asphyxia from fme by dr yaseen mohammad for 3rd year mbbs students

بسم الله الرحمن الرحيمبسم الله الرحمن الرحيم

Asphyxia & asphyxial deaths bydryaseenm@ymail yaseen.muhammad50@facebook.com

definitionconditionsstages causesmechanismclassificationpm findings/ext/internal

Definition:

•Conditions in which the supply of oxygen to the blood and tissues has been reduced below the normal working level by any interference with respiration.

•Asphyxia is used as being equal to “lack of oxygen” or “hypoxia”,

Definition

Any condition that obstruct respiratory passages or

interferes with respiratory process resulting in a lowered O2 (hypoxia) and increased CO2 (Hypercapnia).

Mechanical Asphyxia

ASPHYXIA

• Interference with oxygenation – any where

from environment down to cellular level

Mechanical Asphyxia

CAUSE S OF ASPHYXIA:

Environmental

Obstruction of external respiratory passages

Obstruction of internal respiratory passages

Restriction of respiratory movements

Lung disease

Deficient oxygen transport

Mechanical AsphyxiaMECHANISMS Environmental

Low or no atmospheric oxygen e.g. ships holdsScuba diving, surgical anesthesia, disused

refrigerators

Suffocation Smothering Gagging Choking

Mechanical Asphyxia Throttling

Ligature Strangulation

Hanging

Traumatic asphyxia

Sexual asphyxia

Positional asphyxia

Mechanical Asphyxia

SUFFOCATIONObstruction of mouth and nose

Smothering / overlaying / plastic bags

TRAUMATICPressure fixation of chest wall & abdomen —

burying under debris / vehicle / crowd

pressure- stampede/ knee abdomen pressure /

scissor technique / prone position /overlaying /

anaconda large snakes

Mechanical AsphyxiaSTRANGULATION

Obstruction of air way at the level of larynx

by a ligature directly applied on the neck

HANGING

Compression of the neck structures by

means of ligature-the pressure applied

through suspension of body

Mechanical AsphyxiaMECHANISM OF DEATH

Oxygen deprivation

Carbon dioxide accumulation

Reduced blood flow to and from the brain

Vagal stimulation resulting in cardiac

inhibition

Complex

Mechanical Asphyxia

PATHOLOGICAL CHANGES

•General

▫Cyanosis

▫Congestion

▫Engorgement right side heart

▫Fluidity of blood

▫Petechial hemorrhages / Tardieus spots

Classify Mechanical Asphyxia;what are specific pathological changes in mech asph,give one point in favour for each typePATHOLOGICAL CHANGES

• Specific Evidence of asphyxiating mechanism

Bruising of lips / nose(smothering)

Finger nail marks on the neck (throttling)

Ligature mark on the neck (ligature strangulation)

Signs of trauma to chest ( traumatic asph.)

Specific – Injuries to the largynx (structures)

Mechanical Asphyxia

PATHOLOGICAL CHANGES

•Specific – Injuries to the larynx

▫Hyoid bone

▫Thyroid cartilages

▫Cricoid cartilage

▫Carotid artery

▫Vagus nerve

Mechanical AsphyxiaSexual / Autoerotic Asphyxia / Autoerotic

Deaths

Accidental hangings, failure of safety mechanisms

Male, trasvestism or nudity, masochism,

pornographic material

Scene is diagnostic.

Mechanical AsphyxiaPOSITIONAL ASPHYXIA

Bodily position which obstructs airway

or impairs act of breathing

Typically associated with sedative

intoxication

Usually accidental (alcoholics)

Mechanical Asphyxia

•Environmental asphyxia

▫Due to lack of oxygen in the

environment

Mechanical Asphyxia

SUFFOCATION

Obstruction of nose and mouth

Homicidal, soft smothering

"Overlaying"

Plastic bags, suicidal or accidental

Difficult diagnosis; history and scene.

Mechanical AsphyxiaCHOKING

Obstruction of upper airway or glottis

Gag, homicide, rarely suicide

Accidental in elderly, mental defectives, children

"Cafe Coronary"

Mechanical Asphyxia / ThrottlingTHROTTLING (Manual Strangulation)

Form of mechanical asphyxia where neck structures are compressed by hand / hands

Different grips, different patterns Finger pad bruises, crescent abrasions Neck muscle haemorrhages - thyroid

cartilage fractures Mugging, bansdola / sleeper hold Grip for half a minute.

