters become smaller because of airway constriction? Should classification of which airways are considered small should be done at baseline to allow for direct comparison?Answer: Discussion section, third paragraph in revised text.Thank you for the comment.To our knowledge, the original definition of “small airways” is solely defined based on their diameter. However, what we would like to say is that sixth-generation bronchi are less than 2 mm in diameter in the stable phase and during exacerbation. We changed the section as follows:“In a pathological model of bronchial trees, small airways were reported to comprise the airway generations 8–23 [21]. Since airways with a diameter of < 2 mm are classified as small airways, this study covers small airways”. the zone of small airways may shift according to the changes of airway diameter that occur in asthma. This study clearly showed that small airway shifted toward proximal at asthma exacerbation.” The CT scans were collected at the end of inspiration – which I assume is FRC + TV? Were the lung volumes verified? Specifically, did the authors verify that the images were acquired at the same lung volume during both the baseline and exacerbation scans?　Answer: Materials and methods section, CT data acquisition and image analyses in 　　revised text.Thank you for the comment.The CT images were acquired at the same lung volume during the baseline and exacerbation at the end of inspiration. We checked the lung volume by the lung size and lung architecture in the same lung slice in a CT image.We changed the sentence as follows: (lines 99-101)“A 256-slice CT scanner  was used as previously described [17]. The CT scans were obtained from the suspended end-inspiratory volume at baseline and during exacerbation. We also checked lung size and lung architecture in the same slice to confirm they were obtained at the end-inspiratory volume.” While the manuscript is clear, and it is easy to understand the data collection and interpretation of the results, I believe that the manuscript could benefit from a careful grammar analysis. For example, the first sentence of the abstract should read something like: “Airway obstruction, due to decreased airway diameters and an increased incidence of mucus plugs, are two structural variables that influences the effectiveness of inhaled drugs during an asthma exacerbation.”Answer:Thank you very for the comment.The revised text was reviewed by a native English speaker.AttachmentResponse to reiewers.docxSubmitted filename: Click here for additional data file. 3 Feb 2020Changes in airway diameter and mucus plugs in patients with asthma exacerbationPONE-D-19-25209R1Dear Dr. Takaku,We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.https://www.editorialmanager.com/pone/, click the "Update My Information" link at the top of the page, and update your user information. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.Shortly after the formal acceptance letter is sent, an invoice for payment will follow. To ensure an efficient production and billing process, please log into Editorial Manager at onepress@plos.org.If your institution or institutions have a press office, please notify them about your upcoming paper to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, you must inform our press team as soon as possible and no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact With kind regards,Josué SznitmanAcademic EditorPLOS ONEAdditional Editor Comments :Reviewers' comments:Reviewer's Responses to QuestionsComments to the Author1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.Reviewer #1: All comments have been addressedReviewer #3: All comments have been addressed**********2. Is the manuscript technically sound, and do the data support the conclusions?The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: YesReviewer #3: Yes**********3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: YesReviewer #3: Yes**********4. Have the authors made all data underlying the findings in their manuscript fully available?PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.The Reviewer #1: YesReviewer #3: No**********5. Is the manuscript presented in an intelligible fashion and written in standard English?PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.Reviewer #1: YesReviewer #3: Yes**********6. Review Comments to the AuthorPlease use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. Reviewer #1: The authors adequately addressed all of the comments raised during the initial review. The inclusion of individual data points and new data about patients strengthens the impact of the manuscript.Reviewer #3: (No Response)**********what does this mean?). If published, this will include your full peer review and any attached files.7. PLOS authors have the option to publish the peer review history of their article (If you choose “no”, your identity will remain anonymous but your review may still be made public.Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.Reviewer #1: NoReviewer #3: Yes: Jessica M Oakes 13 Feb 2020PONE-D-19-25209R1 Changes in airway diameter and mucus plugs in patients with asthma exacerbation Dear Dr. Takaku:I am pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. onepress@plos.org.If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact plosone@plos.org. For any other questions or concerns, please email Thank you for submitting your work to PLOS ONE.With kind regards,PLOS ONE Editorial Office Staffon behalf ofProf. Josué Sznitman Academic EditorPLOS ONE


Patient–ventilator asynchrony is associated with increased morbidity and mortality. A direct causative relationship between Patient–ventilator asynchrony and adverse clinical outcome have yet to be demonstrated. It is hypothesized that during trigger errors excessive pleural pressure swings are generated, contributing to increased work-of-breathing and self-inflicted lung injury. The objective of this study was to determine the additional work-of-breathing and pleural pressure swings caused by trigger errors in mechanically ventilated children.Prospective observational study in a tertiary paediatric intensive care unit in an university hospital. Patients ventilated > 24 h and < 18 years old were studied. Patients underwent a 5-min recording of the ventilator flow–time, pressure–time and oesophageal pressure–time scalar. Pressure–time–product calculations were made as a proxy for work-of-breathing. Oesophageal pressure swings, as a surrogate for pleural pressure swings, during trigger errors were determined.Nine-hundred-and-fifty-nine trigger errors in 28 patients were identified. The additional work-of-breathing caused by trigger errors showed great variability among patients. The more asynchronous breaths were present the higher the work-of-breathing of these breaths. A higher spontaneous breath rate led to a lower amount of trigger errors. Patient–ventilator asynchrony was not associated with prolonged duration of mechanical ventilation or paediatric intensive care stay.The additional work-of-breathing caused by trigger errors in ventilated children can take up to 30–40% of the total work-of-breathing. Trigger errors were less common in patients breathing spontaneously and those able to generate higher pressure–time–product and pressure swings.Not applicable. Mechanical ventilation (MV) is one of the most common practiced interventions in the paediatric intensive care unit (PICU) . In the When allowing for spontaneous breathing, it is imperative to achieve good interaction between patient demand and ventilator delivery. Patient–ventilator asynchrony (PVA) arises when the patient and ventilator are out-of-sync at any time point throughout the breathing cycle , 7. It mPVA), especially when there are trigger errors  kPa and median Comfort B score 12   were analysed. Median breaths during the 5-min recording was 180 . The median age was 3.0  months and median weight 5.6  kg. Median time patients were ventilated before data acquisition was 2.9  days. Median duration of MV was 5.9  days. NMB was used in 19 (61%) patients for a median duration of 31.8  hours. At the moment of data acquisition, NMB was stopped for a median duration of 25  hours. Twenty-three (74%) patients were admitted with primary respiratory failure, five (16%) after cardiac surgery, two (7%) for septic shock and one (3%) patient was admitted after trauma. Cuffed ETTs were used in 23 (74%) patients. Twenty-four (77%) patients were