Ventilator-associated Pneumonia (VAP) Diagnostic Stewardship Trial

Description

Overdiagnosis of ventilator-associated pneumonia (VAP) is common among mechanically-ventilated patients and contributes to antibiotic overuse and the generation of multidrug resistant organisms within intensive care units (ICUs). Identification of interventions that safely and effectively lower VAP overdiagnosis and antibiotic overuse are important for antimicrobial stewardship programs. Antibiotic stewardship interventions targeting VAP have heretofore focused on therapeutic interventions-antibiotic de-escalation or discontinuation-in established VAP cases, but have not leveraged interventions at the level of the VAP diagnostic testing pathway to minimize overdiagnosis in the first place. Current microbiologic testing practices-specifically, indiscriminate ordering, collection and interpretation of respiratory cultures-incents VAP overdiagnosis and antibiotic overuse.

This is a single-arm prospective pilot/feasibility trial of a bundled diagnostic stewardship intervention targeting the microbiologic diagnostic testing pathway among mechanically-ventilated patients. This pilot/feasibility trial will implement system-based changes within ICUs in microbiologic diagnostic testing workflows with the goal of safely lowering antibiotic utilization rates in mechanically-ventilated patients. Specifically, the study will sequentially implement the following 3 changes in the diagnostic testing workflow for clinical providers:

1. Ordering respiratory cultures:
2. Current workflow: respiratory cultures can be ordered by frontline clinical providers without preconditions.
3. Study intervention: frontline clinical providers will be required to select a valid indication for respiratory culture collection through a custom order set in the institutional electronic medical record (EMR).
4. Collection of respiratory cultures:
5. Current workflow: providers may collect endotracheal aspirates (proximal lung secretions) or bronchoalveolar lavage (distal lung secretions) for analysis.
6. Study intervention: providers will be required to preferentially use only bronchoalveolar lavage (BAL) to minimize false positive test results (assuming no contraindications to BAL performance). This will be accomplished through a custom order set in the institutional EMR.
7. Reporting of respiratory cultures:
8. Current workflow: positive respiratory culture results are automatically released in the EMR, regardless of likelihood of infection.
9. Study intervention: respiratory culture results will be automatically released in the EMR only for BAL samples with a polymorphonuclear (PMN) percentage of >50% (to minimize false positive test results). Respiratory culture results for BAL samples with PMN% <50% will be released if the primary team calls the microbiology lab directly and requests result release.

All proposed interventions are within the standard of care for routine clinical practice, but have not been operationalized in parallel to each other and studied explicitly with the goal of reducing antibiotic overuse. The interventions will be implemented sequentially in 2-month intervals. The interventions will be operationalized through use of a custom order set in the institutional EMR, as well as through bimonthly provider educational sessions performed by study personnel during morning ICU rounds.

The study population in this trial includes all patients admitted to participating study ICUs for routine clinical care. Providers will engage in routine clinical care utilizing the aforementioned modified diagnostic testing workflows and the study will compare safety outcomes and ICU antibiotic utilization rates pre- and post-intervention implementation. A total of 1500 patients are anticipated to be admitted to participating Michigan Medicine ICUs over the course of the study period.

The study population will also include healthcare providers in participating ICUs who are providing routine clinical care utilizing these novel diagnostic testing workflows. Adherence to study interventions by these healthcare providers will be assessed during this study to inform project feasibility on a larger scale. A total of 200 healthcare providers are anticipated to provide care in participating ICUs during the study time period.

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