Mechanical Asphyxia / Throttling General signs of asphyxia

Congestion of face / bleeding from mouth and nose

Evidence of asphyxiating mechanism

Multiple bruises on the neck / finger nail marks, bruises may

not be obvious if throttling affected through soft material

Bruising of neck muscles

Rupture of intima carotid artery

Fracture of thyroid cartilage one or both superior horns.

# Hyoid bone is rare because of lower position of grip

Mechanical Asphyxia / StrangulationSTRANGULATION Air way obstruction at larynx from pressure by a

ligature / garrotting

Horizontal groove, uniform depth, imprint abrasion, ligature groove may be multiple / knotted

Tied, held, removed – sexual assault

Mechanical Asphyxia / Strangulation Bruises, abrasions

Neck muscle haemorrhages, thyroid cartilage fractures

Suicide uncommon but possible – tourniquet / accident occasional – children playing / babies falling from cot / female pelion rider – dupatta / burqa entangling in the wheel / chain

Mechanical Asphyxia / StrangulationMECHANISM OF HYOID BONE FRACTURE

• Direct compression

• Indirect – pull on the thyro hyoid ligament

Asphyxia or asphyxiation •(from Greek α- "without" and sphyxis,

"heartbeat") is a condition of severely deficient supply of oxygen to the body that arises from being unable to breathe normally

•Asphyxia causes generalized hypoxia, which primarily affects the tissues and organs.

•There are many circumstances that can ;induce asphyxia

Asphyxia can cause coma or death the constriction or obstruction of airways,

such as from asthma, laryngospasm, Respiratory diseases

or simple blockage from the presence of foreign materials;

from being in environments where oxygen is not readily accessible: Exposure to extreme low pressure

such as underwater, in a low oxygen atmosphere, or in a vacuum;

environments where sufficiently oxygenated air is present, but cannot be adequately breathed because of air contamination such as excessive smoke..

Other causes of oxygen deficiency includeCarbon monoxide inhalation, such as from a

car exhaust: carbon monoxide has a higher affinity than

oxygen to the hemoglobin in the blood's red blood corpuscles, bonding with it tenaciously,

Contact with certain chemicals, including pulmonary agents (such as phosgene) and blood agents (such as hydrogen cyanide)

Drug overdose Sleep apnea

•Ondine's curse, •central alveolar hypoventilation syndrome •Acute respiratory distress syndrome.•Hanging•Drowning

Ondine's curse , also called congenital central

hypoventilation syndrome (CCHS) or primary alveolar hypoventilation, is a respiratory disorder that is fatal if untreated. Persons afflicted with Ondine's curse classically suffer from respiratory arrest during sleep.

CCHS is congenital or developed due to severe neurological

trauma to the brainstem

Stages of asphyxia1- Stage of dyspnea:. 2- Stage of convulsions:. 3-Stage of apnea (respiratory paralysis

The respiratory center (RC) is

located in the medulla oblongata, which is the lowermost

part of the brain stem

The groups of nerve cells in the brain which regulates the respiration rhythmically

are collectively known as respiratory centers

Respiratory centre is divided four major groups

• Inspiratory centre (Dorsal respiratory group)

•Location: Dorsal portion of medulla•Nucleus: Nucleus tractus solitarius•Function: causes inspiration while

stimulated.

Expiratory centre (Ventral respiratory group) Location: Antero- lateral part of medulla,

about 5 mm anterior and lateral to dorsal respiratory group

Nucleus: Nucleus ambiguous and nucleus retro ambiguous.

Function: It generally causes expiration but can causes either expiration or inspiration depending upon which neuron in the group are stimulated. It sends inhibitory impulse to the apneustic centre.

Pneumotaxic centre Location: Pons(upper part ) Nucleus: Nucleus parabrachialis Function: It controls both rate and pattern of

breathing. Limit inspiration. Apneustic centre Location: Pons(lower part) Function:

a)It discharges stimulatory impulse to the inspiratory centre causing inspiration.b)It receives inhibitory impulse from pneumotaxic centre and from stretch receptor of lung.c)It discharges inhibitory impulse to expiratory centre.

