Guide for authors

MEDICINA INTENSIVA will consider for publication those works based on topics related to the practice of intensive medicine, medical emergencies, and critical care medicine in coronary units. Manuscripts will be evaluated for publication if they meet the following requirements: the material is original, presentation is clear, the methodology of the study is appropriate, the results are valid, the conclusions are reasonable, and the information is relevant. MEDICINA INTENSIVA complies with the guidelines of the International Committee of Medical Journal Editors: Uniform requirements for manuscripts submitted to biomedical journals. If the authors have further questions that are not answered within these instructions, they should refer to https://www.icmje.org.

Types of articles, sections

The MEDICINA INTENSIVA journal is comprised of the following sections:

Original Articles.This category includes randomised clinical trials, cohort studies, studies on screening or diagnostic tests, cost-effective analyses, meta-analyses, systematic reviews, decision-making evaluation studies, other interventionist studies, case-control studies, and studies based on questionnaires that have received a high response rate.  This section will include clinical articles as well as animal research or experimental studies. The maximum length of the text must not exceed 3,500 words (excluding the Resumen/Abstract,  Tables and References). The information that cannot be included in the manuscript due to this word count limit can be published as electronic supplementary material (ESM), which has no length limitations. The maximum allowed literature references is 40. Up to 6 Figures and 6 Tables will be admitted. In multicentre studies, the number of authors will be limited to 12; the rest will appear at the end of the article. The total number of Tables and Figures will not exceed 6. The length of the structured Resumen/ Abstract will be 250 words.

Review Articles. These articles present updates on a specific topic in the field of intensive care medicine. Reviews will preferably be commissioned by the Editorial Committee, although those proposed by collaborators may be accepted.  Thus, before submitting the manuscript, the authors should always contact the Editorial Committee in order to propose the review article in question, at which time it will be determined whether the journal would be interested in its publication.  The maximum length of the text will not exceed 5,000 words (excluding the Resumen/Abstract, Tables and References). The maximum number of literature references permitted is 80. Authors may also make use of the ESM for more extensive information that cannot be included in the print edition due to the Word count limitations.  Up to 6 Figures and 6 Tables will be allowed. It is recommended to include one or several figures in this type of manuscripts.  The number of authors will be limited to 4. The Resumen/Abstract will not be structured, but it must provide information on its content, with a length limit of 150 words.

Special Articles. This section includes articles written by scientific societies, workgroups or groups of experts (clinical practice guidelines, consensus conferences, systematic reviews, etc.) that review a topic of current interest in intensive care medicine. Other publications include articles sent by renowned experts that analyse current social aspects or those of special interest for our specialty. The maximum length must not exceed 5,000 words (excluding the Resumen/Abstract, Tables and References). The maximum number of references permitted is 80. Up to 4 Tables and 4 Figures will be allowed. It must include an unstructured Abstract in English (and a Resumen in Spanish) of approximately 150 words.

Updates. Reviews commissioned by the Editorial Committee of MEDICINA INTENSIVA  are included in this section and will be part of a series that will review in detail current topics in intensive care medicine in successive issues of the journal. The maximum length must not exceed 5,000 words (excluding the Resumen/Abstract, Tables and References). The maximum number of literature references permitted is 80.  The ESM may be used for information that cannot be included in the print edition due to the word count limit.  Up to include always 6 Tables and 6 Figures will be allowed. It is recommended to include always one or several figures in this type of manuscripts.  The number of authors is limited to 4. It must include an unstructured Abstract in English (and a Resumen in Spanish) of approximately 150 words.

Points of View. The articles included in this section are those in which an opinion is expressed about a controversial topic in the field of intensive care medicine. Points of View will preferably be commissioned by the Editorial Committee, although those proposed by collaborators may be accepted. Thus, before submitting the manuscript, the authors should always contact the Editorial Committee in order to propose the Point of View article in question, at which time it will be determined whether the journal would be interested in its publication. The maximum length of the text must not exceed 1,000 words (excluding Tables and References). The maximum number of references allowed will be 10, and up to 2 Tables and one Figure. The number of authors is limited to 2. It will not have a Resumen /Abstract.

Editorials. Included in this section are works in which the author/s discuss and analyse an Original published in the Journal. The Editorials will always be commissioned by the Editorial Committee. Also included in this section will be articles that summarise the view of a current topic by the Editorial Committee of MEDICINA INTENSIVA or the Board of Directors of Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias (SEMICYUC). The maximum length of the text must not exceed 1,000 words (excluding the bibliography). The maximum number of references allowed is 10 and one Table or Figure will be admitted. The number of authors will be limited to 2. It will not include a Resumen or Abstract.

Scientific letters. A description of one or several clinical cases in which are described new aspects or important added value on the pathophysiology of the disease, its diagnosis or treatment. The maximum length of the text must not exceed 1,000 words, and the text will not be structured into sections. Up to 2 Figures or Tables will be allowed. The number of signatories must not be greater than 6, and the number of literature references is limited to 10. Scientific Letters will not have a Resumen/Abstract.

Letters to the editor. In this open section, objections or comments related to articles recently published in the Journal, and possibly on relevant articles published in other journals of special interest for intensive medicine, or comments on topics of importance associated with the speciality. Letters to the Editor sent to Medicina Intensiva must refer to articles published within the two previous months at most. The maximum length of the text must not exceed 500 words, and up to 5 literature references will be allowed. There must be no more than four signing authors. Those Letters to the Editor that deal with articles previously published in the Journal will have the right to reply. They will be submitted to the author of the original work, who will be able to reply in a letter of the same length within a period of one month. The Editorial Committee will try to publish the Letter to the Editor and the reply together.

Images in Intensive Medicine. This section will publish all types of images that are demonstrative and contain a teaching message by themselves. They must be accompanied by a text of less than10 lines. Whenever possible, the image should include graphic aids (arrows, asterisks). The number of signing authors will be limited to 3, and the image must be of sufficient graphical quality (minimum resolution of 300 dots per inch (dpi). No abstract or references are allowed.

You can submit your manuscript at  https://www.editorialmanager.com/medintensiva

This journal is published in Spanish and in English language.

You can use this list to carry out a final check of your submission before you send it to the journal for review. Please check the relevant section in this Guide for Authors for more details.

Ensure that the following items are present:

One author has been designated as the corresponding author with contact details:

• E-mail address

• Full postal address

All necessary files have been uploaded:

Manuscript

• Include keywords

• All figures (include relevant captions)

• All tables (including titles, description, footnotes)

• Ensure all figure and table citations in the text match the files provided<BR>&bull; Indicate clearly if color should be used for any figures in print

Graphical Abstracts / Highlights files (where applicable)

Supplemental files (where applicable)

Further considerations:

• Manuscript has been 'spell checked' and 'grammar checked'

• All references mentioned in the Reference List are cited in the text, and vice versa

• Permission has been obtained for use of copyrighted material from other sources (including the Internet)

• A competing interests statement is provided, even if the authors have no competing interests to declare

• Journal policies detailed in this guide have been reviewed

For further information, visit our Support Center.

Please see our information on Ethics in publishing.

If the work involves the use of human subjects, the author should ensure that the work described has been carried out in accordance with The Code of Ethics of the World Medical Association (Declaration of Helsinki) for experiments involving humans; Uniform Requirements for manuscripts submitted to Biomedical journals. Authors should include a statement in the manuscript that informed consent was obtained for experimentation with human subjects. The privacy rights of human subjects must always be observed.

All animal experiments should comply with the ARRIVE guidelines and should be carried out in accordance with the U.K. Animals (Scientific Procedures) Act, 1986 and associated guidelines, EU Directive 2010/63/EU for animal experiments, or the National Institutes of Health guide for the care and use of Laboratory animals (NIH Publications No. 8023, revised 1978) and the authors should clearly indicate in the manuscript that such guidelines have been followed.

Studies on patients or volunteers (including organ/tissue donors) require informed consent, which should be documented in the paper. Appropriate consents, permissions and releases must be obtained where an author wishes to include case details or other personal information or images of patients and any other individuals in an Elsevier publication. Written consents must be retained by the author, but copies should not be provided to the journal.

Only if specifically requested by the journal in exceptional circumstances (for example if a legal issue arises) the author must provide copies of the consents or evidence that such consents have been obtained. For more information, please review the Elsevier Policy on the Use of Images or Personal Information of Patients or other Individuals.

Unless the author has written permission from the patient (or, where applicable, the next of kin), the personal details of any patient included in any part of the article and in any supplementary materials (including all illustrations and videos) must be removed before submission.

All authors must disclose any financial and personal relationships with other people or organizations that could inappropriately influence (bias) their work. Examples of potential competing interests include employment, consultancies, stock ownership, honoraria, paid expert testimony, patent applications/registrations, and grants or other funding. Authors must disclose any interests in two places: 1. A summary declaration of interest statement in the title page file (if double anonymized) or the manuscript file (if single anonymized). If there are no interests to declare then please state this: 'Declarations of interest: none'. 2. Detailed disclosures as part of a separate Declaration of Interest form, which forms part of the journal's official records. It is important for potential interests to be declared in both places and that the information matches. More information.

The below guidance only refers to the writing process, and not to the use of AI tools to analyse and draw insights from data as part of the research process.

Where authors use generative artificial intelligence (AI) and AI-assisted technologies in the writing process, authors should only use these technologies to improve readability and language. Applying the technology should be done with human oversight and control, and authors should carefully review and edit the result, as AI can generate authoritative-sounding output that can be incorrect, incomplete or biased. AI and AI-assisted technologies should not be listed as an author or co-author, or be cited as an author. Authorship implies responsibilities and tasks that can only be attributed to and performed by humans, as outlined in Elsevier's AI policy for authors.

Authors should disclose in their manuscript the use of AI and AI-assisted technologies in the writing process by following the instructions below. A statement will appear in the published work. Please note that authors are ultimately responsible and accountable for the contents of the work.

Disclosure instructions

Authors must disclose the use of generative AI and AI-assisted technologies in the writing process by adding a statement at the end of their manuscript in the core manuscript file, before the References list. The statement should be placed in a new section entitled 'Declaration of Generative AI and AI-assisted technologies in the writing process'

Statement: During the preparation of this work the author(s) used [NAME TOOL / SERVICE] in order to [REASON]. After using this tool/service, the author(s) reviewed and edited the content as needed and take(s) full responsibility for the content of the publication

This declaration does not apply to the use of basic tools for checking grammar, spelling, references etc. If there is nothing to disclose, there is no need to add a statement.

Submission of an article implies that the work described has not been published previously (except in the form of an abstract, a published lecture or academic thesis, see 'Multiple, redundant or concurrent publication' for more information), that it is not under consideration for publication elsewhere, that its publication is approved by all authors and tacitly or explicitly by the responsible authorities where the work was carried out, and that, if accepted, it will not be published elsewhere in the same form, in English or in any other language, including electronically without the written consent of the copyright-holder. To verify compliance, your article may be checked by Crossref Similarity Check and other originality or duplicate checking software.

Please note that preprints can be shared anywhere at any time, in line with Elsevier's sharing policy. Sharing your preprints e.g. on a preprint server will not count as prior publication (see 'Multiple, redundant or concurrent publication' for more information).

