Bomb and blast injury

1. Bomb and Blast
Injury
Nathan Muluberhan (MD, EMCC R II)
July, 2018

2. OUTLINE
• Introduction
• Epidemiology
• Pathophysiology
• Clinical Presentation
• Treatment

3. INTRODUCTION
• Complex type of physical trauma resulting from direct or
indirect exposure to an explosion.
• Usually occurs as an act of terrorism, fireworks, household
explosions, industrial accident, motor vehicular accidents

4. • Explosives can be
• High-order explosives:
• TNT, C-4, Semtex, Nitroglycerin, Dynamite, Ammonium Nitrate Fuel Oil (ANFO)
• Low-Order Explosives:
• Pipe bombs, Gunpowder, and Most pure petroleum based bombs (Molotov cocktails,
Aircraft improvised)
• Can also be manufactured and improvised
INTRODUCTION CONT…

5. EPIDEMIOLOGY
• Blast injuries using conventional weapons have emerged as the
terrorist weapon of choice
• Terrorist attacks have increased dramatically over the last decade.
• The U.S National Counterterrorism Center reported more than 14,000
terrorist attacks in 2007, which was a 20% to 30% increase over 2006

6. • Blast victims have
• Increased immediate scene mortality
• Greater hospital mortality
• more frequent need for surgical intervention, longer hospital stays, and
greater use of critical care
EPIDEMIOLOGY CONT…

7. PATHOPHYSIOLOGY
• An explosion is the instantaneous transformation of a solid or liquid
into a gas, releasing tremendous kinetic and heat energy.
• Detonation of a conventional high explosive generates a blast wave
• The blast wave consists of two parts:
• a shock wave of high pressure
• a blast wind, which is air mass in motion

8. • The overpressure from the blast generally follows a well-defined
pressure/time curve, called a “Friedlander wave,”
• An initial near instantaneous spike in the ambient air pressure
• It quickly decays and is followed by a negative pressure wave that sucks debris
into the area.
PATHOPHYSIOLOGY CONT…

10. • Blast injuries are generally categorized as:
• Primary
• Secondary
• Tertiary
• Quaternary
PATHOPHYSIOLOGY CONT…

11. Primary Blast Injury
• Occurs as the shock front and the overpressure blast wave move
through the body.
• Usually affects air-filled structures such as: lungs, ears, and GI tract
• Mechanisms:
• Spalling: displacement and fragmentation of a dense medium into a less
dense medium.
• Shearing (inertia): a stress caused by the blast wave traveling through
different tissue densities at different velocities.
• Implosion: the opposite of spalling, where the less dense material is displaced
into denser material.

12. Secondary Blast Injury
• Occur from objects that have been energized by the explosion to
become projectiles.
• May be
• primary fragmentation: a part of the bomb’s housing.
• secondary fragmentation: local material, such as rocks or glass, that became
airborne due to their proximity to the explosion
• Most penetrating injuries caused by blast-driven projectiles should be
considered as contaminated.

13. • Tertiary Blast Injury: results from the victim being propelled
through the air and striking stationary objects
• Quaternary Blast Injury: a result of burns, smoke inhalation, or
chemical agent release
PATHOPHYSIOLOGY CONT…

15. • Factors affecting blast injury
• Medium through which the blast wave moves is a factor in blast
intensity.
• water allows for faster propagation and a longer duration of positive
pressure, accounting for the increased severity in that environment.
• Distance of victim from explosion:
• The intensity of an explosion pressure wave declines with the cubed root
of the distance from the explosion
PATHOPHYSIOLOGY CONT…

16. • Factors affecting blast injury
• Enclosed vs open space
• The effects of an explosion in a closed space, like a room, bus, or train, are
much greater than in an open space
• The blast wave can reflect off, and flow around, solid surfaces.
• Reflected waves can be magnified eight to nine times
• Quantity of explosive
• Type of explosive
• Embedded shrapnel
PATHOPHYSIOLOGY CONT…

17. CLINICAL FEATURES
• The nature of the injury may produce a multiplicity of external signs
making detection of important internal injuries challenging.
• High-grade clinical expertise is even more in demand to allow optimal
use of resources.

