What characterizes primary blast injury?

Primary blast injury is characterized by the injuries that result from the direct effects of the explosive wave produced by a blast. This type of injury occurs when the shock wave from the explosion causes damage to body tissues, particularly those that contain air, such as the lungs, gastrointestinal tract, and the inner ear. The rapid change in pressure can lead to barotrauma, which is a specific type of injury caused by the blast wave itself affecting these air-filled organs.

In contrast, injuries caused by flying debris pertain to secondary blast injuries, where shrapnel or materials propelled by the force of the explosion cause harm. Body impact with stationary objects would also represent tertiary blast injuries, which happen when individuals are thrown against structures or objects due to the force of the explosion. Lastly, injuries that occur during evacuation relate to circumstances that arise after the initial blast and are not attributed to the primary effects of the explosion. This clarifies why injuries caused by the wave blast itself is the defining feature of primary blast injury, distinguishing it from other types in the context of trauma care following an explosion.