Two workers collapse unconscious inside a deep, recently sealed well during cleaning operations. One dies. Police request guidance on scene processing before the bodies are moved. Which step is MOST important to establish the cause of death?

• A Measurement of atmospheric oxygen and toxic gases at the scene before disturbance ✓
• B Immediate diatom testing of femoral bone marrow
• C Estimation of carboxyhaemoglobin saturation in post-mortem blood alone
• D Histological examination of the lungs for hyaline membranes

Explanation

Deaths in wells, pits, silos and tanks are typically due to environmental suffocation from oxygen displacement by carbon dioxide, hydrogen sulphide or methane. Autopsy findings are entirely nonspecific, consisting of congestion, cyanosis and petechiae, so the diagnosis rests on scene measurement of ambient gases and oxygen concentration before the atmosphere is disturbed. Carboxyhaemoglobin estimation addresses only carbon monoxide, diatom testing relates to drowning, and hyaline membranes suggest adult respiratory distress syndrome rather than simple asphyxiant exposure.

Reference: Knight's Forensic Pathology, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.