Blast Lung Injury

Current trends in global terrorism mandate that emergency medical services, emergency medicine and other acute care clinicians have a basic understanding of the physics of explosions, the types of injuries that can result from an explosion, and current management for patients injured by explosions. High-order explosive detonations result in near instantaneous transformation of the explosive material into a highly pressurized gas, releasing energy at supersonic speeds. This results in the formation of a blast wave that travels out from the epicenter of the blast. Primary blast injuries are characterized by anatomical and physiological changes from the force generated by the blast wave impacting the body's surface, and affect primarily gas-containing structures (lungs, gastrointestinal tract, ears). "Blast lung" is a clinical diagnosis and is characterized as respiratory difficulty and hypoxia without obvious external injury to the chest. It may be complicated by pneumothoraces and air emboli and may be associated with multiple other injuries. Patients may present with a variety of symptoms, including dyspnea, chest pain, cough, and hemoptysis. Physical examination may reveal tachypnea, hypoxia, cyanosis, and decreased breath sounds. Chest radiography, computerized tomography, and arterial blood gases may assist with diagnosis and management; however, they should not delay diagnosis and emergency interventions in the patient exposed to a blast. High flow oxygen, airway management, tube thoracostomy in the setting of pneumothoraces, mechanical ventilation (when required) with permissive hypercapnia, and judicious fluid administration are essential components in the management of blast lung injury.