Lung contusion is the commonest injury following blunt trauma to the chest that requires admission to the hospital. The pathogenesis and cellular mechansims of lung contusion are not well understood in part due to a lack of a reliable small animal model for isolated lung contusion . We have recently developed a reproducible rat model for isolated bilateral lung contusion from blunt trauma in a closed chest to facilitate mechanistic studies.This model is used here to examine the mechanistic inflammatory pathophysiology of lung contusion, as well as its interaction with gastric aspiration, a frequent occurence in trauma patients. Based on our preliminary studies, we hypothesize that acute inflammatory injury in isolated lung contusion resolves by 7 days. In the presence of an additional """"""""second hit"""""""" such as gastric aspiration, this injury progresses to severe respiratory dysfunction (ALI/ARDS).
The Specific Aim #1 examines in detail the cellular mechanisms(role of neutrophils and alveolar macrophages) and specific chemokines(CINC-1, MIP-2 and MCP-1) in the rat model.
The Specific Aim # 2 studies the interaction of lung contusion with combination of acid and particulate aspiration injury to the lung in rats.
This aim examines the role of neutrophils, alveolar macrophages and chemokines (CINC-1, MIP-2 and MCP-1) in the interaction of these two insults. In addition, aim 2 uses genomic profiling to identify other factors that may be important in the pathogenesis of lung contusion with/without gastric aspiration. Animal research is complemented In Specific Aim # 3 by a observational, prospective study in blunt trauma patients with lung contusion . This epidemiological study wil also study the risk factors for unwitnessed gastric aspiration and examine other risk factors that may be associated with the progression of lung contusion to ALI/ARDS. Understanding lung contusion and its interaction with gastric aspiration, two common insults suffered by trauma patients, will greatly aid the development of new diagnostic and therapeutic modalities.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Clinical Investigator Award (CIA) (K08)
Project #
7K08GM073826-04
Application #
7664832
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Somers, Scott D
Project Start
2006-02-01
Project End
2011-01-31
Budget Start
2008-07-01
Budget End
2009-01-31
Support Year
4
Fiscal Year
2008
Total Cost
$81,833
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Surgery
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Raghavendran, Krishnan; Davidson, Bruce A; Hutson, Alan D et al. (2009) Predictive modeling and inflammatory biomarkers in rats with lung contusion and gastric aspiration. J Trauma 67:1182-90
Raghavendran, Krishnan; Notter, Robert H; Davidson, Bruce A et al. (2009) Lung contusion: inflammatory mechanisms and interaction with other injuries. Shock 32:122-30
Raghavendran, Krishnan; Davidson, Bruce A; Huebschmann, John C et al. (2009) Superimposed gastric aspiration increases the severity of inflammation and permeability injury in a rat model of lung contusion. J Surg Res 155:273-82
Raghavendran, Krishnan; Davidson, Bruce A; Knight, Paul R et al. (2008) Surfactant dysfunction in lung contusion with and without superimposed gastric aspiration in a rat model. Shock 30:508-17
Raghavendran, Krishnan; Pryhuber, Gloria S; Chess, Patricia R et al. (2008) Pharmacotherapy of acute lung injury and acute respiratory distress syndrome. Curr Med Chem 15:1911-24
Raghavendran, Krishnan; Wang, Jiping; Belber, Christopher et al. (2007) Predictive value of sputum gram stain for the determination of appropriate antibiotic therapy in ventilator-associated pneumonia. J Trauma 62:1377-82;discussion 1382-3