ASPHYXIA
It is a condition that if oxygen supply to the
blood and tissues is reduced because of
interference with respiration,it is also called
Anoxia\Anoxaemia\Hypoxia.
Causes of asphyxia
 Obstruction to the air passages due to
hanging,strangulation or throttling.
 Causes of external respiratory orifices,as in
smothering.
 Occlusion of the air passages within as in
drowning or laryngeal spasm.
 Pressure on the chest,as in traumatic asphyxia
Inhalation of irrespirable gases like carbon
monoxide.
Spasm of the respiratory muscles,as in
strychnine poisoning.
Paralysis of the respiratory center,as by
narcotics and anesthetics.
Obstruction to the upper respiratory passage
in cases of angioneurotic oedema.
Features of asphyxia
Cyanosis,capillary dilatation,capillary
stasis,rise of capillary pressure.
Increased capillary permeability,Tardieu’s
spots and relaxation of sphincters.

Asphyxia

Reduction in o2 tension
Deficient oxygenation in lungs

Capillary dilatation
 Reduced pulmonary flow

Capillary stasis
 Diminished venous
return to heart

Capillary engorgement
Stasis of blood in organs
Mechanical asphyxial deaths or Violent
asphyxial deaths
Hanging
Strangulation
Suffocation
drowning
Hanging
Hanging is a form of asphyxial death which
is caused by the suspension of the body by
ligature which encircles the neck,the
constricting force being the weight of the
body.
Types
Complete hanging.
Partial hanging.
Typical hanging.
Atypical hanging.
Complete hanging
When feet do not touch the ground and the
weight of the body acts as a constricting
force.
Partial hanging
When the weight of the head and not the
whole body acts as a constricting force is
known as partial hanging.
Typical hanging
The ligature is situated in the midline above
the thyroid cartilage and runs symmetrically
upwards on both sides of the neck to the
occipital region.
Atypical hanging
Any variation of this standard position.
Ligature
Not particular,like ropes,chains,wire,leather
straps,belts,scarf,dhoti,sarees etc.
Its important to match the ligature with the
ligature mark and see if its strong enough to
bear the weight and jerk of the body.
Cut the ligature away from the knot.
Symptoms
So rapid that they are rarely observed.
Flashes of lights before the eyes,ringing in
the ears.
Unconsciousness and death.
The individual can do nothing to help
himself even if it were possible.
Respiration stops before the heart which
may continue for 10-15min.
Causes of death
Asphyxia
Ligature forces the tongue up and occludes
air,15kg tension occludes the trachea.
Cerebral congestion
Obstruction of jugular veins by compression
with 2kg wt tension.
Cerebral anoxia
Carotid artery occludes with 4-5kgs tension
and vertebral artery with 20kgs tension.
Reflex vagal inhibition.
Fracture dislocation of cervical spine t
the level of 2,3,and 4 vertebrae.
Combination of any of the above.
Postmortem appearance
External appearance.
Internal appearance.
External appearance
-Above the ligature.
-Beneath the ligature.
-Below the ligature.
Above the ligature mark
Tilt of the head.
Protrusion of tongue.
Dribbling of saliva.
Le Facia Sympathique.
Tardieu spots.
Congestion of the face.
Petecheal haemorrhages.
Middle ear haemorrhages.
Beneath the ligature
Fixed or running noose.
Position of the knot.
Course of the ligature.
Width and multiplicity.
Point of suspension.
Slipping of ligature.
Weight of the body.
Below the ligature
Postmortem lividity (Glove and Stocking)
Relaxation of sphincters.
Injury to legs.(partial hanging)
Internal appearance
Haemorrhages in the neck.
Dry,white and glistening.
Rupture of platysma and sternomastoid.
Transverse tear in the intima of carotid
artery.
Fracture of hyoid,cricoid and thyroid
cartilages.
Congestion of organs.
Petechial haemorrhages.
Diagnosis
Ligature mark around the neck.
Presence of abrasions,echymosis and
redness around the ligature mark.
Trickling saliva from the mouth.
Echymosis of larynx and trachea.
Rupture of intima of carotids.
Signs of asphyxia.
Medico-Legal Aspects
Was the death due to hanging?
Whether hanging was suicidal,homicidal or
accidental?
Typical oblique,non-continuous,high up
ligature mark.
Abrasions and echymosis above and below
the ligature mark.
Extravasation-tear of the intima of the
carotids.
Saliva and signs of asphyxia.
Suicidal
Usually full suspension.
Ligature tied to beam,hook,fan,tree etc.
Suspension without any platform is unusual
in suicide.
Occasional nail mark-may be self inflicted
while trying to free him\herself.
Suicidal note.
Homicidal
Extremely rare,except in case of lynching.
Difficult,unless the victim is unconscious by
injury or by drugs.
Marks of violence may be seen on the body.
Postmortem hanging\Suspension
Person murdered and the dead body
suspended to simulate suicide.
Usually the rope is tied first to the neck and
then around the beam\hook where beam
shows evidence of rope being pulled from
below upwards.
Ligature mark may be produced if the body
is suspended within 2hrs after death.
Judicial hanging
Drop of 5-7meters.
Fracture dislocation at cervical 2-3 or 3-4.
Transection of spinal cord.
Tear of intima of carotid artery.
Injury to pons and medulla
Strangulation
It’s a form of asphyxial death caused by the
constriction of neck by ligature or by any
means without suspending the body.

