Projectile / Stab

Question 1

What is the Equation of Kenetic energy of a projectile?

Answer 1

• KE = ½ x MASS x VELOCITY x VELOCITY

Question 2

What influence does the size and shape of a projectile have?

Answer 2

• How the object behaves in contact with tissue and in turn how much kinetic energy is given up.

Question 3

What factor of tissue can influence the amount of energy it can absorb?

Answer 3

• How elastic the tissue is.

Question 4

What else may influence the amount of energy absorbed?

Answer 4

• Ballistic protection/body armour

Question 5

What are the two types of gunshot wound GSW?

Answer 5

• Penetrating
  o Where the bullet penetrates and becomes lodged in the body
• Perforating
  o Where the bullet penetrates all the way through the body and exits out at some point

Question 6

What type of wound will be seen in a Handgun?

Answer 6

• Small entry wound

- Lethal range – 200m

Question 7

What type of wound will be seen in a shotgun?

Answer 7

• Multiple entry wounds

- Leathal range 50-100m

Question 8

What type of wound will be seen in a Rifle?

Answer 8

• Small entry wound with either large cavernous exit wound or multiple exit wounds from fragmentation
• Lethal range 1-4km

Question 9

What types of bullets are in use for Rifles/Handguns?

Answer 9

• Full metal jacket – metal casing around a soft core
• Soft point – bullet has exposed tip and rapidly expands
• Hollow point – expanding bullet that can break up within the body

Question 10

What types of shotgun shells are there?

Answer 10

• Birdshot – small pellets
• Buckshot
• Slugs

Question 11

What type of shotgun gauges are there?

Answer 11

• Gauge refers to the diameter of the barrel
• 12 gauge has a diameter of 18.5 mm
• 20 gauge has a diameter of 15.6 mm

Question 12

What is the energy within a projectile dependent upon?

Answer 12

• Velocity
• Weight
• Distance
• Deformation
• Fragmentation
• Type of tissue struck

Question 13

What feet/sec is considered low velocity?

Answer 13

• <2000 feet/sec (600m/s)

Question 14

What feet/sec is considered high velocity?

Answer 14

• > 2000 feet/sec

Question 15

What pathology considerations need to be made in regards to ballistics?

Answer 15

• Can injure hard and soft tissue
• One projectile can cause multi-system trauma
• Be aware of entry and exit wounds, but remember that projectile doesn’t always have to travel in a straight line.
• Foreign material in the wound
• Thermal injuries

Question 16

What are severities of ballistic injuries dependent on?

Answer 16

• Penetration
• Cavitation
• Fragmentation

Question 17

What is entrance wound contact range?

Answer 17

• Is seen when a gun is held up against the skin surface
• Results in searing edges of wound, secondary to flame/hot gasses emanating from the gun
• Will be a hard contact wound
• Gas may enter into the tissue

Question 18

What will entrance wound of intermediate range present as?

Answer 18

• Tattooing on skin
  o Fragments of burning and non-burned gun powder penetrating the skin
• Stippling
  o Fragments abrade the skin but do not penetrate

Question 19

What will an entrance wound look like with intermediate range?

Answer 19

• NO gunpowder burns only bullet wound site.

Question 20

List some knowledge about exit wounds.

Answer 20

• Size does not usually correlate with calibre used
  o Speed is the most important factor
• Irregular wound would suggest – small highly deformed bullet at high speed
• Large, formed bullet would create a regular wound

Question 21

What is the primary damaged caused in GSW?

Answer 21

• Crushing and laceration of the tissue as the bullet impacts and pushes its way through.
• Orangs may become perforated
• Permanent cavity or tunnel is created

Question 22

What is secondary damaged caused in GSW?

Answer 22

• Temporary cavities created due to the shockwaves that exerted outwards from the bullet trajectory.
• Causes a radical stretch injury
• Creates a vacuum that sucks in hot gases and debris causing internal burns and sepsis.
• The cavity can be 40x > diameter than the bullet depending on velocity
• Shockwaves can be as much as 200mmhg.

Question 23

What occurs in tertiary damage in a GSW?

Answer 23

• Multiple fragments created by impacting and shattering bone

Question 24

What does the THREAT acronym stand for?

Answer 24

• T – Threat suppression
• H – Haemorrhage control
• R – Rapid extrication to safety
• A – Assessment by medical providers
• T – Transport to definitive care

Question 25

What Hx taking should be taken at shootings?

Answer 25

• How many gun shots?
• How many times do you think you were shot?
• What position were you shot in?
• How far were you from the barrel end?
• Type of bullet
• Calibre/gauge of bullet/shell
• Last tetanus?

Question 26

What should be the focus on a stab wound when undertaking assessments?

Answer 26

• Situation
• Size
• Appearance
• Orientation
• Direction of infliction
• VSS