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Violent Asphyxial Death (also called)�Mechanical Asphyxia

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Gordon’s classification of anoxia

Anoxia may be

A. Anoxic, - Defective oxygenation of blood in lungs
B. Anaemic,-Oxygen Carrying capacity of blood is reduced: Haemorrhage, CO Poisoning
C. Histotoxic-In this the enzyme system in tissue for utilization of oxygen are poisoned. Ex. Cyanide poisoning
D. Stagnant -Impaired circulation reduces oxygen delivery to tissue. Ex. Heart failure, embolism, shock

The cessation of the vital functions depends upon the product;on of tissue anoxia. This anoxia may be brought about in four different ways.

All aerobic organisms including human being need oxygen for their survival. Oxygen as you know performs several functions in body most important being its use for producing energy at the cellular level. In lung alveoli oxygen is taken up by the iron in haemoglobin of the blood flowing through it in exchange for carbon dioxide which is released in alveolar air. Haemoglobin carries oxygen to all body parts including vital organs like brain and heart where oxygen is taken up by cells for use in metabolism and the carbon dioxide produced by metabolism is transferred to the capillary blood for elimination by lungs. Different tissues have varying degree of tolerance for survival in absence of oxygen. An adult brain has none. If oxygen is cut off from brain then unconsciousness will result within seconds and the person will die within a few minutes. Causes of failure of oxygen to reach tissue was first described by Gordon a professor of medical jurisprudence in Univerrsity of Capetown, who in 1944(Br Med J. 1944 Sep 9; 2(4366): 337–339.) classified death based on type of anoxia.

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Anoxic Anoxia

Anoxic anoxia is asphyxia

1. Primary paralysis of respiration

Narcotic poisoning, electrical shock

2.Lack of oxygen in respired air-mines, wells, sewer gas, Nitrogen gas narcosis
3.Or mechanical obstruction from within or from outside to respiration,

Causing lack of Oxygen and failure to eliminate CO2
Resulting in to unconsciousness and death

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ASPHYXIA

Asphyxia is an interference with respiration leading to anoxic anoxia and retention of CO2 due to external causes
Interference with respiration due to any cause- mechanical, environmental or poison
It is a condition characterised by lack of oxygen in blood

The word asphyxia is from Ancient Greek α- "without" and σφύξις sphyxis, "squeeze" (throb of heart) Meaning Pulselessness however now it signifies interference with normal respiration. Asphyxia-Conditions in which there is inadequate delivery, uptake and/or utilization of oxygen by the body’s tissues/cells, often accompanied by carbon dioxide retention. The extreme condition caused by lack of oxygen and excess of carbon dioxide in the blood, produced by interference with respiration.

Although many natural disease processes may involve inadequate uptake and/or delivery of oxygen (eg, chronic obstructive pulmonary disease [COPD]), the term "asphyxia" is generally reserved for conditions related to abnormal atmosphere and mechanical and chemical effects directly leading to anoxic anoxia and retention of CO2 leading to unconsciousness and or death..

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Asphyxia

Although many natural disease processes may involve inadequate uptake and/or delivery of oxygen (eg, chronic obstructive pulmonary disease [COPD]), the term "asphyxia" is generally reserved for conditions related to abnormal atmosphere and mechanical and chemical effects directly leading to anoxic anoxia and retention of CO2 leading to unconsciousness and or death..

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Stages in Asphyxial Death

Stage of forced respiration:

It is due to stimulation of the respiratory cente causes dyspnea

Stage of convulsions:

It is due to cerebral irritation causes also cyanosis constricted pupil, loss of consciousness,

Stage of paralysis:

Clinical picture: flaccid muscles & lost reflexes, deep cyanosis, dilated pupils, irregular breathing (cheyne-Stokes respiration), death.

