Asphyxia Flashcards
What is asphyxia?
Inability of the body tissues
To utilize oxygen
At cellular level
Mechanical asphyxia is due to physical obstruction
Of the airflow from atmosphere to alveoli
What are the types of mechanical asphyxia?
Suffocation - lack of oxygen in inspired air
Smothering - blocking the oro-nasal orifices by hand or soft fabric
Gagging - blocking the oral cavity by fabric or mouth tape while the nasal passage is patent
Choking - blockage of the upper respiratory tract by foreign body
Manual strangulation / throttling - applying external neck pressure by hands
Ligature strangulation / garroting - applying external neck pressure by ligature
Mugging - applying external neck pressure by an arm-lock from behind
Traumatic - restriction of chest movement
Postural / positional - inability to breathe due to body posture
What is the classification of asphyxia?
Mechanical
- suffocation
- smothering
- gagging
- choking
- manual strangulation
- ligature strangulation
- mugging
- traumatic
- postural
Non mechanical
- CO poisoning
- cyanide poisoning
What are the sequences of events in asphyxiation?
Dyspnoeic phase Convulsive phase Pre terminal respiratory phase Gasping Terminal
Dyspnoea phase - for a minute , expiration dyspnoea , tachypnoea , cyanosis , tachycardia
Convulsive phase - for a couple minutes , loss of consciousness, hypopnoea, facial congestion and edema, bradycardia, hypertension, fits
Pre terminal - for a couple minutes, no breathing, tachycardia, hypertension
Gasping - reflex respiration
Terminal - brainstem death
What are the classic signs of asphyxia?
Petechial haemorrhage in facial skin
Facial congestion
Facial edema
Cyanotic face
Tardieu spots
Right heart congestion
Abnormal fluidity of blood
What are the other features of asphyxiation?
Pain and tenderness in the neck
Damage to larynx cartilages
Damage to hyoid bone
Haemorrhages (mouth, nose, ears)
What are the mechanisms of death in asphyxia?
Jugular venous obstruction
Carotid artery obstruction
Vagal reflex cardiac arrest