Inclusive language acknowledges diversity, conveys respect to all people, is sensitive to differences, and promotes equal opportunities. Content should make no assumptions about the beliefs or commitments of any reader; contain nothing which might imply that one individual is superior to another on the grounds of age, gender, race, ethnicity, culture, sexual orientation, disability or health condition; and use inclusive language throughout. Authors should ensure that writing is free from bias, stereotypes, slang, reference to dominant culture and/or cultural assumptions. We advise to seek gender neutrality by using plural nouns ("clinicians, patients/clients") as default/wherever possible to avoid using "he, she," or "he/she." We recommend avoiding the use of descriptors that refer to personal attributes such as age, gender, race, ethnicity, culture, sexual orientation, disability or health condition unless they are relevant and valid. When coding terminology is used, we recommend to avoid offensive or exclusionary terms such as "master", "slave", "blacklist" and "whitelist". We suggest using alternatives that are more appropriate and (self-) explanatory such as "primary", "secondary", "blocklist" and "allowlist". These guidelines are meant as a point of reference to help identify appropriate language but are by no means exhaustive or definitive.

Reporting guidance

For research involving or pertaining to humans, animals or eukaryotic cells, investigators should integrate sex and gender-based analyses (SGBA) into their research design according to funder/sponsor requirements and best practices within a field. Authors should address the sex and/or gender dimensions of their research in their article. In cases where they cannot, they should discuss this as a limitation to their research's generalizability. Importantly, authors should explicitly state what definitions of sex and/or gender they are applying to enhance the precision, rigor and reproducibility of their research and to avoid ambiguity or conflation of terms and the constructs to which they refer (see Definitions section below). Authors can refer to the Sex and Gender Equity in Research (SAGER) guidelines and the SAGER guidelines checklist. These offer systematic approaches to the use and editorial review of sex and gender information in study design, data analysis, outcome reporting and research interpretation - however, please note there is no single, universally agreed-upon set of guidelines for defining sex and gender.

Definitions

Sex generally refers to a set of biological attributes that are associated with physical and physiological features (e.g., chromosomal genotype, hormonal levels, internal and external anatomy). A binary sex categorization (male/female) is usually designated at birth ("sex assigned at birth"), most often based solely on the visible external anatomy of a newborn. Gender generally refers to socially constructed roles, behaviors, and identities of women, men and gender-diverse people that occur in a historical and cultural context and may vary across societies and over time. Gender influences how people view themselves and each other, how they behave and interact and how power is distributed in society. Sex and gender are often incorrectly portrayed as binary (female/male or woman/man) and unchanging whereas these constructs actually exist along a spectrum and include additional sex categorizations and gender identities such as people who are intersex/have differences of sex development (DSD) or identify as non-binary. Moreover, the terms "sex" and "gender" can be ambiguous--thus it is important for authors to define the manner in which they are used. In addition to this definition guidance and the SAGER guidelines, the resources on this page offer further insight around sex and gender in research studies.

All authors should have made substantial contributions to all of the following: (1) the conception and design of the study, or acquisition of data, or analysis and interpretation of data, (2) drafting the article or revising it critically for important intellectual content, (3) final approval of the version to be submitted.

ContributorsEach author is required to declare his or her individual contribution to the article: all authors must have materially participated in the research and/or article preparation, so roles for all authors should be described. The statement that all authors have approved the final article should be true and included in the disclosure.

Authors are expected to consider carefully the list and order of authors before submitting their manuscript and provide the definitive list of authors at the time of the original submission. Any addition, deletion or rearrangement of author names in the authorship list should be made only before the manuscript has been accepted and only if approved by the journal Editor. To request such a change, the Editor must receive the following from the corresponding author: (a) the reason for the change in author list and (b) written confirmation (e-mail, letter) from all authors that they agree with the addition, removal or rearrangement. In the case of addition or removal of authors, this includes confirmation from the author being added or removed.

Only in exceptional circumstances will the Editor consider the addition, deletion or rearrangement of authors after the manuscript has been accepted. While the Editor considers the request, publication of the manuscript will be suspended. If the manuscript has already been published in an online issue, any requests approved by the Editor will result in a corrigendum.

In line with the position of the International Committee of Medical Journal Editors, the journal will not consider results posted in the same clinical trials registry in which primary registration resides to be prior publication if the results posted are presented in the form of a brief structured (less than 500 words) abstract or table. However, divulging results in other circumstances (e.g., investors' meetings) is discouraged and may jeopardise consideration of the manuscript. Authors should fully disclose all posting in registries of results of the same or closely related work.

Randomized controlled trials should be presented according to the CONSORT guidelines. At manuscript submission, authors must provide the CONSORT checklist accompanied by a flow diagram that illustrates the progress of patients through the trial, including recruitment, enrolment, randomization, withdrawal and completion, and a detailed description of the randomization procedure. The CONSORT checklist and template flow diagram are available online.

Registration in a public trials registry is a condition for publication of clinical trials in this journal in accordance with International Committee of Medical Journal Editors recommendations. Trials must register at or before the onset of patient enrolment. The clinical trial registration number should be included at the end of the abstract of the article. A clinical trial is defined as any research study that prospectively assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects of health outcomes. Health-related interventions include any intervention used to modify a biomedical or health-related outcome (for example drugs, surgical procedures, devices, behavioural treatments, dietary interventions, and process-of-care changes). Health outcomes include any biomedical or health-related measures obtained in patients or participants, including pharmacokinetic measures and adverse events. Purely observational studies (those in which the assignment of the medical intervention is not at the discretion of the investigator) will not require registration.

