Ventilator-associated Pneumonia (VAP) Diagnostic Stewardship Trial

This is a prospective pilot/feasibility trial of a bundled diagnostic stewardship intervention at the level of the microbiologic testing pathway in ventilator-associated pneumonia (VAP). The study utilized a pre/post design and was initially registered as a single-arm trial because the study intervention could only be applied prospectively to a single group (all patients hospitalized in study ICUs requiring ventilation during the trial intervention period). The study objectives are to safely and effectively reduce antibiotic overuse and its attendant hazards (adverse drug events, Clostridioides difficile diarrhea and generation of multidrug-resistant organisms) among mechanically-ventilated patients. Participating ICUs will have the following three modifications made in their respiratory culture workflows for mechanically-ventilated patients: 1) providers will be required to select a valid indication for respiratory culture performance (worsening ventilator requirements, purulent sputum production, and/or new radiographic infiltrate on chest imaging); 2) respiratory cultures will be preferentially obtained via bronchoscopic or nonbronchoscopic BAL (by respiratory therapists) rather than via endotracheal aspiration; and 3) BAL samples will be sent for cell count and differentials, and respiratory culture results will not be released for samples with \<50% neutrophils. The study will carefully monitor adherence to study interventions, ICU-specific antibiotic utilization rates, and important safety metrics including rates of mortality, ventilator-dependence and ventilator-associated events. The trial hypotheses are: * Implementation of a VAP diagnostic stewardship bundle will be successfully implemented without significant increases in mortality or ventilator-associated events. * Implementation of a VAP diagnostic stewardship bundle will be associated with a reduction in ICU-specific antibiotic utilization rates