Blast lung is caused by explosive detonations and is characterized by serious lung damage. Other organs affected by blast injuries include the gastrointestinal tract and the ears.
Blast lung is one of the consequences suffered from increased air pressure directed at tissue following an explosion. While the lungs are most prone to primary blast injury , other gas-containing sites such as the bowels and ears are also susceptible  . Further secondary and tertiary blast mechanisms include penetrating and blunt force traumas well as burns  .
The clinical presentation of blast lung features dyspnea, cough, and hypoxia. Additionally, patients rapidly develop respiratory impairment, which evolves into acute respiratory distress syndrome (ARDS)  . With regards to the prognosis, one study reported that the majority of surviving victims in a bus bombing recovered pulmonary function at the one-year follow-up .
Primary blast injury results in pulmonary barotrauma and encompasses serious sequelae such as pulmonary contusion, pulmonary hemorrhage, pulmonary edema, and venous air embolism. Moreover, blunt force injuries are frequently associated with bone marrow embolism and pulmonary fat embolism , which is a risk factor for ARDS and death . The leading causes of death are hemothorax, pneumothorax, and extrathoracic trauma .
Primary blast injury produces key cardiovascular changes such as bradycardia as well as a drop in stroke volume and cardiac index. Additionally, auscultation of the lungs reveals wheezing, which is suggestive of pulmonary contusion, pulmonary edema, ARDS, and/or inhalation of irritants.
Victims of primary blast injuries must undergo immediate and urgent workup that consists of a complete physical exam including that of the ears. Often, patients require serial exams. Additionally, a thorough evaluation includes the appropriate studies as explained below.
Critical laboratory assessment includes a complete blood count (CBC) to measure hemoglobin and platelet count. Moreover, the patient should be screened for disseminated intravascular coagulation (DIC) with tests such as a coagulation panel, fibrinogen, and fibrin split products. Also, blood type and cross matching are obtained should the patient require transfusion. Urinalysis is also performed in patients with blast injuries.
If carbon monoxide poisoning is suspected, the patient should be tested for carboxyhemoglobin (HbCO) and analyzed for acid/base disturbance with an electrolyte panel and an arterial blood gas (ABG). The patient should be monitored with pulse oximetry. Cyanide poisoning should also be considered and investigated.
Chest radiography is indicated in patients who have encountered overpressure trauma. Moreover, this modality is warranted for victims with respiratory manifestations, abnormal lung sounds, physical signs of chest trauma on inspection, and even patients with tympanic membrane rupture only. Confirmatory findings on chest radiography and computed tomography (CT) scan include the characteristic "butterfly" pattern, possibly pneumothorax, and opacities  .
Abdominal x-rays or CT is necessary for patients with abdominal pain, which may be preceded by a Focused Abdominal Sonography for Trauma (FAST) assessment. Ominous findings warrant emergency surgical exploration.
Histological studies with immunohistochemical staining and scanning electron microscopy on sample lung tissue feature alveolar overdistension, perivascular hemorrhage, edema, and pulmonary fat embolism .