Page 113 - JSOM Winter 2022

An Ongoing Series

Experience With Trauma-Induced ARDS

A Retrospective Study of US Wartime Casualties 2003–2015

Jason J. Nam, MD *; Matthew S. McCravy, MD ; Krista L. Haines, DO ;
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Sarah B. Thomas, MD ; James K. Aden, PhD ; Luke R. Johnston, MD ;
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Phillip E. Mason, MD ; Jennifer M. Gurney, MD ; Valerie G. Sams, MD 9
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ABSTRACT
Background: The purpose of our study was to assess risks/ disease was termed ARDS to distinguish it from a similar pe-
outcomes of acute respiratory distress syndrome (ARDS) in diatric entity and was often accompanied by trauma or toxic
US combat casualties. We hypothesized that combat trauma inhalation. The modern description of ARDS, as well as the
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patients with ARDS would have worse outcomes based on name and diagnostic criteria, was provided by Ashbaugh and
mechanism of injury (MOI) and labs/vital signs aberrancies. colleagues in 1967. Since 1967, numerous entities have been
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Materials and Methods: We reviewed data on military Ser- implicated in causing ARDS such as infection, pancreatitis,
vicemembers serving in Iraq and Afghanistan from 1 January sepsis, and trauma. Indeed, ARDS is currently conceptualized
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2003 to 31 December 2015 diagnosed with ARDS by ICD-9 as the final clinical presentation for a variety of insults.
code. We extracted patient demographics, injury specifics, and
mortality from the Department of Defense Trauma Registry Unsurprisingly, given the numerous potential etiologies, ARDS
(DoDTR). Results: The most common MOI was an explosion, is a heterogeneous process. This heterogeneity can be cate-
accounting for 67.6% of all injuries. Nonsurvivors were more gorized by either physiology, in the case of hyper- or hypo-
likely to have explosion-related injuries, have higher injury se- inflammatory ARDS, or by initial insult. This heterogeneity is
verity score (ISS), higher international normalized ratio (INR), a major impediment to improving the care of ARDS patients.
lower platelet count, greater base deficit, lower temperature, It has been proposed that a reason for negative trials in the
lower Glasgow Coma Scale (GCS) score, and lower pH. There field of ARDS care is due to overly heterogeneous study popu-
was no significant difference in deaths across time. Conclu- lations and a variety of subsets.
sion: By identifying characteristics of patients with higher
mortality in trauma ARDS, we can develop treatment guide- One such subset is trauma-associated ARDS. Despite more se-
lines to improve outcomes. Given the high mortality associ- vere illness, a study of civilians with trauma-associated ARDS
ated with trauma ARDS and relative paucity of clinical data demonstrated improved survival compared with other ARDS
available, we need to improve battlefield data capture to better patients after accounting for overall severity of illness. This
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guide practice and ultimately improve care. The management finding suggested that trauma-associated ARDS is unique in
of ARDS will be increasingly relevant in prolonged casualty a pathophysiological sense. Additionally, it represents a sig-
care (PCC; formerly prolonged field care) on the modern nificant challenge in the care of trauma patients. Currently,
battlefield. trauma-associated ARDS affects 26–33% of critically injured
combat casualties. When compared to uncomplicated trauma,
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Keywords: PCC; PFC; prolonged casualty care; prolonged field trauma-associated ARDS is associated with higher morbid-
care; ARDS; acute respiratory distress syndrome; combat casu- ity and mortality in trauma patients. Hudson et al. found
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alties; combat trauma; mechanism of injury that mortality among trauma patients increased 4.3-fold if
they developed ARDS. Similarly, Miller et al. found that
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trauma patients who had ARDS experienced a 36% mortality
rate compared with non-ARDS patients who had 5% mor-
Background
tality rate (p < .001). Thus, improving the care of trauma-
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Acute pulmonary injury related to combat has been recog- associated ARDS is likely an urgent need in advancing the care
nized by military physicians as early as World War I. The of combat casualties.
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*Correspondence to Jason.nam@duke.edu
1 MAJ Jason J. Nam is a physician affiliated with the Division of Pulmonary, Allergy, and Critical Care Medicine, Duke University Hospital,
Durham, NC and the Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD. Dr Matthew S. McCravy is
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a physician affiliated with the Division of Pulmonary, Allergy, and Critical Care Medicine, Duke University Hospital, Durham, NC. Dr Krista L.
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Haines is a physician affiliated with the Department of Surgery, Duke University Hospital, Durham, NC. Capt Sarah B. Thomas, Col (R) Phillip
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E. Mason, COL Jennifer M. Gurney, and Lt Col Valerie G. Sams are all physicians affiliated with the Brooke Army Medical Center, Fort Sam
Houston, TX. Dr James K. Aken is a scientist affiliated with the Brooke Army Medical Center, Fort Sam Houston, TX. LCDR Luke R. Johnston
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is a physician affiliated with the Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD.
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