Upon acceptance of an article, authors will be asked to complete a 'Journal Publishing Agreement' (see more information on this). An e-mail will be sent to the corresponding author confirming receipt of the manuscript together with a 'Journal Publishing Agreement' form or a link to the online version of this agreement.

Subscribers may reproduce tables of contents or prepare lists of articles including abstracts for internal circulation within their institutions. Permission of the Publisher is required for resale or distribution outside the institution and for all other derivative works, including compilations and translations. If excerpts from other copyrighted works are included, the author(s) must obtain written permission from the copyright owners and credit the source(s) in the article. Elsevier has preprinted forms for use by authors in these cases.

For gold open access articles: Upon acceptance of an article, authors will be asked to complete a 'License Agreement' (more information). Permitted third party reuse of gold open access articles is determined by the author's choice of user license.

Author rights

As an author you (or your employer or institution) have certain rights to reuse your work. More information.

Find out how you can share your research published in Elsevier journals.

You are requested to identify who provided financial support for the conduct of the research and/or preparation of the article and to briefly describe the role of the sponsor(s), if any, in study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication. If the funding source(s) had no such involvement, it is recommended to state this.

Please visit our Open Access page for more information about open access publishing in this journal.

Researcher Academy is a free e-learning platform designed to support early and mid-career researchers throughout their research journey. The "Learn" environment at Researcher Academy offers several interactive modules, webinars, downloadable guides and resources to guide you through the process of writing for research and going through peer review. Feel free to use these free resources to improve your submission and navigate the publication process with ease.

Please write your text in good English (American or British usage is accepted, but not a mixture of these). Authors who feel their English language manuscript may require editing to eliminate possible grammatical or spelling errors and to conform to correct scientific English may wish to use the Language Editing service available from Elsevier's Language Services.

Our online submission system guides you stepwise through the process of entering your article details and uploading your files. The system converts your article files to a single PDF file used in the peer-review process. Editable files (e.g., Word, LaTeX) are required to typeset your article for final publication. All correspondence, including notification of the Editor's decision and requests for revision, is sent by e-mail.

Please submit your article via https://www.editorialmanager.com/medintensiva

The authors may propose a maximum of three people whom they consider qualified to conduct a critical review of the manuscript.  The suggested reviewers should not have collaborated with the authors in the previous three years, nor should they have contributed substantially to the current manuscript. For more details, visit our Support site. Note that the editor retains the sole right to decide whether or not the suggested reviewers are used.

It is required for all manuscripts to be accompanied by a letter of presentation in Editorial Manager, indicating: 1) the section of the journal for which the paper is being submitted; 2) an explanation (max. one paragraph) of the original contribution and relevance of the article to the field of medicine; 3) a declaration that author instructions were followed and ethical responsibilities complied with; 4) if part of the article has been previously submitted for assessment to another journal or had been previously published (redundant or duplicated publication), the details should be specified, and it is necessary to declare whether permission for publication has been granted by the author(s) or Editor.

This journal operates a double anonymized review process. All contributions will be initially assessed by the editor for suitability for the journal. Papers deemed suitable are then typically sent to a minimum of two independent expert reviewers to assess the scientific quality of the paper. The Editor is responsible for the final decision regarding acceptance or rejection of articles. The Editor's decision is final. Editors are not involved in decisions about papers which they have written themselves or have been written by family members or colleagues or which relate to products or services in which the editor has an interest. Any such submission is subject to all of the journal's usual procedures, with peer review handled independently of the relevant editor and their research groups. More information on types of peer review.

This journal uses double anonymized review, which means the identities of the authors are concealed from the reviewers, and vice versa. More information is available on our website. To facilitate this, please include the following separately:

Title page (with author details): This should include the title, authors' names, affiliations, acknowledgements and any Declaration of Interest statement, and a complete address for the corresponding author including an e-mail address.

Anonymized manuscript (no author details): The main body of the paper (including the references, figures, tables and any acknowledgements) should not include any identifying information, such as the authors' names or affiliations.

It is important that the file be saved in the native format of the word processor used. The text should be in single-column format. Keep the layout of the text as simple as possible. Most formatting codes will be removed and replaced on processing the article. In particular, do not use the word processor's options to justify text or to hyphenate words. However, do use bold face, italics, subscripts, superscripts etc. When preparing tables, if you are using a table grid, use only one grid for each individual table and not a grid for each row. If no grid is used, use tabs, not spaces, to align columns. The electronic text should be prepared in a way very similar to that of conventional manuscripts (see also the Guide to Publishing with Elsevier. Note that source files of figures, tables and text graphics will be required whether or not you embed your figures in the text. See also the section on Electronic artwork.

To avoid unnecessary errors you are strongly advised to use the 'spell-check' and 'grammar-check' functions of your word processor.

This section describes the article structure for this journal.

Each part of the manuscript should start on a new page, in the following order: title on the first page, together with the information specified in the previous section, then the text, references, figure and table legends. The figures (diagrams, photos, algorithms) should be attached as independent files through Editorial Manager in the Attach Files section.

Text.The text should be divided into sections. Original articles will have the following headings: Introduction, Patients and Methods, Results and Discussion. Especially complex articles can include subsections to aid in the comprehension of the information.

Contribution of the authors. In the case of Original Articles, the contribution of each of the authors should be explained in detail at the end of the manuscript n on a separate page.

Other sections. The authors should declare any total or partial funding of the study, any grant or other financial support and the existence of any conflicts of interests of any of the authors, regardless of whether it has already been mentioned in the Additional Information section. When mention is to be made of any persons, hospitals or entities that may have collaborated with the study, without being considered authors, it should be included in the Acknowledgements section. The authors are responsible for obtaining the necessary permission from the persons or entities names, as the readers could infer their support of the data and the conclusions of the study.

