What is the main physiological effect observed in a primary blast injury?

The main physiological effect observed in a primary blast injury is shockwave disruption. This type of injury occurs when the body is subjected to the overpressure caused by the explosive wave generated during a blast. Primary blast injuries typically affect air-filled organs, such as the lungs, ears, and gastrointestinal tract, where the sudden change in pressure can lead to significant damage.

While liquefaction of tissues may occur as a result of secondary or tertiary injuries, the defining characteristic of primary blast injury is the direct impact of the shockwave itself, leading to structural and functional disruptions within those air-filled organs. Understanding this concept is critical, as it helps first responders and medical personnel to assess and treat injuries stemming from explosive incidents effectively.