In mass casualty incidents involving explosions, three concentric zones are identified:
In a blast epicenter (kill zone), most people are dead or mortally injured. In the secondary perimeter (critical casualty zone), there are more survivors, but many of them likely have multiple injuries. In the blast periphery (walking-wounded zone), most casualties have non–life-threatening injuries and psychologic trauma.
An explosion creates a blast wave. An intense blast wave can tear tissue. A less intense blast can damage the eardrums, lungs, and abdomen. Blast waves also throw debris at very high speed that can injure any part of the body.
People who have sustained blast injury to the lungs may have shortness of breath, cough (including coughing up blood), chest pain, rapid breathing, and wheezing. People with an abdominal blast injury may have abdominal pain, nausea, vomiting, blood in their vomit, rectal pain, and testicular pain. Other blast injuries include blindness, deafness, spinal cord injury, or pain while walking. Some people may appear to have suffered a stroke or heart attack.
People who have sustained a blast injury are evaluated for multiple trauma, including injury to the lungs and ears. Doctors try to identify any penetrating or crush injury. They take chest x-rays and monitor people with electrocardiography.
People are given oxygen and fluids and are monitored for complications, such as air embolism, acute crush syndrome, and compartment syndrome (a limb-threatening condition caused by excessive swelling of injured muscles—see Compartment Syndrome). Hyperbaric oxygen therapy may be given to people who have deep tissue infections.
The views expressed in this article are those of the author and do not reflect the official policy of the Department of Army, Department of Defense, or the US Government.
Last full review/revision January 2014 by James Madsen, MD, MPH