What is the phase of an explosion in which hollow organs may rupture?

The primary phase of an explosion is characterized by the blast wave that radiates outward from the explosion's epicenter. This shock wave can create significant pressure changes and rapid deceleration forces that can lead to various injuries, particularly to hollow organs such as the lungs and gastrointestinal tract. Due to the rapid changes in pressure and the impact of the wave, these organs are susceptible to rupture.

In contrast, other phases, such as the secondary phase, often involve shrapnel or other debris propelled by the blast, which leads to penetrating injuries. The tertiary phase refers to the impact of individuals being thrown by the explosion, which can cause blunt force trauma. The quaternary phase encompasses other explosion-related injuries and health hazards, such as chemical exposure or burns. Understanding these phases helps responders anticipate the types of injuries that may occur and tailor their assessment and treatment appropriately.