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

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

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

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

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

Hanging (complete vs partial)

Hanging (loop vs slip kont)

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.

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

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

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

Postmortem appearance: external examination (general signs)

Postmortem appearance: external examination (general signs)

Postmortem appearance: external examination (general signs)

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

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

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

Homicidal hanging

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

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

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

Postmortem appearance (external examination) general signs : face

Postmortem appearance (external examination) general signs : face

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

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

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

Throttling :(manual strangulation) constriction of neck by hand

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.

Pm appearance (external examination)

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

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

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

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

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

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

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

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.

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

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

PM Appearance (characteristic features):

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