Blast Injuries
Explosions can inflict multi-system life-threatening injuries to many persons simultaneously. Multiple factors contribute to the injury patterns which result from blasts. Contributing factors include the composition and amount of the materials involved, the environment in which the event occurs, the method of delivery, such as a bomb, the distance between the victim and the blast, and the absence/presence of protective barriers or environmental hazards in the area of the blast. To predict subsequent demand for medical care and resources needed, it is useful to remember that post-blast, half of the initial casualties will seek medical care over the first one-hour period. Those with minor injuries often arrive before the most severely injured, because they go directly to the closest hospitals using whatever transportation is available. Further, where the explosion has resulted in a structural collapse, victims will be more severely injured and their rescue can occur over prolonged time periods.
The two types of explosives, high-order explosives (HE) and loworder explosives (LE), cause different injury patterns. Injury patterns also differ whether the bombs are manufactured or improvised. HE devices, such as TNT, C-4, Semtex, nitroglycerin, dynamite, and ammonium nitrate fuel oil, produce a defining supersonic over-pressurization shock wave. LE devices, such as pipe bombs, gunpowder, and pure petroleum-based bombs (AKA Molotov cocktails), create a subsonic explosion and lack the over-pressurization wave. Manufactured explosives are usually those used by the military, are mass produced, and quality-tested as weapons. Improvised explosives and incendiary (fire) bombs are often individually produced in small quantities and include devices used differently than their initial purpose.
The most common injury for survivors of explosions is penetrating and blunt trauma. Table 6 describes the four basic mechanisms of blast injury. Blast lung is the most common fatal injury among initial survivors. Explosions in confined spaces (mines, buildings, or large vehicles) and/or structural collapse are associated with the greatest morbidity and mortality. Blast injuries can occur to any body system: auditory, digestive, circulatory, central nervous system, extremities, renal, and respiratory. Up to 10 percent of all blast survivors have significant eye injuries. These injuries can occur with minimal discomfort initially and patients can come for care days, weeks, or even months after the event. Symptoms include eye pain or irritation, foreign body sensation, altered vision, periorbital swelling, or contusions. Clinical findings in the gastrointestinal tract may be absent until the onset of complications. Victims can also experience tinnitus, and/or temporary or permanent deafness from blasts.
As part of a community preparedness plan, identify the medical institutions and personnel who can provide the emergency care that will be required, including otologic assessment and audiometry, burn and trauma centers, hyperbaric oxygen chamber, etc.
Ensure that the community preparedness plan includes structure for surge capacity. To estimate the "first wave" of casualties, double the number appearing for care in the first hour. Prepare written communications and instructions for victims who may experience temporary or permanent deafness.
Work with the regional Emergency Management Organization, police, fire, and EMS, to have a plan in place to identify potential toxic exposures and environmental hazards for which the health department will need to help protect responders in the field and the community.
With the hospital community, establish a victim identification registry.
With the mental health community, plan for the reception and intervention with family and friends.
American Public Health Association © 2005 American Public Health Association
Cite this: Types of Disasters and Their Consequences - Medscape - Sep 20, 2005.
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