By ligature.

Manual strangulation
Or

Throttling.
Causes of death





Asphyxia
Anoxia
Congestion
Vagal inhibition
Combination of any of the above
Autopsy finding
Externally-usually those of asphyxia.
Ligature mark
Well defined,slightly depressed at any level
on the neck-usually at the level of thyroid
cartilage or below.
Encircles the neck transversely-more
prominently at the front than the sides.
It may be interrupted by clothing or victims
finger or ornaments.
May be oblique if the victim is sitting and
assailant is standing.
Fold marks on neck
Seen in infants and children with short
neck.
Tight collar may produce a mark similar.
Examination of ligature-for blood,fragments
of epidermis,hair or other substances.
Sign of struggle.
Internal
Laceration of muscles.
Hyoid bone fracture usually not seen.
Fracture thyroid is more common.
Fracture of cricoid is rare,but if pressure is
used may be seen.
Organs are congested.
Medico-Legal aspects
Suicide
Its rare but possible.cord may be used and
twisted with a stick.
Congestion is very prominent because of
slow obstruction.
Homicide
Common form of murder-associated with
sexual offences.
Infanticide-by strangulation with umbilical
cord.
Evidence of struggle,surprise attack,under
intoxication,weak personality.
Common methods of Homicidal strangulation
Throttling
Compression of neck by hands.
Bruises produced by tips of fingers.
More force is used than is necessary.
Marks of thumb on one side and fingers on other
side.
Pressure of nails produce cresentic marks with or
without incision,concavities follow anatomical
shape of the nail margin and nails with straight
border give unpredictable results.
Hyoid bone fracture and bruising can be seen with
careful neck dissection.
Bansdola
Practiced in north India.
Bamboo or sticks are used.
Garrotting
Victim is attacked from behind without
warning,ligature thrown round the neck and
tightened.
Mugging
Strangulation by holding the neck in the bend of the
elbow/knee.
Accidental strangulation
Children may get entangled during play.
Infants are strangled in their cots,when the
neck is caught in sidebars.
Alcoholics,epileptics and insane persons are
susceptible for accidental strangulation.
Suffocation
It’s a form of asphyxia caused by mechanical
obstruction to air passage due to causes other than
constriction of the neck.
Smothering
It’s a form of asphyxia caused by closure of
external respiratory passage either by hand or
other means,or introduction of foreign materials
like cloth or paper etc.
Medico-Legal importance
Suicide
Not possible by hands.
Possible by means of tying polythene bag over
the head/burring the face in mattress.
Creating suffocation in the closed and nonventilated rooms.
Homicidal
Possible when victim is incapacitated by
drugs/alcohol,can be smothered.
Accidental
Infants/children by weight of clothes etc.
While playing with plastic bags.
In adults-plastic bags for auto erotic exercise as
partial anoxia enhances sexual sensation.
Mothers-during breast feeding.
Postmortem findings.
Asphyxial signs.
Abrasions & bruises around the lips and cheeks.
Injuries on inner side of lips.
Gagging
It results from closure of mouth by a cloth
or similar material causing obstruction to
the larynx or force the base of the tongue
against the fauces.
Overlying
Compression of chest to prevent breathing.
Mother infants.
Forceful pressure over the chest.
Burking
Method of homicidal smothering.
Practiced by “Burk” and “Hare”
Chocking
Caused by obstruction within air passage.
Usually accidental.
From diseases-Diphtheria,laryngeal
spasm,infection etc.
Hyoid bone fracture
Inward fracture.
Antero-posterior fracture.
Avulsion fracture.
Inward fracture
Seen in throttling-main force is an inward
compression on the hyoid bone.
Fingers squeeze the greater horns towards
each other,due to which the bone may be
fractured and post fragments displaced
inwards.
Antero-posterior compression fracture
In case of hanging,the hyoid bone is forced
directly backwards due to which,the
divergence of greater horns is increased
which may fracture with outward
displacement of the posterior small
fragments.
Ligature strangulation,run over accidents.
Avulsion fracture
Very rare and is due to over activity of neck
muscles without direct action or injury to
hyoid bone.
IncidenceHanging 15-20% above 40yrs age.
Very common in throttling.
Diagnosis of throttling
Cutaneous bruising and abrasions.
Extensive bruising with/without rupture of
neck muscles.
Engorgement at/above the constriction.
Fracture of larynx,thyroid cartilage and
hyoid bone.
Cricoid I almost exclusively fractured in
case of throttling.
Asphyxial signs.
Chocking
