Prevalence, Clinical Characteristics, and Outcomes Related to Ventilator-Associated Events in Neurocritically Ill Patients

Association between oral microbial dysbiosis and poor functional outcomes in stroke-associated pneumonia patients

BACKGROUND

Despite advances in our understanding of the critical role of the microbiota in stroke patients, the oral microbiome has rarely been reported to be associated with stroke-associated pneumonia (SAP). We sought to profile the oral microbial composition of SAP patients and to determine whether microbiome temporal instability and special taxa are associated with pneumonia progression and functional outcomes.

METHODS

This is a prospective, observational, single-center cohort study that examined patients with acute ischemic stroke (AIS) who were admitted within 24 h of experiencing a stroke event. The patients were divided into three groups based on the occurrence of pneumonia and the use of mechanical ventilation: nonpneumonia group, SAP group, and ventilator-associated pneumonia (VAP) group. We collected oral swabs at different time points post-admission and analyzed the microbiota using 16 S rRNA high-throughput sequencing. The microbiota was then compared among the three groups.

RESULTS

In total, 104 nonpneumonia, 50 SAP and 10 VAP patients were included in the analysis. We found that SAP and VAP patients exhibited significant dynamic differences in the diversity and composition of the oral microbiota and that the magnitude of this dysbiosis and instability increased during hospitalization. Then, by controlling the potential effect of all latent confounding variables, we assessed the changes associated with pneumonia after stroke and explored patients with a lower abundance of Streptococcus were more likely to suffer from SAP. The logistic regression analysis revealed that an increase in specific taxa in the phylum Actinobacteriota was linked to a higher risk of poor outcomes. A model for SAP patients based on oral microbiota could accurately predict 30-day clinical outcomes after stroke onset.

CONCLUSIONS

We concluded that specific oral microbiota signatures could be used to predict illness development and clinical outcomes in SAP patients. We proposed the potential of the oral microbiota as a non-invasive diagnostic biomarker in the clinical management of SAP patients.

CLINICAL TRIAL REGISTRATION

NCT04688138. Registered 29/12/2020, https://clinicaltrials.gov/ct2/show/NCT04688138 .

Ventilator-associated pneumonia in neurocritically ill patients: insights from the ENIO international prospective observational study

BACKGROUND

Acute brain injured (ABI) patients are at high risk of developing ventilator-associated pneumonia (VAP). However, incidence, risk factors and effects on outcome of VAP are not completely elucidated in this population. The primary aim of this study was to determine the incidence of VAP in a cohort of ABI patients. The secondary objectives included the identification of risk factors for development of VAP, and the impact of VAP on clinical outcomes. Clinical outcomes were defined as intensive care unit length of stay (ICU-LOS), duration of invasive mechanical ventilation (IMV), and ICU mortality.

METHODS

Pre-planned sub-analysis of the Extubation strategies in Neuro-Intensive care unit (ICU) patients and associations with Outcomes (ENIO) international multi-center prospective observational study. Patients with available data on VAP, who received at least 48 h of IMV and ICU-LOS ≥ 72 h were included.

RESULTS

Out of 1512 patients included in the ENIO study, 1285 were eligible for this analysis. The prevalence of VAP was 39.5% (33.7 cases /1000 ventilator-days), with a high heterogeneity across countries and according to the type of brain injury. VAP was significantly more frequent in male patients, in those with smoke habits and when intraparenchymal probe (IP), external ventricular drain (EVD) or hypothermia (p < 0.001) were used. Independent risk factors for VAP occurrence were male gender, the use of IP, hypothermia, and the occurrence of tracheobronchitis during ICU stay. VAP was not an independent risk factor for ICU mortality (Hazard Ratio, HR = 0.71 95%CI 0.43-1.16, p = 0.168), but was independently associated with longer ICU stay (OR = 2.55 95%CI 2.01-3.23, p < 0.001).

CONCLUSIONS

VAP is common in ABI patients. Male gender, IP and EVD insertion, tracheobronchitis, and the use of therapeutic hypothermia were significantly associated with VAP occurrence. VAP did not affect mortality but increased ICU-LOS.

