A rat model for isolated bilateral lung contusion from blunt chest trauma.
Lung contusion affects 17%-25% of adult blunt trauma patients, and is the leading cause of death from blunt thoracic injury. A small animal model for isolated bilateral lung contusion has not been developed. We induced lung contusion in anesthetized rats by dropping a 0.3-kg weight onto a precordial protective shield to direct the impact force away from the heart and toward the lungs. Lung injury was characterized as a function of chest impact energy (1.8-2.7 J) by measurements of arterial oxygenation, bronchoalveolar lavage (BAL) albumin and cytology, pressure-volume mechanics, and histopathology. Histology confirmed bilateral lung contusion without substantial cardiac muscle trauma. Rats receiving 2.7 J of chest impact energy had 33% mortality that exceeded prospectively defined limits for sublethal injury. Hypoxemia in rats with maximal sublethal injury (2.45 J) met criteria for acute lung injury at < or =24 h, improving by 48 h. BAL albumin levels were highest at < or =24 h, and remained elevated along with increased BAL leukocytes and decreased lung volumes at 48 h. We concluded that an impact energy of 2.45 J induces isolated, bilateral lung contusion and provides a useful model for future mechanistic pathophysiological assessments.
Raghavendran
Krishnan
K
Departments of *Surgery, †Anesthesiology, and ‡Pathology, State University of New York (SUNY) at Buffalo, Buffalo; and §Department of Pediatrics, University of Rochester, Rochester, New York.
Davidson
Bruce A
BA
Helinski
Jadwiga D
JD
Marschke
Cristi J
CJ
Manderscheid
Patricia
P
Woytash
James A
JA
Notter
Robert H
RH
Knight
Paul R
PR
D000418:Albumins / Q000032:analysis; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D003288:Contusions / Q000378:metabolism / Q000473:pathology*; D008168:Lung / Q000473:pathology; D055370:Lung Injury; D008297:Male; D010100:Oxygen / Q000097:blood; D051381:Rats; D020318:Rats, Long-Evans; D013898:Thoracic Injuries / Q000378:metabolism / Q000473:pathology*; D014949:Wounds, Nonpenetrating / Q000378:metabolism / Q000473:pathology*
D000418:Albumins; D010100:Oxygen