Obstruction within the air passages.
Accidental inhalation of food when the victim is
laughing or crying.
Vomited material may be inhaled by a person
under the influence of drink or anesthetic drug.
Large food bolus,piece of meet seeds or
fish,teeth(loose),marbles in children.
From diseases-diphtheria,laryngeal
edema,bronchial growths.Hemorrhages.
Causes of death
Asphyxia,vagal inhibition,laryngeal
spasm,infection.
Café coronary
Impaction of food in the sensitive larynx causes
sudden death due to cardiac arrest.
Healthy intoxicated person in hotel while eating
suddenly turns blue,coughs violently-collapses and
dies.
At autopsy a large food bolus seen in the
respiratory tract-larynx obstructing air passage.
Signs of chocking are absent because of high
blood alcohol which inhibits the gag reflex.
Post-mortem appearance-the foreign body is
embedded in a thick mucus in the trachea.
Traumatic asphyxia
Its due to respiratory arrest due to mechanical
fixation of chest so that the respiratory
movements are prevented.
E.g.:Stampede in a theatre or in places where
crowded gatherings are there.Fall of earth-coal
mines,tunneling accidents etc.
Post-mortem appearances
An intense deep purple red colour of the
head,neck and upper part of chest above the level
of constriction.
Sexual asphyxias
Partial asphyxia causes cerebral disturbances with
feeling of sexual gratification.
Pressure on carotids/trachea leads to
hallucinations of an erotic nature.
Associated with masochism and transvestitism.
Usually can be seen in young males.
Place-victims own house-bed/bath room.
Padding of neck.
Ligature,a running noose,the free end of
which is tied to limb,weight of the body is
used to control the ligature.
Naked,pornographic literature etc.
Its due to retrograde displacement of blood
from superior venacava into subclavian
veins of the head and neck due to sudden
compression of the chest blood does not
enter the upper limbs due to the valves.
Blood goes into the valve less veins of the
head & neck causing stasis and
engorgement of the vessels and rupture of
the distal venules and capillaries causing
petecheal hemorrhages.
If patient survives-purple colour gradually
disappears within 14-15 days.
Drowning
Drowning is a form of asphyxial death due
to aspiration of fluid into the air passages
by submersion of the body in water or fluid
medium.
Complete submersion not
necessary,submersion of nose and mouth is
enough.
Classification
Typical
Atypical
Typical drowning
Obstruction of air passages and lungs by
inhalation of fluid and is known as “Wet
drowning”.
Typical signs are found at autopsy.
Atypical drowning
Conditions in which there is very little or no
inhalation of water or fluid in the air
passages.
Dry drowning.
Immersion syndrome(vagal inhibition).
Submersion of the unconscious.
Secondary drowning syndrome/neardrowning.
Typical drowning
 Fresh water drowning.
 Salt water drowning.
Fresh water drowning
 Water cross the alveolar membrane into the circulation.
 Produces marked hypervolaemia.
 Red cells swell or burst-hemolysis-liberation of
potassium.
 Circulation will suffer 50% dilution within 2-3 min.
The heart is submitted to the insult of
anoxia,hypervolaemia,potassium excess and
sodium deficit.
Ventricular fibrillation due to anoxia and
potassium excess within 4-5 min.
Salt water drowning
Marked hypertonicity of the inhaled water cause
loss of fluid from circulation into the lungsfulminating pulmonary edema and progressive
hypovolaemia.
Circulatory shock and cardiac arrest.
Atypical drowning
Dry drowning
Intense laryngeal spasm due to entry of water
into nasopharynx and larynx.
Very little water enters into lungs.
Best case for resuscitation.
Immersion syndrome
Due to sudden impact with very cold water and
causes death from cardiac arrest.
Victims are young people with excess of alcohol.
It also result from falling or diving with feet or
duck diving by the inexperienced swimmers.
Loss of consciousness instantaneous and death
occurs in few minutes.
Autopsy disclose non of the usual signs of
drowning.
Submersion of the unconscious
Commonly seen if the victim is suffering from
disease like epilepsy,heart diseases and is drunk
or head injury during fall.
Ballooning of the lungs may be absent.
Formation of the foam my be negligible.
Complete picture of death by drowning is not
found.
Secondary drowning/near-drowning
Its mainly due to infection from inhalation of
contaminated water.
Lung complications,oxygen lack,tired heart
muscle and cerebral edema.
A victim look alert and breathing,may respond to
initial resuscitation.
Late stage-respiratory distress,hypotension and
cardiac arrhythmia may cause death.
Vicious cycle of drowning

