BLAST INJURIES

BLAST INJURIES & GUNSHOT WOUNDS:PRINCIPALS OF MANAGEMENT : 

BLAST INJURIES & GUNSHOT WOUNDS:PRINCIPALS OF MANAGEMENT PREETI

BLAST: : 

BLAST: Explosions are physical, chemical, or nuclear reactions involving a large, rapid release of energy

BLAST PHYSIOLOGY: : 

BLAST PHYSIOLOGY: Blast injury – Based on mechanism of tissue injury & physical tissue damage defined and broken into 4 categories Primary Secondary Tertiary quaternary

BLAST PHYSIOLOGY: : 

BLAST PHYSIOLOGY:

PRIMARY BLAST INJURY: : 

PRIMARY BLAST INJURY: Result of the physical properties of the blast wave occurs as a function of an increase in atmospheric pressure over time, referred to as blast over preassure Measure of over pressure is dependent upon: energy of the explosion distance from detonation distance from detonation

PRIMARY BLAST INJURY: : 

PRIMARY BLAST INJURY: Molecules in air are constantly in a state of motion referred to as the state of the gas Due to blast / explosion this state is disturbed from normal conditions resulting in: escalation of molecular speed increase in the no of molecules occupying a defined space density, pressure & temperature of gas increases a shock wave, or blast wave, develops moving at supersonic speeds (3000 to 8000 m/sec) loses its pressure and velocity as distance increases

PRIMARY BLAST INJURY: : 

PRIMARY BLAST INJURY: blast front- leading edge of the blast wave creates a high-pressure region, or positive phase, called blast wind Leaves behind a negative pressure area which reverses the movement of gas damage can occur from both In nuclear blast- precursor shock wave is observed. shock front near the ground of heated air and moves ahead of the blast wave.6

PRIMARY BLAST INJURY: : 

PRIMARY BLAST INJURY: victim positioning relative to the primary wave results in varied damage: perpendicular fashion to blast wave - greatest amount of impact and injury horizontal fashion - less direct surface contact for impact underwater detonations: force of blast wave greatest at the deepest depths & begins to dissipate as blast wave approaches the surface

PRIMARY BLAST INJURY: : 

PRIMARY BLAST INJURY: Essentially barotrauma little or no effect on solid or fluid-filled organs maximal destruction - air-containing organs Hallmarks : Perforation of eardrums (overpressure 15-50 psi) pneumothoraces (over[ressure 50-100 psi) At psi 65 – fatality rate approaches 99% Other injuries: Intestinal /hollow viscus injury Brain injuries Paucity of obvious external signs

PRIMARY BLAST INJURY: : 

PRIMARY BLAST INJURY: Factors potentiating outcome to blast injuries magnitude of the explosion potential building collapse open air versus enclosed space (6 fold ↑ in pulmonary injuries in confines spaces) Enhanced wounding measures – Ball bearings, nails, incendiary Other pathognomonic findings : presence of air emboli in pulmonary & coronary vessels Representing leading cause of death in victims of pulmonary blast injury

SECONDARY INJURIES: : 

SECONDARY INJURIES: Injury from flying debris Classic shrapnel injuries Of various velocities Primary bomb fragments Secondary fragments or missiles Inert from inanimate objects Biological – allogenic bone fragments etc may be HIV, HBSAg infected Potential for pathogen transmission Cases seen in israel n iraq

SECONDARY INJURIES: : 

SECONDARY INJURIES: Environmental debris such as glass, splinters, soil, and various structural particles may be major cause. Interface of debris with skin – characteristic skin pattern called spalling More common than primary injury: Reason - Victim doesn’t have to be near blast site No 1 military killer in 20th century

TERTIARY BLAST INJURIES: : 

TERTIARY BLAST INJURIES: Injuries from deceleration and structural collapse Axial load injuries Wide range blunt injuries: Spine Orthopedic Head Solid & hollow organ Crush syndrome - time delay to recovery and weight of falling debris

QUATERNARY BLAST INJURY: : 

QUATERNARY BLAST INJURY: result of the byproducts of explosion Inhalational injuries: From dust and gases Burns : Thermal Radiation Chemical describes the sequela of reflective of “dirty bomb” in which chemical or radiologic-laden detonations may occur

HUMAN SUICIDE BOMB: : 

HUMAN SUICIDE BOMB:

HUMAN SUICIDE BOMB: : 

HUMAN SUICIDE BOMB: “walking smart bomb.” High grade explosive material used Ability to precisely time the explosion Ability to detonate in close proximity to victims Large load of heavy shrapnel as well as explosive material body parts acting as missile fragments and projectiles may carry with them HIV, hepatitis, and other serious and yet to be identified threats Suicide Bomb victims suffer with the worst of both – ie Explosion and Penetrating shrapnel

SPECIAL CONSIDERATIONS IN PREGNANCY : 

SPECIAL CONSIDERATIONS IN PREGNANCY Fetus' hollow organs are void of air offering protection from primary blast injury However, amniotic fluid, potentially amplifies 3-fold the blast wave, as in underwater detonations concern of potential maternal-fetal injury Penetrating shrapnel (2° injuries) ↑ concern for possible fetal injury the closer to term – greater potential for fetal injury

SPECIAL CONSIDERATIONS IN PREGNANCY : 

SPECIAL CONSIDERATIONS IN PREGNANCY Tertiary blast effects of deceleration - blunt trauma in pregnancy Women with previous history of C-sections greater risk for uterine rupture risk of (40-50% ) abruptio placenta Chemical injuries: Spontaneous abortions (about 4 fold ↑ in bhopal disaster) Teratogenicity not proved

SPECIAL CONSIDERATIONS IN PREGNANCY : 

SPECIAL CONSIDERATIONS IN PREGNANCY Radiation injuries depend on: gestational age at time of the exposure period between the 2-8 weeks - extremely sensitive At significant risk is the central nervous system fetal dose of absorption. low birth weight best chance for fetal survival is that of the stability of the mother suffering traumatic injury

BLAST LUNG INJURY ( BLI ): : 

BLAST LUNG INJURY ( BLI ): Second most susceptible organ (1st TM) Direct consequence of blast wave on the body Overpressure needed - about 40 psi (40 psi being produced by 20Kg TNT exploding 6 meters away) Most common CRITICAL Injury in victims close to bomb Can be life threatening May not have obvious external injury to chest

BLAST LUNG INJURY ( BLI ): : 

BLAST LUNG INJURY ( BLI ): Other pulmonary injuries include: Pneumothorax Hemothorax Pneumomediastinum Subcutaneous emphysema Air emboli

BLAST LUNG INJURY ( BLI ): : 

BLAST LUNG INJURY ( BLI ): Results in tearing, hemorrhage, contusion and edema Micro -hemorrhages in alveoli Disruption and weakening of alveolar walls perivascular and peribronchial tissue Resultant Ventilation-Perfusion mismatch

BLAST LUNG INJURY ( BLI ): : 

BLAST LUNG INJURY ( BLI ): Symptoms: Dyspnoea, Haemoptysis, cough, chest pain Signs: Tachypnoeic, hypoxic, cynosis, wheezing X-Ray features similar to pulmonary contusion, bihilar (butterfly pattern) shadows pneumothorax, haemothorax Can have bronchopleural fistula Air embolism from pulmonary disruption Other injuries may add to haemodynamic instability

Slide 28: 

Tension pneumothorax of the right lung after blunt chest trauma

G I SYSTEM: : 

G I SYSTEM: Most commonly results in tissue tearing hemorrhage. GI blast injury more commonly occurs after blast wave propagation in water. GI hemorrhage and perforation is most common in lower small intestine or cecum, where gas accumulates. Perforations can be delayed May develop 24 to 48 hrs post blast Manifestations of peritonitis can occur hours or days later

HEAD INJURY: : 

HEAD INJURY: Loss of consciousness Headache, seizures, dizziness, memory problems Gait/balance problems, nausea/vomiting, difficulty concentrating. Visual disturbances, tinnitus, slurred speech. Disoriented, irritability, confusion. Extremity weakness or numbness

CRUSH INJURY: : 

CRUSH INJURY: results when muscle reperfusion injury occurs as a result of the release of compressive forces on the tissues or compartment syndrome physiologic outcome - traumatic rhabdomyolysis myoglobin, potassium, and phosphorus leach into the circulation Clinically, compression of large skeletal muscle is necessary for this syndrome About 33% of the patients with rhabdomyolysis will develop acute renal failure mortality rate of 30-50%

CRUSH INJURY: : 

CRUSH INJURY: General cond. of pt with crush injury dictated by: other injuries delay in extrication environmental conditions SIGNS OF COMPARTMENT SYNDROME Pain, Pallor, Paresthesia, Paralysis, Pulselessness Progression of symptoms (the 6th P)

GUNSHOT WOUNDS: : 

GUNSHOT WOUNDS: An explosive force is applied to a projectile that is propelled down a tube to fly towards its target

GUNSHOT WOUNDS: : 

GUNSHOT WOUNDS: Firearms Type of weapon Low-velocity- shot gun, pistol High-velocity- rifle Caliber Missile size Bullet construction Tumbling/yaw Distance traveled

PROJECTILES: : 

PROJECTILES:

RANGE OF FIRE: : 

RANGE OF FIRE: Wound characteristics vary: Contact The most devastation Close Range Arm’s length Distant Most handguns: significant decrease in KE at 100 m Most military rounds: retain large KE at 500m

MECHANISM OF INJURY: : 

MECHANISM OF INJURY: 2 areas of projectile–tissue interaction in missile-caused wounds permanent cavity - localized area of cell necrosis, proportional to size of projectile temporary cavity - transient lateral displacement of tissue, after passage of the projectile. Elastic tissue skeletal muscle, blood vessels, and skin, may be pushed aside but then rebound Inelastic tissue bone or liver, may fracture.

MECHANISM OF INJURY: : 

MECHANISM OF INJURY:

GUNSHOT WOUNDS: : 

GUNSHOT WOUNDS: Entry wound Smaller May be darkened, burned Exit wound One, none, or many Larger May be ragged Imp to know to determine: Anatomy damaged Type of surgical procedure Entry and exit wounds can lie ! ! ! ! ! ! Projectiles do not have to follow a straight line !

PATHOPHYSIOLOGY: : 

PATHOPHYSIOLOGY: Internal wound Tissue contact damage High-velocity transfer of energy Shock waves Temporary cavity Damage proportional to tissue density Highly dense tissue sustains more damage Distal embolization can occur when a projectile slows enough and enters the vascular system

PATHOPHYSIOLOGY: : 

PATHOPHYSIOLOGY: 50 % of deaths are due to exsanguination require rapid pressure application and evacuation exception – Gun Shot Wound to head large bore IV’s are needed for fluid replacement 10 % from CNS injury • Do not delay transport for ANY REASON ! ! ! ! ! ! !

GUNSHOT INJURIES: : 

GUNSHOT INJURIES:

MANAGEMENT: : 

MANAGEMENT: Prehospital trauma care: For severely injured patients, survival is time-dependent! Golden Hour From moment of injury To definitive treatment EMS “platinum 10 minutes” “scoop & run” OR “stay & play” Assessment and management Every action must have lifesaving purpose Organized, detail-oriented, selective, rapid

MANAGEMENT: : 

MANAGEMENT: Scene Size-up Standard precautions Scene safety Initial triage (total number of patients) Need for more help or equipment? Mechanism of injury? Expect combined injuries

TRAUMA SYSTEM: : 

TRAUMA SYSTEM: DEFINITION: an organized approach to acutely injured patients in a defined geographical area that provides full and optimal care and that is integrated with the local or regional Emergency Medical Service (EMS) system. provide the full range of care (from prehospital to rehabilitation).

TRAUMA SYSTEM GOAL: : 

TRAUMA SYSTEM GOAL: To get the right patient to the right hospital at the right time

TRIAGE: : 

TRIAGE: French word – meaning ‘to separate, sort, sift or select’ the sorting of allocation of treatment to pts esp. battle and disaster victims acc. to a system of priorities designed to maximize the no of survivors

TRIAGE UNIT: : 

TRIAGE UNIT: Determine location of triage areas Clear and assemble the walking wounded using verbal instructions Conduct Primary triage ensure all pts. are assessed & sorted Communicate resources required Secondary triage more in-depth assessment usually conducted in treatment Unit

TREATMENT UNIT: : 

TREATMENT UNIT: Determine location for treatment area Coordinate with the Triage unit to move patients from the triage treatment areas Establish communication with Incident Command Reassess patients conduct secondary triage to match patient with resources

TRANSPORTATION UNIT: : 

TRANSPORTATION UNIT: Management of patient movement from the scene to the receiving Hospitals Establishes adequately sized, easily identifiable patient loading area

STAGING AREA: : 

STAGING AREA: Location designated to collect available resources near incident area Several staging areas may be required

TRIAGE TAG: : 

TRIAGE TAG: Alerts care providers to patient priority Prevents re-triage of the same patient Serves as a tracking system

TRIAGE TAG: : 

TRIAGE TAG: carried with Diagnostic Equipment in all EMS kits should be considered on all calls involving ≥3 pts general placement location for tags one of the patient’s arms or hung around the patients neck.

TRIAGE CATEGORIES: : 

TRIAGE CATEGORIES: IMMEDIATE: Life-threatening but treatable injuries requiring rapid medical attention DELAYED: Potentially serious injuries, but are stable enough to wait a short while for medical treatment

TRIAGE CATEGORIES: : 

TRIAGE CATEGORIES: MINIMUM / MINOR: Minor injuries that can wait for longer period of time prior to treatment MORGUE/EXPECTANT: Death or lack of spontaneous respiration after airway is opened

TRIAGE SCORING SYSTEMS : 

TRIAGE SCORING SYSTEMS

‘START’ TRIAGE METHOD: : 

‘START’ TRIAGE METHOD: Simple Triage And Rapid Transport Triage assessment based on 3 criteria RPM Respirations ( > or < 30/min) Perfusion (Capillary Refill > or< 2/ sec) Mental Status (Follow ssimple commands) MNEMONIC: 30 – 2 – CAN DO

REVERSE TRIAGE: : 

REVERSE TRIAGE: conditions where less wounded are treated in preference to more severely wounded such as: war - where military setting may require soldiers be returned to combat as quickly as possible disaster situations - where medical resources are limited where significant numbers of medical personnel are among the affected patients

CAUTION: : 

CAUTION: Personal protective equipment is always needed at trauma scenes Do not approach until Scene Size-up is complete!

ASK SOME QUESTIONS…. : 

ASK SOME QUESTIONS…. What type of explosive and how much? Where was victim located with respect to the blast? Were fire/fumes present to cause inhalational injury? What was orientation of head and torso to the blast?

“You see what you look for” – Stephen Sondheim : 

“You see what you look for” – Stephen Sondheim

MANAGEMENT: : 

MANAGEMENT: Primary survey Many components are assessed simultaneously Airway- maintenance with cervical spine protection Breathing and ventilation Circulation with hemorrhage control Disability; neurologic status Exposure/Environment (completely undress the pt and prevent hypothermia)

MANAGEMENT: AIRWAY : 

MANAGEMENT: AIRWAY Assume Cervical Spine Injury Maintain inline cervical spine stabilization Airway Suction Blood Mucus Dental fragments Open Airway Head Tilt-Chin Lift Jaw Thrust (if Cervical Spine Injury is suspected) Maintain Airway Oropharyngeal Airway Nasopharyngeal Airway

MANAGEMENT: BREATHING : 