Respiratory center depression•Depression of a respiratory center can be

a result of next reasons:•medical drug action (opioids, sedatives

and etc.)•sudden cessation of blood circulation in

brain•heavy brain trauma•sharp neuroinfections•brain tumors•damage of a brainstem

The pattern repeats, with each cycle usually taking 30 seconds to 2 minutes. It is an oscillation ( periodic variation )of ventilation between apnea and hyperpnoea

A convulsion is a medical condition where body muscles contract and relax rapidly and repeatedly, resulting in an uncontrolled shaking of the body.[

General Post Mortem Appearance

.petechial hemorrhages: in the skin and eyes (particularly the eyelids, conjunctiva, sclera,

face, lips and behind the ears).

External Appearances:- .Face: oedematous and congested.

.Lividity appears early and is well formed.

.Deep cyanosis: especially in nails and lips.

.Eye: proptosis due to retro-orbital oedema.

Petechial HemorrhageSites of formation:

•A petechial hemorrhage is a tiny pinpoint red mark that is an important sign of asphyxia caused by some external means of obstructing the airways. They are sometimes also called petechiae. Their presence often indicates a death by manual strangulation, hanging, or smothering.

in the skin and eyes( particularly the eyelids, conjunctiva, sclera, face , lips and behind the ears

Mechanism of formation

•The hemorrhages occur when blood leaks from the tiny capillaries in the eyes, which can rupture due to increased pressure on the veins when the airways are obstructed.

• If petechial hemorrhages and facial congestion are present, it is a strong indication of asphyxia by strangulation as the cause of death.

External Postmortem (PM) picture1- Petechial hemorrhages3- Cyanosis2- Postmortem hypostasis is well-

developed and dark in color 4- Rigor mortis is rapid5- Putrefaction is rapid.

Dark:- due to the large amount of reduced hemoglobin. Fluid:- release of fibrinolysin

shortly after death.

Internal Appearances:-

.Visceral congestion. .Petechial hemorrhages: in the visceral pleurae

and pericardium are often known as "Tardieu's

spots". Tardieu's spots ; spots of ecchymosis under the pleura after death

.Blood:

Internal Postmortem (PM) picture

•Petechial hemorrhages under the pleura and pericardium and in the internal organs. Congestion and edema of the viscera

•The blood is dark in color and more fluidly.

•The right heart and great veins are engorged with blood.

Classification of asphyxia

1-Mechanical Asphyxia

2-Toxic Asphyxia

3-Pathological Asphyxia

4-Neonatal Asphyxia

5-Electrical Asphyxia

6-Asphyxia Due To Low Atmospheric Oxygen Content

pertaining to force and matter, as distinguished from mental, vital, chemical,

etc.

MECHANICAL ASPHYXIA;

A-Hanging B-Strangulation; - Throttling ;(it is a manual strng) Mugging Ligature Bansdola ;a form of strangulation where the

neck is compressed in between two bamboo or other sticks, one in front and the other behind

Garroting A garrote (a Spanish word; is a weapon, referring to a handheld ligature of chain, rope, scarf, wire used to strangle a person

Suffocation's- Smothering Choking Gagging drowning Traumatic asphyxia -D

Strangulation•It is a form of violent asphyxia• caused by constricting the neck by some

mean ,other than wt of bodythrottlingmugging,bansdola,Garroting

are types of strang.

•HANGING ;It is violent form of Asphyxial death caused by suspension of the body by a ligature around the neck, the constricting force being the weight of the body.

Lynching; is a condition where several persons acting jointly overpower an individual &hang him by rope

...

suffocation ;smothering ;obstruction to air passages

from outside)nose ,mouth by hand or cloth

ChokingObststruction from inside by solid object( foreign body) results reflex spasm , death is due to vagal inhibition or

laryngeal spasm

It is a form of violent asphyxia in which death results from submersion of mouth and nostrils of a living person under water

Drowning

traumatic asphyxia or crush asphyxia is usually used to describe compressive asphyxia resulting from being crushed or pinned under

a large weight or force

Violent Asphyxial Deaths1- Hanging It is Asphyxial death caused

by suspension of the body by a ligature around the neck, the constricting force being the weight of the body.

2- Ligature strangulation A violent Asphyxial death caused by constricting the neck by a ligature

3- Manual strangulation (Throttling)4- Smothering:5- Choking6- Traumatic asphyxia (Crush asphyxia)

.Hanging:- suspension of the body by the use of a ligature. It resembles Ligature strangulation except for the fact that in hanging the constriction Force

being the weight of the body and the force of gravity as well.

1- Hanging It is Asphyxial death caused by suspension of the body by a

ligature around the neck, the constricting force being the weight of the body.