ventilated using pressure controlled (PC) / assist control (AC), 6 (19%) were supported with continuous positive airway pressure (CPAP) plus pressure support (PS) and one patient was on pressure-regulated volume control (PRVC/SIMV) + PS. During the recordings, median Vte was 6.9  mL/kg actual bodyweight, median end-tidal COr = 0.537, p = 0.006), higher measured PIP  and higher Pmean . Patients had significantly lower TE-index if they had higher spontaneous breath rate  and higher PTPBREATH .Nine-hundred-and-fifty-nine trigger errors in 28 (90%) patients were identified, yielding a median TE-index of 9.7% . Patients had significantly lower TE-index when they were ventilated with a higher set inspiratory pressure , PIP , Pmean  and higher mandatory breath rate , especially when there spontaneous breath rate was significantly lower .The median PTPTOTAL significantly increased if patients were breathing more spontaneously  and mandatory breath rate was reduced . Patients able to generate a higher PTP for a single effective breath  and had higher levels of PTPTOTAL  spent less time on the ventilator.PTPoes was 2.93 cm H2O  when the triggering was effective and 1.94 cm H2O  (p = 0.06) when there was a trigger error. This resulted in a median ΔPoes-ineffective / ΔPoes-effective of 0.79 . The median work patients generated during effective triggering (PTPBREATH) was 0.41 cm H2O*s . This was significantly higher compared with the work generated during ineffective triggering PTPPVA . This resulted in a median PTPPVA/PTPBREATH of 0.69 . We found that patients with a higher ΔPoes-ineffective/ΔPoes-effective had a higher ITI  if they did not have spontaneous breaths outside the mandatory breath rate. ITI was significantly lower when patients had a total breath rate greater than the mandatory breath rate . Similar observations were made for PTPPVA/PTPBREATH .Median ΔPCUMULATIVE_PVA > 75th percentile, > 17.7 cm H2O*s)  did not yield different results regarding patient discomfort, duration of MV or PICU stay , 30. In To our best knowledge this is the first study investigating the physiological effects of trigger errors in a heterogeneous group of ventilated children. Our main finding was that the additional work-of-breathing caused by trigger errors showed great variability among patients. Overall we found that the more asynchronous breaths were present the higher the work-of-breathing of these breaths. Our data also suggested that preserved respiratory muscle strength and higher spontaneous breath rate led to a lower amount of trigger errors. Yet, in our study PVA was not associated with prolonged duration of MV or PICU stay.2O*s/min  during + 10 cmH2O pressure support ventilation, 101 cmH2O*s/min  on CPAP + 5 cmH2O and 135 cmH2O*s/min  5 min post-extubation without any positive pressure support in 409 children undergoing a spontaneous breathing trial (SBT)  before and 83 cmH2O*s/min  during the SBT ) during the 5-min recording. Taking the previously reported PTP values into consideration, the added work from trigger errors in our study may thus be interpreted as negligible and of little clinical importance [MV is initiated to reduce the respiratory muscle workload until the clinical condition of the patient has at least partially improved. However, there is limited data on acceptable levels of PTP in mechanically ventilated children. In healthy adults, PTP varies between 50 and 150 cm H2O*s/min . Khemanial (SBT) . Others  the SBT . The PTPportance , 31. Nonoes in mechanically ventilated children. In our study ΔPoes during trigger errors for the entire population and for the patients with severe PVA were below values Mortamet et al. and Rubin et al. described in paediatric population receiving MV [oes for trigger errors were below pleural pressure swings during conventional MV it may be supposed these pleural pressure swings did not contributed to patient self-inflicted lung injury. During the first 2 years of life there is a substantial reduction in chest wall compliance [There is also very little data on ΔPiving MV , 32. Becmpliance . Hence, CUMULATIVE PVA increased with more asynchrony. In addition, with an increase in asynchrony we found that also PTP and ΔPoes for an individual trigger error increased. These observations may have clinical implications. If trigger errors are merely detected using flow- and pressure—time tracings and not by measuring true patient effort using oesophageal pressure tracings, differentiation between “acceptable” and “harmful” trigger errors is not possible. This differentiation might be important, because the variability in PTP and ΔPoes for an individual ineffective breath could partially explain that PVA has different effects on patient outcome. To illustrate, de Wit et al. and Blanch et al. described that PVA in the first 24 h and throughout MV was associated with prolonged ventilation time and mortality [In our study, PTPortality , 15. In ortality . It may ortality . When thSome limitations of our study must be addressed. First, our data represents a single-center study, limiting generalizability. Second, in this study we found a lower TE-index than we previously did . This isThe additional work-of-breathing caused by trigger errors in ventilated children can take up to 30–40% of the total work-of-breathing. Trigger errors were less common in patients breathing spontaneously and those able to generate higher PTP and pressure swings.Additional file 1. Data supplement to; Additional work of breathing from trigger errors in mechanically ventilated children. Data containing the local ventilation guideline. Subgroup analysis of patients with an TE-index >75th percentile and PTPCUMULATIVE_PVA >75th percentile.


Kidney dysfunction is a common complication in patients with severe liver cirrhosis. There is a need for discovery and validation of novel biomarkers for earlier AKI detection. The aim of this study was to determine if tubular injury markers: NGAL and KIM-1 could be helpful in the early diagnosis of AKI in patients undergoing therapeutic paracentesis. This preliminary study included 24 adult patients diagnosed with liver cirrhosis who had been hospitalized due to massive ascites requiring paracentesis. Pre- and post-paracentesis plasma samples were taken from each patient and biomarkers were measured.p = 0.06). Serum NGAL level, post-procedure, was 3 times greater in AKI subgroup. Before paracentesis, the levels of serum and urinary NGAL were similar between patients and controls; while urinary KIM-1 was markedly increased in liver cirrhotic patients . Although urinary NGAL levels in AKI patients were 5-time greater than in non-AKI subgroup, the difference did not reach statistical significance (13.2 vs 1.5 pg/mL,  Kidney injury markers, especially serum NGAL, may be useful for the early detection of AKI. However, further research is required to determine if biomarkers of kidney injury may help identify patients with cirrhosis who would most likely benefit from early AKI prevention and treatment. Kidney dysfunction is a common complication in patients with severe liver cirrhosis related to the abnormal hemodynamics of systemic and splanchnic arterial vasodilatation and extrahepatic vasoconstriction . Acute kKIM-1, a marker of proximal tubular injury, is a transmembrane protein upregulated by renal ischemia. It is barely detectable in the urine of healthy subjects but substantially increased in patients with acute tubular necrosis (ATN). Of note, no increase was observed in patients with prerenal azotemia, urinary tract infection and chronic kidney disease ,9. In a Neutrophil gelatinase-associated lipocalin (NGAL) is a 25 kDa protein belonging to the lipocalin superfamily ,12. Whilpostparacentesis syndrome, which occurs in up to 80% of cases when a large volume paracentesis is performed without anticipatory therapeutic volume replacement, was firstly described by Gines et al. in 1988  + 11.2 × ln [INR] + 9.57 × ln [serum creatinine (mg/dL)] + 6.43 . GlomeruAKI was defined as a rise in creatinine of equal or more than 0.3 mg/dL or 50% from baseline as recommended by a working group composed of members of the IAC and ADQI who based this cutoff on Stage 1 of the AKIN criteria .The analysis was performed using MedCalc 18.6 licensed software . Quantitative variables are presented as means with 95% confidence interval or medians with interquartile range (1–3Q), due to non-parametric distribution on numerous parameters. Qualitative variables