L8: Violent Asphyxia Flashcards
Def of Asphyxia
- Any condition that interferes with the air flow in respiratory passage and exchange of gases in lungs, leading to hypoxia, hypercapnia and respiratory acidosis.
Causes of Asphyxia
- Pathological
- Poisonous
- Environmental
- Violent
Pathological causes of Asphyxia
- As diphtheria, edema of epiglottis and tumor in air passage.
Poisonous Causes of Asphyxia
Environmental causes of Asphyxia
- Breathing in vitiated atmosphere, As in high altitude, climbing, flying, inhalation of CO or pure helium.
Def of Violent asphyxia
- It means mechanical interference with respiratory function of body resulting in depriving the vital organs from 02 supply necessary for their survival
Examples of violent asphyxia
- Drowning.
- Strangulation.
- Suffocation.
- Hanging.
- Throttling.
- Sexual Asphyxia
Def of Sexual Asphyxia
- It means abnormal sexual behavior to feel pleasure through induction of hypoxia which may result in accidental asphyxia.
External post-mortem signs of asphyxia
- Swollen Face
- Prominent Eye
- Bluish Discoloration
- Bloody Froth
- Protruded Tongue
- Dark Blue Hypostasis
Swollen Face
External post-mortem signs of asphyxia
- The face is swollen, bluish and marked with peticheal hemorrhages.
Prominent Eye
External post-mortem signs of asphyxia
- The eye balls appear prominent, Due to retro-orbital oedema and congestion.
- Conjunctivae are injected and show sub conjunctival hemorrhage (Tardieu spots) and pupils are dilated.
Bluish Discoloration
External post-mortem signs of asphyxia
The lips, ears, finger nails show deep bluish discoloration.
Bloody Froth
External post-mortem signs of asphyxia
- From nose and mouth, due to increased transudation and rupture of fragile anoxaemic capillaries in the air passage.
Protruded Tongue
External post-mortem signs of asphyxia
- The tongue is protruded, swollen and sometimes bruised and bitten.
Dark Blue Hypostasis
External post-mortem signs of asphyxia
Postmortem lividity is well developed and is dark blue in colour.
Def of Drowning asphyxia
Asphyxia caused by submersion of mouth and nostrils under water
- leading to obstruction of the air passages by water.
- It is the commonest cause of mechanical asphyxia.
Time needed for death in Drowning Asphyxia
Death takes 2-5 minutes to occur due to complete obstruction of the air passages
Cause of Death in Drowning
External PM Picture of drowning
Probable Signs:
- External signs of asphyxia
- Postmortem cooling
- Postmortem rigidity
- Putrefaction
- Hypostasis
- Adipocere formation
- Appearance “Floatation” of the body
- Glove & stocking skin
- Goose skin “Cutis Anserina”
- Postmortem wound
- Washer Woman Hand
Sure Signs:
- Froth
- Cadaveric Spasm
PM cooling in drowning
Rapid takes ½ the time which taken in air.
PM rigidity in Drowning
Early disappear, Due to muscle exhaustion.
Putrefaction in Drowning
Delayed but start immediately after extraction of body from water.
Hypostasis in Drowning
- Presents in upper ½ of the body
- “Most dependent part of body” “Head, neck & shoulder”.
Adipocere formation in Drowning
starts to appear if prolonged submersion under water.
Appearence “Flotation” of the body in Drowning
Occurs after 5-8 days in summer, double this period in winter.
what does Flotation of the body depend on?
- Rate of putrefaction.
- Specific gravity of body: fatty bodies float earlier.
- Nature of the water: it occurs earlier in salty water than in fresh water.
Characters of Glove & Stocking skin in Drowning
Occurs after 2 weeks
Etiology of Glove & Stocking skin in Drowning
Due to separation of epidermis from dermis in hands & feet.
Characters of Goose skin:
“Cutis Anserina” in Drowning
Granular & puckered skin with erection of hair
Etiology of Goose skin:
“Cutis Anserina” in Drowning
Due to spasm in erector pillae muscle
PM wounds in Drowning
It may be found, due to fishes or propellers of ships.
Characters of Washer woman hands in Drowning
Wrinkled, bleached & sodden skin of the hand
“Like washer woman’s hand”
what are sure signs of Drowning?
- Froth
- Cadaveric spasm
Etiology of wahser woman hand in Drowning
Due to loss of skin tone “after submersion under water for 12-18 hrs”.
Def of Hanging
It is suspension of body from neck by a ligature, in which the force is applied to the ligature through body weight.
Classification of Hanging
Signs of Homicidial Hanging
Very rare, except when
- murderer suspends victim after narcotizing him, or in P.M. suspension is done to simulate suicide.
Causes of death in Hanging
Signs of suicidal hanging
The commonest form in this case there are:
- Circumstantial evidence, (locked door from inside, suicide note, efc.)
- Absence of signs of resistance and struggle.
- Presence of other means of suicide (i.e. previous attempts).
