Blast Injuries: Prehospital Assessment and Management Jeffrey P Salomone, MD, FACS Past President, Eastern Association for the Surgery of Trauma

Disclosures Editor / Associate Editor, Prehospital Trauma Life Support 5e, 6e, 7e Contributor PHTLS 8e NO financial relationships

Background Explosive agents / Blast devices Blast Physics Scene Management Injury Types Patient Management

Blasts and Blast Injuries Bombings / WMDs Terrorism Middle East / Asia IEDs GWOT: Iraq / Afghanistan

Unintentional Explosions Gas leaks Industry Fertilizer Petroleum Explosives/ fireworks Grain Illicit- drug manufacturing (meth) Deaths- unusual: only 150 in US (2004)

Worldwide Terrorism Israel- Tel Aviv ( 2001, 2006) Madrid (2004)- bombs on commuter trains London (2005)- 4 bombs on trains / bus Mumbai (2008)- 11 shooting & bombing attacks over 4 days

US Bombings

Murrah Federal Bldg ( 1995) 168 killed Almost 700 injured Photo Courtesy of the City Of Oklahoma City

Atlanta Olympic Park Bombing July 27, 1996 1:30 am

Olympic Park Bombing 111 victims + news reporter All transported to 11 area hospitals within 32 minutes by 30 EMS units 35 + reporter to Grady Memorial Hosp Reporter 1st to arrive, CPR in progress 35 with shrapnel injuries 15 admitted- 10 required surgery in 1st 12 hrs Ortho, vascular, thoracotomy, laparotomy, facial expl 19 treated and released

Olympic Park Bombing 61 pts to 3 downtown hospitals AMC: 4 operations: 2 wound closures; 2 shrapnel removal 15 minor victims to 7 other area hospitals

September 11, 2001 Commercial aircraft used as “bombs” Twin towers- World Trade Center Pentagon

Boston Marathon Bombing April 15, 2013 3 killed 243 injured 152 presented to ED within 24 hrs of blast All survived

Blast Devices

Blast Agents High-order explosive: HE Nitroglycerin (NTG) Dynamite Plastic Ammonium nitrate/ fuel oil (ANFO) Trinitrotoluene (TNT) Triacetone triperoxide (TAPT) Low-order explosive: LE Petroleum products (“Molotov cocktail”) Gunpowder (“black” powder) Can become HE, if contained (e.g., pipe bomb)

Blast Devices Improvised explosive devices (IEDs) Incendiary bombs Car and truck bombs (Oklahoma City, World Trade Center I) Letter and parcel bombs (Idaho “Unabomber”) Pipe bombs (Atlanta Olympics) Backpack and satchel bombs (Israel, London) Incendiary bombs Airplane bombs (World Trade Center II, Pentagon) Rocket propelled grenades (RPGs) Surface to air missiles (SAMs)

Blast Devices IEDs Improvised/“homemade” explosive devices Made from explosives, commercial blasting supplies, or fertilizer and household ingredients Designed to cause injury and death Often packed with metal objects such as nails or ball bearings; Could contain toxic chemicals or radiological materials (dirty bomb)

Blast Physics Rapid chemical conversion of a solid or liquid into highly pressurized gases Gases expand rapidly and compress the surrounding air

Blast Physics Blast wave- causes an almost instantaneous rise in atmospheric pressure (barotrauma) Normal is 14.3 psi Overpressure: can exceed 4 million psi Underpressure Blast wind Air pushed out of area, creating vacuum Wind speed can be hundreds of mph

Blast Physics Importance of Injury Types vs. Distance Emergency War Surgery, 3rd Edition

Scene Management: SAFETY / SITUATION

Initial Staging Safe Distance Stage upwind / uphill Assess with binoculars Liquids, contaminants, etc Number of victims Need for Incident Command

Scene Safety: Hazards Secondary devices Shrapnel Building collapse Air-borne contaminants Contaminated patients Contaminated scene/environment Perpetrators Terrorist patients