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GENERAL SIGNS OF ASPHYXIA

Cyanosis- relevant only in fresh bodies
Tardieu’s spots-under conjunctiva, pleura, pericardium, peritoneum, and meninges
Congestion- pulmonary and systemic congestion
Right side heart full, left side empty
Pulmonary oedema- as a result of congestion
Fluidity of blood- due to liberation of fibrinolysin in blood

Cyanosis is a bluish color of mucous membranes and/or skin. Cyanosis is a bluish discoloration of the skin due to poor circulation or inadequate oxygenation of the blood. The name cyanosis literally means "the blue disease" or "the blue condition". It is derived from the color cyan, which comes from kyanós, the Greek word for "blue".^[5it is classically described as occurring if 5.0 g/dL of deoxyhemoglobin or greater is present.^[2] This was based on an "estimate" of capillary saturation based on a mean of arterial versus peripheral venous blood gas measurements.^[3] Since estimation of hypoxia is usually now based either on arterial blood gas measurement or pulse oximetry, this is probably an overestimate, with evidence that levels of 2.0 g/dL of deoxyhemoglobin [unoxygenated hemoglobin (deoxyhemoglobin)] may reliably produce cyanosis.^[4] Since, however, the presence of cyanosis is dependent upon there being an absolute quantity of deoxyhemoglobin, the bluish color is more readily apparent in those with high hemoglobin counts than it is with those with anemia. Also the bluer color is more difficult to detect on deeply pigmented skin. When signs of cyanosis first appear, such as on the lips or fingers, intervention should be made within 3–5 minutes because a severe hypoxia or severe circulatory failure may have induced the cyanosis.

Tardieu”s spot- Tardieu’s ecchymoses or petechial haemorrhagic spots are common in asphyxial death Small haemorrhagic areas on conjunctiva, meninges, pleura, pericardium, peritonium, mucosa of mouth etc.

Subpleural, epicardial and pericranial ecchymoses have been described in cases of suffocation since the 18th century. In the 19th century, great diagnostic importance was attributed to ecchymoses. Tardieu was the most determined defender of the specificity of ecchymoses for suffocations. He thought that he could diagnose violent suffocation by means of ecchymoses and claimed that he was able to differentiate violent suffocation from other unnatural causes of death (hanging, choking, strangulation, and drowning). Other physicians, among them numerous German medical examiners, proved Tardieu's opinions wrong by means of observations and animal studies. The most dedicated disputant against Tardieu's false doctrines was Liman. According to today's knowledge of pathophysiology, the haemorrhages concerned cannot have a specificity for suffocation or even a specific form of suffocation. Therefore, the confusing term of "suffocation haemorrages" should be avoided.

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Cyanotic lips

Also look for cyanosis in fingers

Action should be taken within minutes

Cyanosis is a bluish color of mucous membranes and/or skin. While this is most frequently attributable to increased amounts of unoxygenated hemoglobin (deoxyhemoglobin) in the vasculature, there are other causes of bluish skin color. According to Lundsgaard and Van Slyke (1923), as well as subsequent investigators, cyanosis generally becomes apparent when the subpapillary capillaries contain from 4 to 6 gm/dl of deoxyhemoglobin. Since this measurement was difficult to obtain directly, they proposed estimating it by averaging the amount of deoxyhemoglobin in arterial blood with that in venous blood. If one assumes a normal cardiac output, hemoglobin, and tissue extraction of O₂, an arterial O₂ saturation of approximately 80% would be required to cause cyanosis. It should be noted that the conclusion of Lundsgaard and Van Slyke was based on measurements of deoxyhemoglobin in peripheral venous blood and did not involve sampling of arterial blood. Their proposal of 5 gm/dl deoxyhemoglobin in mean capillary blood as a threshold for detecting cyanosis has not been confirmed or refuted by more sophisticated techniques.(Clinical Methods, 3rd edition The History, Physical, and Laboratory Examinations Editors: H Kenneth Walker, MD, W Dallas Hall, MD, and J Willis Hurst, MD. Emory University School of Medicine, Atlanta, Georgia Boston: Butterworths; 1990.ISBN-10: 0-409-90077-X)

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Van Slyke Ph.D born in Pike, N. Y., Mar. 29, 1883- 4^th May 1971

In 1925 he was rated by the American Chemical Society as one of the 39 most eminent American Clinical chemists. Described 5gm/dl deoxyhemoglobin as threshold for development of cyanosis now with arterial blood gas analysis and pulse oximeter study led to an estimation of 2gm/dl as threshold for cyanosis.