Deep inspiration
Need for air

Water enters resp.passage
Air driven out of lungs
Cough reflex
Medico legal aspects
Whether the death was due to drowning or other
cause?
Length of time the body was in water.
Whether it was accidental/suicidal/homicide?
“Brides of the bath case”
Postmortem findings
External findings
Fine froth at the nose and mouth.its white or
rarely blood stained,leather-like,abundant and
increases in amount with compression of the
chest.
Rarely the presence of weeds,mud etc in the
tightly clinched hand.
Cutis anserina(Goose skin)
Due to spasm of the erector pilae muscles and due
to exposure to cold water at the time of death.
Rarely seen in India.
Skin appears granular and puckered,with hair
standing on the end.
Extremities are mainly affected.
The skin of the finger,palms and later the soles
of the feet may be wrinkled,bleached and
sodden.
Due to osmotic action of water,on thickened
epidermis.
This immersion changes known as Hands and
Feet of a Washer-Woman.
Internal findings
Lungs & respiratory tract:Airways filled with froth,sand,weeds etc found in
the water.
Lungs are voluminous,edematous,doughy to feel
with rib markings.
Paltauf’ hemorrhages seen.
C/s:- Oozing out of blood stained frothy fluid and
ballooning of the lungs is known as
“Emphysema Aquosum”.
Wt upto 2 kgs.
Watery fluid transudates into pleural cavities
during putrefaction.
Hydrostatic lung:- 2meters depth-20min.
Hemorrhages in the middle ear & mastoid air
cells.
Water in the stomach & intestine.
Biochemical changes
“Getlers test”
Chloride content in chambers of the heart
normally 600mg/100ml.
Chloride decreases by 50% in fresh water &
increases of 40% in salt water.
Test is of doubtful value in
-Septal defects
-Putrefaction
-Death due to vagal inhibition
-Chloride in water
Diatoms
Microscopic unicellular algae present in water.
Silicaceous cell wall which resists acid
digestion,heat and putrefaction.
Size 10-80 microns.
Only a live body with a circulation can transport
diatoms from lungs to the brain or bone marrow.
Isolation- acid digestion of tissue commonly bone
marrow,lung,blood and kidney-centrifugation and
washing.residue is examined under phase contrast
microscopy.
Cause of death
Asphyxia
Ventricular fibrillation
Laryngeal spasm.
Vagal inhibition.
Exhaustion.
Injuries.
Fatal period 4-8min.
Diagnosis of drowning
Froth
Weeds & gravel/soil in hand.
Voluminous lungs.
Diatoms in tissues.