1. Asphyxia II
Dr. Asmaa Fady
Ph D., MSC, M.B, B.Ch

2. Learning objectives: By the end of the lecture, the student should
Types of violent asphyxia deaths.
hanging (mechanism of infliction, postmortem appearance and medico-legal importance).
strangulation (mechanism of infliction, postmortem appearance and medico-legal importance).
throttling (mechanism of infliction, postmortem appearance and medico-legal importance).
Smothering & chocking(mechanism of infliction, postmortem appearance and medico-legal importance).
Diagnosis of traumatic asphyxia.
اسم ورقم المقرر – Course Name and No.
6/7/2019

3. Violent asphyxia deaths
Neck violence
Hanging
strangulation
throttling
drowning
suffocation
smothering
chocking
Traumatic asphyxia

4. 1) Hanging (suspension of body)
Asphyxial death caused by body suspension by a ligature around neck, the force applied to the neck is derived from the gravitational weight of the body or part of the body.
Types
Supported or not
complete
partial
Site (thyroid cartilage)
typical
atypical
ligature
loop
Running noose

5. Types (medicolegal terms)
Complete
Feet do not touch the ground. Constricting force: weight of whole body
Partial:
Feet or knees are touching the ground. Constriction force: weight of the upper part of the body only.
Typical
Ligature position: in midline, above thyroid cartilage
Runs symmetrically upwards on both sides of the neck to the occipital region
Atypical:
Any other position of the ligature
N.B. Ligature: Material sufficient for bear body weight as rope, belt, wire, clothes …. etc.
Form of ligature:
Loop: the ligature is knotted "fixed knot"
Running noose: one end of the ligature pass through the loop "slip knot"
اسم ورقم المقرر – Course Name and No.
6/7/2019

6. Hanging (complete vs partial)

7. Hanging (loop vs slip kont)

8. Mechanism of death in hanging
1) Cerebral anoxia (anemia): The constricting force exerted on the neck by the body weight leads to stretching of the neck structures including the carotid arteries leading to their occlusion 2)Cerebral congestion or apoplexy: Due to occlusion of neck veins The external jugular system is most affected, but any significant pressure on the neck will also occlude the internal jugular system leads to rapid rise in venous pressure in the head. This factor is responsible for appearance of the classic signs of congestion, cyanosis, edema & Petechial hemorrhage.

9. Mechanism of death in hanging
3) Asphyxia: May result either from: *Direct compression of larynx or trachea *Lifting of larynx so that the root of the tongue closes it. 4) Reflex vagal inhibition (Cardiac arrest): *Pressure on the baroreceptors (in Cortaid sinus and carotid body) *Death occur suddenly with no classic signs of asphyxia 5) Injury to spinal cord: Especially in judicial hanging: fracture and or dislocation of 3rd , 4th cervical vertebrae. 6) Combination of any of above causes
اسم ورقم المقرر – Course Name and No.
6/7/2019

10. Postmortem appearance: External examination (general signs)
Neck: stretched, head is inclined to opposite sit of knot. Face: -Color: *Pale: both arteries & veins are closed **Congested & swollen: incomplete carotid arteries obstruction -Eye balls: prominent -Tongue: Swollen, may protrude Exposed part may become dark brown or even black due to dryness -Saliva: In some cases seen dribbling from the corner of mouth opposite to the side of knot due to pressure on salivary glands. It is a vital sign & indicates that the victim was alive when suspension took place

11. Postmortem appearance: (ligature mark)
pressure mark on the neck at site of ligature, appears as depression (pale yellow then brown).
Characters:
-Dry, hard & parchment like
-In the bed of depression: abrasions & contusions
- Fibers from ligature may be found adhering to the skin.
Site: (typical)
-Over upper part of neck above level of thyroid cartilage
Direction:
-Obliquely upwards along line of mandible & reaches mastoid process behind the ears.
Color:
-pale later may be yellowish brown.
اسم ورقم المقرر – Course Name and No.
6/7/2019

12. Postmortem appearance: external examination (general signs)

13. Postmortem appearance: external examination (general signs)

14. Postmortem appearance: external examination (general signs)

15. Postmortem appearance: external examination (local signs): (ligature mark)
Definition
Shape (upper & lower edge)
Color
Situation
Direction
Complete or not
(noose)

16. Postmortem appearance: external examination (local signs): (ligature mark)

17. MLI of hanging Death due to hanging or not???
Suicide, homicide or accidental (manner of death)???

18. Homicidal hanging

19. Medicolegal questions
1- Was death due to hanging or not?
Absence of fatal injuries, poisoning
Marks of dribbled saliva
Congestion & hemorrhage in lymph nodes above and below the ligature mark
Tear of intimae of carotid arteries with extravasations of blood within their wall
2- Suicide, homicide or Accidental?
A- Suicide: Is suspected when:
History of failure, depression or psychic troubles
Suicidal note
Calm place with no signs of struggle
Signs of previous suicidal attempt as cutting wrist
B- Homicide: Is suspected when:
History of threatening or quarrel
No signs of struggle
The mouth is gagged
The knots is tied on the back of the neck
May be evidence of taking drinks or drugs
C- Accidental: rare in case of
Children playing while imitating judicial hanging
In toddlers slipping from restraining straps
Sexual (masochistic) asphyxia.
اسم ورقم المقرر – Course Name and No.
6/7/2019

