Forensic aspects of trauma Flashcards
What are some significant factors in the mechanism of injury?
Force applied
Area over which force acts
What are some possible results of excessive mechanical force?
Compression
Traction
Torsion
Tangential (shearing)
What are the main factors determining damage?
Type of mechanical force
Nature of target tissue
Which factors are used to classify injury?
Appearance (abrasion, contusion, laceration etc.)
Manner of causation (suicidal, accidental, homicidal etc.)
Nature of injury (blunt/sharp force. explosive)
What kind of injuries can result from blunt force?
Contusion
Abrasion
Laceration
What is a contusion?
Blood vessels in skin injured
Bruising
What are tramline bruises?
Imprinted parallel lines of bruising
Impact with long rod like a broom handle
Stretching at the sides of where the rod impacts
Leaves contusion/tearing at sides and line of pallor in middle
What is finger tip bruising?
Small, round, red bruises
Typical of finger tip marks left from gripping
What are some factors affecting bruising prominence?
Skin pigmentation
Depth and location
Age
Coagulative disorders
Where does bruising more readily occur?
Over loose skin
High fat areas
Where do bruises less readily develop?
More easily stretched and compresses
Force more easily spread
Buttocks
Abdomen
What can skin tags in abrasion tell us?
May indicate direction of the force of impact
What might close, linear, parallel scratch abrasions indicate?
Serrated blade
What might we think of with larger semi-circle made of small round abrasions?
Bite
What are some signs we look for in strangling?
Broad areas of abrasions
Small linear abrasions which may correspond to finger nails
What is a laceration?
Splitting of skin due to blunt force trauma
Where are lacerations usually found?
Where skin overlies bone
What are some typical features of laceration?
Rough edges
Tissue bridges
Stellate branching
What are the 2 main types of sharp force injury?
Incised
Stab wound
What is an incised wound?
Longer on skin surface than it is deep
Slash
What is a stab wound?
Deeper than length of surface cut
What are some things to look for in stab wound?
Is it squared off at one end of cut or both ends sharp?
Shape of wound
What does a lighting bolt stab wound indicate?
Scissors
What might indicate movement of the blade within the wound?
Additional cuts/notches coming off
Don’t know what was actually moving tho
How do we identify self inflicted injuries?
Usually sharp force
Wrists/forearms, chest/abdomen
Parallel, multiple tentative incisions
Position of clothing
What are the main factors in consequences of an injury?
Type of mechanical insult
Type of target tissue
Forces involved
Number of impacts
What are the main kind of head injury fractures?
Linear
Depressed
Base of skull e.g. ring around foramen magnum
What kind if haemorrhage may result from rapid rotational movement like for a punch?
Traumatic subarachnoid haemorrhage
Describe the pathophysiology of traumatic subarachnoid haemorrhage.
Trauma ruptures vessels at base of brain where they cross the dura
Usually distal intracranial vertebral arteries
Immediately unconscious with cardiac arrest
How does diffuse axonal injury present?
Immediate and prolonged coma with no apparent mass lesion or metabolic abnormality
How do blunt force injuries usually affect the lungs?
Contusions
Lacerations
How do sharp force injuries usually affect the lungs?
Penetration
Haemorrhage
Collapse
How do sharp force injuries usually affect the heart?
Penetration
Tamponade
Haemothorax
How do blunt force injuries usually affect the heart?
Bruising
Laceration
Commotion cordis
How do blunt force injuries usually affect the abdomen?
Bowel tears
Mesenteric haemorrhage/laceration
Liver and spleen lacerations
What kind of injuries may be expected for resuscitation?
Bruising neck and chest Gingers marks Bruising/lacerations of lips gums, lungs Teeth damage Sternal and rub fractures Venepuncture and cannulation Pleural cavity haemorrhage Heart rupture