are presented as absolute values and percentages.t-test and the Mann–Whitney U-tests, when appropriate. Correlation coefficients were calculated according to Spearman. For all analyses, p-value below 0.05 was considered as statistically significant.The chi-square test was used for qualitative variables. The inter-subgroup differences were assessed with the Student p < 0.001), platelet count ; albumin , and near significantly lower eGFR values  than the controls. As expected patients with liver cirrhosis had higher serum bilirubin , C-reactive protein (36.9 vs. < 5 mg/L), and INR  than controls. Before paracentesis, the levels of serum and urinary NGAL were similar between patients and controls; while urinary KIM-1 was markedly increased in liver cirrhotic patients.The clinical characteristics of the patients with liver cirrhosis (mostly Child-Pugh class B or C) and apparently healthy controls are summarized in R = 0.510; p = 0.01) but not urinary  NGAL levels in patient with liver cirrhosis. The association with eGFR was weaker . There was no association between kidney function measures and urinary KIM-1 levels.There was a strong correlation between serum creatinine and serum   .Serum NGAL level, post-procedure, was 3 times greater in AKI subgroup . In the There was no significant correlation between post-procedural changes in serum creatinine and changes in either serum and urinary NGAL or urinary KIM-1 levels .In cirrhosis, both renal impairment and ascites result from the circulatory dysfunction characterized by splanchnic arterial vasodilatation and results in a reduced effective arterial blood volume. Thus, the most important cause of kidney injury in cirrhosis is pre-renal injury, that may be additionally caused by large-volume paracentesis . There iSome studies were evaluating the usefulness of both urinary and serum biomarkers for the detection of AKI in patients with chronic liver failure. However, they were quite different than our study. Jiang et al. evaluated the AKI in acute-on-chronic liver failure, but they excluded patients with liver cirrhosis . The othn = 188), levels of kidney injury markers were comparable between patients with and without progression of AKI, even though the elevation was associated with poorer prognosis [To summarize all the observations above, one may say that predicting which patients will suffer progressive AKI is still a challenge. On the other hand, the injury markers may serve to identify patients at a highest risk for the worst outcomes who may benefit from early intervention. According to Belcher et al., the likelihood of progression and death is progressively higher with the increasing number of elevated biomarkers. As such, their elevation may precede the deterioration of the patient’s clinical status. In our study, we observed changes only in serum NGAL and KIM-1, associated with the increase in serum creatinine levels post paracentesis. This may be caused by a low number of participants. However, as previously reported by other authors in a larger number of participants .In conclusion, kidney injury markers may be useful for the early detection of AKI and are more sensitive than serum creatinine levels. However, further research in a large cohort is required to determine if biomarkers of kidney injury may help identify patients with cirrhosis who would most likely benefit from early AKI prevention and treatment.


The relationship between measured blood pH and HCO3−, and the sSID variables was examined using forward stepwise linear regression. Cox proportional hazard models were constructed to assess associations between potential predictor variables and mortality of goats during hospitalization.Retrospective study. Calculated tot acidosis were acid‐base disorders frequently encountered in sick goats. In sick goats, the sSID variables explained 97% and 100% of the changes in blood pH and HCO3−, respectively. The results indicated that changes in the respiratory rate (<16 respirations per minute), USI, and pH at admission were associated with increased hazard of hospital mortality in sick goats.Hypocapnia, hypokalemia, hyperchloremia, hyperlactatemia, and hyperproteinemia were common abnormalities identified in sick goats. Respiratory alkalosis, strong ion acidosis, and AsSID approach is a useful methodology to quantify acid‐base disorders in goats and to determine the mechanisms of their development. Clinicians should consider calculation of USI in sick goats as part of the battery of information required to establish prognosis.The  These 3 variables are the arterial partial carbon dioxide pressure (PaCO2), the strong ion difference (SID), and the total weak acid concentration (Atot−). The PaCO2 is regulated by the lungs and influences plasma H+ activity in a linear fashion.+, K+, Ca2+, Mg2+) and strong anions , D‐lactate−, uremic acids, ketoacids, and unmeasured strong ions (USI) to the changes in plasma pH and HCO3− concentration.tot− includes important nonvolatile weak buffers (mostly proteins and phosphate) that exert an independent effect on plasma H+ activity.sSID approach has been used to determine the acid‐base balance of healthy goats.sSID.Sick goats often are presented to tertiary hospitals with critical conditions such as acute diarrhea, pneumonia, gastrointestinal parasitism, pregnancy toxemia, mastitis, and urinary diseases such as urolithiasis. Regardless of presentation, these clinical abnormalities frequently result in marked acid‐base, fluid, electrolyte, and plasma protein disorders. The mechanisms contributing to acid‐base disorders in sick goats have not been extensively investigated. The few published studies focused on analysis of acid‐base disorders in goats with pregnancy toxemia− have been reported in critically ill humanIncreased concentrations of USI other than L‐lacsSID approach, to establish the quantitative contribution of the measured strong ion difference (SIDm), PCO2, USI, and total plasma proteins (TPP) to changes of blood pH and HCO3− concentration. Our study also aimed to investigate whether clinical, acid‐base, and biochemical variables, especially USI, on admission are associated with the mortality of sick goats. We hypothesized that sSID variables explain the majority of the changes in blood pH and HCO3− concentration of sick goats, and that admission concentrations of USI and L‐lac− are associated with mortality of sick goats.Our objectives were to investigate the acid‐base status of sick goats using the 22.1Medical records of all goats admitted at the Large Animal Hospital of the University of Florida, College of Veterinary Medicine, between January 2017 and September 2019 were reviewed. Goats were included in the study if they were >3 months of age, and if they had blood gas and TPP concentrations determined on admission before any treatment was instituted.vCO2, mm Hg), bicarbonate concentration , electrolyte concentrations , anion gap , blood glucose concentration (mg/dL), blood ß‐hydroxybutyrate (BHB) concentration, and blood creatinine concentration (mg/dL). All blood gas analyses were corrected for the patient's rectal temperature using a standard method employed by the blood gas analyzer.The following data were extracted from each record: age, breed, sex, heart rate , respiratory rate , rectal temperature , packed cell volume , TPP (g/dL), blood pH, venous partial pressure of carbon dioxide : [HCO3−] = S × PCO2 × 10(pH – pK1) with experimentally determined values for S (0.0307 [mmol/L]/mm Hg) and pK1 (6.095 at [NaCl] = 0.16 mmol/L) in plasma. The glucose, creatinine and L‐lac− concentrations were determined using an enzymatic‐amperometric technique. The PCV was measured using a microhematocrit tube and TPP concentration was determined using refractometry . The BHB concentration was also determined using an enzymatic‐amperometric technique .Venous blood samples were collected in plastic blood collection tubes containing sodium heparin and obtained from the jugular vein at the time of admission. Venous blood gas analysis (VBGA), electrolyte, glucose, and creatinine concentrations were determined using a blood gas analyzer . The Na2.3sSID variables were calculated using the formulas previously described for cattlem, mEq/L) was calculated using the concentrations of 6 strong ions as: SID6 = (Na+ + K+ + Ca2+ + Mg2+) – (Cl− + L‐lac−). The Atot (mmol/L) was calculated as: Atot = [3.43 × (TPP)], where TPP is in grams per deciliter. The USI (mEql/L) concentration was