Chapter 8 - Asphyxia Flashcards
What does the term Asphyxia mean ?
“Lack of Oxygen”
Etymology: absence of pulsation
Asphyxial deaths are caused by failure of cells to receive/utilize oxygen ?
True
Classical features of Asphyxia include all of the following except :
- Petechial haemorrhages
- Congestion/ edema
- Cyanosis
- Postmortem fluidity of blood
- Rigor Mortis
5
Petechial haemorrhages greater than 2mm are termed ?
Ecchymoses
What is the cause of Petechial haemorrhages?
An acute rise in venous pressure that in turn causes overdistension and rupture of thin walled peripheral venules.
In what areas are Petechial haemorrhages seen most ?
Skin,sclera,conjuctivae,and serous membranes
What conditions can cause Non-asphyxial petechiae?
Violent sneeze Child birth Electrocution Vomiting Seizures Cardiac death
True /false, petechiae are affected by posture ?
True
True/false Petechial haemorrhages are specific for asphyxial deaths ?
False
Regarding congestion /edema, it results from obstruction of venous return ?
True
In strangulation, what internal organs can become congested?
Tongue
Pharynx
Larynx
True/false. Congestion and edema are even more non specific for asphyxia than petechiae?
True
What is cyanosis ?
Means “dark blue”. It’s a phenomenon resulting from reduced oxyhemoglobin in RBCs in blood.
Atleast reduced by 5g/100mL before cyanosis is evident.
Postmortem fluidity of blood is not characteristic of any cause of death ?
True
Asphyxial conditions can be classified into mechanical or chemical types. Give examples of each
- Chemical : cyanide poisoning, Carbon monoxide poisoning
2. Mechanical : suffocating, smothering, Gagging/choking, strangulation
