BLAST INJURIES, An approach towards a patient that has suffered a blast injury.

"A blast injury", is a complex type of physical trauma resulting from direct or indirect exposure to an explosion. Blast injuries range from internal organ injuries, including lung and traumatic brain injury (TBI), to extremity injuries, burns, hearing, and vision injuries. Explosions cause familiar trauma .There may be LOTS of casualties with LOTS of injuries. Secondary blast trauma is the biggest killer. The efficiency of the Emergency Response Teams, in how quickly they could identify the injuries and their ability to shift the patients the a proper healthcare facility for timely surgical interventions can save lives.

1. “BLAST INJURIES” Dr.Riffat Khattak Consultant Surgeon- ENT FGPMI. ISLAMABAD.

2. PEWSHAWAR BOMB BLAST, Jan.1 st ,2023, 89 killed.

3. DEFINITION A blast injury is a complex type of physical trauma resulting from direct or indirect exposure to an explosion. Blast injuries range from internal organ injuries, including lung and traumatic brain injury (TBI), to extremity injuries, burns, hearing, and vision injuries.

4. INTRODUCTION: Explosions have the capability to cause multisystem, life-threatening injuries in single or multiple victims simultaneously. These types of events present complex triage, diagnostic and management challenges for the health care providers. Explosions can produce classic injury patterns from blunt and penetrating mechanisms to several organ systems.

5. The extent and pattern of injuries produced by an explosion are a direct result of several factors including: The amount and composition of the explosive material. The surrounding environment ( eg , the presence of intervening protective barriers). The distance between the victim and the blast. The delivery method if a bomb is involved. Any other environmental hazards (No two events are identical and the spectrum and extent of injuries produced varies widely).

6. PATHOPHYSIOLOGY Blast injuries traditionally are divided into 4 categories: Primary. Secondary. Tertiary. Quaternary injuries.

7. PRIMARY BLAST INJURIES A Primary blast injury is caused solely by the direct effect of blast overpressure on tissue. Air is easily compressible, unlike water. As a result, a primary blast injury almost always affects air-filled structures such as the lung, ear, and gastrointestinal (GI) tract.

8. SECONDARY BLAST INJURIES A Secondary blast injury is caused by flying objects that strike people.

9. TERTIARY BLAST INJURIES A Tertiary blast injury is a feature of high-energy explosions. This type of injury occurs when people fly through the air and strike other objects.

10. QUATERNARY BLAST INJURIES Quaternary blast related injuries : Encompasses all other injuries caused by explosions.

11. IMMEDIATE EFFECTS OF BLAST INJURIES

12. Mechanisms of Blast Injury Category Characteristics Body Part Affected Types of Injuries Primary Unique to HE, results from the impact of the over-pressurization wave with body surfaces.  Gas filled structures are most susceptible - lungs, GI tract, and middle ear. Blast lung (pulmonary barotrauma ) TM rupture and middle ear damage  Abdominal hemorrhage and perforation - Globe (eye) rupture- Concussion (TBI without physical signs of head injury)  Secondary Results from flying debris and bomb fragments.  Any body part may be affected. Penetrating ballistic (fragmentation) or blunt injuries Eye penetration (can be occult) Tertiary Results from individuals being thrown by the blast wind. Any body part may be affected. Fracture and traumatic amputation  Closed and open brain injury Quaternary  All explosion-related injuries, illnesses, or diseases not due to primary, secondary, or tertiary mechanisms.  Includes exacerbation or complications of existing conditions. Any body part may be affected. Burns (flash, partial, and full thickness) Crush injuries Closed and open brain injury Asthma, COPD, or other breathing problems from dust, smoke, or toxic fumes Angina Hyperglycemia, hypertension

13. Morbidity/Mortality : Unique patterns of injury are found in all bombing types. Injury is caused both by direct blast overpressure (primary blast injury) and by a variety of associated factors. Enclosed-space explosions , including those occurring in busses, and in water explosions produce more primary blast injury. Explosions leading to structure collapse produce more orthopedic injuries. Land mine injuries are associated with a high risk of below and above the knee amputations.

14. APPROACH TO THE PATIENT (subject to the specific situation ) EMS History Clinical examination Diagnostic Studies Immediate Hospitalization for appropriate Management

15. EMS PROVIDERS Airway control - minimize airway pressures as much as possible. Positive pressure ventilation only when necessary. Pulse oximetry if possible. Identify and treat hemorrhage at once. Tourniquet is the appropriate treatment. Good IV access : Monitor fluid administration carefully. Avoid overhydration /ARDS! Frequent vital signs . GCS.

16. HISTORY (Imp. questions to be asked after establishing that the patient is responsive): Can you hear me? / Do you have ear pain? Tympanic membrane rupture Hearing loss Ear injuries do not need special care in the field

17. HISTORY Can you breathe? First subjective complaints of pulmonary contusion, pneumothorax , hemothorax , or shock. The more exertion required to elicit dyspnea , the better your patient is Do you have chest pain?

