UNASSIGNED: Serum anion gap (AG) can potentially be applied to the diagnosis of various metabolic acidosis, and a recent study has reported the association of AG with the mortality of patients with coronavirus disease 2019 (COVID-19). However, the relationship of AG with the short-term mortality of patients with ventilator-associated pneumonia (VAP) is still unclear. Herein, we aimed to investigate the association between AG and the 30-day mortality of VAP patients, and construct and assess a multivariate predictive model for the 30-day mortality risk of VAP.
UNASSIGNED: This retrospective cohort study extracted data of 477 patients with VAP from the Medical Information Mart for Intensive Care III (MIMIC-III) database. Data of patients were divided into a training set and a testing set with a ratio of 7:3. In the training set, variables significantly associated with the 30-day mortality of VAP patients were included in the multivariate predictive model through univariate Cox regression and stepwise regression analyses. Then, the predictive performance of the multivariate predictive model was assessed in both training set and testing set, and compared with the single AG and other scoring systems including the Sequential Organ Failure Assessment (SOFA) score, the confusion, urea, respiratory rate (RR), blood pressure, and age (≥65 years old) (CURB-65) score, and the blood urea nitrogen (BUN), altered mental status, pulse, and age (>65 years old) (BAP-65) score. In addition, the association of AG with the 30-day mortality of VAP patients was explored in subgroups of gender, age, and infection status. The evaluation indexes were hazard ratios (HRs), C-index, and 95% confidence intervals (CIs).
UNASSIGNED: A total of 70 patients died within 30 days. The multivariate predictive model consisted of AG (HR =1.052, 95% CI: 1.008-1.098), age (HR =1.037, 95% CI: 1.019-1.055), duration of mechanical ventilation (HR =0.998, 95% CI: 0.996-0.999), and vasopressors use (HR =1.795, 95% CI: 1.066-3.023). In both training set (C-index =0.725, 95% CI: 0.670-0.780) and testing set (C-index =0.717, 95% CI: 0.637-0.797), the multivariate model had a relatively superior predictive performance to the single AG value. Moreover, the association of AG with the 30-day mortality was also found in patients who were male (HR =1.088, 95% CI: 1.029-1.150), and whatever the pathogens they infected (bacterial infection: HR =1.059, 95% CI: 1.011-1.109; fungal infection: HR =1.057, 95% CI: 1.002-1.115).
UNASSIGNED: The AG-related multivariate model had a potential predictive value for the 30-day mortality of patients with VAP. These findings may provide some references for further exploration on simple and robust predictors of the short-term mortality risk of VAP, which may further help clinicians to identify patients with high risk of mortality in an early stage in the intensive care units (ICUs).

Ambient air pollutants can be hazardous to human health, especially for vulnerable children. The impact of ambient air pollutant exposure before and during intensive care unit (ICU) stays on the development of ventilator-associated pneumonia (VAP) in critically ill children has not been established. We aimed to determine the correlations between short-term exposures to ambient fine particulate matter (PM2.5) and VAP in pediatric cardiac surgery patients in the ICU, and explore the effect of delayed exposure.
The medical record of 1755 child patients requiring artificial ventilation in the ICU between December 2013 to December 2020, were analyzed. The daily average concentrations of particulate matters (PM2.5 and PM10), sulfur dioxide (SO2), and ozone (O3) were calculated from public data. Interactions between these pollutants and VAP were simulated with the distributed lag non-linear model.
Three hundred forty-eight cases (19.829%) of VAP were identified in this study, while the average concentrations of PM2.5, PM10, O3 and SO2 were 58, 118, 98 and 26 μg/m3, respectively. Exposure to increased levels of PM2.5 two days prior (lag 2-day) to VAP diagnosis is significantly correlated with an enhanced risk for VAP development. Even a slight increase of 10 μg/m3 in PM2.5 can translate to a 5.4% increase in VAP incidence (95% CI: 1.4%-9.5%) while the VAP incidence increased to 11.1% (95%CI: 4.5-19.5%) when PM2.5 concentration is well below the National Ambient Air Quality standard (NAAQS) of 50 μg/m3. The association was more pronounced in those aged below 3-months, with low body mass index or suffered from pulmonary arterial hypertension.
Short-term PM2.5 exposure is a significant risk for development of VAP in pediatric patients. This risk is present even with PM2.5 levels below the NAAQS. Ambient PM2.5 may represent a previously unrecognized risk factor for pneumonia and the current environmental pollution standards need to be reevaluated to consider susceptible populations.
The trial was registered with the National Clinical Trial Center: The correlation between ambient air pollution and the complications in ICU underwent cardiac surgery.
ChiCTR2000030507. Date of registration: March 5, 2020. URL of trial registry record: http://www.chictr.org.cn/index.aspx .

