Trauma patients meeting both Centers for Disease Control and Prevention's definitions for ventilator-associated pneumonia had worse outcomes than those meeting only one

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.

Ventilator-associated Events Surveillance in a Trauma Intensive Care Unit: A Prospective Study of Incidence, Predictive Values, Sensitivity, Specificity, Accuracy, and Concordance with Ventilator-associated Pneumonia

Introduction

The Centres for Disease Control and Prevention (CDC) introduced a new definition of ventilator-associated events (VAEs) in 2013 in place of longstanding ventilator-associated pneumonia (VAP) definition. Three entities under VAE, ventilator-associated condition (VAC), infection-related ventilator-associated complication (IVAC), and possible ventilator-associated pneumonia (PVAP), were introduced.

Objectives

To assess the incidence of all VAEs in a tertiary care trauma ICU and to find the predictive value of VAE and sensitivity of VAE definitions for VAP.

Design

Cohort prospective study at trauma intensive care unit (ICU) of PGIMER, Chandigarh, from July 2018 till June 2019.

Materials and methods

Patients admitted in trauma ICU were checked for VAP and VAE criteria defined by CDC.

Results

Four hundred and sixty five patients were observed. Around 378 patients were included in the study with 4046 patient days and 3031 mechanical ventilation (MV) days. Incidence rate of PVAP, IVAC, VAC, and VAP was 2.97, 6.60, 10.23, and 9.24 per 1000 ventilator days, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value (NPV) of diagnosing VAP were 0.61, 0.97, 0.68, and 0.97 for VAC; 0.80, 0.97, 0.57, and 0.99 for IVAC; and 0.78, 0.94, 0.25, and 0.9 for PVAP, respectively. Kendall's W test showed that there was very poor concordance between VAP and VAE.

How to cite this article

Kaur K, Jain K, Biswal M, Dayal SK. Ventilator-associated Events Surveillance in a Trauma Intensive Care Unit: A Prospective Study of Incidence, Predictive Values, Sensitivity, Specificity, Accuracy, and Concordance with Ventilator-associated Pneumonia. Indian J Crit Care Med 2022;26(5):584–590.

Surgical Infection Society Research Priorities: A Narrative Review of Fourteen Years of Progress

Background: In 2006, the Surgical Infection Society (SIS) utilized a modified Delphi approach to define 15 specific priority research questions that remained unanswered in the field of surgical infections. The aim of the current study was to evaluate the scientific progress achieved during the ensuing period in answering each of the 15 research questions and to determine if additional research in these fields is warranted. Methods: For each of the questions, a literature search using the National Center for Biotechnology Information (NCBI) was performed by the Scientific Studies Committee of the SIS to identify studies that attempted to address each of the defined questions. This literature was analyzed and summarized. The data on each question were evaluated by a surgical infections expert to determine if the question was answered definitively or remains unanswered. Results: All 15 priority research questions were studied in the last 14 years; six questions (40%) were definitively answered and 9 questions (60%) remain unanswered in whole or in part, mainly because of the low quality of the studies available on this topic. Several of the 9 unanswered questions were deemed to remain research priorities in 2020 and warrant further investigation. These included, for example, the role of empiric antimicrobial agents in nosocomial infections, the use of inotropes/vasopressors versus volume loading to raise the mean arterial pressure, and the role of increased antimicrobial dosing and frequency in the obese patient. Conclusions: Several surgical infection-related research questions prioritized in 2006 remain unanswered. Further high-quality research is required to provide a definitive answer to many of these priority knowledge gaps. An updated research agenda by the SIS is warranted at this time to define research priorities for the future.

Ventilator-associated events, not ventilator-associated pneumonia, is associated with higher mortality in trauma patients

BACKGROUND

Ventilator-associated events (VAE), using objective diagnostic criteria, are the preferred quality indicator for patients requiring mechanical ventilation (MV) for greater than 48 hours. We aim to identify the occurrence of VAE in our trauma population, the impact on survival, and length of stay, as compared to the traditional definition of ventilator-associated pneumonia (VAP).

METHODS

This retrospective review included adult trauma patients, who were Washington residents, admitted between 2012 and 2017, and required at least 3 days of MV. Exclusions included patients with Abbreviated Injury Scale head score greater than 4 and burn related mechanisms of injury. We matched trauma registry data with our institutional, physician-adjudicated, and culture-confirmed ventilator event database. We compared the clinical outcomes of ventilator-free days, intensive care unit length of stay, hospital length of stay, and likelihood of death between VAE and VAP.

RESULTS

One thousand five hundred thirty-three trauma patients met criteria; 124 (8.1%) patients developed VAE, 114 (7.4%) patients developed VAP, and 63 (4.1%) patients met criteria for both VAE and VAP. After adjusted analyses, patients with VAE were more likely to die (hazard ratio [HR], 2.86; 95% confidence interval [CI], 1.44-5.68), than those with VAP, as well those patients with neither diagnosis (HR, 2.83; 95% CI, 1.83-4.38). Patients with VAP were no more likely to die (HR, 1.55; 95% CI, 0.91-2.68) than those with neither diagnosis. Patients with VAE had fewer ventilator-free days than those with VAP (HR, -2.71; 95% CI, -4.74 to -0.68).

CONCLUSION

Critically injured trauma patients who develop VAE are three times more likely to die and utilize almost 3 days more MV than those that develop VAP. The objective criteria of VAE make it a promising indicator on which quality indicator efforts should be focused. Future studies should be aimed at identification of modifiable risk factors for VAE and their impact on outcome, as these patients are at high risk for death.

LEVEL OF EVIDENCE

Retrospective cohort study, level III.

Antibiotic consumption and ventilator-associated pneumonia rates, some parallelism but some discrepancies

Ventilator-associated pneumonia (VAP) is a common infection in intensive care units (ICUs) but its clinical definition is neither sensitive nor specific and lacks accuracy and objectivity. New defining criteria were proposed in 2013 by the National Healthcare Safety Network (NHSN) in order to more accurately conduct surveillance and track prevention progress. Although there is a consistent trend towards a decrease in VAP incidence during the last decade, significant differences in VAP rates have been reported and are persistently lower in NHSN and other American reports (0.0 to 4.4 VAP per 1,000 ventilator-days in 2012) compared to the European Centre for Disease Prevention and Control (ECDC) data (10 VAP per 1,000 ventilator-days in 2014). In the United States, VAP has been proposed as an indicator of quality of care in public reporting, and the threat of financial penalties for this diagnosis has put pressure on hospitals to minimize VAP rates that may lead to artificial lower values, independently of patient care. Although prevention bundles may contribute for encouraging reductions in VAP incidence, both pathophysiologic and epidemiologic factors preclude a zero-VAP rate. It would be expected from the trend of reduction of VAP incidence that the consumption of antibiotics would also decrease in particular in those hospitals with lowest VAP rates. However, ICU reports show a steadily use of antibiotics for nosocomial pneumonia in 15% of patients and both ECDC and NHSN data on antibiotic consumption showed no significant trend. Knowledge of bacterial epidemiology and resistance profiles for each ICU has great relevance in order to understand trends of antibiotic use. The new NHSN criteria provide a more objective and quantitative data based VAP definition, including an antibiotic administration criterion, allowing, in theory, a more comprehensive assessment and a reportable benchmark of the observed VAP and antibiotic consumption variability.