A)A)It may be either complete or partial:It may be either complete or partial: on the basis of degree of suspensionon the basis of degree of suspensionB) It may be either typical or atypical:B) It may be either typical or atypical: on the basis of position of knoton the basis of position of knot

CompleteComplete ; when wt of the body acts as constricting ; when wt of the body acts as constricting forceforce

IIncompletencomplete; ; when part of the body act as constricting when part of the body act as constricting forceforce

TypicalTypical;; Knot at the occipitKnot at the occipit

AtypicalAtypical; ; Knot at any site other than the occipitKnot at any site other than the occipit

Running noose Fixed knot

Types of knot

Complete hanging

Incomplete hanging

hanging

That form of asphyxial death, caused by suspension of body by a ligature round the neck, constricting force is wt of the body.

.Cause of death 1-asphyxia due to blocking of air passages, by

ligature. 2-cerebral congestion due to compression of

jugular veins(congestive hypoxia)3 -pressure on carotid arteries, obstruction of

arterial blood, thus cerebral anoxia &coma.4-vagal shock from compression of trigger area.5 -injury to spinal cord as in judicial hanging.

Mechanical Asphyxia / Hanging

Mechanism of Death in Hanging

•Asphyxia – anoxic hypoxia

•Reflex cardiac arrest

•Cerebral anoxia

•Cerebral congestion

•Fracture dislocation cervical vertebrae

Mechanical Asphyxia / HangingAUTOPSY FINDINGS

• Body partly / completely suspended by ligature

around the neck

• Brown leathery ligature furrow, imprint abrasion

• Fixed noose-inverted v-shape, knot mark

• Running noose – horizontal

Mechanical Asphyxia / Hanging•Low suspension point – groove less

marked, lower, horizontal

•Typically no classical asphyxial features

•Scene shows preparation and precautions

Mechanical Asphyxia / HangingINTERNAL SIGNS: Bruising – occasionally rupture of neck

muscles – sternomastoid

Bleeding between pharynx and spine

Injury to carotid arteries with bleeding in the walls or horizontal breech of the intima at the level of ligature

Mechanical Asphyxia / Hanging Fracture of Hyoid bone – greater cornu at

junction of outer third with inner two thirds esp. after age 40

Fracture thyroid cartilage – great horn/s

Fractures of Hyoid and thyroid may occur alone or together – may not occur in low suspensions

Mechanical Asphyxia / HangingJUDICIAL HANGING

Body given a drop of 2 – 4 feet, the noose

tightening and cervical spine receiving a jerk –

dislocation and fracture at 3rd and 4th or 2nd and

3rd cervical vertebrae severing the upper part of

spinal cord – instantaneous death , heart may

continue to beat for a few minutes

Mechanical Asphyxia / Hanging

•Incomplete Suspension

▫Body not completely suspended –

continuous pressure of ligature causes

asphyxia

Death is instantaneous usualy but,5-8 minutes is common fatal period.

Pm appearances;

ext-dribbling of saliva due to stimulation of salivary glands by ligature is a vital sign, indicating that victim was alive at the time of suspension.

Ligature mark on the neck;

in complete hanging mark is situated over the level of thyroid cartilage b/w larynx&chin.seen in front, sides of neck.

Lig knot may form a fixed or running noose

Internal appearance; local injury ,spinal cord inj

Ml aspects;

1-wether death was due to hanging; ligature mark is usually found, 2-lig mark e pet hmrge, dribble saliva, carotid art tear, absence of fatal inj &poisoning. Suicidal hang; it is common in men, there is no signs of struggle, farewell note will be present.

Is it suicidal, homicidal, or accidental hanging?Suicidal: (most common):•Circumstantial evidence (history of

failure).•Absence of signs of struggle.•Presence of signs of previous suicidal

attempts.•Suicidal note

Homicidal hanging;

is suspected ,when knot is tied in the back of neck,

mouth is gagged , limbs are tied, injuries on body, signs of struggle are present. Lynching; is a condition where several

persons acting jointly overpower an individual &hang him by rope.

Sexual asph (auto erotic hanging) also described.

Externally:•The neck is stretched. •The face is pale or bluish.• The rest of the body is cyanosed. •Saliva may be seen dripping from the mouth (It is a vital sign and is present only in

hanging but not in postmortem suspension).

Ligature mark:•Shape:It is a depression at the site of the

ligature •Situation: Transverse and complete (if running noose).•The pattern of the ligature:Is imprinted on the neck as a pressure

abrasion.

