Asphyxia and Medico legal aspects of Death| Forensic Medicine | Budding Forensic Expert

 Asphyxia and Medico legal aspects of Death

Thanatology, Death and its Cause in Asphyxia, types of Asphyxia, Symptoms of Asphyxia.

Prepared by Mr. Milik Ahmed

OVERVIEW & PURPOSE

The basic importance of study of ‘Medicolegal aspects of Death’ is to find out the actual cause of death. Either it’s Natural, Homicidal or Suicidal Death. This information greatly helps in Crime investigations in order to correlate and establish a relationship between suspect and victim. OBJECTIVES

1. To understand the basic meaning of Medicolegal Aspects of Death 

2. To study the Modes of Death 

3. To study different types of Cause of Death

4. Vicious cycle of asphyxia.

5. Thanatology and stages of Death.

OUTCOMES OF THE TOPIC

Steps to check for student understanding:

1. What do you mean by ‘Medicolegal aspects of Death’?

2. What is Thanatology?

3. What is Asphyxia?

4. What are the Types of Asphyxia?

5. What do you understand by Cause of Death?

Topic in Details:

Thanatology:

Thanatology is the scientific study of Death; cause of death and all the phenomena related to Death.

Thanatology originates from the Greek word “Thanatos” which means Death.

Death occurs in two stages:

1. Somatic, systemic or Clinical Death:

It is the complete and irreversible stoppage of the circulation, respiration and brain functions (Bishop's tripod of life), but there is no legal definition of death.

2. Molecular or Cellular Death

It means the death of cells and tissues individually, which takes place usually one to two hours after the stoppage of the vital functions.

Dying: Dying is a process of losing vital functions.

Death: Death may be defined as permanent & irreversible cessation of three interlinked vital systems of the body, called tripod of life, namely -the nervous,circulatory & respiratory systems.

According to IPC section 36; Death denotes death of a human being unless the contrary appears from the context.

Modes of Death:

According to Bichat, there are three modes of death.

1. Coma

2. Syncope 

3. Asphyxia 

You can also Read: AMMUNITION AND TYPES OF AMMUNITION

ASPHYXIA:

Death is said to have taken place from asphyxia when the respiratory function stops before the heart ceases to act.

Asphyxia is a condition caused by interference with respiration, or due to lack of oxygen in respired air, due to which the organs and tissues are deprived of oxygen (together with failure to eliminate C02) causing unconsciousness or death.

Types and  Cause of Asphyxia:

1. Mechanical: Mechanical obstruction to the air passages, e.g., foreign bodies, exudations, tumours, suffocation and drowning by blocking their lumen from within ; strangulation and hanging by their compression from without; and spasm of the glottis from mechanical irritation and irritant gases.

2.Pathological: In this, the entry of oxygen to the lungs is prevented by disease of the upper respiratory tract or of the lungs, e.g., bronchitis, acute oedema of the glottis, laryngeal spasm, tumours and abscess. Paralysis of the respiratory muscles may result from acute poliomyelitis.

3. Environmental: Absence of sufficient oxygen, as in high altitudes or the presence of inert gases in the atmosphere.

4. Toxic: Poisonous substances prevent the use of oxygen. (a) The capacity of haemoglobin to bind oxygen is reduced, e.g., poisoning by CO. (b) The enzymatic processes, by which the oxygen in the blood is utilised by the tissues are blocked, e.g., cyanides. (c) Respiratory centers may be paralysed by poisoning by opium, barbiturates, strychnine, etc. (d) The muscles of respiration may be paralysed by poisoning by gelsemium.

5. Traumatic: Stoppage of movements of the chest resulting from exhaustion of the respiratory muscles due to cold or debility; paralysis of the respiratory muscles from disease or injury of the medulla or phrenic or pneumogastric nerves, mechanical pressure on the chest or abdomen, and tonic spasm due to tetanus or poisoning by strychnine.

6. Postural asphyxia: This is seen where an unconscious or stuporous person, either from alcohol, drugs or disease, lies with the upper half of the body lower than the remainder.

7. Iatrogenic: It is mainly associated with anaesthesia.

You can also Read: BRIEF INTRODUCTION TO TOXICOLOGY AND POISON

Symptoms of Asphyxia:

These are divided into three stages : 

(1) Stage of Dyspnoea: The excess of carbon dioxide in the blood stimulates the respiratory centre. The respiratory movements become increased in rate and amplitude, blood pressure is increased, pulse rate increases and there is slight cyanosis.

(2) The stage of convulsions: In this stage the expiratory muscles of respiration become more active with spasmodic movements, which are followed by convulsions of nearly all the muscles of the body. At the same time there is relaxation of the sphincters.

(3) The stage of exhaustion: In this stage the respiratory centres are paralysed. The muscles become flaccid, there is insensibility, the reflexes are lost, and the pupils are widely dilated. Prolonged sighing inspirations occur at longer and longer intervals until they cease altogether, and death ensues. The pulse is scarcely perceptible, but the heart may continue to beat for some minutes after respirations have quite ceased.

(Reference: The Essential of Forensic Medicine and Toxicology, Medical Jurisprudence And Toxicology and Sciencedirect website)