18. CARDIOPULMONARY SYSTEM
• The lung is very susceptible to primary blast injury.
• The blast wave’s impact upon the lung results in tearing, hemorrhage,
contusion, and edema with resultant ventilation perfusion mismatch.
• Blast Lung injury is a clinical diagnosis

19. • Blast lung Injury
• Symptoms: dyspnea, hemoptysis, cough, and chest pain.
• Signs: tachypnea, hypoxia, cyanosis, apnea, wheezing, decreased breath
sounds, and hemodynamic instability
• Associated pathology may include bronchopleural fistula, air emboli, and
hemothoraces or pneumothoraces.
CARDIOPULMONARY CONT…

20. • Chest radiography is necessary for
anyone who is exposed to a blast
• A characteristic “butterfly” pattern
may be revealed upon x-ray.
CARDIOPULMONARY CONT…

21. CARDIOPULMONARY CONT…
• Air embolism is another well-recognized consequence of blast lung
injury
• One of the major factors leading to cardiac dysfunction and immediate death
after blast wave exposure.
• Pneumothorax, hemothorax, pneumomediastinum, great vessels
rupture, cardiac injury and subcutaneous emphysema can occur from
the blast injury.

22. Management
• In general, managing blast lung injury is similar to caring for
pulmonary contusion and acute respiratory distress syndrome
• Supplemental high flow oxygen sufficient to prevent hypoxemia
• Monitoring of respiratory rate and room-air pulse oximetry, as well as
serial chest radiographs, may be needed.
• Fluid administration should ensure tissue perfusion without volume
overload.
CARDIOPULMONARY CONT…

23. Management
• Mechanical Ventilation
• Aggressive methods of oxygenation (extracorporeal membrane oxygenation
or intravascular oxygenation) may become necessary within hours of the
injury.
• Air embolism: oxygen supply, supine position, transferred to a
hyperbaric chamber.
CARDIOPULMONARY CONT…

24. • There are no definitive guidelines for observation, admission, or
discharge of patients with possible blast lung injury.
• In general, asymptomatic patients (normal chest radiographs and
normal room-air pulse oximetry)
• Consider discharge after 4 to 6 hours of observation as long as there is no
clinical deterioration
CARDIOPULMONARY CONT…

25. EAR
• The most susceptible organ to primary blast injury.
• Blast injury to the ear may result in symptoms of tinnitus, earache,
hearing loss, or vertigo.
• Injury to the external ear is caused most often by flying debris
• Degloving of the cartilage may occur; considered to be a serious injury

26. • The TM is exquisitely sensitive to variations of atmospheric
pressure
• Blast overpressure enters the external auditory canal,
stretching and displacing the TM medially
• A spectrum of injury may be seen, ranging from intra-tympanic
hemorrhage in minor cases to total tympanic membrane
perforation in powerful blasts.
EAR CONT…

27. • Middle Ear
• Disruption of the ossicular chain may occur, especially in larger
blasts
• Cholesteatoma within the middle ear & mastoid cavity may occur
• Inner Ear
• Damage to auditory and vestibular components may also occur
• The typical blast-injured patient will experience a temporary
hearing threshold change;
• most regain hearing within hours, for others resolution take days to weeks
EAR CONT…

28. Initial Management
• Address basic life saving measures and severe injuries initally
• Otoscope evaluation of the TM and external auditory canal
• Tympanic membrane injury should raise clinical suspicion and evaluation for additional primary
blast injury
• Manage as other soft tissue injuries
• Attention to foreign body removal, cleaning and irrigation of wounds, and closure
• Wounds should be closed primarily
• If the cartilage of the pinna is degloved
• it should be buried in the post auricular pouch (may require the expertise of an otolaryngologist
EAR CONT…

29. • Treatment of TM perforations is usually expectant
• The ear should be kept clean and dry, and the patient should be referred to a
specialist
• Antibiotic eardrops for TM perforations or ear canal lacerations
• Middle and inner ear injuries typically can be deferred until an
otolaryngologist is available
• Baseline audiometry in all blast-injured patients has been advocated
EAR CONT…

30. ABDOMINAL INJURY
• Reported injury rates are low,
• Missed injuries may carry significant morbidity due to delayed intestinal
perforation and necrosis.
• A review of the literature on abdominal trauma from primary blast
• An incidence of 1.3% to 33%.
• The terminal ileum and cecum were the most commonly injured areas.

