Explosives and Blast Injuries

Overview

Explosions can cause unique patterns of injury seldom seen outside combat.

Most injuries among survivors involve standard penetrating and blunt trauma. Blast lung is the most common fatal injury among initial survivors.

Explosions in confined spaces (mines, buildings, or large vehicles) and/or structural collapse generally cause more injuries and death than open space blasts.

Half of all initial casualties will seek medical care over a one-hour period. This can be useful to predict demand for care and resource needs. Expect an "upside-down" triage - the most severely injured arrive after the less injured, who bypass EMS triage and go directly to the closest hospitals.

Background

Explosions can produce unique patterns of injury seldom seen outside combat. When they do occur; they have the potential to infl ict multi-system life-threatening injuries on many persons simultaneously.

The injury patterns following such events are a product of the composition and amount of the explosives involved, the surrounding environment, the distance between the casualty and the blast, and any intervening protective barriers or environmental hazards.

Few U.S. health professionals have experience with explosive-related injuries. This section introduces information relevant to the care of casualties from explosives and blast injuries. As the risk of terrorist attacks increases in the U.S., it is necessary to understand the type of injuries associated with explosions and must be prepared to assess and treat the people injured by them.

Classification of Explosives

Explosives are categorized as high explosives (HE) or low explosives (LE).

High explosives (HE) produce a defining supersonic overpressurization shock wave. Examples of HE include TNT, C-4, Semtex, nitroglycerin, dynamite, and ammonium nitrate fuel oil (ANFO). Low explosives (LE) create a subsonic explosion and lack HE's over-pressurization wave. Examples of LE include pipe bombs, gunpowder, and most pure petroleum-based bombs such as Molotov cocktails or aircraft improvised as guided missiles.

HE and LE cause different injury patterns. Explosive and incendiary (fire) bombs are further characterized based on their source. "Manufactured" implies standard military-issued, mass produced, and quality-tested weapons. "Improvised" describes weapons produced in small quantities, or use of a device outside its intended purpose, such as converting a commercial aircraft into a guided missile.

Manufactured (military) explosive weapons are exclusively HE-based. Terrorists will use whatever is available - illegally obtained manufactured weapons or improvised explosive devices (also known as "IEDs") that may be composed of HE, LE, or both.

Manufactured and improvised bombs cause markedly different injuries.