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Auguste Ambroise Tardieu

10/04/1818- 12/01/1879

Paris France

a French medical doctor and the pre-eminent forensic medical scientist

President of the French Academy of Medicine, as well as Dean of the Faculty of Medicine and Professor of Legal Medicine at the University of Paris.

The son of artist and mapmaker Ambroise Tardieu. Tardieu's specialties were forensic medicine and toxicology. Over his 23-year career, Tardieu participated as a forensic expert in 5,238 cases, including many famous and notorious historical crimes. Using his cases as a statistical base, Tardieu wrote over a dozen volumes of forensic analysis, covering such diverse areas as abortion, drowning, hanging, insanity, homosexuality, poisoning, suffocation, syphilis, and tattoos.

In recognition of his first clinical descriptions of battered children, battered child syndrome is also known as Tardieu's syndrome.

Tardieu's ecchymoses, subpleural spots of ecchymosis that follow the death of a newborn child by strangulation or suffocation, were first described by Tardieu in 1859, and were so named in his honor.^[2]

Also called, Tardieu petechiae , Tardieu spots (tahr-dyu' ek'ē-mō'sēz, pĕ-tē'kē-ē, spots) subconjuuctival, Subpleural and subpericardial petechiae or ecchymoses (or both), observed in the tissues of people who have been strangled or otherwise asphyxiated. ardieu spots can appear as rash-like.

Tardieu Spots

Location[edit]

In cases of hanging or strangulation, they appear in the area above the level of obstruction.

Tardieu spots are found in lax unsupported tissues such as the forehead, skin located behind the ears, circumoral skin, eyelids and conjunctivae.

Cause[edit]

Tardieu spots are produced by mechanical obstruction to the venous return of blood to the specific part affected. This results in acute rise in venous pressure in an over-distension and rupture of the thin-walled peripheral venules.

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Types of Asphyxia

Pathological- Asthma, Acute respiratory distress syndrome, perinatal asphyxia
Chemical (Poisoning)- Carbon monoxide inhalation, Phosgene or Hydrogen cyanide poisoning, nitrogen gas inhalation
Mechanical Asphyxia- Hanging, strangulation, suffocation

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Violent Asphyxial Death/ Mechanical Asphyxia

Violent- Uncontrolled, strong, rough physical force:
Mechanical- Relating to or controlled or operated by physical forces

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VIOLENT ASPHYXIAL DEATH

Constriction or pressure over neck:-

Hanging - suicidal
Strangulation ( by ligature, garrotting, lasso, throttling, mugging, & Bansdola)- homicidal

Suffocation

Closure of nose and mouth - Smothering
Occlusion of lumen of air passage- Choking
Restriction of the movement of chest wall:- Traumatic asphyxia

Replacing air by fluid in environment:- Drowning

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Hanging

Hanging is a form of violent asphyxial death ,produced by suspending the body with a ligature round the neck, constricting force being the weight of body or a part of the body weight.
Typical hanging, atypical hanging, complete hanging, & partial hanging
Nature of ligature used

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Causes of Death in Hanging

Asphyxia-With 15 kg pressure epiglottis and root of tongue pressed against the posterior wall of pharynx- Majority of cases
Venous congestion-Due to blockage of jugular veins in neck.
Cerebral Ischaemia-With 4.5kg Pressure carotid arteries & 30 kg vertebral blocked
Shock- pressure on vagus causes cardiac arrest
Fracture dislocation of cervical vertebrae-Fall of about 2 metre required
Combined asphyxia and cerebral congestion

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Post- Mortem Findings

External Appearance

Ligature Mark,- Pressure abrasion

Character -pale groove, parchment-like,

situation-oblique, interrupted, directed upwards, in upper part of neck, margin especially upper congested

Other signs-

PM Lividity- stocking & Gloves

Stretching of neck,

Lefacie sympathique,

Dribbling of saliva,

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PM Finding

Internal Findings- Signs of asphyxia

Tissue under ligature not injured, Blood dark & fluid, Rt side of heart, pulmonary arteries and venacava full, abdominal organs congested. Brain and lungs may be congested or pale. In judicial hanging fracture dislocation of 2^nd-3^rd cervical vertebrae, less commonly of of 3^rd & 4^th or still less commonly of 1^st & 2^nd may be seen. Spinal cord then lacerated near foramen magnum. Inner coat of carotid arteries may show transfer tear.

Hyoid bone may be fractured in older age.

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Medico-Legal Aspects

Similar ligature mark may be produced post mortem
Diagnosis based on

Positive findings like:-

Saliva stain, slight abrasion & ecchymoses around ligature mark. Tear in carotid and signs of asphyxia, PM Lividity

And Negative findings:-

No evidence of struggle, injuries over body, nail marks, other fatal injuries or evidence of poisoning, injuries in the soft tissue of neck

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Homicidal & Accidental hanging

Hanging as a rule is suicidal
Homicidal shows mark of violence over body unless very weak or drugged.
Lynching- A form of homicidal hanging in which a group of persons jointly hang the victim as a mode of punishment
Accidental rare except in children or in sexual asphyxia

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STRANGULATIONS

Form of violent Asphyxial death in which breathing is prevented by compressing the neck by methods other than hanging
Types :-

Strangulation by ligature

Garrotting, Lasso

Manual strangulation or throttling
Mugging
Bansdola

Manner of death- Usually homicidal

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STRANGULATION BY LIGATURE

Breathing is prevented by constricting the neck with a ligature, the constricting force being external and Not the weight of the body
Ligature material:- Any thing which can be tied round the neck or used from behind to compress the neck

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PM Finding In Strangulation By Ligature

Ligature mark is horizontal or transverse in lower part of neck usually complete and often with more than one turn
Abraded and contuses
Associated injuries on neck, nail scratches and other injuries on body are commonly found
Face is usually congested and cyanosed
Eye balls and tongue may be protruding
Tardieu’s spot more abundant
May have passed urine or defaecated while being strangulated.

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PM Finding(Cont.)

Internal Findings:-

Skin of Ligature mark soft with abrasions
Subcutaneous tissue under ligature contused
Larynx & Trachea congested, there may be petechial haemorrhagic spots
Lungs intensely congested and haemorrhagic spots
Superior horn of thyroid cartilage fractured in elderly
Brain with meninges congested, Petechae present more abundant above the ligature

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Strangulation by ligature

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Garrotte

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Killing by Garrotting

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Garrotting being done

Spanish Garrotte

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Lasso

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THROTTLING

Neck is compressed by one or both hands
Finger tip bruises are characteristic
Nail scratches on neck are common
There are usually associated injuries like bruises and abrasions on other parts of body
Soft tissue of neck contused extensively
Hyoid bone and thyroid cartilage generally fractured in adults

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Single left handed person

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MUGGING

Neck compressed in the fold of elbow or by knee
As the pressure is in wide area by soft tissue elbow or knee, finding on neck vague or minimal
Signs of asphyxia pronounced as the person continues to inhale some air.

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Mugging by Knee

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BANSDOLA

Neck is compressed between two Bamboo sticks one in front and one behind or with one Bamboo stick neck being pressed against the ground
Injury to neck structure are very extensive and gross
Thyroid cartilage and tracheal rings fractured
There may even be fracture of cervical vertebrae

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SUFFOCATION

Suffocation means a group of conditions of violent asphyxial deaths where passage of air between the atmosphere and lungs is prevented by lack of oxygen in the environment or mechanical obstruction in the air passages other than constriction of neck or drowning
Types:- Smothering, Gagging, Choking, Burking, Overlying, & Traumatic asphyxia

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SMOTHERING

Breathing is prevented by closure of mouth and nose or lowered concentration of oxygen in environment
Cause of death- Only by asphyxia
Accidental- By plastic bags, or trapped in place with low oxygen concentration. Less than 16% dangerous. Less than 5 % fatal in a few minutes
Homicidal-Pressing face with pillow, quilt
Suicidal- Rare

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Gagging

A gag (rolled up cloth) is pushed in to mouth sufficiently deep to block the pharynx Initially ventilation maintained till cloth dry.
In adults done to prevent shouting for help and death is usually not intended
In infants and children may be homicidal

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OVERLAYING

In this form of asphyxial death an adult often under the influence of alcohol overlays an infant during sleep causing compression of chest to the extent that breathing is not possible.
Flattening of nose, face and thorax may be present
Nostrils may be filled with blood stained secretions
Condition is not very common