Summary of a manuscript structure (Original Article)

1. Title

2. Abstract: a) Objective, b) Design, c) Setting, d) Patients or participants, e) Interventions, f) Main variables of interest, g) Results, h) Conclusions

3. Text: a) Introduction, b) Patients and Methods, c) Results, d) Discussion

4. Contribution of the Authors

5. Funding

6. Conflict of Interest

7. Acknowledgements

8. References

9. Tables

10. Figures

The introduction should be clear and concise while establishing the purpose of the study and reasonably summarising the current situation of the topic to be discussed.  The introduction should prepare the reader to comprehend the text that follows.  It should not be a review of the topic itself, nor a hurried discussion. It should finish with a clear and specific description of the study objectives.

This section should provide sufficient details so that a specific experience can be reproduced based on the information given.  It should indicate the hospital where the experiment or research has been conducted, its duration, characteristics of the series studied, selection criteria used, variables of interest (primary and secondary) and the techniques used (devices used with name and city of manufacturer in parentheses), drugs used with generic name, dose and means of administration).  If the methods or procedures are widely used and well known, the corresponding bibliographic reference should be provided to avoid a detailed description.  In the case of clinical trials with randomised distribution, randomisation methods should be explained and it should be stated whether the random assignation was blinded.  The statistical methods used should be appropriately described.

The findings should be quantified and presented with the appropriate indicators for error or uncertainty (such as confidence intervals).  This section should state, but not discuss, the observations made of the patients and the method used, in logical sequence.  The results can be expressed in detail in the text or rather in the form of tables and ¿gures, but unnecessary repetitions should be avoided of the results shown in the tables and ¿gures.  Manuscripts that present results of a clinical trial of parallel groups with random distribution should include the CONSORT flowchart, which illustrates the distribution and patient progress throughout the study.  Manuscripts that present reports about systematic reviews or meta-analyses will follow the guidelines from the PRISMA declaration.  The manuscripts that assess the utility of diagnostic tests should follow the STARD format.

The authors should expand on their own opinion about the topic without repeating data provided in the Introduction or Results.  This section should include the following aspects: a) the most relevant findings; b) the practical application of the results; c) the possible methodological limitations and the reasons for which the results are valid; d) the correlation with similar publications and the analysis of the similarities and differences with the findings of other authors; and e) the indications and suggestions for further research, providing new hypotheses when justified, and clearly stating them as such.  It is not necessary to include conclusions; these should be exclusively derived from the study.

It is not necessary to include conclusions; these should be exclusively derived from the study. The main conclusions of the study may be presented in a short Conclusions section, which may stand alone or form a subsection of a Discussion or Results and Discussion section.

If there is more than one appendix, they should be identified as A, B, etc. Formulae and equations in appendices should be given separate numbering: Eq. (A.1), Eq. (A.2), etc.; in a subsequent appendix, Eq. (B.1) and so on. Similarly for tables and figures: Table A.1; Fig. A.1, etc.

• Title. Concise and informative. Titles are often used in information-retrieval systems. Avoid abbreviations and formulae where possible.

• Author names and affiliations. Please clearly indicate the given name(s) and family name(s) of each author and check that all names are accurately spelled. You can add your name between parentheses in your own script behind the English transliteration. Present the authors' affiliation addresses (where the actual work was done) below the names. Indicate all affiliations with a lower-case superscript letter immediately after the author's name and in front of the appropriate address. Provide the full postal address of each affiliation, including the country name and, if available, the e-mail address of each author.

• Corresponding author. Clearly indicate who will handle correspondence at all stages of refereeing and publication, also post-publication. This responsibility includes answering any future queries about Methodology and Materials.Ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author.

• **Present/permanent address.**If an author has moved since the work described in the article was done, or was visiting at the time, a 'Present address' (or 'Permanent address') may be indicated as a footnote to that author's name. The address at which the author actually did the work must be retained as the main, affiliation address. Superscript Arabic numerals are used for such footnotes.

• ***Word count.***It is important to include the word count, indicate the number of words in the abstract in Spanish and English and the number of words in the main text (excluding the abstract, references, tables, and figure legends).

A concise and factual abstract is required. The abstract should state briefly the purpose of the research, the principal results and major conclusions. An abstract is often presented separately from the article, so it must be able to stand alone. For this reason, References should be avoided, but if essential, then cite the author(s) and year(s). Also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself.

In the Reviews, Special Articles and Updates, the abstracts will not be structured but should be equally informative about the content and should have an approximate length of 150 words.

Original abstracts will include an Abstract of 250 words of extension, structured in the following sections:

Objective. It will state the reason for the study that will be evaluated or the hypothesis that is established.

Design. The basic design of the study will be described, including the study period and follow-up period. The following terms should be used:

• For interventionist studies: clinical trial with randomised distribution; clinical trial with non-randomised distribution; double blind; placebo controlled; crossover design.

• For studies on diagnostic tests: reference standard (this is a widely accepted test with which the new or alternative diagnostic test will be compared); this term is preferable to the "gold Standard" or "gold pattern"; blind comparison; validation population.

• For prognostic studies: starting cohort (subjects collected at an early stage of the study disease or process that are subsequently followed-up), cohort (subjects observed in a long-term follow-up but do not necessarily have a common starting point); validation cohort or validation sample in clinical prediction model studies.

• For association or causality studies: clinical trial with randomised distribution; prospective cohort study; case control studies.

• For the description of clinical signs and symptoms or diseases: case series.

• For financial evaluation studies: cost-effectiveness analysis; cost-benefit analysis.

