Blast Injury Classifications

• Bodily and structural damage from an explosion depend on explosive type, explosion location, and proximity to the epicenter.
• Healthcare providers determine injury types and casualty numbers by multiplying first-hour casualties by two.

Blast Injury Classifications

• Primary blast injuries are unique to high-order explosives.

• Primary blast injuries result from over-pressurization waves impacting body surfaces.

• Air-filled organs and air-fluid interfaces, like the middle ear, lungs, and GIT, are commonly involved in primary blast injuries.

• Primary blast injury types include blast lung, TM rupture, abdominal hemorrhage and perforation, and globe rupture.

• The tympanic membrane is the structure most frequently injured by a blast.

• Tympanic membrane injuries include rupture, ossicle dislocation, and oval or round window disruption.

• Symptoms of tympanic membrane injuries include hearing loss, tinnitus, vertigo, bleeding from the external canal, and mucopurulent otorrhea.

• Secondary blast injuries are due to flying debris and bomb fragments and can result in penetrating ballistic or blunt injuries.

• Secondary blast injuries are the leading cause of death in military and civilian terrorist attacks, except in major building collapses.

• Secondary blast injury wounds can be grossly contaminated.

• Tertiary blast injuries occur when people are thrown into fixed objects by the wind of explosions or due to structural collapse and fragmentation of buildings or vehicles.

• Tertiary blast injuries can cause extensive blunt trauma, crushing injuries, fractures, traumatic amputation, and closed and open brain injury.

• Quaternary blast injuries include explosion-related injuries or illnesses not due to primary, secondary, or tertiary injuries.

• Quaternary blast injuries exacerbate pre-existing conditions like asthma, COPD, CAD, HTN, and DM.

• Quaternary blast injuries also include burns (chemical and thermal), toxic inhalation, radiation exposure, and asphyxiation (CO, cyanide).

General Considerations

• Confined spaces increase penetrating and primary blast injuries.
• Blast waves reflecting off solid surfaces may result in a person next to a wall sustaining a greater primary blast injury.
• Underwater bomb detonations produce more damage than air detonations because water is incompressible.
• Half of all initial casualties seek medical care within the first hour.
• Expect upside-down triage where most severely injured arrive after less injured who bypass EMS and self-transport.
• Initial explosions attract law enforcement and rescue personnel, risking second explosion injuries.
• In open spaces, shrapnel can travel long distances (>100m), causing less primary blast injury.

Enclosed Spaces

• Enclosed spaces can lead to increased mortality, blast pressure, and complicated rescue scenarios.
• Structural collapse increases mortality from primary blast waves and tertiary and quaternary injuries.

Management Elements of an Explosion

• Management elements include search and rescue, triage, initial stabilization, definitive medical treatment, and evacuation.

ATLS Primary Survey

• The ATLS Primary Survey manages airway and cervical spine immobilization by assessing and maintaining airway patency, assessing for foreign bodies and fractures, and immobilizing the cervical spine.
• Assess for bilateral chest wall movement, auscultate and visualize chest wall and lung fields for breathing and ventilation.
• Identify pneumothorax, flail chest, hemothorax, and open pneumothorax

Other Considerations

• Consider hypovolemia the cause of hypotension until proven otherwise for circulation.
• Assess LOC, skin color, and pulse for signs of hypovolemia and hypoxia and identify and control external and internal hemorrhage.
• Assess Glascow Coma Scale, pupil size, and reactivity for disability and neurologic deficit, and decreased LOC may require intubation.
• Expose the patient to view all body surfaces for evidence of injury, cover with warm blankets, and use warmed intravenous fluids in exposure and environmental control.

ATLS Secondary Survey Physical Examination

Body System Examination

• Assess LOC, sensory and motor function, and pupillary response for neurologic assessment; consult neurosurgery and obtain a head CT if head injury is suspected.
• Examine the head and scalp for injury and fractures, assess vision and pupils, and address hemorrhage, penetrating injury, lens dislocation, and ocular entrapment. Contacts should be removed.
• Assess for maxilofacial fractures and soft-tissue injury, placing a gastric tube orally in suspected or confirmed facial fractures.
• Maintain spine precautions, and auscultate breath and cardiac sounds on the chest; obtain a chest x-ray.
• Unexplained hypotension may be the result of internal hemorrhage in the abdomen; peritoneal lavage, ultrasound, and abdominal CT may be necessary.
• Assess for perineum, rectum, and vagina contusions, hematomas, lacerations, and bleeding, and perform a rectal exam prior to placing a Foley catheter.
• Assess all extremities, pelvic ring, peripheral pulses, and thoracic and lumbar spine in musculoskeletal; obtain X-rays when the patient is stabilized.
• CNS Injury - Concussion, closed and open brain injury, stroke, spinal cord injury Renal - Renal contusion, laceration, acute renal failure due to rhabdomyolysis, hypotension, and hypovolemia Extremity Injury Traumatic amputation, fractures, crush injuries, compartment syndrome, burns, cuts, lacerations, acute arterial occlusion, air embolism-induced injury

Blast Injuries

• Auditory injuries include TM rupture, ossicular disruption, cochlear damage, and foreign body.
• Eye, orbit, and face injuries include perforated globe, foreign body, and fractures.
• Respiratory injuries include blast lung, hemothorax, pneumothorax, pulmonary contusion and hemorrhage, and airway epithelial damage.
• Digestive injuries include bowel perforation, hemorrhage, ruptured liver or spleen, and sepsis.
• Circulatory injuries include cardiac contusion, myocardial infarction from air embolism, shock, hypotension, peripheral vascular injury, and air embolism-induced injury.