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BURKING

William Burke, & William Hare in Edinburgh killed 16 persons between 1827 –1828 (about 8 months) and sold their bodies to Dr. Robert Knox for teaching anatomy
They invited their victims to their house gave them plenty of alcohol and then Burke used to sit on his chest and close his nose and mouth by hand. Hare meanwhile used to drag him by feet round the room
Death by combined effect of smothering and traumatic asphyxia

The murders highlighted the crisis in medical education and—along with a series of cases like John Bishop's which became known as the London Burkers—led to the subsequent passing of the Anatomy Act 1832, which expanded the legal supply of medical cadavers to eliminate the incentive for such behaviour. The Act authorised persons who had legal custody of a dead body to send it to a medical school before burial, so that it might be used for the study of anatomy and practice of surgery. If relatives could not be found, Public Health Authorities, Parish Councils and Boards of Guardians etc. counted as legal custodians. About the law, an editorial in The Lancet stated:

Burke and Hare ... it is said, are the real authors of the measure, and that which would never have been sanctioned by the deliberate wisdom of parliament, is about to be extorted from its fears ... It would have been well if this fear had been manifested and acted upon before sixteen human beings had fallen victims to the supineness of the Government and the Legislature. It required no extraordinary sagacity, to foresee that the worst consequences must inevitably result from the system of traffic between resurrectionists and anatomists, which the executive government has so long suffered to exist. Government is already in a great degree, responsible for the crime which it has fostered by its negligence, and even encouraged by a system of forbearance.^[51]

Earlier along with order to hang judges also ordered that the body be dissected for anatomy teaching. The Act also ended anatomising as part of the death sentence for murder.^[52]

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Hare became King’s evidence and was released. His wife was not prosecuted. McDougal (mistress of Burke) was released after the charge against her was found to be not proven. Burke given death sentence. His body to be publicly dissected and bones preserved.

Anatomist Knox was not prosecuted, despite public outrage at his role in providing an incentive for the 16 murders. Burke swore in his confession that Knox had known nothing of the origin of the cadavers

1828-29

Burke and Hare's alleged accomplices were Burke's mistress, Helen McDougal, and Hare's wife, Margaret Laird.From their acts came the now archaic British word "burking”, originally meaning to smother a victim or to commit an anatomy murder but which later passed into general use as a word for any suppression or cover-up.^[2] As at similar institutions, doctors teaching at the Edinburgh Medical School, which was universally renowned for medical sciences, relied increasingly on body-snatchers for a steady supply of "anatomical subjects". The activities of these so-called "resurrectionists" gave rise to particular public fear and revulsion,^,^] but, such were the financial inducements, the illegal trade continued to grow. It was a short step from grave-robbing to anatomy murder. Contrary to popular images and representations of Burke and Hare, they never robbed graves themselves.. Both were tried but Hare turned approval and was released Burke was sentenced to death. Judge’s order “I am disposed to agree that your sentence shall be put in execution in the usual way, but accompanied with the statutory attendant of the punishment of the crime of murder, viz.- that your body should be publicly dissected and anatomized. And I trust, that if it is ever customary to preserve skeletons, yours will be preserved, in order that posterity may keep in remembrance of your atrocious crimes.”

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CHOKING

That form of asphyxia in which there is obstruction within the air passage
Almost always accidental
Usually seen in very young, old, weak, diseased, psychiatric
While drunk
Commonly during eating or aspiration of vomitus
Asphyxial Changes well marked

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CAFÉ CORONARY

Typical example of choking due to impaction of food bolus in larynx during meal especially while drunk
The person gasps for breath, becomes cyanosed and collapses. Initially was thought to be a case of heart attack but on dissection impacted food bolus can be seen in larynx.

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Traumatic Asphyxia

It is said to be the cause of death when thorax is compressed to the extent that respiratory movement of chest is not possible or where due to extensive injury to ribs and respiratory muscles or resulting in pneumothorax breathing is not possible
Usually accidental Ex. Building/ bridges collapse, stampede, mines disasters etc

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PM Finding

Extreme congestion in head, face and neck, and also petechial haemorrhage above the area of compression
Pallor at the site of compression
Injuries to the chest wall, including fracture of ribs, and even sternum
Signs of asphyxia well developed.

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