calculated as: USI = SID6 – HCO3− – ([Atot−]/(1 + 10(pKa‐pH))), where pKa (7.08) is the effective dissociation constant of bovine plasma weak acids. Species‐specific values for Ka and Atot have not been experimentally determined for goats, therefore values experimentally determined for calvesThe 2.4sSID variables were outside of the reference ranges  was examined using a forward stepwise linear regression.R2 value.R or the potential contribution of the added variable for explaining the variation within the model was assessed by subtracting the R of the previous model from R of the current model.The relationship between measured blood pH and HCO+, K+, Cl−, Ca2+, Mg2+, L‐lac−, pH, PvCO2, HCO3−, AG, SID6, and USI. The sex of the goats was categorized as male, female, or wether. Martingale residuals were plotted against the continuous variables to assess the linearity of each continuous predictor variable offered to the Cox proportional hazard models. If the variable failed to meet the linearity assumption, it was categorized as follows based on biologically relevant ranges3− concentration as <20, 20 to 30, and >30 mmol/L; AG as ≤24 or >24 mmol/L; K+ as <4.2, 4.2 to 6, and >6 mmol/L; and Cl− as <98 mmol/L, 98 to 110, and >110 mmol/L. Collinearity among variables was tested using Pearson correlation coefficients and if r> 0.6, only 1 variable was retained in the model. Variables with moderate statistical associations (P < .2) with the outcome of interest in univariable models subsequently were included in the multivariable analyses. A manual backward stepwise multivariable regression analysis was used for the different models. Variables were retained in the multivariable model if P < .05 or if the effect of removing the variable resulted in a change of at least 20% in the coefficient of a significant variable, indicating potential confounding. Two‐way interactions were evaluated between variables based on evidence from the literature and retained in the model if significant. Model fit was assessed using the test of proportional hazards for the Cox proportional hazards models. Harrell's C concordance statistic for each survival model was calculated to evaluate overall predictive ability. Harrell's C concordance statistic is calculated by taking all possible pairs of subjects consisting of 1 subject that experienced the event of interest and 1 subject that did not experience the event of interest. The statistic is the proportion of such pairs in which the subject that experienced the event had a higher predicted probability of experiencing the event than the subject that did not experience the event. A value of C = 0.5 corresponds to non‐informative prediction, whereas, C = 1.0 corresponds to perfect prediction.P‐values <.05 were considered significant.To determine which clinicopathological variables were associated with the outcome of sick goats (discharged or euthanized or died), Cox proportional hazard models were constructed to assess the potential predictor variables and the outcome of interest. Days from admission to the hospital until discharged or died or euthanized was used as the time variable. Variables included into the analysis were sex, HR, RR, rectal T (T), creatinine, glucose, PCV, TPP, NaFor continuous variables that were significant in the final survival models, a cutoff was determined by receiver operator characteristics curve (ROC) analysis. The optimal cutoff point was based on the Youden's index and the corresponding sensitivity, specificity, and area under the curve were calculated for this cutoff point. Statistical analyses were performed using Minitab 19  and STATA 14  statistical software.33.1sSID variables for all 143 goats are presented in Supplementary Table One‐hundred forty‐three goats met the inclusion criteria. Seventy‐five (53%) goats were presented in 2017, 45 (31%) in 2018, and 23 (16%) in 2019. The age was recorded for 140 goats; median age on admission was 2 years . Of the 143 goats, 101 (71%) were females, 18 (12%) were males, and 24 (17%) were wethers. Breed distribution was similar to that of the general hospital population, with Nigerian Dwarf  being the most commonly represented. Remaining breeds included La Mancha , Nubian , Oberhasli , Boer , Pygmy , Toggenburg , Alpine , and other breeds . The values  for HR, RR, T, VBGA, electrolyte concentrations, TPP, and the H‐H and 3.2Nineteen (13%) goats were diagnosed with acute diarrhea, 19 (13%) with urolithiasis, 16 (11%) were presented for dystocia, 14 (10%) with haemonchosis, 13 (9%) with pregnancy toxemia, 10 (7%) with pneumonia, and 7 (5%) with clinical mastitis. Forty‐five (32%) goats were diagnosed with other diseases including azalea toxicity , hypocalcemia , simple indigestion , vagal indigestion , neoplasia , ruminal foreign body , and peritonitis .sSID variables for 98 goats with selected diseases are presented in Table P < .05). Blood glucose concentration was higher  in goats with diarrhea than in other groups (P < .05), except the urolithiasis group. Goats with urolithiasis had blood creatinine concentration  higher than did the other groups (P < .05), except the clinical mastitis group, whereas goats with dystocia had higher concentration of Cl−  than did the other groups (P < .05). The Atot was signifficantly lower in goats with haemonchosis  than other groups . Goats with pregnancy toxemia had a higher concentration of USI  than did goats with acute diarrhea, urolithiasis, haemonchosis, and clinical mastitis (P < .05). Concentrations of BHB (mmol/L) were only measured in goats with pregnancy toxemia with a median of 3 mmol/L  and SID6 acidosis . A USI acidosis was diagnosed in 14 (10%) goats, whereas Atot alkalosis was present in 17 (12%), and Atot acidosis in 84 (59%) goats.Based on the H‐H approach, the most common acid‐base disorders in sick goats were respiratory alkalosis  and metabolic acidosis . Anion gap acidosis was detected in only 2 (1%) goats. When using the sSID acid‐base disorders in goats with acute diarrhea, pneumonia, urolithiasis, mastitis, and dystocia were respiratory alkalosis and SID6 acidosis. In goats with pregnancy toxemia, respiratory alkalosis, SID6 acidosis and USI acidosis frequently were detected . Hypoproteinemic (Atot) alkalosis and hyperproteinemic (Atot) acidosis were commonly detected in goats with haemonchosis  and acute diarrhea , respectively.The most common 3.33− concentrations as dependent variables showed that, in sick goats, PvCO2 was the most important variable associated with variations in the measured blood pH and calculated HCO3−. The SID6, USI, and Atot also were associated with changes in the measured blood pH and HCO3− .One‐hundred sixteen (81%) goats survived to hospital discharge whereas 27 (19%) did not. Six (22%) of the 27 nonsurviving goats died during hospitalization and 21 (80%) were euthanized. Eight goats were euthanized (n = 7) or died (n = 1) on day 1 of hospitalization. The goat that died on day 1 of hospitalization was being treated for haemonchosis by blood transfusion. Diagnoses of euthanized goats on day 1 of hospitalization included end stage liver disease (n = 2), severe trauma from dog attack (n = 1), urolithiasis (n = 1), diarrhea (n = 1), and chronic bronchopneumonia (n = 1). Diagnoses of the goats that died during hospitalization (n = 6) included haemonchosis (n = 2), peritonitis (n = 1), meningitis (n = 1), pregnancy toxemia (n = 1), and bronchopneumonia (n = 1). Diagnoses of the goats that were euthanized during hospitalization (n = 20) included neoplasia (n = 3), end stage liver disease (n = 2), emaciation (n = 2) pregnancy toxemia (n = 2), urolithiasis (n = 2), diarrhea (n = 1), nephrotic syndrome (n = 1), severe trauma from dog attack (n = 1), caprine arthritis‐encephalitis (n = 1), vagal indigestion (n = 1), toxic mastitis (n = 1), chronic pneumonia (n = 1), listeriosis (n = 1), and dystocia (n = 1). The time of hospitalization (median and range) for surviving goats was 3 days (0‐20 days) and for nonsurviving goats was 2 days . The optimal cut point for USI was determined to be −0.49 mmol/L based on Youden's index. At this cut point, the sensitivity, specificity and area under the ROC curve for predicting nonsurvival was 52%, 69%, and 0.60, respectively. The second multivariable Cox proportional model using blood pH for predicting hospital mortality included the variables RR <16 rpm and blood pH. The SID6 was retained in the latter model because it changed the coefficient of pH by >20% indicating a potential confounding effect  of blood gas, electrolytes, acid‐base and selected laboratory variables of surviving and nonsurviving sick goats are presented in Supplementary Table 46 acidosis, and Atot acidosis were acid‐base disorders frequently encountered in hospitalized goats. The results also indicated that changes in RR (<16 rpm), USI, and blood pH on admission were associated with hospital mortality in sick goats. According to our results, sSID variables accounted for most of the changes in blood pH and HCO3−. The sSID variables explained 97% and 100% of the changes in blood pH and HCO3−, respectively. Similar results were reported in sick calvessSID contributed to 85% to 93% of the change in blood pH and 98% of the change in HCO3−, whereas in foals, sSID variables explained 83% to 94% of the changes in blood pH.We found that hypocapnia, hypokalemia, hyperchloremia, hyperlactatemia, and hyperproteinemia were common abnormalities identified in sick goats, and that respiratory alkalosis, SIDsSID approach provides an accurate evaluation of acid‐base homeostasis because it was able to detect complex mixed alteration in SID6, PvCO2, USI, and Atot.3, whereas a metabolic disorder will be rapidly compensated by alteration in pCO2 by the respiratory system. Describing primary and compensatory responses to acid‐base disturbances using HCO3− is qualitative and offers little information of the physiological status of the patient.sSID approach determines quantitatively how a primary acid‐base disturbance in PCO2, Atot or SID6 produces an effect on the other 2 variables to initiate a compensatory response. The sSID approach states that SIDm (SID6 in our study) has a normal value of approximately 40 mmol/L in a single compartment system where Atot and PCO2 remain constant at normal values.m, PCO2, and Atot exists when the system is defined as whole body acid‐base balance.+ activity including that in plasma, intracellular and interstitial fluids. An acute, but especially chronic, change in PCO2 stimulates alterations in SIDm that are adjusted mostly by alteration in the Na+ and Cl− ratio by kidney regulation of Cl−.− decreases, resulting in hyperchloremia, and subsequently lowering SIDm. Therefore, in cases of primary respiratory alkalosis, SID6 acidosis should not be interpret as a mixed acid‐base disorder, but rather as a new “normal” SID6 value.Our findings are in agreement with previous research in cattle and horses showing that the 6 acidosis, USI acidosis, or Atot acidosis. Changes in SID6 could result from a high [Cl−] relative to [Na+] , increased [L‐lac−]  or increased USI . The effect of high [Cl−] relative to [Na+] on blood pH and HCO3− has been demonstrated in children,−] losses were lower than those of [Na+] and urinary excretion of [Cl−] was decreased.−] then increases, lowering SIDm, and causing SID acidosis.In a subset of goats enrolled in our study, respiratory alkalosis could be a compensatory response to the changes in blood pH because of SIDm, leading to SID6 acidosis. Hyperlactatemia traditionally has been attributed to dehydration and tissue hypoxia.1) deficiency negatively impacts oxidative energy productionHyperlactatemia was diagnosed commonly in sick goats, especially diarrheic goats and those with haemonchosis. Several studies in humans,tot alkalosis and acidosis, respectively.tot alkalosis in goats with haemonchosis likely resulted from protein‐losing enteropathy, whereas it could have resulted from volume expansion (which occurs during pregnancy) in goats with dystocia.tot acidosis was diagnosed frequently, likely because of a decrease in plasma water content because of decreased water intake and loss of protein‐poor body fluids . Of the goats that presented to our institution with mastitis, most were acute cases, but in chronic cases it is possible that hyperglobulinemia could have affected the TPP concentration, leading to Atot acidosis.In our study, changes in TPP also were associated with acid‐base disorders in which hypoproteinemia and hyperproteinemia lead to AsSID approach offers a calculation to determine the USI and their effect on blood pH and HCO3. In our study, USI acidosis was detected in the majority of goats with pregnancy toxemia likely because of increased concentration of BHB. Four goats included in the “other” diseases group also had USI acidosis, 1 goat had end‐stage liver disease, 2 had polytraumatic lesions associated with dog attack, and 1 had peritonitis. The source and nature of the USI in critically ill patients is unknown, but their concentrations are increased in humans and calves with liver and kidney injuries tot calculation and, therefore, the USI concentration.Contrary to the H‐H approach, the 3−, L‐lac−, AG corrected by albumin and standard base excess.The concentration of USI and values of blood pH on admission were associated with higher hazard ratios of hospital mortality in sick goats. Our models indicated that for every 1 mEq/L increase in USI, measured at admission, the hazard for nonsurvival, at any point in time during hospitalization, increased by 13%. In addition, for each 0.01 pH unit increase measured at admission, the hazard for nonsurvival to hospital discharge decreased by 6.6%. The experimental design of our study prevented us from identifying a true cause and effect relationship between pH and USI and mortality, but acidemia and USI acidosis are important markers of disease severity in humanvCO2, PvO2, and total CO2 concentration. Generally, at our institution blood sample collection is performed using 2 mL plastic tubes containing sodium heparin. The collection is continued until blood stops flowing and aspiration of air into the tube is avoided during the process. The tubes are inverted several times to mix the blood with the anticoagulant, and the collected samples are processed immediately. Although this sampling process could have minimized the effects of preanalytical factors on the measured variables, the results of our study should be interpreted taking this limitation into consideration.Our study investigated the acid‐base status of a selected group of sick goats using the sSID approach, and the clinicopathological variables associated with the mortality of sick goats. The results likely were biased toward sicker patients because the sample included only sick goats referred to a single teaching hospital. Therefore, our results cannot be directly extrapolated to any other population. However, the cases admitted to our teaching hospital included sick goats with a variety of diseases similar to those admitted to other tertiary referral hospitals. The retrospective design of our study prevented identification of preanalytical effects such as the exact time from sample collection to processing,Because of the retrospective nature of our study, data collection was not standardized, and categorization of clinical signs and treatments was not possible. This prevented assessment of the effect of individual treatment variations on the survival analysis. The outcome of the survival analysis could have been affected by the number of euthanized goats included in the nonsurvival group. However, the diagnosis of most euthanized goats carried a poor prognosis even in the presence of unlimited economic resources. A recent studysSID approach is a useful methodology to quantify acid‐base disorders in goats and to determine their mechanism of development. We also demonstrated that USI and pH can aid in establishing the prognosis of sick goats. Additional investigations evaluating the dynamic of USI during hospitalization and their association with morbidity and mortality in sick goats are warranted.In conclusion, we showed that the Authors declare no conflict of interest.Authors declare no off‐label use of antimicrobials.Authors declare no IACUC or other approval was needed.Authors declare human ethics approval was not needed for this study.Supplementary Table 1 Admission values of selected clinical and laboratory variables of 143 sick goats.Click here for additional data file.Supplementary Table 2 Admission values (median and range) of blood gas, electrolytes, acid‐base and selected laboratory variables of 143 sick goats.Click here for additional data file.Supplementary Table 3 Results of the univariable Cox proportional hazard models assessing the association between selected admission clinical and laboratory variables and outcome of 143 sick goats.Click here for additional data file.


