Question

A dead body with suspected poisoning is having hypostasis of red brown or deep blue colour. It is suggestive of poisoning due to:

• A. Nitrates.
• B. Carbon monoxide.
• C. Cyanides.
• D. Barbiturates.

Hint:

Match the lividity color to the poison: cherry red suggests carbon monoxide or cyanide, while brown that can turn bluish suggests a methemoglobin former like nitrates.

Answer 1

The Correct Option is A

Step 1: Understanding the Question.
Postmortem lividity, called hypostasis, is the purplish discoloration blood produces when it settles under gravity after death. Certain poisons change its usual color, and this color is used at autopsy as a clue to the poison involved.

Step 2: Key Concept.
Cherry red or pink lividity points to carbon monoxide or cyanide, since both keep the blood bright red. Brown lividity that can shift toward a bluish tinge points to a poison that forms methemoglobin, such as nitrates and nitrites.

Step 3: Detailed Explanation.
Option (1) nitrates: nitrates and nitrites oxidize hemoglobin into methemoglobin, which is chocolate brown. As the methemoglobin level rises further, the skin and lividity can also take on a bluish, cyanotic shade, matching the red brown to deep blue picture described.
Option (2) carbon monoxide: carboxyhemoglobin gives a bright cherry red or pink lividity, not a brown or blue one, so this does not fit.
Option (3) cyanides: cyanide blocks cytochrome oxidase, so the tissues cannot use the oxygen already in the blood, and the blood stays bright red, again giving pink or cherry red lividity, not brown or blue.
Option (4) barbiturates: barbiturate deaths usually show a plain dusky purple lividity from simple respiratory depression and hypoxia, without the specific brown tint described here.

Step 4: Final Answer.
Only nitrate or nitrite poisoning explains both the brown component and the blue component of the lividity.
\[ \boxed{\text{Nitrates}} \]