Wounding/ injuries Flashcards
Wound definition
Damage to any part of the body due to the application of mechanical force
Classification
Abrasions – grazes or scratches
Contusions – bruises
Lacerations – cuts or tears
Incised wounds – cuts, slashes or stabs
Tangential or Brush Abrasions
Caused by lateral rubbing action.
Direction of force: tags of epidermis dragged to the terminal end.
Crushing Abrasions
Vertical force to the skin.
Epidermis is crushed.
Weapon may stamp its shape or surface pattern on the skin (Imprint abrasion)
Bruising under the dermis often is present.
Fingernail Abrasions
Child abuse cases, sexual assaults, and manual strangulation.
Upper arms are a frequent site for gripping and restraint.
Marks may be superimposed
Bruises
Caused by blunt force trauma.
Leakage of blood from ruptured blood vessels (veins, venules and small arteries) into the surrounding tissue.
Lies beneath the intact epidermis
May be seen in muscles or any internal organs.
Often associated with abrasions and lacerations
Movement of bruises
May appear away from the point of impact.
Extravasated blood tracks along natural/traumatic planes of least resistance influenced by gravity and body movements.
Blow on temple: Bruise on Cheek
Fractured jaw: Bruising on Neck
Fractured hip: Bruise on thigh
Forehead trauma: Black eye
Age and colour changes in bruises
Red (fresh) 0-1 day
Bluish brown: 1-3 days
Green: 4-5 days
Yellow: 7-10 days
Disappears: 14-15 days
Degradation of red blood cells in the blood
Patterns of bruising
Impact with hard, patterned object with ridges and grooves e.g. tyre mark, shoe mark, car bumper, gun muzzle
Finger pad bruises
Round, oval, larger than finger tips.
Due to gripping by fingertips in forceful restraint
Periorbital haematoma (black eye)
Blow in the orbit
Fractured skull
Suction bruises (love bites)
Small petechiae caused by oral suction on the skin
Common on neck and breast in sexual assault.
Tramline bruises
Due to rod shaped weapon or stick
Two parallel lines of bruising with an undamaged zone in the centre
Laceration
Full thickness tearing of the skin due to blunt trauma.
Typically seen over bony prominences where tissue is crushed against underlying bone
Laceration characteristics
Ragged edges (torn apart), bulging fat, crushed hair bulbs.
Associated bruising and abrasion of skin edges.
Presence of tissue strands across the wound.
Why does a laceration sometimes appear to be a incision?
Crushing impact of a blunt object on skin supported by bone
Determining laceration
A laceration can be distinguished by:
Bruising or crushed margins
Bridging (presence of tissue strands across wound including vessels and nerves)
Absence of a sharply linear injury in the underlying bone
Incised wounds
Injury caused by sharp objects.
Clean division of the full thickness of skin and tissue by sharp edged instruments
Characteristics of incised wounds
Clean cut
Everted edges
Linear or elliptical shape, often gapes
No tissue bridges
Anatomy of skin
Epidermis
Dermis
Subcutaneous tissue
Deep fascia
Muscle
Cuts and slashes
Length is greater than the depth.
Swiping motion rather than a stabbing motion.
Also commonly seen in cases of suicide on the wrists.
Typically they tend to be deepest at point of first insertion and lessen in depth along the length.
Self-inflicted cut wounds
Commonly seen on:
Wrists, neck, cubital fossa, chest, abdomen, groin
Suicidal cut throat:
Multiple superficial tentative cuts/hesitation marks
Deep cut starting from the left, across the midline, up towards the right ear
Cut slopes upwards and backwards
Stab wounds
Most common method of homicide.
Depth is greater than the length.
Knives are the weapons most frequently involved
More dangerous than slashed wounds as can penetrate deep into internal organs
Description of stab wounds
Damage to clothing
Stabs through folds, blood flow, drip pattern
Site in relation to anatomical landmark
Shape
Size: length & width with edges opposed
Direction
Depth and wound track
Damage to tissues along track
Effects: haemorrhage, haemothorax etc.
Cleavage lines
Langer`s lines.
Direction of collagen fibres
Different appearances even when the same blade is used.
Movement of the knife in the wound.
Can result in loss of evidence as to the size of the blade.
If knife is wiggled, the wound will be longer than if the blade inserted and removed in the same direction.
Knife is twisted-V shaped wound will result.