31. • Blast abdominal injury should be suspected in anyone exposed
to an explosion and with:
• Abdominal pain
• Nausea & vomiting
• Hematemesis
• Rectal pain
• Tenesmus
• Testicular pain
• Unexplained hypovolemia
• Any findings suggestive of an acute abdomen
ABDOMINAL INJURY CONT…

32. Most common abdominal blast injuries include:
• Primary: abdominal hemorrhage and perforation (colon is most
vulnerable to perforation)
• Secondary: penetrating and blunt abdominal trauma
• Tertiary: blunt and penetrating abdominal trauma
• Quaternary: crush injury to abdomen and abdominal wall
ABDOMINAL INJURY CONT…

33. Initial Management
•ABCs
•Nothing by mouth
•Avoid removal of penetrating objects in ER
•Antibiotics and tetanus immunization
•Serial exams and laboratory monitoring
• Radiological studies: plain abdominal films, CT scan, FAST
ABDOMINAL INJURY CONT…

34. HEAD INJURY
• The clinical examination may be misleading for penetrating
injuries.
• Shrapnel are low-velocity missiles, often producing small
entry wounds in survivors.
• Evidence for TBI may initially be benign or masked by
anesthesia as the patient undergoes treatment for other life
threatening injuries.
• Neuroimaging is an important early diagnostic tool

35. VASCULAR INJURY
• Small entry wounds from shrapnel may mask severe vascular injuries.
• Carefully assess and document pulses and perfusion in affected limbs.
• Observe for delayed presentation of compartment syndrome,
• Difficult to diagnose, especially in patients receiving anesthesia.
• Measure compartment pressure if any signs or symptoms develop.
• Early angiography and intervention are indicated if pulses are lost.

36. OCULAR INJURY
• Occur in up to 28% of survivors
• The eye is resistant to traumatic rupture resulting from a blast wave.
• Usually due secondary blast injury, caused by flying debris or
fragments,
• Rapidly accelerated sharp particles, large or small, can lacerate or rupture the
cornea or sclera and enter the eye.
• Frequently, injuries are bilateral

37. • Range from minor corneal abrasions and foreign bodies to extensive
eyelid lacerations, open globe injuries, intraocular foreign bodies
(IOFB), or orbital fractures.
• Ruptured globes or IOFBs may be very subtle:
• 360-degree conjunctival hemorrhage
• Misshapen pupil
• Brown or pigmented tissue outside the globe
• Clear, gel-like tissue outside the globe
• Abnormally deep or shallow anterior chamber
OCULAR INJURY CONT…

38. Initial management
• Do not force the lids open to examine the eye
• Defer examining the eye if there is massive swelling or hematoma of the lids
• Assume all eye injuries harbor a ruptured globe
• Do not put any pressure on an eye that may be ruptured
• Do not apply a patch or bandage to the eye
• Use a convex plastic or metal shield, to protect the globe
• Do not remove impaled foreign bodies
• The distal aspect of the foreign body may be in a location that requires special extraction
techniques
OCULAR INJURY CONT…

39. Initial management
• Administer tetanus
• Administer anti-emetics to reduce nausea and vomiting
• Administer IV broad-spectrum antibiotics if a ruptured globe is
suspected;
• current suggestions include the combination ceftazadime/vancomycin
• consider IV clindamycin for dirty soil/ organic material-contaminated
wounds
OCULAR INJURY CONT…

40. EXTERNAL HEMORRHAGE
• Bleeding from wounds is likely to be the most commonly encountered
life-threatening finding.
• Quickly control external bleeding with direct pressure.
• Apply tourniquets for extremity hemorrhage whenever blood loss
cannot be controlled with direct pressure.
• Angiographic vascular occlusion is an attractive treatment option if
the time and staff are available.
• Victims of blast mass casualty incidents may require massive amounts
of blood and blood products

41. GENERAL MANAGEMENT
• Tend to be unexpected
• Occur outside of regular working hours
• Often produce moderate to large numbers of simultaneously arriving
casualties
• Drills and checklists are critical for successful implementation of rarely
used protocols.