MedDietScore was negatively associated with intima-media-thickness (p < 0.001) and serum prolactin levels (p = 0.05). Multi-adjusted analysis revealed that the inverse relation of SHIM-5 and prolactin levels remained significant only among patients with low adherence to the Mediterranean diet (p = 0.012). Conclusion: Consumption of Mediterranean diet benefits cardiovascular hemodynamics, while suppressing serum prolactin levels. Such physiology may enhance erectile ability independently of the of the left ventricle ejection fraction.Background: Mediterranean diet was evaluated on erectile performance and cardiovascular hemodynamics, in chronic heart failure patients. Methods: 150 male stable heart failure patients were enrolled in the study  classes I–II, ejection fraction ≤40%). A detailed echocardiographic evaluation including estimation of the global longitudinal strain of the left ventricle and the systolic tissue doppler velocity of the tricuspid annulus was performed. Erectile dysfunction severity was assessed by the Sexual Health Inventory for Men-5 (SHIM-5) score. Adherence to the Mediterranean diet was evaluated by the MedDietScore. Results: The SHIM-5 score was positively correlated with the MedDietScore ( The prevalence of chronic heart failure (CHF) is estimated around 2% of the adult population, mainly older aged men . CHF cauDietary habits are recognized as important and modifiable risk factors of cardiovascular disease (CVD), not only in primary, but also in secondary prevention ,10. SincThe scope of this work was to examine the role of Mediterranean diet on erectile function and cardiovascular hemodynamics, in patients with chronic heart failure, in order to illustrate central and peripheral vessel rheology and prolactin physiology.This is an epidemiological study that was conducted at the First Cardiology Clinic of Hippokration General Hospital of Athens, in Greece, during 2019–2020.We enrolled 157 clinically stable CHF, male patients (62 ± 10 years) who consecutively visited the outpatient unit of our hospital. Eligibility criteria included age of at least 18 years, with left ventricular ejection fraction of ≤40% and symptoms according to New York Heart Association (NYHA) class II or higher symptoms. Patients were receiving standard medical therapy on an optimal tolerated dose, including an angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker or a sacubitril-valsartan combination, a mineralocorticoid receptor antagonist plus a beta-blocker and diuretic. If indicated, they were treated with appropriate device therapy . Newly  diagnosed heart failure patients were excluded, as well individuals with cancer, active infection or other major systemic disease.The study conformed to the principles of the Declaration of Helsinki and was approved by the Ethics Committee of Cardiology Clinic of the Hippokration Hospital . All subjects had signed a written informed consent form.Nutritional habits assessment was based on a validated semi-quantitative food-frequency questionnaire . All par2) was estimated by dividing measured weight (kg) by measured standing height squared (m2). Arterial blood pressure was measured in patients in a sitting position, calm for at least 30 min; those with average systolic/diastolic blood pressure levels ≥140/90 mmHg or who were under antihypertensive medication were classified as hypertensives. Hyperlipidemia was defined as a history of hypolipidemic treatment or and total blood cholesterol level ≥200 mg/dL. The presence of diabetes mellitus was defined as receiving hypoglycemic medication or having fasting glucose at least 126 mg/dL or HbA1c  > 6.5%. Serum prolactin and testosterone levels were measured by a radio-immuno-assay method. Patients were instructed to abstain from food and smoking for 12 h and blood samples were taken before 9:00 am.Baseline evaluation included information about socio-demographic characteristics, history of hypertension, dyslipidemia and diabetes mellitus as well as dietary and other lifestyle habits . In particular, smokers were defined as those who were currently smoking at least 1 cigarette/day during the past year. Frequency and duration per time of the engagement in physical activities, e.g., organized sport clubs, free style, was recorded and physical fitness levels were calculated in metabolic equivalents per minute/day (METS). Body mass index (BMI)  and tissue doppler imaging  technology. Left ventricular ejection fraction (EF) was calculated by the Simpson’s method, while right ventricular systolic function was evaluated upon the systolic component of the Tissue Doppler velocity of the tricuspid annulus (SRV). Left atrial (LA) maximal volume and global longitudinal strain of the left ventricle (GLPS) were measured (biplane modified Simpson method). In cardiorespiratory exercise (ergometric bicycle) VO2max (maximum oxygen consumption), VE/VCO2 (ratio of ventilation to carbon dioxide) and the METS  achieved were evaluated. The ultra-sonographic examinations were carried out by a group of 4 clinicians who had at least 5-year experience in ultra-sonography in a clinical setting.®, Artech Medical, Pantin, France) allowing online pulse wave recording and automatic PWV calculation was used. Wave reflection amplification analysis was performed by a radial artery tonometry device  [Carotid intima-media thickness (IMT) measurements were performed with the patient lying in the supine position and with the neck rotated to the opposite side of the examination; it was measured in both right and left common carotid artery , the carotid bulb and the internal carotid artery . Three measurements of the maximal IMT in the far wall during diastole were averaged, and the summary was calculated for both carotid arteries. The presence of plaque was defined as a clearly identified area of focally increased IMT greater than 1.5 mm or 50% increase as compared to adjacent wall IMT . Carotidstralia) . PeripheDiagnosis and evaluation of the severity of erectile dysfunction were based on clinical symptoms, duration of the erectile disorder, and the score of the five-item form of the International Index of Erectile Function, the Sexual Health Inventory for Men (SHIM-5) score (less than 21 indicates erectile dysfunction). The lower the score the more severe the erectile pathology ,17. The n = 150 participants was found to be adequate, i.e., achieving 83% statistical power, to evaluate 1 standard deviation changes (two-sided hypotheses) on the tested hemodynamic markers by tertile change of the MedDietScore, at 5% significance level. Continuous variables are presented as mean values ± standard deviation. Categorical variables are presented as absolute values and relative frequencies. One-way analysis of variance (ANOVA) was used to evaluate associations between mean values of continuous variables between 3 or more independent groups. The normal distribution of the continuous variables was assessed using the Shapiro-Wilk test. The Kruskal-Wallis test was used as an alternative non-parametric approach in the case on non-normally distributed variables. Correlations between continuous variables were evaluated by the calculation of Pearson’s r-coefficient or the partial correlation coefficient, after adjusting for potential confounding factors. Linear regression models were estimated to assess the association of vascular measurements, SHIM-5 score, GLPS and hormone levels with adherence to the Mediterranean diet. Regression estimates are presented as standardized b-coefficients. Mediation analysis, using Baron and Kenny’s approach, was applied to evaluate the potential intervening role of the Mediterranean diet on the relationships between prolactin, testosterone levels and cardiac hemodynamic markers. All reported p values are based on two-sided tests. The SPSS statistical software package version 23.0  was used for all statistical