Asphyxia

Question 1

Asphyxia

Answer 1

Lack of oxygen

Question 2

Medicolegal issues:

Answer 2

• Cause of death/injury
  
  • Proving it - difficult as injuries relatively minimal
  • Time needed
  • Amount of force needed

Question 3

Clinical stages:

Answer 3

1. Effort to breath
   
   2. Laboured respiration
   3. Loss of consciousness, convulsions, incontinence, vomiting
   4. Death

Question 4

Classical signs:

Answer 4

• Facial congestion and oedema/swelling
  
  • Cyanosis - discolouration
  • Petechial haemorrhages - tiny red dots where vessels rupture
  • To do with raised venous pressure, most when there is pressure to neck

Question 5

Suffocation:

Answer 5

• Reduction in oxygen
  
  • Obstruction to external respiratory orifices (smothering)
  • Death often rapid
  • Few signs
  • Agriculture/industry

i.)smothering - old ppl, infants
Ii.) plastic bag - rapid, no signs

Question 6

Choking:

Answer 6

• Internal obstruction of upper airways
  
  • Death may be rapid or can get classical signs
  • Object: dentures, toys, food, vomit, gagging
  • Food in larynx - choking symptoms/sudden death
  • Aspiration of vomit: alcohol, anaesthesia, illness
  • Autopsy findings: objects may be removed by ppl saving by time death occurs, after death body regurgitates gastric contents

Question 7

Pressure on neck:

Answer 7

• Manual strangulation - finger bruises, scratches etc
  
  • Ligature strangulation - horizontally
  • Hanging - pressure of individuals body, ligature rises to point of suspension

Structures affected by pressure on neck:
- Larynx
- Jugular veins
- Carotid arteries
- Baroreceptors in carotid arteries

Question 8

Traumatic asphyxia: - pressure on neck

Answer 8

• Stadium disorders e.g. Hillsborough disaster
  
  • Overturned vehicles
  • Industrial accidents
  • Postural asphyxia e.g. ppl end up in awkward position, head down, organs and body press on chest

External signs:
- Injuries from compressing agent
- Congestion, cyanosis, petechiae

Question 9

Drowning:

Answer 9

150,000 deaths year worldwide

- Accident: males, children, alcohol
- Suicide: elderly 

Water in lungs and airways - cannot breathe

Survival:

- Salt water - 80%
- Fresh water - 50% - osmotic pressure lower than blood so large amount of water is absorbed into blood 
- Depends on initial resuscitation - speed and effectiveness
- Morbidity - chronic brain damage due to lack of oxygen

Signs:

- Froth in airways - transient - out nose and mouth 
- Waterlogging of lungs - "dry" drowning 
- Overinflation of lungs - other causes e.g. asthma 

- General issues - decomposition, resuscitation