42. • Checklists should be:
• Concise
• Never more than one to two pages
• Available in a location known to everyone
• Implement the hospital plan for management of mass casualty
incidents.
GENERAL MANAGEMENT CONT…

43. • Obtain details about the explosion from patients and rescue teams.
• The nature and location of the blast
• Size and type of charge
• Location in open or closed space
• Structural collapse
• Associated fire or smoke, and toxic agent release
GENERAL MANAGEMENT CONT…

44. • Patient triage will be needed when multiple patients arrive.
• Station an experienced emergency physician or surgeon at the ED
entrance to triage
• Patients must be triaged to categories of urgency based on
relevant criteria
• Many triage methods have been in use in various parts of the world, with
varying success and scientific foundation
GENERAL MANAGEMENT CONT…

45. • Apply the basic ATLS principles of primary and secondary surveys
within the logistic limitations that may occur temporarily or
permanently.
• Administer IV fluids and blood products judiciously.
• Preventing fluid overload is important for lung- and brain injured patients.
• Activated factor VII administration or tranexamic acid may be
considered in select cases of uncontrollable bleeding.
GENERAL MANAGEMENT CONT…

46. • Copiously irrigate and disinfect wounds urgently
• Definitive debridement and closure may wait a few hours.
• Temporary splinting, traction, and dressings are generally sufficient
for initial management of musculoskeletal injuries
• Consider prophylactic antibiotics for:
• Severely soiled wounds
• Penetrating abdominal and thoracic wounds, and open fractures
• In patients with diabetes or who are immunocompromised
GENERAL MANAGEMENT CONT…

47. • Address pain management after life-threatening emergencies have
been evaluated
• Reserve opiates for patients with severe pain because opiate supplies may
become limited
• Patients exposed to open-space explosions and who have no
apparent significant injury, normal vital signs, and an unremarkable
physical examination generally can be discharged after 4 to 6 hours of
observation.
GENERAL MANAGEMENT CONT…

48. • Secondary assessments of all casualties should be done before discharge.
• Instruct all discharged patients to return for reevaluation
• Breathing problems, abdominal pain, or vomiting.
• Provide relevant follow-up instructions in writing including:
• ENT follow-up
• Wound care
• Immunization schedules
• Medications
• Psychological support
• Social services
GENERAL MANAGEMENT CONT…

49. SPECIAL POPULATIONS
PREGNANT WOMEN
• Direct injury to the fetus is uncommon (surrounded by amniotic fluid)
• Injuries to the placenta, however, are more common.
• Admit patients in the 2nd or 3rd trimester of pregnancy to the labor
area for continuous fetal monitoring and further testing & evaluation.
• Pelvic us, biophysical, and obstetrics consultation should always be obtained.
• Consider Rh IG administration if the mother’s blood type is Rh -ve

50. STAFF SAFETY
Issues that may affect staff safety include:
1.Possible infiltration of the ED by perpetrators intent on causing second
attacks in the hospital
2.Unexploded explosives inadvertently brought into the ED
3.Transmissible disease in the setting of body fluid exposure or needle
sticks during stressful, rapid work
4.Contamination of victims by chemical, radiologic, and biologic hazards,
either accidental or intentionally caused by the perpetrators
SPECIAL POPULATIONS CONT…

51. FORENSIC ISSUES
• Police, crime scene investigators and other security services, have
legitimate interests in securing forensic and other information.
• Efforts should be made to accommodate them, but never at the expense of
medical care.
• Prior coordination with all relevant authorities should establish
protocols, such as
• who and how many persons from these agencies are allowed in, when, into
which parts of the ED, who controls them, and who is empowered to limit
their entry and work.
SPECIAL POPULATIONS CONT…

52. INFORMATION MANAGEMENT
• Blast injury is often part of a large event, thus information becomes a
critical component of appropriate management.
• Information concerns include:
1.Clinical charting and other patient care centered information (imaging…)
2.Command and control information, such as casualty flow data, resource
management data, and interface with other agencies
3.Information provided to relatives
4.Information provided to the media
5.Information recorded for quality improvement and research.
SPECIAL POPULATIONS CONT…

53. REFERENCE
• Tintinalli’s Emergency Medicine 8th edition
• Blast fact sheet professionals National Center for Injury Prevention
and Control (CDC)

54. Thank You!!!