Blast Lung Injury

An understanding of blast injury and its effect on lungs is critical for all pulmonologists and critical care specialists in the 21st century. Recently, a bomb explosion ripped through the busiest airport in Moscow, resulting in casualties: 31 dead and over 130 injured. Previous bomb explosions on trains since 1995 have killed several people and injured many individuals. These include bomb explosions on trains in Paris (1995), Moscow (1996), Sri Lanka (1996), Manila (2000), Angola (2001), Chechnya (2003), Madrid (2004), London (2005), Mumbai, India (2006), and Panipat, India (2007).

Many of the terrorist acts across the world have increased the awareness of injuries from explosive detonations that release energy at supersonic speeds from the epicenter of the blast. This blast event contributes to primary blast injuries that often affect the head, ear, abdomen, and lung. Secondary injuries may also occur as a result of bomb fragments and other debris that are thrown out. It can also result in tertiary injuries to the individual if he or she gets thrown out from the blast, resulting in head injuries and bone fractures. Other blast-related injuries that are not due to the above three mechanisms are referred to as quaternary injuries, and they include burns and exacerbation of previous medical conditions.

Blast lung injury is one of the major causes of morbidity and mortality among the victims of explosion. The incidence of pulmonary blast injury varies from 17% to 63%. There is tissue damage from the pressure changes, and the severity depends on factors such as the explosive used, intensity of the blast wave, its duration, and the proximity of the victim to the epicenter of blast. Pulmonary contusion, hemorrhage, and edema are seen from parenchymal and vascular damage. Blast lung can be associated also with pneumothoraces, hemothoraces, bronchopleural fistula, air/fat embolization, and other pleural and parenchymal injuries. Body armor may not protect against blast lung injury. Pulmonary symptoms may include cough, dyspnea, chest pain, and hemoptysis. On physical examination, apnea, tachypnea, cyanosis, cough, wheezing, and/or decreased breath sounds may be present. Blast lung is suspected when patients present with respiratory difficulty and hypoxemia without external chest injury. The key aspects of management are maintaining oxygenation, careful fluid resuscitation, addressing pneumo/hemothoraces, and initiating mechanical ventilation for respiratory failure.

Dr. Angeline A. Lazarus, FCCP
Vice-Chair