A Method to Explore Variations of Ventilator-Associated Event Surveillance Definitions in Large Critical Care Databases in the United States

The Centers for Disease Control has well-established surveillance programs to monitor preventable conditions in patients supported by mechanical ventilation (MV). The aim of the study was to develop a data-driven methodology to examine variations in the first tier of the ventilator-associated event surveillance definition, described as a ventilator-associated condition (VAC). Further, an interactive tool was designed to illustrate the effect of changes to the VAC surveillance definition, by applying different ventilator settings, time-intervals, demographics, and selected clinical criteria.

DESIGN

Retrospective, multicenter, cross-sectional analysis.

SETTING

Three hundred forty critical care units across 209 hospitals, comprising 261,910 patients in both the electronic Intensive Care Unit Clinical Research Database and Medical Information Mart for Intensive Care III databases.

PATIENTS

A total of 14,517 patients undergoing MV for 4 or more days.

MEASUREMENTS AND MAIN RESULTS

We designed a statistical analysis framework, complemented by a custom interactive data visualization tool to depict how changes to the VAC surveillance definition alter its prognostic performance, comparing patients with and without VAC. This methodology and tool enable comparison of three clinical outcomes (hospital mortality, hospital length-of-stay, and ICU length-of-stay) and provide the option to stratify patients by six criteria in two categories: patient population (dataset and ICU type) and clinical features (minimum Fio₂, minimum positive end-expiratory pressure, early/late VAC, and worst first-day respiratory Sequential Organ Failure Assessment score). Patient population outcomes were depicted by heatmaps with mortality odds ratios. In parallel, outcomes from ventilation setting variations and clinical features were depicted with Kaplan-Meier survival curves.

CONCLUSIONS

We developed a method to examine VAC using information extracted from large electronic health record databases. Building upon this framework, we developed an interactive tool to visualize and quantify the implications of variations in the VAC surveillance definition in different populations, across time and critical care settings. Data for patients with and without VAC was used to illustrate the effect of the application of this method and visualization tool.

Effect of chronic obstructive pulmonary disease combined with ventilator-associated pneumonia on patient outcomes: A systematic review and meta-analysis

The purpose of the present systematic review and meta-analysis was to uncover whether chronic obstructive pulmonary disease (COPD) as a co-morbidity influences outcomes of patients with ventilator-associated pneumonia (VAP) compared to VAP alone and whether the development of VAP in patients with COPD is associated with poor outcome in comparison to COPD alone. An electronic search of the PubMed, Embase, Scopus, BioMed Central, CENTRAL and Google scholar databases for all types of studies assessing the influence of COPD on outcomes of patients with VAP and vice versa was performed. A total of 7 studies were included. Of these, 3 studies assessed the impact of COPD on outcomes of patients with VAP. Meta-analysis indicated that the presence of COPD significantly increased the mortality of patients with VAP [risk ratio (RR): 1.37, 95% CI: 1.14-1.65, I²=3%, P=0.007]. The analysis failed to demonstrate any significant effect of COPD on the duration of mechanical ventilation in patients with VAP [mean difference (MD): 2.37, 95% CI: -5.77 to 10.50, I²=38%, P=0.57]. However, the duration of the intensive care unit (ICU) stay was significantly longer in patients with COPD and VAP as compared with that of patients with VAP without COPD (MD: 5.53, 95% CI: 0.73-10.33, I²=0%, P=0.02). A total of 4 studies assessed the impact of VAP on outcomes of patients with COPD. Meta-analysis indicated that the presence of VAP significantly increased mortality of patients with COPD (RR: 1.52, 95% CI: 1.08-2.12, I²=71%, P=0.02). Pooled analysis indicated that the presence of VAP in patients with COPD significantly increased the duration of mechanical ventilation (MD: 13.73, 95% CI: 7.86-19.61, I²=92%, P<0.00001) and the duration of the ICU stay as compared to patients with COPD but without VAP (MD: 17.36, 95% CI: 9.55-25.17, I²=90%, P<0.0001). To conclude, within the limitations of the study, the present results indicated that the combination of COPD and VAP significantly increased patient mortality and the duration of ICU stay. The development of VAP in patients with COPD also significantly increased the duration of mechanical ventilation. Further case-matched studies are required to assess the influence of the severity of COPD in combination with VAP on patient outcomes.