Asphyxia and Asphyxial Death: Overview

Asphyxia and Asphyxial Death

• Asphyxia and asphyxial death are a broad topic, encompassing violent asphyxial deaths, hanging, strangulation, throttling, smothering, choking, and traumatic asphyxia.
• Learning objectives include understanding various types of violent asphyxia deaths, their mechanisms of infliction, postmortem appearance, and medico-legal significance.
• Objectives also include learning about diagnosing traumatic asphyxia.

Violent Asphyxia Deaths

• Violent asphyxia encompasses various forms, including hanging, strangulation, throttling, smothering, and choking, and traumatic asphyxia. These actions lead to death by the obstruction of the airway and subsequent deprivation of oxygen to the body

Hanging (Suspension of Body)

• Asphyxial death from body suspension by a ligature around the neck
• Force exerted on neck comes from the weight of the body part
• Presented types of hanging include complete, partial, typical, and atypical, differentiating by the position of body and ligature relative to the ground and to the thyroid cartilage.
• Ligature can include a rope, belt, wire, etc. and can be a loop or running noose.
• Complete hanging: feet do not touch the ground; constricting force=weight of whole body.
• Partial hanging: feet or knees are on/touching the ground; constricting force = weight of upper body.
• Typical hanging: ligature positioned above thyroid cartilage, running symmetrically along neck to occipital region.
• Atypical hanging: ligature positioned at or below the thyroid cartilage.

Mechanism of Death in Hanging

• Cerebral anoxia (anemia): constricting force on neck by body weight stretches neck structures, including the carotid arteries, leading to occlusion
• Cerebral congestion or apoplexy: obstructed venous return from neck veins leading to rapid rise in venous pressure in the head.

Asphyxia: May Result Either From

• Direct compression of larynx or trachea: causing the root of tongue to close.
• Reflex vagal inhibition (Cardiac arrest): Pressure on baroreceptors in carotid sinus and carotid body leads to sudden death.

Injury to Spinal Cord

• Particularly in judicial hanging
• Leads to fracture and/or dislocation of 3rd or 4th cervical vertebrae.

Postmortem Appearance: External Examination (General Signs)

• Neck: stretched, head inclined to opposite side of knot.
• Face: pale, congested, swollen, incomplete carotid arteries obstructing. Eyes: prominent. Tongue: swollen, may protrude.
• Exposed parts may become dark brown to black: due to dryness
• Saliva: Sometimes found dribbling from mouth, side opposite the knot.

Postmortem Appearance: External Examination (Ligature Mark)

• Mark on neck at ligature site: appears as depression, usually first pale yellow, then brown (deepens over time).
• Characterisations: dry, hard, dry parchment like, abrasions and contusions, fibers from ligature may adhere to the skin.
• Site: over the upper neck above thyroid cartilage, follows mandible to mastoid behind ears
• Direction: generally oblique, running upwards along the mandible, to the mastoid process
• Colour: pale, becoming yellowish brown (deepens over time)

Postmortem Appearance: External Examination (Local Signs) (Ligature Mark)

• Definition, shape, and color: critical medico-legal factors.
• Situation: location on the neck.
• Direction: path followed by the ligature.
• Complete/Not: in relation to ligature forming a noose.

Postmortem Appearance (External Examination) - General Signs; Face

• Facial and eyes features (e.g., color, swelling)
• Visible signs on the face.

Postmortem Appearance (External Examination) - (Local Signs); (Ligature Mark)

• Defines the physical characteristics of the ligature mark.
• Local signs such as shape, color, direction, situation, and complete/not status of the ligature mark provide a basis for medicolegal interpretation..

Medicolegal Questions- Hanging

• Was death due to hanging?
• Determine if death was caused by suicide, homicide, or accident.
• Assess signs of ante-mortem neck violence through examination.

Medicolegal Questions- Strangulation

• Was death due to strangulation?
• Determine the mode of death (suicide, homicide, or accident).
• Examine for signs of ante-mortem violence.

Medicolegal Questions- Smothering

• Was death due to smothering?
• The manner of death (suicide, homicide, or accident) and related signs.

Medicolegal Questions- Choking

• Was death due to choking?
• Determine the manner of death (accidental, suicide, or homicide).
• Examine for signs of ante-mortem neck injuries.

Throtting (manual strangulation)

• Mechanism of death from constriction of the neck by hand

Traumatic Asphyxia

• Violent asphyxia caused by trauma to the chest or abdomen, preventing respiratory movements.
• Possible causes include homicidal acts (e.g., burking), accidents (e.g., crush injuries in road traffic accidents, chest compression in crowds), and falls of heavy objects.

Postmortem Appearance (thorattic trauma)

• Signs of chest trauma (e.g. fractured ribs).
• Deep cyanosis.
• Petechial hemorrhage.
• A demarcating line.
• Failure of chest expansion.

Explore the complex topic of asphyxia and asphyxial deaths, including hanging, strangulation, and choking. This quiz covers the mechanisms of these violent acts, their postmortem appearances, and their medico-legal implications. Gain insights into diagnosing traumatic asphyxia and understanding various forms of airway obstruction.