UNASSIGNED: Basic studies show that selective 5-hydroxytryptamine type 3 (5-HT3) serotonin-receptor antagonists can protect organs from inflammatory injury and have shown lung protection. Whether 5-HT3 receptor antagonists ondansetron benefits patients with mechanical ventilation is unclear in the intensive care unit (ICU).
UNASSIGNED: The Medical Information Mart for Intensive Care-IV (MIMIC-IV) database was reviewed to identify patients on mechanical ventilation (aged >16 years) in the ICU, which was divided into two groups according to whether ondansetron is used. Demographic characteristics, medical history data, clinical parameters, diagnosis and treatment measures were included as covariates. Ondansetron use was defined as any kind of ondansetron administration regardless of the dose before the induction of mechanical ventilation. The primary outcome was in-hospital death. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated by multivariable Cox regression. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were performed to further adjust for confounding factors. Kaplan-Meier (KM) curves with log-rank test were also performed.
UNASSIGNED: A total of 18,566 patients on mechanical ventilation were included (5,735 with ondansetron use). The overall in-hospital mortality rate of patients on mechanical ventilation was 18.9% (3,512/18,566). Approximately 13.0% (746/5,735) and 21.6% (2,766/12,831) in-hospital mortality rates occurred in the ondansetron and non-ondansetron use groups, respectively. Multivariable regression indicated that ondansetron usage was associated with a 33% and 32% lower risk of in-hospital and 60-day death (HR =0.77, 95% CI: 0.70-0.85, P<0.001; HR =0.68, 95% CI: 0.62-0.75, P<0.001) in the whole sample. Multivariable regression post-PSM indicated that ondansetron usage was associated with a 38% and 31% lower risk of in-hospital and 60-day death (HR =0.62, 95% CI: 0.56-0.68, P<0.001; HR =0.69, 95% CI: 0.62-0.77, P<0.001). Log-rank test for the KM curve of ondansetron and 60-day death was statistically significant (P<0.001). The duration of ventilator use pre- and post-PSM was statistically different (P<0.001 and P=0.007) in the two groups.
UNASSIGNED: Ondansetron usage was significantly associated with a lower mortality risk of ventilated patients in the ICU. The 5-HT3 receptor antagonist use is may be new potential adjunctive therapeutic strategy for patients on mechanical ventilation in the ICU.

To investigate the effects of ICU quality control indicators on the VAP incidence rate and mortality in China throughout 2019.
This was a retrospective study. A total of 1267 ICUs from 30 provinces in mainland China were included. Data were collected using the National Clinical Improvement System Data that report ICU information. Ten related quality control indicators were analyzed, including 5 structural factors (patient-to-bed ratio, physician-to-bed ratio, nurse-to-bed ratio, patient-to-physician ratio, and patient-to-nurse ratio), 3 process factors (unplanned endotracheal extubation rate, reintubation rate within 48 h, and microbiology detection rate before antibiotic use), and 2 outcome factors (VAP incidence rate and mortality). The information on the most common infectious pathogens and the most commonly used antibiotics in ICU was also collected. The Poisson regression model was used to identify the impact of factors on the incidence rate and mortality of VAP.
The incidence rate of VAP in these hospitals in 2019 was 5.03 (2.38, 10.25) per 1000 ventilator days, and the mortality of VAP was 11.11 (0.32, 26.00) %. The most common causative pathogen was Acinetobacter baumannii (in 39.98% of hospitals), followed by Klebsiella pneumoniae (38.26%), Pseudomonas aeruginosa, and Escherichia coli. In 26.90% of hospitals, third-generation cephalosporin was the most used antibiotic, followed by carbapenem (24.22%), penicillin and beta-lactamase inhibitor combination (20.09%), cephalosporin with beta-lactamase inhibitor (17.93%). All the structural factors were significantly associated with VAP incidence rate, but not with the mortality, although the trend was inconsistent. Process factors including unplanned endotracheal extubation rate, reintubation rate in 48 h, and microbiology detection rate before antibiotic use were associated with higher VAP mortality, while unplanned endotracheal extubation rate and reintubation rate in 48 h were associated with higher VAP mortality. Furthermore, K. pneumoniae as the most common pathogen was associated with higher VAP mortality, and carbapenems as the most used antibiotics were associated with lower VAP mortality.
This study highlights the association between the ICU quality control (QC) factors and VAP incidence rate and mortality. The process factors rather than the structural factors need to be further improved for the QC of VAP in the ICU.

[This corrects the article DOI: 10.3389/fmicb.2022.782210.].