Injuries from scissors
Often seen in domestic disturbances.
Shape of the wound will differ based on whether the scissor was used open or closed.
Typically shaped like a Z
Defence wounds
Most obvious are those seen in knife attacks.
Fingers, wrists, and forearms
Medico-legal significance, as they indicate that the victim was conscious.
Head injury
Heaviest part of the body (3-6 kg)
Secured only by the tone of the neck muscles and ligaments.
Scalp is commonly damaged in trauma that causes injury to underlying skull and brain.
Facial injuries
Common injury
Usually not life threatening
Commonly associated with fatal cranial damage
Haemorrhage-aspiration asphyxia
Others:
Abrasions, bruises, ruptured frenulum
Periorbital haematoma (Black Eye)
Falls
Combination of injuries can occur
Multiple lacerations.
Multiple fractures (ribs, arms etc.)
Severe abdominal injuries:
Rupture of liver, lung, spleen, heart.
Intracranial injuries - Extradural (epidural) haemorrhage.
Bleeding between inner surface of skull and dura mater
Usually associated with fracture of the skull. (blow to the side of the head)
15% occurs in intact skull.
Rupture of Middle meningeal artery
Intracranial injuries - Subdural Haemorrhage
Blood between dura and arachnoid
Not usually associated with fracture
Violent shaking can cause SDH
Intracranial injuries - Subarachnoid Haemorrhage
More common than SDH
Bleeding between arachnoid and pia
Traumatic or spontaneous
Brain Injury
Cerebral contusion/bruising
Cerebral laceration
Skull Anatomy
Skull
Dura
Arachnoid
Pia mater
Brain
Mechanism of injury
Blast:
Pressure waves causes tissue disruption.
Tears blood vessels and disrupt alveolar tissue.
Traumatic diaphragm rupture.
Crush:
Body is compressed between an object and a hard surface.
Direct injury of chest wall and internal structures.
Laceration of solid organs and blow out of hollow organs.
Penetrating:
Low energy
High Energy
Injury to chest wall
Contusions or haematomas, rib/sternum fractures (Flail chest), fractures of clavicle and shoulder girdle
Rib fractures
Ribs 1-3 requires great force to fracture (direct violence from kicking, heavy punching or RTAs)
Ribs 4-9 are most commonly fractured
Ribs 9-12 less likely to be fractured
Transmit energy of trauma to internal organs.
If fractured, suspect liver and spleen injury.
Injuries to liver
Commonly injured from trauma to the:
8th-12th ribs on right side of the body
Upper central part of abdomen
Injuries to lungs
Contusions, lacerations, pneumothorax, haemothorax
Injuries to the heart
Pericardial temponade, myocardial contusion
Injury to the spleen
Injured from blunt trauma to lower left chest, flank or upper left abdomen
Associated intra-abdominal injuries common
Injury to the stomach and intestine
Commonly damaged due to penetrating trauma
Small and large intestine: can be by compression force
Injuries to the kidney and pancreas
Blunt or penetrating
Injuries to the pelvis
Serious skeletal injury
Potential injury to pelvic organs:
Ureter, Bladder, Urethra, Prostrate, Rectum, Anus
Mechanisms:
Compression in head on collision.
Lateral compression in side impacts.
Vertical shears in fall from heights.
Types of blast injuries
Primary
Secondary
Tertiary
Quaternary
Primary blast injury
Unique to high explosives
Due to impact of over-pressurisation wave with body surfaces
Most commonly involve air-filled organs and air-fluid interfaces
Types of injuries:
Blast lung
Tympanic Membrane rupture
Abdominal haemorrhage and perforation
Eye Globe rupture
Traumatic brain injury without physical signs of head injury
Secondary blast injury
Due to flying debris and bomb fragments
Penetrating ballistic or blunt injuries
Leading cause of death in military and civilian terrorist attacks
Tertiary blast injury
Due to persons being thrown into fixed objects by wind of explosions
Also due to structural collapse and fragmentation of building and vehicles
Structural collapse may cause extensive blunt trauma
Quaternary blast injury
Explosion related injuries or illnesses not due to primary, secondary, or tertiary injuries
Exacerbations of pre-existing conditions, such as asthma, COPD, CAD, HTN, DM, etc.
Burns (chemical and thermal)
Toxic inhalation
Radiation exposure
Asphyxiation (carbon monoxide and cyanide)
