At autopsy, livor mortis is found to be fully fixed (not shifting on turning the body) and bright pink. The most likely interpretation is:

• A Body was refrigerated post-mortem; pink colour is from preserved oxyhaemoglobin
• B Cyanide poisoning — cherry-red livor due to cytotoxic hypoxia with preserved oxyHb
• C Both refrigeration and CO poisoning can cause this; CO is distinguished by elevated COHb on spectroscopy ✓
• D Carbon monoxide poisoning — cherry-pink carboxyhaemoglobin persists even after cooling

Explanation

Both CO poisoning and refrigeration can produce bright pink/cherry-red livor mortis. CO poisoning causes carboxyhaemoglobin (COHb), which is cherry-pink and stable; refrigeration preserves oxyhaemoglobin from oxidising to methaemoglobin, also producing pink livores. Distinction requires spectroscopic analysis of blood for COHb levels (>50% in fatal CO poisoning) and scene correlation. Cyanide also causes cherry-red tissues and blood but is due to venous oxyHb preservation (oxygen cannot be utilised by tissues). The question's 'fixed' and 'pink' finding requires both causes to be considered.

Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.

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Written and medically reviewed by the StethoPrep medical team.