What primarily causes primary blast injuries?

Primary blast injuries are primarily caused by the physiological effects of the blast wave. When an explosion occurs, it generates a rapid over-pressure wave that travels through the air. This wave can impact the body in various ways, particularly affecting air-filled organs such as the lungs, ears, and gastrointestinal tract. The sudden increase in pressure can result in barotrauma, which is damage to tissues due to the difference in pressure between the inside of the body and the external environment.

The severity of primary blast injuries can vary depending on the magnitude of the explosion, the distance from the blast, and the orientation of the victim relative to the explosion. While propelled fragments, external pressure changes, and radiation are potential hazards in explosion scenarios, they do not specifically refer to the primary effects of the blast wave itself, which is where the direct physiological impact originates. This understanding is critical for first responders and medical personnel when assessing and treating victims of blast-related injuries.