BACKGROUND: Ventilator-associated pneumonia (VAP) is a common nosocomial infection in the intensive care unit (ICU), with high in-hospital mortality. Current scoring systems are limited in predicting nosocomial death of VAP. This study aimed to develop and validate a more accurate and effective prediction model for in-hospital mortality in ICU patients with VAP.
METHODS: This was a retrospective cohort study. The demographic and clinical data of 8,182 adult patients with VAP were extracted from the Medical Information Mart for Intensive Care (MIMIC-III) database. All patients were randomly classified as a training set (n=4,629) and a test set (n=1,984) with a ratio of 7:3. The outcome was in-hospital mortality and the follow-up was terminated at discharge. Univariate and multivariate logistic regression analyses were used to identify the independent predictors and develop the prediction model in the training set, and internal validation was carried out in the test set. The receiver operating characteristic (ROC) curve and calibration curve were plotted to evaluate the performance of the model.
RESULTS: Ethnicity, lung cancer history, septicemia history, hospital length of stay (LOS), fraction of inspired oxygen (FIO2) level, oxygen saturation (SPO2) level, Simplified Acute Physiology Score (SAPS II) score, Sequential Organ Failure Assessment (SOFA) score, and duration of invasive ventilation were all independently associated with the mortality of VAP. The algorithm of the prediction model was as follows: lnP/(1-P) = -0.700 + 0.493 Other Ethnicity + 0.789 Lung Cancer (Yes) + 0.693 Septicemia (Yes) - 0.074 Hospital LOS - 0.008 FIO2 - 0.032 SPO2 + 0.104 SOFA Score + 0.047 SAPS II + 0.004 Invasive Ventilation. The AUC was 0.837 in the training set and 0.817 in the test set, which indicated that the model performed well. The calibration curve also confirmed good calibration.
CONCLUSIONS: A model with good performance was developed to predict the individual death risk of VAP patients in the ICU, which might have the potential to provide ancillary data to support decision-making by physicians. External validation requires further evaluation of the model performance.

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a common cause of ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients, but its infection and colonization state are difficult to distinguish. If the judgment is wrong, it may aggravate the abuse of antibiotics and further accelerate the evolution of drug resistance. We sought to provide new clues for the diagnosis, pathogenesis and treatment of CRAB VAP based on lower respiratory tract (LRT) microbiota.
A prospective study was conducted on patients with mechanical ventilation from July 2018 to December 2019 in a tertiary hospital. Multi-genomics studies (16S rRNA amplicon, metagenomics, and whole-genome sequencing [WGS]) of endotracheal deep aspirate (ETA) were performed.
Fifty-two ICU patients were enrolled, including 24 with CRAB VAP (CRAB-I), 22 with CRAB colonization (CRAB-C), and six CRAB-negative patients (infection-free) (CRAB-N). Diversity of pulmonary microbiota was significantly lower in CRAB-I than in CRAB-C or CRAB-N (mean Shannon index, 1.79 vs. 2.73 vs. 4.81, P < 0.05). Abundances of 11 key genera differed between the groups. Acinetobacter was most abundant in CRAB-I (76.19%), moderately abundant in CRAB-C (59.14%), and least abundant in CRAB-N (11.25%), but its interactions with other genera increased in turn. Metagenomics and WGS analysis showed that virulence genes were more abundant in CRAB-I than in CRAB-C. Multi-locus sequence typing (MLST) of 46 CRAB isolates revealed that the main types were ST208 (30.43%) and ST938 (15.22%), with no difference between CRAB-I and CRAB-C.
Lower respiratory tract microbiota dysbiosis including elevated relative abundance of Acinetobacter and reduced bacterial interactions, and virulence enrichment may lead to CRAB VAP.