Triage Field triage Unique patterns: Safe distance SALT / START Dynamic process Unique patterns: Multiple injuries Occult / hidden / internal injuries

Triage Walking wounded Many non-critical patients who require time intensive workups Up to 75% of victims self-refer to hospital via private transportation)

Crime Scene Life saving takes precedence Avoid disturbing or compromising evidence (chain of custody) Documentation of statements by victims and witnesses

Blast Injuries

Blast Injury: Severity Nature of device – agent, amount Method of delivery – incendiary, explosive Nature of environment – open, closed Distance from device Intervening protective barrier Other environmental hazards

Blast Injuries: Categories Primary injury Caused by blast wave → over pressure Secondary injury Caused by flying debris → shrapnel wounds Tertiary injury Caused by blast wind → forceful impact Quaternary injury Caused by other vectors → heat, radiation

Blast Injuries: Primary Blunt trauma from over pressure wave Unique to high-order explosives Results from the impact of the over-pressurization wave with body surfaces Barotrauma: blunt force injuries

Blast Injuries: Primary Most common injuries: Tympanic membrane (eardrum) rupture Middle ear damage Blast lung—pulmonary barotrauma Abdominal organ perforation ( esp. colon) Abdominal hemorrhage (solid organs) Traumatic brain injury (TBI), concussion

Blast Injuries: Blast Lung

Blast Injuries: Secondary Most common cause of death in a blast event is secondary blast injuries Caused by flying debris generated by the explosion Pieces of bomb / environment (glass) Added screws, nails, etc.

Blast Injuries: Secondary Most common types of secondary blast injuries are: Penetrating trauma to the head, neck, chest, abdomen, and extremities Fractures Traumatic amputations Soft tissue injuries

Blast Injuries: Secondary Penetrating trauma (shrapnel wounds) Foreign bodies follow unpredictable paths through body May have only mild external signs Have a low threshold for imaging studies (plain radiographs, computed tomograms) Consider all wounds contaminated

Blast Injuries: Tertiary Tertiary injuries result from individuals being thrown by the blast wind. The most common types of tertiary blast injuries are: Head injuries Skull fractures Fractures

Blast Injuries: Quaternary Includes: Burns Biologic / radiologic / chemical contamination Crush injuries Exacerbation of chronic health conditions

Patient Assessment and Management

Airway / Breathing Intubate if necessary Positive pressure ventilation in blast lung can result in air emboli

Blast Lung Clinical manifestations Treatment Tachypnea Hypoxia Cyanosis Apnea Wheezing Decreased breath sounds Hemoptysis Cough Chest pain Dyspnea Hemodynamic instability Treatment High flow oxygen sufficient to prevent hypoxemia via non-rebreather mask CPAP Endotracheal intubation Judicious fluid administration Needle decompression

Circulation: Hemorrhage / Shock Tourniquets Manufacture ( NOT improvised) Topical hemostatic agents IV therapy / fluid resuscitation

Tourniquets

Abdominal Injuries Clinical manifestations include: Abdominal pain Rectal bleeding Rebound tenderness / Guarding Diminished / absent bowel sounds Signs of hypovolemia / unexplained shock Nausea & vomiting

Blast Injuries: Combined Injuries Avoid tunnel vision Treatment protocols are often contradictory Blast lung vs. burn injury Blast lung vs. crush injury Judicious fluid administration

Blast Injury: Combined Injuries Typical confined space (e.g., a bus) injuries Primary—blast lung, intestinal rupture, TM rupture Secondary—penetrating injury to head, eye, chest, abdomen Tertiary—traumatic amputation, fractures to the face, pelvis, ribs, spine Quaternary— crush injuries, superficial and partial to full thickness burns

Special Considerations Pregnancy- placental injuries Children- pulmonary contusions Evidence of chest injury Elderly- disabilities, medical conditions, osteoporosis

Transport Destination Trauma Centers capable of managing injuries

Summary Scene safety issues Injuries can be very complex Hemorrhage control Support ventilation / oxygen