Ligature mark:•Shape: as in hanging.•Situation: At the level of thyroid

cartilage or below.•Transverse and •complete (this is the usual).

Mechanical Asphyxia / Hanging Almost all hangings are suicidal

Sudden compression of the neck blocks the blood

vessels disrupting blood supply to and from the

brain

Usual point of suspension is the side of the neck

(typical hanging) followed by back and front

(atypical hanging)

Strangulation

It is a form of violent asphyxia caused by constricting the neck by some means other than wt of body.The means used may be ;ligature, hand((throttling) , elbow(mugging)or stick(bansdola) Strangulation should be assumed to be homicidal, until contrary is provedMugging; strangulation by compression neck against forearmgarroting; strng by grasping the throat , throwing a lig over neck.Throttling ;it is a manual strng

.Strangulation

2- Ligature strangulation A violent Asphyxial death caused by

constricting the neck by a ligature. Mechanism of death: Asphyxia: from compression of air

passage Cerebral congestion or apoplexy: Reflex vagal inhibition Cerebral anoxia: Combination of any of the above

3- Manual strangulation (Throttling)

•caused by constricting the neck by the hand.

•Autopsy appearances:•Externally:•Injuries on the neck:•Abrasions (caused by finger nails).•Contusions (caused by finger pads).

.Throttling:- constriction of the neck by the use of hands.

Suffocation; this is a form of asph ,caused by mechanical obstruction of air

passages,by means other than constriction of neck

It includes ; smothering (obstruction to air passages from

outside)nose ,mouth by hand or cloth. Choking ;obstr from inside by solid object( foreign

body) results reflex spasm , death is due to vag inhibition or laryngeal spasm.

Drowning; submersion of mouth&nostrils under water

Traumatic asph;obst to resp movements

Autopsy appearances:•Externally:•The face is either pale or bluish and

congested. The rest of the body is cyanosed.

•The tongue may be protruded, swollen and bitten.

•Bleeding from ears and nose may be seen.

4- Smothering: Caused by mechanical occlusion of the

air passages from outside (i.e. the mouth and nostril) by hand or by any object.

PM picture Asphyxial signs will be present except in

case of plastic bag suffocation. Abrasions and contusions on the skin of

the face around mouth and nose(Absent if a soft material, such as a pillow,

is used).

Smothering :Is blockage of external air passages by (fabric, sheet,

solid material) Groups of risk are elderly , infants

A part from classical signs of asphyxia such as

petechiea may appear and there is usually a lack of objective finding.

Plastic bag suffocation can be rapid and symptomless depending on how it is done.

The death in plastic bag facial occlusion is some rapid cardio inhibitory mode rather than purely hypoxic process.

.Smothering:-occlusion of external respiratory openings

5- Choking

•Caused by mechanical occlusion of the air passage from inside.

Mechanism of death:Asphyxia: due to either complete occlusion

of air passage, or partial occlusion that is completed by

spasm, edema and mucus secretion.

. Choking:- Obstruction to the air passage due to foreign body impaction.

Accidental: (most common)

May arise from:•Inhalation of irritant fumes.•Impaction of foreign material, such as

food or denture.•Inhalation of dust and sand in falling of

houses.•Inhalation of vomit or blood during

operations.•Falling back of the tongue epileptic fit.

Choking

Refer to the blockage of the internal air way( glottis or trachea) by foreign bodies . Almost Accidental

Death can be of purely hypoxic origin from occlusion of airway with characteristic signs of congestion , cyanosis & petechiae.

The groups most at risk are :Children, old people, mentally disorder,

drunk,Greedy Eaters ,Drugged

Café coronaryThis is a condition of accidental choking where a bolus of food produces complete obstruction of larynx .it is so called b.c it mimics heart attack .it may be d/t Suppressed gag reflex – alcoholics, drug intoxicated Reflex cardiac arrest; due to stimulation of laryngeal nerveThe victim who was healthy apparantly collapses & suddenly turns blue while eating

Mechanical Asphyxia Medicolegal Aspects

Mode of death – asphyxia / anoxia / cerebral congestion / vagal inhibition / fracture dislocation cervical vertebrae

Cause of death – suffocation / throttling / strangulation / hanging / drowning

Manner of death – suicidal / homicidal / accidental

Mechanical Asphyxia / Manner of Death Suffocation – accidental / homicidal – plastic bags

Gagging – homicidal

Throttling – homicidal

Strangulation – homicidal – accidental esp. children

Mechanical Asphyxia / Manner of Death Hanging – almost always suicidal – accidental

Suspension of body after death to simulate suicidal

hanging – circumstances / scene / locus examination

Evidence of other cause of death

Sexual asphyxias – accidental

What is a "cafe coronary?

