Characterization of crash-induced thoracic loading resulting in pulmonary contusion.
BACKGROUND
Pulmonary contusion (PC) is commonly sustained in motor vehicle crash. This study utilizes the Crash Injury Research and Engineering Network (CIREN) database and vehicle crash tests to characterize the occupants and loading characteristics associated with PC. A technique to match CIREN cases to vehicle crash tests is applied to quantify the thoracic loading associated with this injury.


METHODS
The CIREN database and crash test data from the National Highway Traffic Safety Administration were used in this study. An analysis of CIREN data were conducted between three study cohorts: patients that sustained PC and any other chest injury (PC+ and chest+), patients with chest injury and an absence of PC (PC- and chest+), and a control group without chest injury and an absence of PC (PC- and chest-). Forty-one lateral impact crash tests were analyzed and thoracic loading data from onboard crash tests dummies were collected.


RESULTS
The incidence of PC in CIREN data were 21.7%. Crashes resulting in PC demonstrated significantly greater mortality (23.9%) and Injury Severity Score (33.1 +/- 15.7) than the control group. The portion of lateral impacts increased from 27% to 48% between the control group and PC+ and chest+ cohort, prompting the use of lateral impact crash tests for the case-matching portion of the study. Crash tests were analyzed in two configurations; vehicle-to-vehicle tests and vehicle-to-pole tests. The average maximum chest compression and deflection velocity from the dummy occupants were found to be 25.3% +/- 2.6% and 4.6 m/s +/- 0.42 m/s for the vehicle-to-pole tests and 23.0% +/- 4.8% and 3.9 m/s +/- 1.1 m/s for the vehicle-to-vehicle tests. Chest deflection versus time followed a roughly symmetric and sinusoidal profile. Sixteen CIREN cases were identified that matched the vehicle crash tests. Of the 16 matched cases, 12 (75%) sustained chest injuries, with half of these patients presenting with PC.


CONCLUSIONS
Quantified loading at the chest wall indicative of PC and chest injury in motor vehicle crash is valuable boundary condition data for bench-top studies or computer simulations focused on this injury. In addition, because PC often exhibits a delayed onset, knowing the population and crash modes highly associated with this injury may promote earlier detection and improved management of this injury.
Gayzik
F Scott
FS
Department of Biomedical Engineering, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA. sgayzik@wfubmc.edu
Martin
R Shayn
RS
Gabler
H Clay
HC
Hoth
J Jason
JJ
Duma
Stefan M
SM
Meredith
J Wayne
JW
Stitzel
Joel D
JD
D015998:Abbreviated Injury Scale; D000054:Acceleration; D000063:Accidents, Traffic; D000293:Adolescent; D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D015331:Cohort Studies; D019245:Compressive Strength / Q000502:physiology; D003288:Contusions / Q000401:mortality / Q000503:physiopathology*; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D055370:Lung Injury / Q000401:mortality / Q000503:physiopathology*; D008297:Male; D008348:Manikins; D008875:Middle Aged; D013898:Thoracic Injuries / Q000401:mortality / Q000503:physiopathology*; D035441:Thoracic Wall / Q000503:physiopathology; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult