Legal Medicine - Asphyxia(1)

asphyxiaThe general term applied to all forms of violent death which results from the interference with the process of respiration.

The condition in which the supply of oxygen to the blood or to the tissues has been reduced below normal level.

TYPES OF ASPHYXIAL DEATH:Anoxic Death: failure of the arterial blood to become normally saturated with oxygen

Anemic-Anoxic Death: due to decreased capacity of the heart to carry oxygen

Stagnant Anoxic Death: brought about by the failure of circulation

Histotoxic Anoxic Death: failure of the cellular oxidative process

anesthesiapulmonary edemaAlcohol CyanideDrowningand ChokingHeart Failure, Shock, A-V mal, embolismHigh altitudePatent foramen ovaleHemorrhage, Foreign body impactionTraumatic crush asphyxiaVaricose veinsTorniquet useSmothering and overlayingCarbon monoxide poisoningPneumonia, Asthma, Emphysemahemoglobinemia

Classification of Asphyxia

hangingstrangulationsuffocationdrowningtraumatic crush asphyxiainhalation of irrespirable gases

HANGING

classification of hanging:

As to the location of the ligature and knot:

- typical- atypical

As to the amount of constricting force:

- complete- partial

As to symmetry:

symmetricalassymetrical

post-mortem findings in hanging:

Neck elongated and stretched with the head inclined on the side opposite the knotLividity or pallor of the face with swollen and protruded tongueEyes closed or partly opened with pupils dilated on one side and small on the otherBlue lips with frothy saliva droolingState of erection or semi-erection of the penis with some seminal fluid on the meatusLividity or ecchymosis on the legs

mechanism of death in hanging:

Tracheal obstructionCarotid compressionVagal stimulationAtlanto-axial dislocation

strangulation by Ligature

RARELY suicidal

Usually homicidal and accompanied by evidence of struggle or marks of violence

other forms of strangulation:

Manual Strangulation or ThrottlingPalmar StrangulationGarrotingMugging or Strangle-holdStick Compression

manual strangulation

COMPARO: HANGING vs. STRANGULATION

Frequently above the Adams apple

Ligature mark is inverted V-shape, the apex is on the site of the knot

Ligature groove is deepest at the site opposite the knot

Usually below the Adams apple

Ligature mark is usually horizontal, knot is on the same horizontal plane

Ligature groove is uniform in depth in its whole course

Asphyxia by SuffocationMECHANISM: Closure of air opening or obstruction of the air passageway

Types:- Smothering- Choking- Burking

types of smothering:

Overlaying

GaggingPlastic bag SuffocationAccidental Smothering of Epileptic

Choking- impaction of foreign body in the respiratory passage such as:

1. Vomitus2. Regurgitation from the stomach3. Bolus of food (caf coronary)4. False teeth5. Blood in oral operations6. Tuberculosis

asphyxiabydrowning

Asphyxia by DrowningSUBMERSIONNostrils and mouth are submerged in water for some time to prevent the free entrance of air into the air passage and the lungs

It is not necessary for the whole body to be submerged

Children drown in shallow pools or ponds

Drunks may drown in shallow creeks

Phases of Drowning:1.Respiracion de Surprise2.Phase of resistance(first apnea)3.Dyspneic phase4.Another apnea5.Terminal respiration

Causes of Death in Drowning:TYPICAL - cause of death is asphyxiaATYPICAL- cardiac inhibition due to vagal stimulation - laryngeal spasm - submersion when unconscious

Time factor in drowning:1 min. , considered fatal4 min. , possibility of revival23 min., average time for death

N.B. the length of time for survival in drowning is proportional to the amount of froth in the respiratory tract

Post-mortem findings:Wet clothes, pale face with foreign bodies clinging on skin surfaceCutis anserina or goose skin or goose fleshFirmly clenched hands with objects, weeds or stones

Mouth closed or half-open with tongue protrudingPhysical injuries due to struggle

Penis and scrotum are retractedWasherwomans hands and feetLivid eyes, conjuctival injection and dilated pupils

Internal findings in DrowningEmphysema aquosumEdema aquosumChampignon d ocume

Tracheo-bronchial congestionFluid with bloody frothRight side of the heart is usually distended

conclusive findings in drowning:

Foreign bodies in hands; cadaveric spasmEmphysema Aquosum Edema AquosumStomach contents: water or fluid, corresponding to the medium where body was submergedFroth, foam or foreign body in the air passage consistent with the mediumWater in the middle ear

floatingNaked body floats after 24 hrs.Those with clothes or apparels take more time

TETE DE NEGRI

Compression AsphyxiaTraumaticor Crush Asphyxia

Causes:LandslideAndMasonry accidents

Highwayaccidents

Rubble of collapsed buildings

Mine Collapse and Stampede

Burking

BURKE and HARE

Murderer sits or kneels on the chest with one hand covering the mouth and nostrils of the victim.

Inhalation of IrrespirableGases

carbon monoxideCARBONIC OXIDESILENT KILLER

From incomplete combustion of carbon fuel as in burning of wood, oil, coal, kerosene, gasoline and charcoal

Limits oxygen carrying capacity of the blood due to its 250 X more affinity to hemoglobin.

carbon dioxide

Product of respiration, complete combustion and fermentation or decomposition of organic matters

Found also in drainage pipes, deep wells, sewage tanks

hydrogen sulfide

hydrogen cyanide

the war gases:

LACRIMATOR or Tear Gas

ChloracetophenoneBromobenzyl CyanideEthyl IodoacetateVESICANT or Blistering GasMustard GasLewisite

STERNUTATOR or Vomiting Gas

Diphenyl ChlorarsineDiphenyl CyanarsineDipenylamine Chlorarsine

ASPHYXIANT or Choking Gas

ChlorinePhosgeneChloropicrineDiphosgene

BLOOD POISONS

Hydrocyanic AcidHydrogen SulfideCarbon MonoxidePARALYSANTS or Nerve GasAnti-cholinesterase

From the lost sea He rises,Creating armies in every shore,Turning men against their brothers,Till Man exists no more.

- NOSTRADAMUS