MANAGEMENT: BREATHING Assess Breathing Ventilation Oxygenation Awake with spontaneous breathing Supplemental 100% Oxygen Delivery Infants under 1 year old: Oxygen Hood Children/Adults: Non rebreather mask with reservoir Conscious with respiratory failure Bag Valve Mask with 100% Oxygen Unresponsive or respiratory failure Orotracheal intubation

MANAGEMENT: BREATHING : 

MANAGEMENT: BREATHING Nasotracheal intubation: in breathing patient without major facial trauma Surgical airways jet insufflation Retrograde intubation cricothyrotomy tracheostomy

BREATHING: PITFALLS : 

BREATHING: PITFALLS Tension Pneumothorax Rib Fractures High risk injury if Fractured ribs 1-3 Associated with significant cardiopulmonary injury Flail chest Pulmonary Contusion Open Pneumothorax Massive hemothorax

MANAGEMENT: CIRCULATION : 

MANAGEMENT: CIRCULATION Level of Consciousness Skin color Central Pulse Child or adult: Carotid pulse or femoral pulse Infant: Brachial Pulse Sites of rapid blood loss Chest Injury Abdominal Injury (especially retroperitoneal) Pelvic Injury Extremity Injury (especially femur)

MANAGEMENT: CIRCULATION : 

MANAGEMENT: CIRCULATION Correct Hypovolemia: Fluid Replacement in Trauma Two large bore IVs (14 or 16 gauge) Shorter tubing provides faster IV rate Replace fluid deficit Infuse Lactated Ringers 2-3 Liters until response Consider blood transfusion Unmatched Type-specific blood may be used OR Low titer O, or Rh- O if other not available Hemorrhage Evaluation Avoid potentially harmful measures Vasopressors Steroids Sodium Bicarbonate

MANAGEMENT: DISABILITY : 

MANAGEMENT: DISABILITY Level of Consciousness: (AVPU system) Alert Vocal Stimuli Painful stimuli Unresponsive GCS Pupil response

EXPOSURE: : 

EXPOSURE: Undress patient do complete visual inspection Keep spine immobilized and ‘log roll’ Prevent Hypothermia Warm crystalloid in microwave or bath to 39C Do not microwave Blood, Plasma or Dextrose Minimize 2° injury RAPID TRANSPORT to Surgical Facility

MANAGEMENT: : 

MANAGEMENT: Resuscitation of vital functions Detailed secondary survey Definitive care Consider abdominal films in all pts with significant blast injury Auscultation of chest & chest X rays DPL / FAST- for unstable pts. CT Scan Abdomen/Pelvis for patients with appropriate signs and symptoms. Hearing in both ears should be tested at bedside. Limb X rays & examination Avoid tunnel vision on one injury.

ABDOMINAL INJURIES: : 

ABDOMINAL INJURIES: Laparotomy - main stay of investigation and management Priorities of the Trauma Laparotomy Hemorrhage control Contamination control Detection of all injuries Missed injury - high mortality and morbidity Tetanus toxoid and Antibiotics initial blood loss on opening abdomen- can be brisk patient rapidly can become unstable Volume resuscitation & blood transfusion

RADIATION MANAGEMENT: : 

RADIATION MANAGEMENT: Radiation deaths are delayed. Management of conventional injuries and acute life threats takes precedence over radiation exposure. Treat injury first, then decontaminate. Contamination issues No medical personnel have ever received an exposure anywhere near the degree to cause radiation effects 95% of decontamination occurs with: Removal of patient’s clothing Soap & water

ENTRAPPED PATIENT TREATMENT : 

ENTRAPPED PATIENT TREATMENT Volume resuscitation before extrication maintain a euvolemic state with brisk urine output (2ml/kg/hr) Limb Stabilization ↓ Vital signs, oxygen, EKG, IV – Additional Rx & transport IS CRUSH SYNDROME OR COMPARTMENT SYNDROME SUSPECTED? Look for injuries on Limbs, Pelvis, Gluteal region & Abdominal muscles

ENTRAPPED PATIENT TREATMENT: : 

ENTRAPPED PATIENT TREATMENT: Crush / compartment injury signs & symptoms if present: TREATMENT – PREHOSPITAL ABCs Treat other injuries Immobilize affected part-dont use constricting bandages TREATMENT – HOSPITAL Fluid resuscitation - Brisk diuresis (2 ml/kg/hr) Diagnose and treat other metabolic derangements – Hyperkalemia, Hypocalcemia Pain control Anxiolysis

ENTRAPPED PATIENT TREATMENT: : 

ENTRAPPED PATIENT TREATMENT: Mannitol - a nonosmotic diuretic Help augments diuresis effective radical scavenger Use of bicarbonate: alkalization of the urine ↓ cast formation ↓ direct toxic effects of myoglobin upon nephrons Hyperkalemia, severe acidosis, and hypervolemia continuous renal replacement therapy If injury is open: Antibiotics, tetanus, jet irrigation. Debridement of nonviable tissues. Early amputation for severely injured limbs may be required Fasciotomy

BLAST LUNG INJURY : 

BLAST LUNG INJURY Was the Bombing in Open or Closed Space? higher incidence of blast lung injury in enclosed spaces Signs/symptoms suggestive of BLI or resp distress?? NO NO YES Management ventilatory failure- intubate Caution with PPV- ↑ BLI, embolism Appropriate Rx & transport

BLAST LUNG INJURY : 

BLAST LUNG INJURY HOSPITAL DIAGNOSTIC EVALUATION Chest radiography Arterial blood gases computed tomography doppler ultrasound to help diagnose BLI and air emboli. Testing conducted per resuscitation protocols Acc to nature of explosion (eg. confined space,fire etc) OXYGENATION High flow O2 via non-rebreather mask, CPAP,or endotracheal intubation.

BLAST LUNG INJURY: : 

BLAST LUNG INJURY: CLOSE OBSERVATION Chest decompression- clinical presentation of tension pneumothorax. Fluid administration enough fluid to ensure tissue perfusion & avoiding volume overload. AIR EMBOLISM Position in prone, semi-left lateral, or left lateral transport to a facility with a hyperbaric chamber.

TENSION PNEUMOTHORAX: : 

TENSION PNEUMOTHORAX: Tension pneumothorax is not an x-ray diagnosis it MUST be recognized clinically Treatment is decompression needle into 2nd intercostal space of mid-clavicular line - followed by thoracotomy tube Insert needle here

MASSIVE HEMOTHORAX: TREATMENT : 

MASSIVE HEMOTHORAX: TREATMENT Large-bore (32 to 36 F) tube to drain blood If moderate sized (500 to 1500 ml) and stops bleeding closed drainage usually sufficient If initial drainage >1500 ml OR continuous bleeding >200 ml / hr OPEN THORACOTOMY

FLAIL CHEST: : 

FLAIL CHEST: “Free-floating” chest segment- multiple ribs # Pain and restricted movement paradoxical movement” of chest wall with respiration Treatment : Ventilate well Humidify oxygen Resuscitate with fluids Manage pain Stabilize chest ventilator

DISPOSITION AND OUTCOME: : 

DISPOSITION AND OUTCOME: No definitive guidelines for observation, admission, discharge Patients diagnosed with BLI may need complex management should be admitted to an intensive care unit suspicious for BLI should be observed in the hospital. Discharge decisions will also depend on: associated injuries other issues related to the event, including the patient’s current social & mental situation. Patients with – normal chest X Rays, blood gases & pulse oximetry no complaints suggesting a BLI can be considered for discharge after 4-6 hours of observation.

BURN INJURY: : 

BURN INJURY: Fluid resuscitation while avoiding fluid overload to prevent further pulmonary injury guided by urine output. Consider monitoring central venous pressure systemic vascular resistance when indicated. Standard burn management

WOUND MANAGEMENT: : 

WOUND MANAGEMENT: Tetanus status. Local exploration. Delayed primary closure. IV followed by oral antibiotics for all but the most trivial wounds