injuries poisoning
Explosives and Blast Injuries
Pathophysiology of Explosive and Blast Injuries
Blast injuries include both physical and psychologic trauma. Physical trauma includes fractures, respiratory compromise, injuries to soft tissue and internal organs, internal and external blood loss with shock, burns, and sensory impairment, especially of hearing and sight. Five mechanisms of blast injury have been described (see table Mechanisms of Blast Injury ). The supersonic blast wave in primary blast injury compresses gas-filled spaces, which then rapidly reexpand, causing shearing and tearing forces that can damage tissue and perforate organs. Blood is forced from the vasculature into air spaces and surrounding tissue. Pulmonary involvement (blast lung injury) may cause pulmonary contusion, systemic air embolism (especially in the brain and spinal cord), and free-radical–associated injuries (thrombosis, lipo-oxygenation, and Disseminated Intravascular Coagulation (DIC) ); it is a common cause of delayed mortality. Primary blast injury also includes intestinal barotrauma (particularly with underwater explosions), acoustic barotrauma (including tympanic-membrane rupture, hemotympanum without rupture, and fracture or dislocation of ossicles in the middle ear), and 