Setting. The setting in which the study has been carried out will be mentioned so that the readers may determine the applicability of the results to their particular work environment.

Patients or participants. The selection criteria must be described, as well as the demographic characteristics of the study subjects, the number of eligible subjects and the number of participating subjects. In case control studies the characteristics used for matching must be specified. In follow-up studies, it must state the proportion of participants that completed the study. In interventionist studies, it must mention the number of patients in whom the intervention was stopped due to the appearance of adverse effects. In prognostic studies, it will mention the percentage losses. The following terms must be employed when referring to the selection process: random sample; consecutive sample: volunteer sample.

Interventions. The essential aspects of each intervention and its duration will be mentioned.

Main variables of interest. It must mention what were the main variables of interest, as were established before starting collecting the data.

Results. A quantitative estimation of the main study variables must be presented, including the confidence intervals (for example, 95%). In comparative studies, mention must be made of the confidence intervals for the differences between the groups studied. In the event that the main variables of interest are subjective measurements, it must state whether the observers knew the group to which each patient had been assigned.

All questionnaire-type studies must mention the response rate. Diagnostic tests studies must report the sensitivity, the specificity and the likelihood ratio. If the predictive value is presented, it must also mention the prevalence or pre-test probability.

Conclusions. Conclusions must only be presented that are based directly on the results and the implications for clinical practice, avoiding speculation and excessive generalisation.

Immediately after the abstract, provide 3 to 10 keywords, using British spelling, to identify the content of the study for its inclusion in national and international biomedical databases. Terms should be used from the Medical Subject Headings of the Index Medicus, available at: http://www.nlm.nih.gov/mesh/meshhome.html.  If no adequate terms are found within the MeSH because if its recent development, commonly used terms can be utilised.  Only abbreviations firmly established in the field may be eligible. These keywords will be used for indexing purposes. These keywords will be used for indexing purposes. Keywords must be included in English and Spanish.

Only commonly used abbreviations in the field of intensive care medicine will be accepted.  The authors should avoid the use of abbreviations in the title and in the abstract of the paper.  When an abbreviation first appears in the paper, it should be preceded by the complete defining term, except in the case of common units of measure.  Units of measure should preferably be expressed in accordance with the International System of Units.  Chemical, physical, biological and clinical units should always be defined. Ensure consistency of abbreviations throughout the article.

Collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. List here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.).

Follow internationally accepted rules and conventions: use the international system of units (SI). If other units are mentioned, please give their equivalent in SI.

This section describes the artwork for this journal.

Whilst it is accepted that authors sometimes need to manipulate images for clarity, manipulation for purposes of deception or fraud will be seen as scientific ethical abuse and will be dealt with accordingly. For graphical images, this journal is applying the following policy: no specific feature within an image may be enhanced, obscured, moved, removed, or introduced. Adjustments of brightness, contrast, or color balance are acceptable if and as long as they do not obscure or eliminate any information present in the original. Nonlinear adjustments (e.g. changes to gamma settings) must be disclosed in the figure legend.

All the graphs, diagrams and photos are considered ¿gures and will be numbered with Arabic numerals in correlation with the order of appearance in the text. They will be sent separately from the text and in as many files as there are ¿gures. Histology photos should indicate the type of stain and the magnification.

General points

o Make sure you use uniform lettering and sizing of your original artwork.

o Embed the used fonts if the application provides that option.

o Aim to use the following fonts in your illustrations: Arial, Courier, Times New Roman, Symbol, or use fonts that look similar.

o Number the illustrations according to their sequence in the text.

o Use a logical naming convention for your artwork files.

o Provide captions to illustrations separately.

o Size the illustrations close to the desired dimensions of the published version. o Submit each illustration as a separate file.

A detailed [https://www.elsevier.com/artworkinstructions guide on electronic artwork](https://www.elsevier.com/artworkinstructions guide on electronic artwork) is available.

You are urged to visit this site; some excerpts from the detailed information are given here.

Formats

If your electronic artwork is created in a Microsoft Office application (Word, PowerPoint, Excel) then please supply 'as is' in the native document format.

Regardless of the application used other than Microsoft Office, when your electronic artwork is finalized, please 'Save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below):

EPS (or PDF): Vector drawings, embed all used fonts.

TIFF (or JPEG): Color or grayscale photographs (halftones), keep to a minimum of 300 dpi.

TIFF (or JPEG): Bitmapped (pure black &white pixels) line drawings, keep to a minimum of 1000 dpi.

TIFF (or JPEG): Combinations bitmapped line/half-tone (color or grayscale), keep to a minimum of 500 dpi.

Please do not:

o Supply files that are optimized for screen use (e.g., GIF, BMP, PICT, WPG); these typically have a low number of pixels and limited set of colors;

o Supply files that are too low in resolution;

o Submit graphics that are disproportionately large for the content.

Please make sure that artwork files are in an acceptable format (TIFF (or JPEG), EPS (or PDF), or MS Office files) and with the correct resolution. If, together with your accepted article, you submit usable color figures then Elsevier will ensure, at no additional charge, that these figures will appear in color online (e.g., ScienceDirect and other sites) regardless of whether or not these illustrations are reproduced in color in the printed version. The expense of the publication of colour photos will be incurred by the authors; beforehand, a cost estimate should be requested from ELSEVIER ESPAÑA, S.L.U., expressly mentioning the desire for the publication in colour.

Further information on the preparation of electronic artwork.

Ensure that each illustration has a caption. Supply captions separately, not attached to the figure. A caption should comprise a brief title (not on the figure itself) and a description of the illustration. Keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used.

Figure legends and captions should contain sufficient information to be able to interpret the data presented without the need to refer to the text.  For explanatory notes under a figure, lower-case letters should be used in superscript and in alphabetical order (a, b).  They will succinctly explain the content of the illustration, as well as the meaning of the signs, arrows, numbers and abbreviations there may be.  Histology images should specify the magnification and staining method.

Please submit tables as editable text and not as images. Tables can be placed either next to the relevant text in the article, or on separate page(s) at the end. Number tables consecutively in accordance with their appearance in the text and place any table notes below the table body. Be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. Please avoid using vertical rules and shading in table cells.

All signs and abbreviations will always be accompanied by an explanatory footnote at the bottom of the table.  Likewise, statistical methods will be specifically identified.  When a statistical method has been applied, the level of significance will be indicated at the bottom of the table, if not already included in the text of the table.

This section describes the references for this journal.

Please ensure that every reference cited in the text is also present in the reference list (and vice versa). These will be presented in Arabic numerals in the order in which they appear in the text with the corresponding correlating number.  When authors are mentioned in the text, their names will be included if there are one or two.  When there are more, only the first author will be named, followed by the expression et al., and, in both cases, the corresponding reference citation number.

Any references cited in the abstract must be given in full. Unpublished results and personal communications are not recommended in the reference list, but may be mentioned in the text. If these references are included in the reference list they should follow the standard reference style of the journal and should include a substitution of the publication date with either 'Unpublished results' or 'Personal communication'. Citation of a reference as 'in press' implies that the item has been accepted for publication. The bibliographic citations should be correctly written and the original publication should always be verified.

 The names of the journals should be abbreviated in accordance with the style used in the Index Medicus, also available at http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=journals.  The citations will be written by strictly following the Vancouver Citation Style Guide (Med Intensiva. 1998;22:110–8), also available at https://www.icmje.org/. Below are examples of bibliographic citation formats.

Increased discoverability of research and high quality peer review are ensured by online links to the sources cited. In order to allow us to create links to abstracting and indexing services, such as Scopus, Crossref and PubMed, please ensure that data provided in the references are correct. Please note that incorrect surnames, journal/book titles, publication year and pagination may prevent link creation. When copying references, please be careful as they may already contain errors. Use of the DOI is highly encouraged.

A DOI is guaranteed never to change, so you can use it as a permanent link to any electronic article. An example of a citation using DOI for an article not yet in an issue is: VanDecar J.C., Russo R.M., James D.E., Ambeh W.B., Franke M. (2003). Aseismic continuation of the Lesser Antilles slab beneath northeastern Venezuela. Journal of Geophysical Research, https://doi.org/10.1029/2001JB000884. Please note the format of such citations should be in the same style as all other references in the paper.

As a minimum, the full URL should be given and the date when the reference was last accessed. Any further information, if known (DOI, author names, dates, reference to a source publication, etc.), should also be given. Web references can be listed separately (e.g., after the reference list) under a different heading if desired, or can be included in the reference list.

This journal encourages you to cite underlying or relevant datasets in your manuscript by citing them in your text and including a data reference in your Reference List. Data references should include the following elements: author name(s), dataset title, data repository, version (where available), year, and global persistent identifier. Add [dataset] immediately before the reference so we can properly identify it as a data reference. The [dataset] identifier will not appear in your published article.

Where a preprint has subsequently become available as a peer-reviewed publication, the formal publication should be used as the reference. If there are preprints that are central to your work or that cover crucial developments in the topic, but are not yet formally published, these may be referenced. Preprints should be clearly marked as such, for example by including the word preprint, or the name of the preprint server, as part of the reference. The preprint DOI should also be provided.

Please ensure that the words 'this issue' are added to any references in the list (and any citations in the text) to other articles in the same Special Issue.

Text: Indicate references by superscript numbers in the text. The actual authors can be referred to, but the reference number(s) must always be given.

List: Number the references in the list in the order in which they appear in the text.

Examples:

Reference to a journal publication Ordinary article. The names of all the authors will be stated if there are six or less; if there are seven or more, the names of the first six should appear, followed by the expression et al.

1. Schiffl H, Lang SM, Fischer R. Daily hemodialysis and the outcome of acute renal failure. N Engl J Med. 2002;346:305-10. https://doi.org/10.1056/NEJMoa010877 2. Bernard GR, Vincent JL, Laterre PF, La Rosa SP, Dhainaut JF, López-Rodríguez A, et al. Eficacy and safety of recombinant human activated protein C for severe sepsis. N Engl J Med. 2001;344: 699-709. https://doi.org/10.1056/NEJMc063207.

Article in electronic journal

3. Cannesson M, Ramsingh D, Rinehart J, Demirjian A, Vu T, Vakharia S, et al. Perioperative goal-directed therapy and postoperative outcomes in patients undergoing high-risk abdominal surgery: a historical-prospective, comparative effectiveness study. Crit Care. 2015; 19:261. https://doi.org/10.1186/s13054-015-0945-2.

Reference to a journal publication with an article number

4. Van der Geer J, Hanraads JAJ, Lupton RA. The art of writing a scientific article. Heliyon. 2018;19:e00205. https://doi.org/10.1016/j.heliyon.2018.e00205.

Study published by a corporation (author is not specified)

5. The hypothermia after cardiac arrest study group. Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest. N Engl J Med. 2002;346:549-56.

Books and other monographs

Personal authors

6. West JB. Ventilation/blood flow and gas exchange. Oxford: Blackwell Scientific Publications; 1977.

Corporative author 7. American Medical Association Department of Drugs. AMA Drug evaluations. 3th ed. Littelton: Publishing Sciences Group; 1977.