•"Cafe coronary" is poorly named because it has nothing to do with a heart attack. This condition got its name because onlookers may think they are witnessing a heart attack when a diner is really choking to death. "Cafe coronary" is blockage in the upper airway, usually caused by food or vomit stuck in the throat. The blockage causes choking and makes it hard to breathe. It can be life threatening.

Choking (Cafe Coronary)

•How does choking occur? •Choking occurs when a piece of food or

some other object gets stuck in the airway. Chicken, fish bones, and pieces of meat that have not been chewed properly get stuck in the throat easily. If you have been drinking alcohol, your risk of choking is greater because you may be careless about chewing food well.

What are the symptoms?

•Symptoms of choking may include:•trouble talking or inability to talk•high-pitched breathing, wheezing, or not

breathing at all• forceful coughing or inability to cough•clutching the throat or chest as a sign of

distress•fainting.

How does choking occur?

•Choking occurs when a piece of food or some other object gets stuck in the airway. Chicken, fish bones, and pieces of meat that have not been chewed properly get stuck in the throat easily. If you have been drinking alcohol, your risk of choking is greater because you may be careless about chewing food well.

What are the symptoms?

•Symptoms of choking may include:•trouble talking or inability to talk•high-pitched breathing, wheezing, or not

breathing at all• forceful coughing or inability to cough•clutching the throat or chest as a sign of

distress•fainting.

What are the symptoms?

•Symptoms of choking may include:•trouble talking or inability to talk•high-pitched breathing, wheezing, or not

breathing at all• forceful coughing or inability to cough•clutching the throat or chest as a sign of

distress•fainting.

Choking (Cafe Coronary)•How can I help someone who is choking? • If someone is choking but still able to breathe and cough and is not turning a bluish color, let them try to cough up the object. If they are having trouble breathing and turning blue,

have someone call while you do the following to help:•Ask the person if they are choking. If they cannot answer you, or they grab their throat, they need help right away.•Give 5 back blows.

▫Stand behind the person and wrap one arm around their chest.▫Firmly strike the person on the back between the shoulder blades 5 times.

• If the back blows do not cause the object to come up (be expelled), give 5 abdominal thrusts.▫Wrap both of your arms around the person's abdomen.▫Make a fist with one of your hands and place it with the thumb side in the center of the person's abdomen.▫Grasp your fist with your other hand and give 5 abdominal thrusts by making a quick, hard movement inward and upward 5 times.

•Repeat this series of 5 back blows and then 5 abdominal thrusts several times until the object is removed or the person becomes unresponsive.•

If the choking person is pregnant or obese, use chest thrusts instead of abdominal thrusts after the back blows. To do chest thrusts:•Standing behind the person, wrap your arms around their chest. •Make a fist with one hand against the middle of the person's breastbone, between the nipples, thumb side in. •Grasp your fist with your other hand and pull straight inward 5 times (do not pull inward and upward as in the abdominal thrusts).•Repeat the series of back blows and chest thrusts until the object is removed or the person becomes unresponsive.•

If the person loses consciousness, lower the person to the floor, call for help, and begin CPR (cardiopulmonary resuscitation). When no one else is available, stop to call for emergency help (EMS or 911), and then go back to rescue efforts. If something can be seen blocking the airway, try to remove it by using 1 finger to sweep the mouth.

•If breathing stops in a child under 1 year old, place the baby face down on your forearm at a 60-degree incline, with the head lower than the rest of the baby's body and your arm resting on your thigh. Give 5 quick blows with the heel of your hand between the shoulder blades. If the baby is still not breathing, lay the baby on his back and use 2 or 3 fingers to give 5 rapid chest compressions over the lower breast bone. Repeat the back blows and chest compressions until the object comes out.

•If the airway cannot be cleared and the windpipe is completely blocked, the person may need an emergency operation called a tracheotomy. This is a procedure in which the emergency medical technician (EMT) or healthcare provider makes a cut through the skin of the throat and into the windpipe. A tube is then put into the windpipe through the cut to let air into the lungs.

