7-23
Blast Injuries
Lt Col John Wightman, USAF, MCIntroduction: High explosive (HE), thermobaric, and nuclear detonations cause extreme compression of
surrounding air or water molecules, creating a blast shock wave. The force of this shock wave can be
transmitted into the human body, causing tissue tearing through pressure differentials and forces at air-tissue
interfaces. The following identifies the most common consequences of blast injury:
Lung: Hemorrhage – Pulmonary contusion, hemoptysis (may threaten airway) hemothorax; Escape of Air –
pneumothorax, pulmonary pseudocyst, arterial gas embolism (AGE).
Gastrointestinal (GI) Tract: Hemorrhage – Hematoma leading to obstruction, upper or lower GI bleeding,
hemoperitoneum; Escape of Contents – Mediastinitis, peritonitis.
Ear: Middle ear – Ruptured tympanic membrane (TM), temporary conductive hearing loss; Inner ear –
Temporary or permanent sensory hearing loss.
See the appropriate sections in the Trauma chapter on CD-ROM for management of specific trauma.
Subjective: Symptoms
Focused History: Pulmonary: Are you short of breath? (Pulmonary contusion inhibits oxygen diffusion and
requires more effort to inhale. Pneumothorax and hemothorax decrease volume of air that can be inspired.
Shock will cause sensation of dyspnea due to poor tissue perfusion.) Do you have chest pain? (Chest pain
indicates possibility of penetrating or blunt trauma, pneumothorax, or myocardial ischemia due to coronary
AGE.) What does your pain feel like? (Chest pain of pulmonary contusion is often described as dull and
diffuse, but breathing may also feel tight due to difficulty expanding the chest. Pain may wax and wane with
respirations. The pain of pneumothorax will often be sharp and focal, but may be lateral or central. It is
usually pleuritic until the lung is completely collapsed. Chest pain that seems like it would be consistent with
myocardial ischemia may be due to AGE.) How much effort is required breathe? (Dyspnea at rest indicates
shock due to external or internal hemorrhage, pneumothorax, or serious pulmonary contusion. The more
exertion required to elicit dyspnea, the less lung injury is likely.)
Abdominal: Do you have abdominal or testicular pain, nausea, urge to defecate, or blood in your stools?
(Penetrating and blunt abdominal trauma cause pain, but primary blast injury of air-containing structures in
the GI tract may cause any of the listed symptoms.) What does your pain feel like? (The pain of stretched
bowel will feel like a persistent gas bubble, though it may have sharp and crampy waves as it is affected
by peristalsis. Once the bowel ruptures, pain will decrease until peritonitis begins. The pain of peritonitis
is usually diffuse and severe).
Special Senses: Do you have pain or problems with your eyes or ears? (evaluate for penetrating or blunt
trauma) What does your pain feel like? (Any eye pain associated with decreased vision is a penetrating
foreign body until proven otherwise. Ear pain caused by a ruptured TM is often initially sharp but wanes
over time.)
Objective: Signs
Using Basic Tools: Perform neurological examination as described in appendix.
General: External hemorrhage, dyspnea, altered mental status, seizures.
Vital Signs: Tachycardia (probable hemorrhage); bradycardia (blast-induced vasovagal reaction); irregular
heart rhythm (shock or AGE); hypotension (hemorrhage, other causes of shock, or vasovagal reaction).
Inspection: Penetrating wounds, traumatic amputations, cyanosis (indicating hypoxia or cyanide); mottling or
blanching of skin (AGE); otorrhea or bleeding from ears (TM rupture or basilar skull fracture).
Auscultation: Unilateral absent breath sounds (pneumothorax or hemothorax).
Palpation: Subcutaneous emphysema (AGE, pneumothorax); abdominal tenderness (penetrating, blunt, or
blast trauma)
Pulse Oximeter: SPO2 < 95% on room air following blast indicates some degree of lung injury, inadequate