Editors or compilers as authors

8. Sackett DL, Straus SE, Richardson WS, Rosenberg W, Haynes RB, editors. Evidence-based medicine. How to practice and teach EBM. 2nd ed. Edinburgh: Churchill Livingstone; 2000.

Chapter of a book

9. Chastre J, Fagon JY. Ventilator-associated pneumonia. En: Hall JB, Schmidt GA, Wood LDH, editors. Principles of critical care. 2nd ed. New York: McGraw-Hill; 1998. p. 617-52.

Reference to a website

10. Cancer Research UK. Cancer statistics reports for the UK, http://www.cancerresearchuk.org/aboutcancer/statistics/cancerstatsreport/; 2003 [accessed 13 March 2003].

Reference to a dataset

[dataset] 11. Oguro M, Imahiro S, Saito S, Nakashizuka T. Mortality data for Japanese oak wilt disease and surrounding forest compositions, Mendeley Data, v1; 2015. https://doi.org/10.17632/xwj98nb39r.1.

Note shortened form for last page number. e.g., 51-9, and that for more than 6 authors the first 6 should be listed followed by 'et al.' For further details you are referred to 'Uniform Requirements for Manuscripts submitted to Biomedical Journals' (J Am Med Assoc 1997;277:927-34)(see also http://www.nlm.nih.gov/bsd/uniform_requirements.html

Elsevier accepts video material and animation sequences to support and enhance your scientific research. Authors who have video or animation files that they wish to submit with their article are strongly encouraged to include links to these within the body of the article. This can be done in the same way as a figure or table by referring to the video or animation content and noting in the body text where it should be placed. All submitted files should be properly labeled so that they directly relate to the video file's content. In order to ensure that your video or animation material is directly usable, please provide the file in one of our recommended file formats with a preferred maximum size of 150 MB per file, 1 GB in total. Video and animation files supplied will be published online in the electronic version of your article in Elsevier Web products, including ScienceDirect. Please supply 'stills' with your files: you can choose any frame from the video or animation or make a separate image. These will be used instead of standard icons and will personalize the link to your video data. For more detailed instructions please visit our video instruction pages. Note: since video and animation cannot be embedded in the print version of the journal, please provide text for both the electronic and the print version for the portions of the article that refer to this content.

Supplementary material such as documents, reference lists, images, applications and sound clips, can be published with your article to enhance it. Submitted supplementary items are published exactly as they are received (Excel or PowerPoint files will appear as such online). Please submit your material together with the article and supply a concise, descriptive caption for each supplementary file. If you wish to make changes to supplementary material during any stage of the process, please make sure to provide an updated file. Do not annotate any corrections on a previous version. Please switch off the 'Track Changes' option in Microsoft Office files as these will appear in the published version.

This journal encourages and enables you to share data that supports your research publication where appropriate, and enables you to interlink the data with your published articles. Research data refers to the results of observations or experimentation that validate research findings, which may also include software, code, models, algorithms, protocols, methods and other useful materials related to the project.

Below are a number of ways in which you can associate data with your article or make a statement about the availability of your data when submitting your manuscript. If you are sharing data in one of these ways, you are encouraged to cite the data in your manuscript and reference list. Please refer to the "References" section for more information about data citation. For more information on depositing, sharing and using research data and other relevant research materials, visit the research data page.

If you have made your research data available in a data repository, you can link your article directly to the dataset. Elsevier collaborates with a number of repositories to link articles on ScienceDirect with relevant repositories, giving readers access to underlying data that gives them a better understanding of the research described.

There are different ways to link your datasets to your article. When available, you can directly link your dataset to your article by providing the relevant information in the submission system. For more information, visit the database linking page.

For supported data repositories a repository banner will automatically appear next to your published article on ScienceDirect.

In addition, you can link to relevant data or entities through identifiers within the text of your manuscript, using the following format: Database: xxxx (e.g., TAIR: AT1G01020; CCDC: 734053; PDB: 1XFN).

One set of page proofs (as PDF files) will be sent by e-mail to the corresponding author (if we do not have an e-mail address then paper proofs will be sent by post) or a link will be provided in the e-mail so that authors can download the files themselves. To ensure a fast publication process of the article, we kindly ask authors to provide us with their proof corrections within two days. Elsevier now provides authors with PDF proofs which can be annotated; for this you will need to download the free Adobe Reader, version 9 (or higher). Instructions on how to annotate PDF files will accompany the proofs (also given online). The exact system requirements are given at the Adobe site.

If you do not wish to use the PDF annotations function, you may list the corrections (including replies to the Query Form) and return them to Elsevier in an e-mail. Please list your corrections quoting line number. If, for any reason, this is not possible, then mark the corrections and any other comments (including replies to the Query Form) on a printout of your proof and scan the pages and return via e-mail. Please use this proof only for checking the typesetting, editing, completeness and correctness of the text, tables and figures. Significant changes to the article as accepted for publication will only be considered at this stage with permission from the Editor. We will do everything possible to get your article published quickly and accurately. It is important to ensure that all corrections are sent back to us in one communication: please check carefully before replying, as inclusion of any subsequent corrections cannot be guaranteed. Proofreading is solely your responsibility.

The corresponding author will, at no cost, receive a customized Share Link providing 50 days free access to the final published version of the article on ScienceDirect. The Share Link can be used for sharing the article via any communication channel, including email and social media. For an extra charge, paper offprints can be ordered via the offprint order form which is sent once the article is accepted for publication. Corresponding authors who have published their article open access do not receive a Share Link as their final published version of the article is available open access on ScienceDirect and can be shared through the article DOI link.

Visit the Elsevier Support Center to find the answers you need.  Here you will find everything from Frequently Asked Questions to ways to get in touch.

You can also check the status of your submitted article or find out when your accepted article will be published.