calculations.The working sample of 2 (8.7), whereas 45.8% were considered as obese . Demographic and clinical characteristics of the participants by level of adherence to the Mediterranean diet are presented in p = 0.05), IMT (p < 0.001), and a positive association with testosterone (p = 0.02) and SHIM-5 score (p = 0.006). No other significant associations between Mediterranean diet and cardiovascular hemodynamics markers were observed in the unadjusted analyses.The majority of the patients, i.e., 89%, were NYHA class II, and the rest 11% were class III. Mean EF was 30.5% (7.9) , mean MedDietScore was 27.9 (3.4) , and mean body mass index (BMI) was 30.0 kg/mp = 0.019) and the SHIM-5 index (p = 0.002), as well as an inverse association with AIx (p = 0.014), and IMT (p = 0.004). No significant associations were observed between MedDietScore with cardiac hemodynamic markers, as well as testosterone and prolactin levels .However, residual confounding may exist, therefore, multi-adjusted models were fitted having MedDietScore as independent factor and various hemodynamics markers as outcomes, adjusting for age, BMI, physical fitness levels of the participants and history of diabetes, hyperlipidemia and hypertension . Data anp = 0.010), and IMT (p = 0.01), after adjusting for age, BMI, history of diabetes, hyperlipidemia, hypertension, EF.Moreover, the impact of physical fitness on the hemodynamic variables examined was also evaluated; it was revealed that physical fitness was inversely associated with AIx (p < 0.001), with Aix (p = 0.03), and inversely correlated with VO2 at max (p = 0.03), as well as with SHIM-5 score (p = 0.01). Testosterone was inversely correlated with prolactin (p < 0.001), and positively with SHIM-5 score (p = 0.04). Furthermore, SHIM-5 score was inversely correlated with age , and positively correlated to AIx . To further evaluate the role of Mediterranean diet adherence on the relationships between sex-related hormones and cardiac hemodynamics, a mediation analysis was applied. In particular, when the level of adherence to the Mediterranean diet was taken into account prolactin levels were not associated anymore with SRV (p = 0.959), or VO2 max (p = 0.528). Moreover, prolactin levels were associated with reduced SHIM-5 score only among participants with low adherence to the Mediterranean diet , whereas among the other higher adherence groups no significant association between prolactin and erectile function was observed. In addition, adherence to the Mediterranean diet seemed to play a mediating role in the relationship between testosterone levels and erectile function. In particular, among participants who reported low adherence, testosterone levels were not associated with SHIM-5 score; however, among those who reported good or very good adherence , testosterone levels were positively associated with SHIM-5 score .To further evaluate the role of sex-related hormones, i.e., testosterone and prolactin, on cardiac hemodynamics of CHF patients, multi adjusted correlation analyses were applied . ProlactThe present study revealed a multifaceted beneficial impact of the Mediterranean diet in middle-aged men with CHF, by ameliorating central hemodynamics, right ventricular function and deescalating parameters of arterial stiffness, while exerting atheroprotective effect with suppressed circulating serum prolactin levels. Such physiology enhances erectile performance, an important component of quality of life in the male population with heart failure.Several studies underlined the anti-inflammatory properties of the MedDiet and its components and the positive impact on primary and secondary cardiovascular prevention ,18,19,20According to previous studies, in patients with systolic heart failure, the presence of right ventricular dysfunction is frequent and has been related to increased mortality. In our study, right ventricular function, as it was evaluated by tissue Doppler imaging, was positively related to MedDiet linking higher adherence to a healthy diet with amelioration of the right ventricular systolic function. Interestingly, the favorable effect of the MedDiet on right ventricular systolic function was independent of the left ventricle ejection fraction. We suggest that the MedDiet regime with the unique anti-inflammatory properties may induce vasodilation and lessen resistance of the pulmonary vascular bed. Such physiology reduces right ventricular afterload and enhances SRV independently of the left ventricular ejection fraction. It is well known that inflammation correlates with diastolic systolic dysfunction, and this may be an explanation for the deterioration from compensated to de-compensated heart failure ,25,26.Moreover, in this study, a greater MedDiet score was associated with a higher augmentation index and improved erectile function; while there was a trend with GLPS. These seemingly contradictory findings may be interpreted by the fact that heart failure physiology of the cardiovascular system is fundamentally distinct and that functions of the LV and the peripheral arterial system are interactive . Thus, in order to compensate the reduced left ventricular pumping force and consequently the forward pulse wave, peripheral resistance augments to such point that both actions lessen the wave reflection amplification signal. This may be falsely interpreted as reduced arterial stiffness. High adherence to the MedDiet may reduce inflammation, assist vasodilation and help improving peripheral vascular resistance. Such action reassures erectile potency, a nitric oxide phenomenon based on the capacity of the penile arteries to dilate and augment blood flow to the corpus cavernosum. We clinically identified such physiology by the SHIM-5 score, a simple, cost effective and reliable tool that evaluates erectile dysfunction.Regarding the reflected wave amplification, a higher AIx may be interpreted as the result of improved vascular performance in the periphery that permits first the reflexion of the forward pulsed volume by the falling myocardium and second to such a degree that it finally enhances the pulse signal. Therefore, in such heart failure conditions a higher AIx may be interpreted as a sign of reduced stiffness mainly in the peripheral vascular bed . The facRegarding the role of prolactin in heart and vessels diseases, it is increasingly recognized that this hormone is involved in cardiovascular pathophysiology, exerting pleiotropic unfavourable haemodynamic and pro-atherosclerotic actions, raising overall cardiovascular risk ,9,28,29.This study revealed the association between prolactin and IMT, confirming prolactin’s atherogenic properties . HoweverHeart failure remains the late serious clinical condition of CVD. As cardiovascular system works in a conduit of the heart and the whole arterial tree, any alterations in cardiac function have impact on arterial properties, and vice versa. The measured central aortic pressure waveform represents the sum of the forward arterial wave, generated by the left ventricle during ejection, and the backward moving wave, caused by the reflection of the forward moving wave within the arterial system. Thus, central aortic pressure waveform expresses the systolic function of the left ventricle, the elastic properties of the entire arterial tree and the interaction between ventricle and aorta, described as aorto-ventricular coupling ,34. In tIn conclusion, adherence to the MedDiet regime in systolic heart failure male patients posed a significant improvement in cardiovascular physiology including systolic function, parameters of arterial stiffness, atheromatosis and erectile performance. In this particular finding on a male patient population with raised mortality and morbidity MedDiet dietary pattern can be highly recommended as a lifestyle culinary option to maintain cardiovascular health and the sense of wellbeing.