•How long will the effects last? •The choking will last as long as the food or object remains stuck in the airway. After a minute or so of being unable to breathe or cough, the person may faint (become unconscious).•

After the object is removed, the throat may be sore if it was scratched by the object.•What can be done to help prevent choking? •Take these steps to prevent choking:•Cut food into small pieces. Do not try to swallow large pieces of food.•Eat slowly and be careful to chew foods thoroughly, especially when you are drinking alcoholic beverages.•Avoid drinking too much alcohol before or during meals. Alcohol dulls your judgment as well as the nerves that help swallowing.•Don't eat when you are talking, laughing, walking, running, or playing. This reduces the chance that you will inhale a piece of food that can get stuck in your throat.•Make sure dentures fit properly. Loose-fitting dentures may make it hard to chew and to feel objects in your mouth.

Crush asphyxia

traumatic asphyxia or crush asphyxia is usually used to describe compressive asphyxia resulting from being crushed or pinned under a large weight or force

Ex..collapsing trenches, panic in crowds, car-jack while repairing from below, even

anacondas(monstor snake) and pythons(ajdaha)

These case tend to exhibit gross congestion,cyanosis,and petechiae of the face, neck and shoulder with bleeding from the ear and the nose

Pressure on the chest and abdomen due to:

•Burial in earth following house collapse.

•Crushing by a crowd, as in case of a fire.

.Drowning:-This is due to submersion of the respiratory openings under

water or any other fluids.

It is a form of violent asphyxia in which death results from submersion of mouth and nostrils of a

living person under water

•Classification (types) of drowning:1- Typical (wet) drowning: 2- Dry drowning.3- Secondary drowning (Near-

drowning).

Drowning is...

•Death secondary to asphyxia while immersed in a liquid, usually water, or within 24 hours of submersion

In drowning...air hunger and usually panic

Reflex inspiratory efforts lead to aspiration of water and laryngospasm

asphyxia and hypoxaemia / acidosis

AsphyxiaLaryngospasm maintained

Respiratory arrest

Cardiac arrest

“Dry drowning”

Relaxation of the airway

Water enters lungs

Surfactant washout

“Wet drowning”

*mechanism in fresh and salt water slightly different

2- Sure external signs:A-Froth:(Fine – White – Odorless _ increase)

B-Cadaveric spasm of the hands on weeds, mud, sand, etc.

Immersion is suffocatioin of mouth &nostrils in liquid •goose-skin, or anserina cutis, which is

roughening, or pimpling of the skin, skin maceration, or washer-woman's skin, which is swelling and wrinkling of the skin, and adipocere, which is the transformation of the fatty layer beneath the skin into a soap-like material - a process requiring many weeks or months

External appearances

1. Signs of immersion:These are found in any body found dead in

water (whatever the cause of death).• Coolness of the body.• Goose-skin the skin is wrinkled.• Washerwoman-skin: the skin is sodden.• Peeling of the epidermis in the form of

gloves and stockings.• Hypostasis

Goose skin

Goose

Washerwoman’s hands

Internal appearances•Voluminous lungs with indentation marks of ribs on their lateral surfaces.

•Respiratory passages contain froth (having the same characters of that found externally at the mouth and nostrils),

Diatoms:•These are microscopic, unicellular algae, found in fresh as well as salt water.

•When a live person is drowned in water, they penetrate his alveolar membrane and pass with the circulation to distant organs.

•But when a dead body is thrown into water, the absence of beating heart prevents circulation of diatoms to distant organs.

The medico-legal (ML) importance of diatoms:

•1- Sure signs of drowning,•2- Could still be identified in putrefied

bodies,•3- Could give an evidence of the site of

drowning (fresh or salt water species).

In putrefied bodies:

•Only diatoms could be identified

2-Toxic Asphyxia

.Cyanide.

.Carbon monoxide.

.Organic Phosphate fertilizers.

.Due to intoxication with poisons such as:

3-Pathological Asphyxia

Pulmonary Embolism.Glottic Oedema.Acute Pulmonary Oedema.

4-Neonatal AsphyxiaHypoxic hypoxia due to distorted umbilical cord or uterus spasm.

5-Electrical Asphyxia•Convulsions and spasm of respiratory

muscles.

Asphyxia is due to

•Central due to depression of respiratory center.

6-Asphyxia Due To Low Atmospheric Oxygen Content

Ambient Anoxic Anoxia.

Specially in:

•high altitudes

•Presence of CO2 or N2