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Weapons Effects. Overview. Epidemiology of Injuries Mechanism of Injury Antipersonnel Landmines Small Arms. Epidemiology of Injuries. Two Major Categories of Weapons Explosives: artillery, grenades, mortars, bombs, hand grenades Small Arms Fire: pistols, rifles, machine guns
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Overview • Epidemiology of Injuries • Mechanism of Injury • Antipersonnel Landmines • Small Arms
Epidemiology of Injuries • Two Major Categories of Weapons • Explosives: artillery, grenades, mortars, bombs, hand grenades • Small Arms Fire: pistols, rifles, machine guns • Most common pattern or injury is multiple small fragment wounds of extremities
Mechanism of Injury: Projectiles • There are two areas of projectile-tissue interaction • Permanent cavity: localized area of tissue injury that is proportional to the size of the projectile • Temporary cavity: Transient displacement of tissue, which occurs after passage of the projectile. • Elastic tissue, such as skeletal muscle, blood vessels and skin, may be pushed aside after passage of the projectile, but then rebound. • Inelastic tissue, such as bone or liver, may fracture in this area.
Mechanism of Injuries: Explosives • Explosives have three mechanisms of injury: • Ballistic • Blast • Thermal
Mechanism of Injury • Ballistic: • Injuries caused by fragments created by explosives • Typically cause multiple wounds • Blast • This occurs more closely to the explosion compared to ballistic injury • The ears are most often affected by the overpressure, followed by lungs and gastrointestinal organs. • The explosion creates a blast wind that can throw victims against solid objects, causing blunt trauma. • Thermal • The result of combustion, may cause burns
Antipersonnel Landmines • Tree types of antipersonnel landmines • Static • Bounding • Horizontal spray
Antipersonnel Landmines • Static: small landmines that detonate when stepped on and result in 2 types of injury • Partial or complete traumatic amputation • More proximally, tissue and other debris is pushed up along fascial planes, stripping tissue from bone
Antipersonnel Landmines • Bounding: a mine that is propelled to 1-2m in height and then explodes, causing multiple small fragment wounds. This type of mine is associated with the highest mortality. • Horizontal spray mines: propel fragments in one direction, causing multiple small fragment wounds
Small Arms • In the past, differentiation made between HI and LOW velocity weapons but now felt not to be totally different entities. • Change to higher velocity weapons a result of change to smaller and lighter automatic weapons • Automatic weapons more effective Most combat actions < 200 meters Most infantry not great marksman • Smaller, lighter ammo developed Less recoil, better aim Each soldier can can carry more rounds
Small Arms (cont) • To maintain wounding power, higher bullet velocities were necessary • Higher velocities developed to increase FIREPOWER, not wounding power (same) • Always potential for higher energy transfer with higher velocity, but this is not always the case • Surgeon should always be concerned with the individual wound, rather than the “worst case scenario”
Fragmentation/ Expansion • Some missiles are designed to fragment or expand Dum-dums, Hollow-points, Non-jacketed, Some fragments despite copper jacket (M-16) • Fragments cause multiple tracts of permanent and temporary cavities • Expansion makes the permanent cavity wider
Yaw • Yaw is the deviation in the longitudinal axis of the bullet from its line of flight (tumbling) • Yaw is usually 180 degrees and can be caused by striking foliage or tissue • It increases the area of permanent and temporary cavitation • Important in the injuries caused by AK-47, AK-74
Shotgun Injuries Shotgun shells have a big powder charge with a large mass of lead balls • Destructive potential depends on range • At close range, it can cause a large wound with severe disruption of anatomy by direct crush alone • Long range (>25m) cause usually only skin wounds • Wadding is a projectile too