20. Ligature Strangulation
form of violent asphyxia caused by neck constriction by a ligature "no suspension, body weight play no role. constricting force is exerted by the assailant
Mechanism of death:
Asphyxia
Cerebral anemia
Cerebral congestion
Vagal inhibition
combination

21. Postmortem appearance in strangulation
External appearance:
Signs of resistance and struggle may be found allover of the body.
The same facial findings as in hanging
Neck sign (Ligature mark):
A pressure mark on the neck at site of ligature, appears as depression
Characters:
-Dry, hard parchment like
-Along edges: hyperemia & echymoses
-In the bed of depression: abrasions & contusions
-Minute fibers or any other material from ligature may be found on neck
Site:
Around neck as a depression usually at level of thyroid cartilage or below (low down)
Direction: usually symmetrical, complete & transverse.
Color: pale later may be yellowish brown.
On dissection: fracture laryngeal cartilages.
اسم ورقم المقرر – Course Name and No.
6/7/2019

22. Postmortem appearance (external examination) general signs : face

23. Postmortem appearance (external examination) general signs : face

24. Postmortem appearance: (external examination): local signs- ligature mark
Definition
Shape (upper & lower edge)
Color
Situation
Direction
Complete or not

25. MLI of Strangulation Death due to strangulation or not???
Suicide, homicide or accidental???

26. Medicolegal Questions
Was death due to ligature strangulation or not?:
Exclude the possibility of other causes of death.
Signs of ante-mortem neck violence during internal examination
(What are the expected signs??)
Suicide, homicide or accidental:
Suicide: rare
Accidental:
Newborn: umbilical cord twisted around neck
Children: playing with ropes
Adults: necktie or scarf caught in moving machinery.
Homicidal: common, suspicion arises if:-
Presence of signs of struggle
Knot is tied on back of neck
Mouth is gagged
Signs of struggle
Female victim with signs of sexual assault
اسم ورقم المقرر – Course Name and No.
6/7/2019

27. Throttling :(manual strangulation) constriction of neck by hand

28. Pm appearance (throttling)
A form of violent asphyxia caused by constriction of the neck by hands
PM picture
External appearance
as in ligature strangulation
Neck signs:
-Nail abrasions (Semilunar or triangular) & bruises (discoid) in the front and sides of the neck mainly around, above the larynx
If one hand is used:
A single bruise on one side (thumb) and multiple bruises on the other side (fingers)
If both hands are used:
Multiple bruises on both sides of the neck, minimal injuries may be found in case of clothes intervening between the assailant hand and the victim neck.
Dissection: fracture laryngeal cartilages are common.

29. Pm appearance (external examination)

30. MLI of throttling
Death due to throttling or not???
Manner???

31. Medicolegal questions Whether death was due to throttling or not
Exclude the possibility of other causes of death
Signs of ante-mortem neck violence during internal examination
Suicidal, homicidal or accidental
Suicidal impossible
Accidental rare
Sudden neck compression leads to reflex Vagal inhibition
Homicidal
Common
May be in case of victims under the effects of drugs or drink
اسم ورقم المقرر – Course Name and No.
6/7/2019

32. Smothering (mechanical occlusion of air passages from outside)
General signs of asphyxia
Struggle in cases of homicidal smothering

33. Pm appearance (external examination) : local signs
Nail abrasions & bruises around nose & mouth
Bruises, may be contused wounds inside lips & cheeks
torn frenulum
Loose or broken teeth
Fracture nasal septum
Signs of trauma at other parts of the body.
These signs may be absent if smothering by pillow or in old debilitated cadavers or children

34. MLI of Smothering Manner ???
Commonly homicide in overpowered person "infant, young children, person under effect of certain drugs"
Accidental: as in alcoholics and overlaying
NB suicide impossible by hand

35. Chocking (mechanical occlusion of air passages from inside)
Mechanism of death:
Asphyxia
Reflex vagal inhibition
Pulmonary infection

36. MLI of Chocking (manner)
Accidental is the commonest manner: Commonly accidental because of:
Impaction of F.B. in air passages
In halation of some irritants
Epileptic fit with falling back ward of tongue

37. Café coronary
A bolus of food produces a complete obstruction of the larynx
It is so called, because it mimics a heart attack.
It occurs commonly when the gag reflex suppressed e.g. following intake of tranquilizers or alcohol.
Death is due to reflex cardiac arrest from stimulation of laryngeal nerve endings.

38. Traumatic asphyxia
Violent asphyxia Caused by trauma to chest or pressure on chest & abdomen  Prevention of respiratory movements
Homicidal as in burking
Accidental
Crush injury in road traffic accidents
Chest compression in crowds & Heavy objects falling on the chest

39. PM Appearance (characteristic features):
Signs of chest trauma (fractured ribs, hemothorax)
Deep cyanosis, petechial hemorrhage.
A demarcating ling

40. PM Appearance (characteristic features):

41. اسم ورقم المقرر – Course Name and No.
6/7/2019