SuffocationBy Muhd Ariff Mahdzub

Suffocation

• Major Form in Asphyxia• Def: Suffocation is a general term used to

indicate death due to lack of oxygen, either from lack of the gas in the breathable environment or from obstruction of the external air passages.

• Asphyxia = lack of oxygen in respired air causing hypoxaemia and hypercapnia

Smothering

• Asphyxia by smothering is caused by the mechanical obstruction or blocking of the external airways, (nose and mouth)

• Deaths such as these are usually either homicide or suicide,

Suicidal smothering

• suicide eg head covered in plastic bag• Mechanism: hood of impervious substance,

usually polythene or other plastic, is placed over the head down to neck level. • The plastic is usually in the form of an open-

ended bag, either transparent or a ‘supermarket’ shopping bag

(DiMaio2001)

• Figure 4.7 Plastic bag suicide, with an open bag placed loosely over the head.

• Figure 8.l• (A) Suicide of elderly

female who secured plastic bag over head withtie around neck.

Cont.

• Figure 14.6 Plastic bag suicide. The bag is sometimes tied around the neck,

Classic signs of asphyxia

-petechial haemorrhage, -cyanosis, congestion, -swelling soft tissue (oedema)

• Petechiae are caused by an acute rise in venous pressure causing overdistension and rupture of thin walled peripheral venules,

• especially in lax tissues(eyelid), & unsupported serous membranes (pleura and epicardium)

Cont.

• Petechiae of the epicardium or pleural surfaces of the lung were sometimes present, but these are so nonspecific

• Petechiae of the face, sclerae, and conjunctivae were virtually always absent.

-Knight F.

• Cynosis: The colour of blood depends on quantity of oxyhaemoglobin

• When oxygen is lacking (cyanosis), normal pink colour of well-oxygenated skin may change to purple/ blue

• The Congestion & oedema is due to reduce venous return, result of rapid transudation thru capillary and venule walls,

-Knight F.