Blast injury
Blast injury | |
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Floor-by-floor breakdown of the injuries/deaths in the Alfred P. Murrah Federal Building from the April 1995 Oklahoma City bombing | |
Specialty | Emergency medicine, trauma surgery |
A blast injury is a complex type of
Classification
Blast injuries are divided into four classes: primary, secondary, tertiary, and quaternary.
Primary injuries
Primary injuries are caused by blast
Extensive damage can also be inflicted upon the auditory system. The tympanic membrane (also known as the eardrum) may be perforated by the intensity of the pressure waves. Furthermore, the hair cells, the sound receptors found within the cochlea, can be permanently damaged and can result in a hearing loss of a mild to profound degree.[4] Additionally, the intensity of the pressure changes from the blast can cause injury to the blood vessels and neural pathways within the auditory system.[4][5] Therefore, affected individuals can have auditory processing deficits while having normal hearing thresholds. The combination of these effects can lead to hearing loss, tinnitus, headache, vertigo (dizziness), and difficulty processing sound.[5]
In general, primary blast injuries are characterized by the absence of external injuries; thus internal injuries are frequently unrecognized and their severity underestimated. According to the latest experimental results, the extent and types of primary blast-induced injuries depend not only on the peak of the overpressure, but also other parameters such as number of overpressure peaks, time-lag between overpressure peaks, characteristics of the shear fronts between overpressure peaks, frequency resonance, and electromagnetic pulse, among others. There is general agreement that spalling, implosion, inertia, and pressure differentials are the main mechanisms involved in the pathogenesis of primary blast injuries. Thus, the majority of prior research focused on the mechanisms of blast injuries within gas-containing organs and organ systems such as the lungs, while primary blast-induced traumatic brain injury has remained underestimated. Blast lung refers to severe pulmonary contusion, bleeding or swelling with damage to alveoli and blood vessels, or a combination of these.[6] It is the most common cause of death among people who initially survive an explosion.[7]
Secondary injuries
Secondary injuries are
Most casualties are caused by secondary injuries as shrapnels generally affect a larger area than the primary
Tertiary injuries
Displacement of air by the explosion creates a blast wind that can throw victims against solid objects.[3] Injuries resulting from this type of traumatic impact are referred to as tertiary blast injuries. Tertiary injuries may present as some combination of blunt and penetrating trauma, including bone fractures and coup contre-coup injuries. Children are at particularly high risk of tertiary injury due to their relatively smaller body weight.[8]
Quaternary injuries
Quaternary injuries, or other miscellaneous named injuries, are all other injuries not included in the first three classes. These include flash burns, crush injuries, and respiratory injuries.[8]
Traumatic amputations quickly result in death, unless there are available skilled medical personnel or others with adequate training nearby who are able to quickly respond, with the ability for rapid ground or air medical evacuation to an appropriate facility in time, and with tourniquets (for compression of bleeding sites) and other needed equipment (standard, or improvised; sterile, or not) also available, to treat the injuries. Because of this, injuries of this type are generally rare, though not unheard of, in survivors. Whether survivable or not, they are often accompanied by significant other injuries.[8] The rate of eye injury may depend on the type of blast.[8] Psychiatric injury, some of which may be caused by neurological damage incurred during the blast, is the most common quaternary injury, and post-traumatic stress disorder may affect people who are otherwise completely uninjured.[8]
Mechanism
Blast injuries can result from various types of incidents ranging from industrial accidents to deliberate attacks.
Neurotrauma
Blast injuries can cause hidden sensory
Individuals exposed to blast frequently manifest
Blast wave PTSD research
In addition to known post-traumatic stress disorder (PTSD) risk factors experienced by both civilians and military personnel in combat areas, in early 2018, 60 Minutes reported[13] that neuropathology specialist, Dr. Daniel "Dan" Perl, had conducted research on brain tissue exposed to traumatic brain injury (TBI), discovering a causal relationship between IED blast waves and PTSD. Perl was recruited to the faculty of the Uniformed Services University of the Health Sciences as a professor of pathology and to establish the Center for Neuroscience and Regenerative Medicine mandated by Congress in 2008.[14]
Casualty estimates and triage
Explosions in confined spaces or which cause structural collapse usually produce more deaths and injuries. Confined spaces include mines, buildings and large vehicles. For a rough estimate of the total casualties from an event, double the number that present in the first hour. Less injured patients often arrive first, as they take themselves to the nearest hospital. The most severely injured arrive later, via emergency services ("upside-down" triage). If there is a structural collapse, there will be more serious injuries that arrive more slowly.[15]
See also
References
- ^ Blast Injury Translating Research Into Operational Medicine. James H. Stuhmiller, PhD. Edited by William R. Santee, PhD Karl E. Friedl, PhD, Colonel, US Army. Borden institute (2010)
- ISBN 978-1-316-47292-7.
- ^ a b c d Chapter 1: Weapons Effects and Parachute Injuries, pp. 1–15 in Emergency War Surgery (2004)
- ^ PMID 24653882.
- ^ PMID 23341279.
- S2CID 2912045.
- S2CID 44680290.
- ^ ISBN 978-0-7817-4986-2.
- ^ S2CID 13746434.
- ISBN 1-932235-00-0.
- ^ Lawson, B. D., & Rupert, A. H. (2010). Vestibular aspects of head injury and recommendations for evaluation and rehabilitation following exposure to severe changes in head velocity ambient pressure. In Proceedings of the Human Performance at Sea Symposium. University of Strathclyde, Glasgow, UK.
- ^ a b Cernak, I., and L. J. Noble-Haeusslein. 2010. Traumatic brain injury: An overview of pathobiology with emphasis on military populations. J Cereb Blood Flow Metab 30(2):255-266.
- ^ Pelley, Scott "How IEDs may be physically causing PTSD"; 60 Minutes, 1 April 2018.
- ^ USUHS Archived 2019-07-08 at the Wayback Machine Center for Neuroscience and Regenerative Medicine; Uniformed Services University; Bethesda, Maryland.
- ^ "Explosions and Blast Injuries: A Primer for Clinicians" (PDF). CDC. Retrieved 2013-12-29.. Occasionally updated.
- General
- Editorial Board, Army Medical Department Center & School, ed. (2004). Emergency War Surgery (3rd ed.). Washington, DC: Borden Institute. Archived from the original on 2011-06-23. Retrieved 2010-11-01.