Introduction
Ventilator-associated pneumonia (VAP) is a well-known complication of invasive mechanical ventilation in critically ill patients (Metersky and Kalil, 2018). We read with great interest the article entitled “Description of Clinical Characteristics of VAP Patients in MIMIC Database (Liu et al., 2019).” We would like to congratulate the authors for their application of the Medical Information Mart for Intensive Care (MIMIC) database to identify the clinical characteristics of VAP patients in ICU. However, we would like to make a few comments on the methodology and the interpretation of the findings of this study.
Definition of Pathogen
In the abstract, the authors claimed that “The main pathogens were YEAST (16.71%), STAPH AUREUS COAG+ (11.63%), Staphylococcus, COAGULASE NEGATIVE (8.68%), GRAM NEGATIVE ROD (S) (6.14%), and Pseudomonas aeruginosa (5.73%).” We understood that this may just be the results they got from the database, but it should be interpreted properly.
For one thing, according to the traditional clinical microbiology, the description “STAPH AUREUS COAG+ (11.63%), Staphylococcus, COAGULASE NEGATIVE (8.68%)” is not appropriate, as the coagulase-positive Staphylococci includes Staphylococcus aureus and Staphylococcus lugdunensis. “GRAM NEGATIVE ROD (S) (6.14%)” using Gram negative bacillus might be more appropriate (Busse et al., 1996).
For another, in the MIMIC database, the sites of the infection/culture were specified. But in this report, it seems that the author did not include any of those data in the analysis. If the intention were to describe the distribution of pathogens in VAP, it may be useful to include this information. Because culture-positive could be colonizing microorganisms, which is largely site-specific (Jarvis, 1996).
Last but not least, the definition of the pathogen is “a specific causative agent of disease.” Culture positive means the presence of the microorganisms but they are not necessarily the causes of pneumonia or VAP (Messika et al., 2018). In this report focusing on VAP, however, yeast and coagulase-negative Staphylococci, etc., are mostly colonized on the respiratory system and rarely the cause of the infection (Guidelines for the manage, 2005). We understand these culture results were recorded in the database, but some interpretations are needed if those were supposed to be of guidance for diagnosis and treatment of VAP (Papazian et al., 2020).
Methodology and Interpretation of Results
As for the methodology, we are not sure what was the purpose of categorizing patients based on gender. In Table 1, the authors compared the basic characters of study participants while summarized the basic characteristics in two columns. And we feel this is hardly justifiable. Is gender a risk factor or confounder for VAP according to previous studies? Furthermore, the author claimed, “Both males and females had a highest proportion of survival.” We are not sure what this indicates or to whom the highest “proportion of survival” was compared?
In the third paragraph of the result, “the rest were other pathogenic bacteria (52.83%).” In MIMIC, the specific types of pathogens were clearly recorded. As the authors listed yeast as the most common bacteria, we feel it could be likely that some of the important pathogens were inappropriately combined in this category.
In the fourth paragraph of the result, the authors listed “synthetic antibacterials” as a category of antibiotics. We feel this might not be appropriate. Several types of antibiotics were synthetic, covering different mechanisms (Mohr, 2016; Balaban et al., 2019). Classification based on whether the antibiotics were synthetic may be of limited clinical reference.
We understood that the study would be limited by the nature of MIMIC, a retrospective database. Again, we would like to congratulate the authors for a nicely done study.
Statements
Author contributions
XZ designed the General Commentary; YL drafted the manuscript.
Funding
This study was supported by the Program of Research and Development of Medical Big Data and Artificial Intelligence of Chinese PLA General Hospital (2019MBD-014).
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
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Summary
Keywords
ventilator-associated pneumonia, pathogenic bacteria, MIMIC database, colonization, infection
Citation
Li Y and Zhang X (2021) Commentary: Description of Clinical Characteristics of VAP Patients in MIMIC Database. Front. Pharmacol. 12:736447. doi: 10.3389/fphar.2021.736447
Received
05 July 2021
Accepted
30 August 2021
Published
09 September 2021
Volume
12 - 2021
Edited by
Despoina Koulenti, University General Hospital Attikon, Greece
Reviewed by
Marios Karvouniaris, University General Hospital of Thessaloniki AHEPA, Greece
Updates
Copyright
© 2021 Li and Zhang.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Xuan Zhang, 13581793301@163.com
This article was submitted to Respiratory Pharmacology, a section of the journal Frontiers in Pharmacology
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.