BACKGROUND: The purpose was to investigate the effect on quality of life and inflammatory factor levels of patients with acute respiratory distress syndrome (ARDS) and ventilator-associated pneumonia (VAP).
METHODS: A total of 110 ARDS patients with VAP were randomly divided into an experimental group and control group. The control group received routine nursing while the experimental group received ICU nursing risk management combined with the cluster nursing model to compare the clinical efficacy in the two groups of patients.
RESULTS: There were no significant differences in general information (P>0.05). The total clinical effective rate of patients in the experimental group was significantly higher than that of the control group (P<0.05). The Acute Physiology and Chronic Health Evaluation (APACHE II) scores of all patients after nursing were significantly lower than those before nursing (P<0.001), and the APACHE II score in the experimental group after nursing was significantly lower than that in the control group (P<0.001). The interleukin-8 (IL-8), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels of all patients after nursing were significantly lower than those before nursing (P<0.001), and the levels in the experimental group after nursing were significantly lower than those in the control group (P<0.001). The vital capacity (VC), total lung capacity (TLC), and forced expiratory volume 1 second (FEV1)/forced vital capacity (FVC) levels of all patients after nursing were significantly higher than those before nursing (P<0.001), and the levels in the experimental group after nursing were significantly higher than those in the control group (P<0.001). The MOS 36-item short form health survey (SF-36) scores of all patients after nursing were significantly higher than those before nursing (P<0.001), and the scores in the experimental group after nursing was higher than that in the control group (P<0.001).
CONCLUSIONS: ICU nursing risk management combined with the cluster nursing model can effectively and significantly reduce inflammatory reactions, improve pulmonary function, and enhance the quality of life of ARDS patients with VAP, making it worthy of promotion and application.
BACKGROUND: Chinese Clinical Trial Registry ChiCTR2100048112.

UNASSIGNED: Ventilator-associated pneumonia (VAP) is a major public health problem and is most commonly caused by Acinetobacter baumannii (Ab) infection. In our study, we investigated the profiles of exosomal microRNAs (miRNAs) extracted from the bronchoalveolar lavage fluid (BALF) and serum of patients with Acinetobacter baumannii ventilator-associated pneumonia (Ab-VAP). We also examined the serum metabolomic profiles of these patients. Our aim was to study the associations between lung tissue-derived exosomal miRNAs and changes in global metabolism in patients with Ab-VAP.
UNASSIGNED: Consecutively sampled patients admitted to an intensive care unit (ICU) for pulmonary infection treatment were enrolled in this study. Demographic information and biochemical measurements were collected. Serum samples were obtained following overnight fasting on admission. Bronchoscopies were performed and BALF samples were collected from each patient. Exosomes were extracted using kits from System Biosciences (SBI) and miRNA sequencing was performed. Non-targeted metabolomics were used to express metabolic profiles.
UNASSIGNED: We found significant changes in the miRNA profiles of patients with Ab-VAP; these changes occurred in both BALF exosomal miRNA and serum exosomal miRNA. Gene Ontology analysis further identified the function of miRNA in system metabolism. Serum metabolomic profiles and ratios of biological significance were found to be differentially regulated in Ab-VAP patients. This differential regulation was correlated with the differential expression of miRNAs.
UNASSIGNED: Our data summarizes the dysregulation of serum metabolism and exosomal miRNA excretion that occurs in Ab-VAP patients. The correlation found between BALF exosomal miRNA and dysregulated metabolism, as indicated by the irregular expression of metabolites in the cellular metabolic pathway, highlights potential biomarkers for the diagnosis and treatment of Ab infection.

BACKGROUND: Ventilator-associated pneumonia (VAP) is a severe complication that occurs within patients who must use ventilators in the intensive care unit (ICU). Ventilator care bundles (VCB) have been applied across many developed regions and have produced positive results in controlling VAP. In this study, we report on the implementation and effects of using VCBs to manage VAP in a general tertiary hospital in the Inner Mongolia Autonomous Region of China.
METHODS: A targeted surveillance method was used to survey all the patients (n=4,716) in the ICU from June 1, 2017 to May 31, 2019. Patients from June 1, 2017 to May 31, 2018, and June 1, 2018, to May 31, 2019, were respectively divided into 2 groups: the control group (2,029 patients) and intervention group (2,687 patients). These dates were selected because VCB was implemented from June 1, 2018, in our institution. The variables that were associated with VCB and observed were the head-of-bed elevation, oral care, maintenance of the pressure for the cuff of the endotracheal tube, aspiration of subglottic secretion, daily sedation vacation protocol, daily extubation assessment results, and hand hygiene. After collecting the data, the compliance of VCB, ventilator use ratio, and the incidence rate of VAP in these 2 groups were compared.
RESULTS: We observed that compliance with all of the intervention measures for VCB improved results in the intervention group compared to the control. Furthermore, the compliance rate of hand hygiene increased from 71.99% to 91.97%, and the head-of-bed elevation of 30°-45° increased from 62.02% to 85.96%. All differences between these two groups were statistically significant, according to the χ 2 -test. The ventilator use ratio was statistically and significantly lower in the intervention group (34.86%) compared to the control group (40.29%) (χ 2 =95.513, P<0.001). The incidence rate of VAP was statistically and significantly lower in the intervention group (13.70‰) compared to the control group (18.85‰) (χ 2 =5.471, P=0.019).
CONCLUSIONS: Our results show that VCB prevents VAP. Therefore, personnel training, clinical supervision, and surveillance feedback could promote a reduction in intervention measures.