18. HISTORY Do you have nausea, abdominal pain, urge to defecate ….etc. Early markers for GI injuries. May be absent/altered with other trauma.

19. HISTORY Do you have eye pain or problems with your vision? Markers for blunt and penetrating eye trauma. 1o % of explosion victims will have eye trauma.

20. Examination RESPIRATORY SYSTEM: Ecchymosis or petechiae in hypopharynx Cough Tachypnea Dyspnea Hemoptysis Rales or crepitations Wheezes Chest pain Asymmetric chest movement Subcutaneous emphysema

21. Examination : CARDIOVASCULAR: Tachycardia Stress , hemorrhage, hypoxia, exertion. Bradycardia Vasovagal . Delayed capillary refill. Hypotension. Hemorrhage , AGE, vasovagal reaction. Arrhythmias Shock, coronary AGE.

22. Examination GASTROINTESTINAL: Nausea/vomiting Abdominal tenderness Hematochezia Hematemesis

23. Examination Neurologic : Vertigo Vertigo is NOT usually due to auditory trauma Coma Altered sensorium Focal numbness Paresthesias Seizures Retrograde amnesia

24. Examination OPHTHALMOLOGICAL : Difficulty focusing. Blindness. Fundoscopic findings of retinal artery air embolism. Loss of red reflex on fundoscopic examination.

25. Examination OTOLARYNGOLOGICAL : Blood oozing from mouth or nose. Hyperemia, hemorrhage or rupture of TM. Deafness. Tinnitus.

26. Examination: Middle ear: Ruptured tympanic membrane (TM). Temporary conductive hearing loss . Inner ear: Temporary sensory hearing loss . Permanent sensory hearing loss .

27. Diagnostic studies Chest X-ray: Should be done on almost all patients. Pulse oximetry : With multiple casualties consider intermittent monitoring. FAST Scan. CT Scan: of head, chest, or abdomen if HX and PE suggest NOT optional in comatosed patients .

28. Diagnostic studies CBC: Serial hemoglobin / hematocrit measurements Stool occult blood. Other labs may be helpful… but order on case to case basis.

29. Overview of Explosive-Related Injuries System Injury or Condition Auditory TM rupture, ossicular disruption, cochlear damage, foreign body  Eye, Orbit, Face Perforated globe, foreign body, air embolism, fractures Respiratory Blast lung, hemothorax, pneumothorax, pulmonary contusion and hemorrhage, A-V fistulas (source of air embolism), airway epithelial damage, aspiration pneumonitis, sepsis Digestive Bowel perforation, hemorrhage, ruptured liver or spleen, sepsis, mesenteric ischemia from air embolism Circulatory Cardiac contusion, myocardial infarction from air embolism, shock, vasovagal hypotension, peripheral vascular injury, air embolism-induced injury CNS Injury Concussion, closed and open brain injury, stroke, spinal cord injury, air embolism-induced injury  Renal Injury 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 

30. Treatment Pulmonary: High flow oxygen Consider intubation Respiratory distress Hemoptysis Use lowest airway pressure possible PEEP and high ventilation pressures cause POP If intubated , consider chest tube(s).

31. Treatment Hypotension Blood loss from wounds Blood loss due to GI hemorrhage Blood loss due to intra-abdominal organ rupture Pneumothorax Air embolism Vagal reflex Volume support Consider blood products – early LOOK for the CAUSE !

32. Treatment Auditory: Most resolve spontaneously. Avoid irrigating or probing the auditory canal. Avoid swimming. Refer to ENT if no healing or complications occur Complications include ossicle disruption, cholesteatoma, perilymphatic fistula, and permanent hearing loss. Steroids may be helpful in sensorineural hearing loss

33. Treatment Wound management: Avoid primary closure. Use delayed primary closure. Consider all wounds to be puncture wounds and have an imbedded FB. Carefully explore every wound. Consider CT, US, or MRI to look for radiolucent foreign bodies.

34. TREATMENT AIR EMBOLISM : Aspirin may be helpful in AGE. May reduce inflammation-mediated injury in pulmonary barotrauma . Weigh bleeding risk in acute trauma setting.

35. TREATMENT Burns require special management. Copious lavage and removal or particles and debris. Rinse with 1% copper sulfate solution Combines with phosphorous particles and impedes further combustion. Cardiac monitor Hypokalemia and hyperphsophatemia common. Consider moistened face masks to protect from phosphorous pentoxide gas exposure. Avoid use of flammable anesthetic agents and excessive oxygen.

36. Summary Explosions cause familiar trauma There may be LOTS of casualties with LOTS of injuries Secondary blast trauma is the biggest killer Primary blast injuries of the lung Leads to pulmonary contusion with possible arterial gas embolism to the brain or heart May rapidly worsen if casualty exercises (including walking) May affect evacuation decisions (air vs. ground) – air evac only at LOW altitude Management of other injuries adjusted Spontaneous breathing or low airway pressures Highest level of oxygen supplementation Just enough fluid or blood to restore perfusion May help to position differently than supine

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