Follow-up lung ultrasound to monitor lung failure in COVID-19 ICU patients

Michaela Barnikel; Annabel Helga Sophie Alig; Sofia Anton; Lukas Arenz; Henriette Bendz; Alessia Fraccaroli; Jeremias Götschke; Marlies Vornhülz; Philipp Plohmann; Tobias Weiglein; Hans Joachim Stemmler; Stephanie-Susanne Stecher

doi:10.1371/journal.pone.0271411

Peer Review History

Original SubmissionJanuary 16, 2022
18 Apr 2022 Decision Letter - Robert Jeenchen Chen, Editor PONE-D-22-00632Follow-Up lung ultrasound to monitor lung failure in COVID-19 ICU patientsPLOS ONE Dear Dr. Barnikel, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please revise. Please submit your revised manuscript by Jun 02 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Robert Jeenchen Chen, MD, MPH Academic Editor PLOS ONE Journal Requirements: When submitting your revision, we need you to address these additional requirements. 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf 2. Please provide additional details regarding participant consent. In the ethics statement in the Methods and online submission information, please ensure that you have specified (1) whether consent was informed and (2) what type you obtained (for instance, written or verbal, and if verbal, how it was documented and witnessed). If your study included minors, state whether you obtained consent from parents or guardians. If the need for consent was waived by the ethics committee, please include this information. If you are reporting a retrospective study of medical records or archived samples, please ensure that you have discussed whether all data were fully anonymized before you accessed them and/or whether the IRB or ethics committee waived the requirement for informed consent. If patients provided informed written consent to have data from their medical records used in research, please include this information. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. 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: Partly Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: No Reviewer #2: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The 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. Reviewer #1: No Reviewer #2: 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: No Reviewer #2: Yes ****** 5. Review Comments to the Author Please 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. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: Overall the study is clear but the hypothesis of the study is not new and the design of study is poor. The authors perform follow-up Lung ultrasound in patients on ICU to explore LU as a tool for monitoring lung failure caused by SARS-CoV2. furthermore, they evaluate the difference in LUS over the course between invasive and non-invasive ventilated patients. In my opinion the study did not add relevant information to the current knowledge in this specific ield of research and it could be limited interest by the readers. Overall confirmed results previously published by other group of research. The authors should clarify the novelty of the study. methodologically; please clarify who pwerformed the analysis of US and perform analysis in terms of inter and intra variability. furthermore should be clarified how do you set the mechanical ventilation in particular regarding the PEEP selection. How do you manage the LU evaluation in case of pneumothorax during lenght of stay. Reviewer #2: The problem described in the paper is actual. The diagnostic tools for monitoring the patients with coronavirus disease are in demand. The point-of-care lung ultrasound is promising because it is radiation free, comparatively available. Authors provided an adapted protocol for severe patients due to their limited positioning options. The research shown that the lang ultrasound can be a useful tool to monitor lung failure in COVID-19 ICU patients. The dynamics of lung ultrasound score is correlated with progression and regression of respiratory failure. The manuscript is structured, written in clear English. Raw data is not provided in manuscript and supporting materials, only mean values and standard deviations are given. Statistically computations have been performed appropriately. ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. 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: No Reviewer #2: No [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0271411.r001
Revision 1