Signs of Accidental Hanging
Rare and may occur in case of:
- Children playing with ropes.
- Falling men from scaffold and entangled in ropes.
External Postmortem picture of Death From Hanging
Def of Ligature Mark
- Pressure mark on neck at the site of ligature.
- Appears as a depression “Groove” which has same characteristic pattern of ropo.
Color of Ligature Mark
- Early; it appears pale.
- Late: it turns yellowish brown, dry, hard & parchment.
Site of Ligature Mark
- High up in neck above thyroid cartilage
Shape of Ligature Mark
- Area of hyperaemia, bruises & abrasions occasionally present”
- May be complete & horizontal or incomplete and oblique.
Def of Strangulation
- Constriction the neck by a ligature, which presses on the air passages from outside preventing the air from passing to lungs.
Classification of Strangulation
- Ligature strangulation
- Manual strangulation or Throttling
- Mugging
Ligature strangulation
When ligature material is used to compress neck.
Manual strangulation or Throttling
- When human fingers, palms or hands are used to compress the neck.
Causes of death in case of strangulation
Mugging
Strangulation caused by holding the neck of the victim in bend of elbow or knee of the assailant.
Homicidal Strangulation
almost the commonest.
Accidental Strangulation
It may occur in the following cases:
- During delivery, when umbilical cord turns around infant’s neck.
- Children playing with ropes.
Suicidal (self) strangulation
rare
Difference between hanging and strangulation
External Postmortem picture of Death From Strangulation
Def of Throttling (Manual Strangulation)
Constriction of neck by hands for two minutes or more.
Suicidal (self) Throttling
- Impossible because as soon as person loses consciousness, relaxation of his hands occurs with released neck grip.
Causes of Death in Throttling (Manual Strangulation)
Homicidal Throttling
- The commonest.
- It is accompanied with signs of resistance and struggle.
Accidental Throttling
Rare
External Postmortem picture of Death From throttling
What Medicolegal cases cause fracture of hyoid bone?
- Throttling
- Strangulation
- Hanging
- Trauma of the neck
Fracture of hyoid bone in Throttling
- Fracture of hyoid bone is (Commonest).
- It leads to inward fracture.
Difference between fracture of hyoid bone in throttling & Traumatic fracture
- Sometimes couses subluxation of joint botwoon cornu and body the bone, which is symmetrical with smooth surface and lined with a synovial membrane
- Traumatic fracture is asymmetric with irregular odgos and bruising around, occurs in subjects above 40 years old.
Fracture of hyoid bone in Strangulation
- Fracture of the hyoid bone is (Less common).
- leads to outward fracture.
Fracture of hyoid bone in hanging
- Fracture of the hyoid bone is outward fracture, due to stretch of the supra-hyoid muscles.
Def of Suffocation
- Form of asphyxia caused by mechanical obstruction to passage of air into the respiratory tract by means other than constriction of neck or drowning.
Types of Suffocation
- Smothering
- Overlying
- Burking.
- Choking and gagging
- Traumatic asphyxia
Def of Smothering
It is a manual obstruction of external respiratory orifices, i.e. mouth and nostrils.
Homicidal Smothering
almost the Commonest.
Suicidal (self) Smothering
Not recorded
Accidental Smothering
- It occurs in cases of fallen houses, when heaps of dust or sand occlude respiratory orifices.
- Among epileptics and drunkers,
- Children may die by smothering during playing with plastic bags.
- When an infant turns into a prone position and buries its face in a pillow.
External Postmortem picture of Death From Smothering
Def of Choking
- It is an inside occlusion of the air passages by foreign bodies.
Types of Choking
- Pathological
- Accidental
- Homicidal choking (Gagging)
Pathological Choking
- Diphtheria
- Angio-neurotic oedema of glottis.
Accidental Choking
Irritant fumes inhalation:
- leading to oedema of glottis and choking
Foreign body impaction:
- Vomitus or tooth, as in coma or anesthesia
- Or aspirated blood or gauze after operations as
tonsillectomy - Or coins; or solid particles of some food materials.
Homicidial Choking (Gagging)
It is rare and often occurs in infanticide by
packing infant’s pharynx with a piece of cotton.
Def of Overlying
- Occurs when sleeping mother overlays her suckling infant by rolling on it or by accidental resting her arm or her heavy lactating breast on its respiratory orifices
Def of Traumatic asphyxia
- Asphyxia resulting from respiratory arrest due to mechanical fixation of chest, So that normal movements of chest wall are prevented.
Causes of Traumatic asphyxia
- Due to house collapse, accidentally or in wars/earthquake.
- Stampede by crowd, running in panic,
e.g. outbreak of fire /public gathering. - Run over by a vehicle or overturned vehicle (especially tractors).
Causes of death in falling houses
- Vagal inhibition
- Concussion
- Vital organ injury
- Choking
- Traumatic asphyxia.
Def of Burking
It is a combination of
- Homicidal smothering
- Traumatic asphyxia.
