A. Carbon monoxide.
B. Hydrogen sulphide.
Ans:A. Carbon Monoxide
Post mortem lividity shows Bright red cherry discolouration of Skin.
- Livor mortis (postmortem lividity / hypostasis / suggillation)is the fourth stage and one of the signs of death.
- Purple coloration of dependent parts, except in areas of contact pressure, appearing within 30 minutes to 2 hours after death, as a result of gravitational movement of deoxygenated blood within the vessels.
Colour of post mortem lividity (hypostasis)
- Normal – Bluish pink which later turns into bluish purple
- Carbon monoxide – Bright cherry red
- Cyanide – Pink
- Phosphorous – Dark brown
- Nitrates – Reddish brown
- Chlorates – Chocolate brown
- Hydrogen sulphide – Bluish Green
- Aniline – Deep blue
- Opiates – Black
Postmortem findings of CO-poisoning
- Fine froth at mouth and nose.
- Bright cherry red discolouration of skin, mucous membranes, nail-beds, blood, tissues and internal organs as shown in the picture above. Cyanide poisoning and exposure to cold causes similar redness.
- Blood is fluidish thin, hyperemia (congestion) is general, and serous effusion are common.
- Skin blisters or red patches due to hypoxia in areas that contact the ground or appositional skin e.g. axilla, inner thigh, buttock, calves, knee.
- Lungs show congestion with pink fluid blood, followed by pulmonary edema and bronchopulmonary consolidation.
- Pleural and pericardial anoxic haemorrhage, tiny focal necroses in myocardium are late changes (5 days).
- Bilateral symmetrical necrosis and cavitation of basal ganglia (esp globus pallidus and putamen)
- Spectroscopic examination, Hoppe – Seyler’s test (10% NaOH), kunkel’s (tannic acid) test and adding water (15 ml) in 2 drops of blood can detect CO.