Inhaler selection is important when managing respiratory conditions; a patient’s inhalation technique should be appropriate for the selected device, and patients should ideally be able to use a device successfully regardless of disease severity. The NEXThaler is a multidose dry-powder inhaler with a breath-actuated mechanism (BAM) and dose counter that activates only following inhalation, so effectively an ‘inhalation counter’. We assessed inspiratory flow through the NEXThaler in two studies and examined whether inhalation triggered the BAM.The two studies were open-label, single-arm, and single visit. One study recruited patients with asthma aged ≥ 18 years; the other recruited patients with chronic obstructive pulmonary disease (COPD) aged ≥ 40 years. All patients inhaled twice through a placebo NEXThaler. The inspiratory profile through the device was assessed for each inhalation using acoustic monitoring, with flow at and time to BAM firing, peak inspiratory flow (PIF), and total inhalation time assessed.A total of 40 patients were enrolled in the asthma study: 20 with controlled asthma and 20 with partly controlled/uncontrolled asthma. All patients were able to trigger the BAM, as evidenced by the inhalation counter activating on closing the device. Mean flow at BAM firing following first inhalation was 35.0 (range 16.3–52.3) L/min; mean PIF was 64.6 (35.0–123.9) L/min. A total of 72 patients were enrolled in the COPD study, with data analysed for 69 (mean forced expiratory volume in 1 s 48.7% predicted [17–92%]). As with the asthma study, all patients, regardless of airflow limitation, were able to trigger the BAM. Mean flow at BAM firing following first inhalation was 41.9 (26.6–57.1) L/min; mean PIF was 68.0 (31.5–125.4) L/min. Device usability was rated highly in both studies, with 5 min sufficient to train the patients, and a click heard shortly after inhalation in all cases (providing feedback on BAM firing).Inhalation flows triggering the BAM in the NEXThaler were similar between patients with controlled and partly controlled/uncontrolled asthma, and were similar across COPD airflow limitation. All enrolled patients were able to activate the device.The online version contains supplementary material available at 10.1186/s12890-021-01430-9. Inhaler selection is an important consideration in overall therapy choice when managing respiratory conditions , 2, and ½ L/min . To inhale a dose of medication, the patient only has to open the cover, which makes the dose available. When the patient then inhales through the device, a click is felt or heard as the BAM fires, indicating successful dose release. Then, when the cover is closed, if the dose has been inhaled the counter will count down. If the inhalation was not successful, for example if the patient did not generate sufficient inspiratory flow, just exhaled through the device, or only opened and closed the cover, the counter will not count down, and the dose is not wasted. Data on dose- and flow-independency of the NEXThaler across various inspiratory flows have previously been published  or peak expiratory flow [PEF] ≥ 80% predicted]). For the COPD study, the aim was to recruit 10–20 patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) Grade 1 airflow limitation (post-bronchodilator FEV1 ≥ 80% predicted), and 20 patients with Grades 2 to 4 . Assuming a screening failure rate of 10%, it was estimated that 44 patients would need to be screened for the asthma study, and 89 for the COPD study. Descriptive statistics are provided for each variable, analysed separately for the first and second inhalation.There was no formal sample size calculation for either study. For the asthma study, 40 patients were considered to be sufficient to assess inhalation profile through the device, 20 with controlled asthma, and 20 with partly controlled asthma , with mean PEF 91.6 ± 13.1% predicted , ranging from 60.9 to 116.0%.A total of 40 patients were enrolled: 20 with controlled asthma and 20 with partly controlled or uncontrolled asthma. The mean ± SD age of these enrolled patients was 43.2 ± 16.5 years (range 18–77 years); 60% were female. Mean FEVAll patients were able to trigger the BAM, as evidenced by the inhalation counter activating on closing the device. Inspiratory flow through the NEXThaler was higher in patients with controlled asthma than in those with partly controlled or uncontrolled asthma, both by individual timepoint Fig.  and by P1 ≥ 80% predicted (GOLD Grade 1); 20 with FEV1 50–80% (Grade 2); 21 with FEV1 30–50% predicted (Grade 3); and 10 with FEV1 < 30% predicted (Grade 4). Three patients were excluded from the analyses . For the remaining 69 patients, mean ± SD age was 67.9 ± 8.3 years (range 44–80 years), 58 (84.1%) were male, 21 (30.4%) were current smokers, post-bronchodilator FEV1 was 48.7 ± 20.0% predicted (range 17–92%), with post-bronchodilator FEV1 to forced vital capacity ratio 0.52 ± 0.11 (0.22–0.69).A total of 72 patients were enrolled: 21 with post-bronchodilator FEVAll patients, regardless of airflow limitation, were able to trigger the BAM, as evidenced by the inhalation counter being activated on closing the device. Inspiratory flow through the device was consistent with the degree of airflow limitation, being slightly higher in patients with GOLD Grades 1 and 2 than Grades 3 and 4  was steep and consistent across GOLD Grades Fig. . FurtherAll patients in both studies were able to generate sufficient inspiratory flow to trigger the BAM, with firing occurring with a flow as low as 14.4 L/min in the asthma study and 18.1 L/min in the COPD study. The mean flow at BAM was similar in the two asthma groups, and was similar across the four airflow limitation categories in the COPD study, as was the time to BAM firing, indicating that disease characteristics did not impact the ability to trigger dose delivery in either disease. Furthermore, the mean time to BAM firing was early in the inhalation manoeuvre. Importantly, the inhalation counter activated on closure for all patients, confirming that all patients were able to activate the device, and a click was heard soon after inhalation in all cases, providing additional confirmation of BAM firing.Interestingly, the inspiratory flows generated through the NEXThaler in the COPD study were overall larger than those in the asthma study. Although this may appear counter-intuitive , thThe combination of the BAM and the dose counter only being activated following adequate inhalation means that the dose counter on the NEXThaler is effectively an ‘inhalation counter’ providing feedback on successful dose release. This is a key distinction between the NEXThaler and the Ellipta and the Turbuhaler multi-dose DPIs . In thesThe usability assessments in these two studies were consistent with the results of a previous study conducted in patients with asthma, in which the usability of the NEXThaler was compared with the Diskus and Turbuhaler . In thisThe NEXThaler multi-dose DPI has a BAM with a dose counter that activates solely following inhalation . The two studies demonstrated that patients with controlled and partly controlled/uncontrolled asthma, and those with a range of severities of COPD were able to trigger the BAM and consequently activate the inhalation counter, thus receiving feedback on inhalation.Additional file 1. Device usability questionnaire and results.