Key Concepts

• Bombs and explosions can cause unique patterns of injury seldom seen outside combat 
• Expect half of all initial casualties to seek medical care over a one-hour period 
• Most severely injured arrive after the less injured, who bypass EMS triage and go directly to the closest hospitals 
• Predominant injuries involve multiple penetrating injuries and blunt trauma 
• Explosions in confined spaces (buildings, large vehicles, mines) and/or structural collapse are associated with greater morbidity and mortality 
• Primary blast injuries in survivors are predominantly seen in confined space explosions 
• Repeatedly examine and assess patients exposed to a blast 
• All bomb events have the potential for chemical and/or radiological contamination 
• Triage and life saving procedures should never be delayed because of the possibility of radioactive contamination of the victim; the risk of exposure to caregivers is small 
• Universal precautions effectively protect against radiological secondary contamination of first responders and first receivers 
• For those with injuries resulting in nonintact skin or mucous membrane exposure, hepatitis B immunization (within 7 days) and age-appropriate tetanus toxoid vaccine (if not current)

Blast Injuries

• Primary: Injury from over-pressurization force (blast wave) impacting the body surface 
  • TM rupture, pulmonary damage and air embolization, hollow viscus injury 
• Secondary: Injury from projectiles (bomb fragments, flying debris) 
  • Penetrating trauma, fragmentation injuries, blunt trauma 
• Tertiary: Injuries from displacement of victim by the blast wind 
  • Blunt/penetrating trauma, fractures and traumatic amputations 
• Quaternary: All other injuries from the blast 
  • Crush injuries, burns, asphyxia, toxic exposures, exacerbations of chronic illness

Primary Blast Injury

• Lung Injury
• Signs usually present at time of initial evaluation, but may be delayed up to 48 hrs 
• Reported to be more common in patients with skull fractures, >10% BSA burns, and penetrating injury to the head or torso 
• Varies from scattered petechiae to confluent hemorrhages 
• Suspect in anyone with dyspnea, cough, hemoptysis, or chest pain following blast 
• CXR: "butterfly" pattern 
• High flow O2 sufficient to prevent hypoxemia via NRB mask, CPAP, or ET tube 
• Fluid management similar to pulmonary contusion; ensure tissue perfusion but avoid volume overload 
• Endotracheal intubation for massive hemoptysis, impending airway compromise or respiratory failure 
  • Consider selective bronchial intubation for significant air leaks or massive hemoptysis 
  • Positive pressure may risk alveolar rupture or air embolism 
• Prompt decompression for clinical evidence of pneumothorax or hemothorax 
• Consider prophylactic chest tube before general anesthesia or air transport 
• Air embolism can present as stroke, MI, acute abdomen, blindness, deafness, spinal cord injury, claudication 
  • High flow O2; prone, semi-left lateral, or left lateral position 
  • Consider transfer for hyperbaric O2 therapy

Abdominal Injury

• Gas-filled structures most vulnerable (esp. colon) 
• Bowel perforation, hemorrhage (small petechiae to large hematomas), mesenteric shear injuries, solid organ lacerations, and testicular rupture 
• Suspect in anyone with abdominal pain, nausea, vomiting, hematemesis, rectal pain, tenesmus, testicular pain, unexplained hypovolemia 
• Clinical signs can be initially subtle until acute abdomen or sepsis is advanced

Ear Injury

• Tympanic membrane most common primary blast injury 
• Signs of ear injury usually evident on presentation (hearing loss, tinnitus, otalgia, vertigo, bleeding from external canal, otorrhea)

Other Injury

• Traumatic amputation of any limb is a marker for multi-system injuries 
• Concussions are common and easily overlooked 
• Consider delayed primary closure for grossly contaminated wounds, and assess tetanus immunization status 
• Compartment syndrome, rhabdomyolysis, and acute renal failure are associated with structural collapse, prolonged extrication, severe burns, and some poisonings 
• Consider possibility of exposure to inhaled toxins (CO, CN, MetHgb) in both industrial and terrorist explosions 
• Significant percentage of survivors will have serious eye injuries

Disposition

• No definitive guidelines for observation, admission, or discharge 
• Discharge decisions will also depend upon associated injuries 
• Admit 2nd and 3rd trimester pregnancies for monitoring 
• Close follow-up of wounds, head injury, eye, ear, and stress-related complaints 
• Patients with ear injury may have tinnitus or deafness; communications and instructions may need to be written

This fact sheet is part of a series of materials developed by the Centers for Disease Control and Prevention (CDC) on blast injuries. For more information on blast injuries, visit CDC on the Web at: www.emergency.cdc.gov/BlastInjuries.

U.S. Department of Health and Human Services
Centers for Disease Control and Prevention
June 2009