30 Apr 2022 Author Response Dear Editor, Dear Editorial Board Members, Dear Reviewers, Thank you for handling and reviewing our manuscript. We found the reviewers´ comments very helpful and adapted the manuscript accordingly. Please find a point-by-point response below. Best regards, Michaela Barnikel and Stephanie-Susanne Stecher (on behalf of all co-authors) Reviewer 1 Overall the study is clear but the hypothesis of the study is not new and the design of study is poor. The authors perform follow-up Lung ultrasound in patients on ICU to explore LU as a tool for monitoring lung failure caused by SARS-CoV2. Furthermore, they evaluate the difference in LUS over the course between invasive and non-invasive ventilated patients. In my opinion the study did not add relevant information to the current knowledge in this specific field of research and it could be limited interest by the readers. Overall confirmed results previously published by other group of research. The authors should clarify the novelty of the study. Response: Thank you for this remark. We agree that numerous studies deal with lung ultrasound, especially during the pandemic. However, while performing our survey in 2020, lung ultrasound was just established in COVID-19 ICU patients. And as far as we know there are still only a few papers dealing with follow-up lung ultrasound in mechanical ventilated COVID-19 patients. Most of them handle lung ultrasound as an initial assessment of lung failure but not in follow-up. And so, we feel confident that our results are of interest to the readers of the PLOS ONE Journal. Exemplary, we listed some of the topical papers: Vetrugno L, Bove T, Orso D, Barbariol F, Bassi F, Boero E, et al. Our Italian experience using lung ultrasound for identification, grading and serial follow-up of severity of lung involvement for management of patients with COVID-19. Echocardiography. 2020;37(4):625-7. Hoffmann T, Bulla P, Jodicke L, Klein C, Bott SM, Keller R, et al. Can follow up lung ultrasound in Coronavirus Disease-19 patients indicate clinical outcome? PLoS One. 2021;16(8):e0256359. Methodologically; please clarify who performed the analysis of US and perform analysis in terms of inter and intra variability. Response: We have now clarified in our manuscript that only one senior physician with expertise in lung ultrasound supervised the performance of lung ultrasound and scored the images. A randomly selected number of ultrasound examinations were blinded and examined by another senior physician to obtain reliable results. We have now added a Bland Altman analysis for performing analysis in terms of inter variability. Furthermore should be clarified how do you set the mechanical ventilation in particular regarding the PEEP selection. Response: We thank the reviewer for broaching this issue. In our study cohort, best-PEEP selection was handled by performing PEEP trials by arterial blood gas analysis at different PEEP levels. We did not define best-PEEP by evaluating lung ultrasound when conducting this study. How do you manage the LU evaluation in case of pneumothorax during length of stay. Response: Thank you for this mindful remark. While performing lung ultrasound, sonographic signs of pneumothorax, e.g., lack of lung sliding, lack of B lines, and barcode sign, were considered throughout. X-ray of the thorax was amended in case of suspected pneumothorax by sonography. However, there was no case of pneumothorax. We have now added this information to our manuscript. Reviewer 2 The problem described in the paper is actual. The diagnostic tools for monitoring the patients with coronavirus disease are in demand. The point-of-care lung ultrasound is promising because it is radiation free, comparatively available. Authors provided an adapted protocol for severe patients due to their limited positioning options. The research shown that the lang ultrasound can be a useful tool to monitor lung failure in COVID-19 ICU patients. The dynamics of lung ultrasound score is correlated with progression and regression of respiratory failure. The manuscript is structured, written in clear English. Raw data is not provided in manuscript and supporting materials, only mean values and standard deviations are given. Statistically computations have been performed appropriately. Response: We thank the reviewer for dealing with our manuscript. We have now provided raw data in an excel-sheet. Please take heed of the attachment file. Attachments Attachment Submitted filename: Response to Reviewers.rtf https://doi.org/10.1371/journal.pone.0271411.r002
10 May 2022 Decision Letter - Robert Jeenchen Chen, Editor PONE-D-22-00632R1Follow-Up lung ultrasound to monitor lung failure in COVID-19 ICU patientsPLOS ONE Dear Dr. Barnikel, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please revise. Please submit your revised manuscript by Jun 24 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Robert Jeenchen Chen, MD, MPH Academic Editor PLOS ONE [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. 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: (No Response) Reviewer #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: Partly Reviewer #3: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: No Reviewer #3: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The 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. Reviewer #1: Yes Reviewer #3: Yes ****** 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: Yes Reviewer #3: Yes ****** 6. Review Comments to the Author Please 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. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: The authors satisfied partially my previous comments and in my opinion the novelty of the study remain poor. However, I appreciate the efforts of the authors in orders to improve the quality of the paper. The authors reported that the novelty of the study regarding the follow-up lung ultrasound in mechanical ventilated COVID-19 patients. In my opinion, this is not clearly express in the text and I suggest to avoid confusion about the terms follow-up and the tool useful “to assess the progression or regression of respiratory failure.” Furthermore, the second aim is related to the first outcome. I strongly recommend to revise carefully it in according to the design of the study. In other words, I think that the study would like to evaluate the progression of the severity of disease and consequently assess if the LUS score could be useful to help in the decision of intubate or not intubate. This is the major point that should be addressed by the authors. I appreciate the analysis performed to evaluate the inter – variability. I am not sure that this test is appropriate to test it. Please revise this aspect with an expert statistician before the publication of the paper. The authors reported that “In our study cohort, best-PEEP selection was handled by performing PEEP trials by arterial blood gas analysis at different PEEP levels”. This approach probably reflect the clinical practice but not reflect a good scientific sound. This aspect “We did not define best-PEEP by evaluating lung ultrasound when conducting this study” should be included in the main limitation of the study and please discuss the optimal approach taking into account the following papers in your discussion and add appropriate references ( doi: 10.1186/s13054-020-03311-9; doi: 10.1097/CCM.0000000000004640; doi: 10.1186/s40560-020-00499-4.) Reviewer #3: The authors reponse well, however, I still have one minor suggestions. Please delete the second paragraph in the discussion section because this is not the focus of this study. The discussion about lung ultrasound should be written first. ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. 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: No Reviewer #3: No [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0271411.r003
Revision 2
15 May 2022 Author Response Dear Editor, Dear Editorial Board Members, Dear Reviewers, Thank you for handling and reviewing our manuscript again. We found the reviewers´ comments very helpful and adapted the manuscript accordingly. Please find a point-by-point response below. Best regards, Michaela Barnikel and Stephanie-Susanne Stecher (on behalf of all co-authors) Reviewer 1 The authors satisfied partially my previous comments and in my opinion the novelty of the study remain poor. However, I appreciate the efforts of the authors in orders to improve the quality of the paper. The authors reported that the novelty of the study regarding the follow-up lung ultrasound in mechanical ventilated COVID-19 patients. In my opinion, this is not clearly express in the text and I suggest to avoid confusion about the terms follow-up and the tool useful “to assess the progression or regression of respiratory failure.” Furthermore, the second aim is related to the first outcome. I strongly recommend to revise carefully it in according to the design of the study. In other words, I think that the study would like to evaluate the progression of the severity of disease and consequently assess if the LUS score could be useful to help in the decision of intubate or not intubate. This is the major point that should be addressed by the authors. Response: We thank the reviewer for revealing this remarkable issue. We have now adapted our manuscript accordingly to enhance its quality. I appreciate the analysis performed to evaluate the inter – variability. I am not sure that this test is appropriate to test it. Please revise this aspect with an expert statistician before the publication of the paper. Response: We have now revised this aspect with the expert statistician of our department (Dr. Ujjwal Mukund Mahajan, PhD) to make sure our inter-variability test is valid. He confirmed our analysis, we have now mentioned him in our acknowledgment. The authors reported that “In our study cohort, best-PEEP selection was handled by performing PEEP trials by arterial blood gas analysis at different PEEP levels”. This approach probably reflect the clinical practice but not reflect a good scientific sound. This aspect “We did not define best-PEEP by evaluating lung ultrasound when conducting this study” should be included in the main limitation of the study and please discuss the optimal approach taking into account the following papers in your discussion and add appropriate references ( doi: 10.1186/s13054-020-03311-9; doi: 10.1097/CCM.0000000000004640; doi: 10.1186/s40560-020-00499-4.) Response: We have now added this information in the discussion of our manuscript as a main limitation of our study. Furthermore, we added a paragraph to discuss the optimal approach for defining best-PEEP, including your suggested references. Reviewer 3 The authors reponse well, however, I still have one minor suggestions. Please delete the second paragraph in the discussion section because this is not the focus of this study. The discussion about lung ultrasound should be written first. Response: Thank you for this remark. We have now deleted the second paragraph in the discussion section and modified the order of the paragraphs. Attachments Attachment Submitted filename: Response to Reviewers .rtf https://doi.org/10.1371/journal.pone.0271411.r004
