The longitudinal microbiology and immunology of the airway in mechanically ventilated adults

Project Leader:

Manuel Vilchez, M.D.
Instructor of Medicine
Geisel School of Medicine at Dartmouth

Co-Investigators:

Richard Zuckerman, M.D., M.P.H.
Associate Professor of Medicine
Geisel School of Medicine
Section of Infectious Disease and International Health
Dartmouth Hitchcock Medical Center

Harold Manning, M.D.
Professor of Medicine
Geisel School of Medicine
Section of Pulmonary and Critical Care Medicine
Dartmouth Hitchcok Medical Center

George A O'Toole, Ph.D.
Professor
Department of Microbiology & Immunology
Geisel School of Medicine at Dartmouth

The Purpose of this study is to determine if the presence or change in abundance of marker microorganisms or immune markers found in sputum of intubated patients can predict the development and/or severity of ventilator associated pneumonia (VAP) Knowledge about human-associated microbiota, defined as the microorganisms inhabiting specific organ and body system niches, has increased rapidly in recent years. Several studies suggested that the presence or composition of microbiota in a given niche can be a determinant of whether site-specific inflammation or disease is present.

In 2002, an estimated 250,000 healthcare-associated pneumonias developed in U.S. hospitals and 36,000 of these were associated with death. VAP is an important cause of morbidity and mortality despite improved antimicrobial therapy, supportive care, and prevention. Intubation and mechanical ventilation greatly increase the risk of nosocomial bacterial pneumonia because they alter first-line patient defenses by allowing direct access from oral flora to deeper lung structures and by inhibiting the cough reflex. The diagnosis of VAP is complicated due to highly variable patient characteristics; therefore additional diagnostic modalities are needed.