20 May 2022 Decision Letter - Robert Jeenchen Chen, Editor PONE-D-22-00632R2Follow-Up lung ultrasound to monitor lung failure in COVID-19 ICU patientsPLOS ONE Dear Dr. Barnikel, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please revise. Please submit your revised manuscript by Jul 04 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Robert Jeenchen Chen, MD, MPH Academic Editor PLOS ONE Journal Requirements: Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. 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 addressed Reviewer #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: Yes Reviewer #3: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #3: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The 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. Reviewer #1: Yes Reviewer #3: Yes ****** 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: Yes Reviewer #3: Yes ****** 6. Review Comments to the Author Please 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. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: The authors satisfied my previous comments. i suggest to improve the quality of the figure and i suggest to include a rappresentative case. Please revise the figure in according with the guidelines of the journal. (delete the black) I would like to congratulate with the authors for the efforts done to improve the quality of the paper. Reviewer #3: The authors response well, so I have no more comment. I recommend that the manuscript can be accepted now. ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. 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: No Reviewer #3: No [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0271411.r005
Revision 3
2 Jun 2022 Author Response Dear Editor, Dear Editorial Board Members, Dear Reviewers, We thank the Reviewers for their input and have now adapted the manuscript accordingly. Please find a point-by-point response below. Best regards, Michaela Barnikel and Stephanie-Susanne Stecher (on behalf of all co-authors) Reviewer 1 The authors satisfied my previous comments. I suggest to improve the quality of the figure and i suggest to include a representative case. Please revise the figure in according with the guidelines of the journal. (delete the black) I would like to congratulate with the authors for the efforts done to improve the quality of the paper. Response: Thank you for your previous comments and your efforts to improve our manuscript. We have now included a representative case to demonstrate the course of LUS and increased the resolution of our figures to improve their quality and to be in line with the guidelines of the journal. Reviewer 3 The authors response well, so I have no more comment. I recommend that the manuscript can be accepted now. Response: We thank the reviewer for his/her support. Attachments Attachment Submitted filename: Response to Reviewers.rtf https://doi.org/10.1371/journal.pone.0271411.r006
30 Jun 2022 Decision Letter - Robert Jeenchen Chen, Editor Follow-Up lung ultrasound to monitor lung failure in COVID-19 ICU patients PONE-D-22-00632R3 Dear Dr. Barnikel, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- 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 onepress@plos.org. Kind regards, Robert Jeenchen Chen, MD, MPH Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. 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 addressed Reviewer #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: Yes Reviewer #3: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #3: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The 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. Reviewer #1: No Reviewer #3: Yes ****** 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: Yes Reviewer #3: Yes ****** 6. Review Comments to the Author Please 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. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: i have no further comments. the reviewers satisfied my previous comments. Congratulation for this nice paper Reviewer #3: The authors response well, so I have no more suggetsion. The present form can be recommended as accept ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. 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: No Reviewer #3: No ******** https://doi.org/10.1371/journal.pone.0271411.r007
Formally Accepted
6 Jul 2022 Acceptance Letter - Robert Jeenchen Chen, Editor PONE-D-22-00632R3 Follow-Up lung ultrasound to monitor lung failure in COVID-19 ICU patients Dear Dr. Barnikel: I'm 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. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, 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 onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Robert Jeenchen Chen Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0271411.r008

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