Asphyxial Deaths: Forensic Classification
Forensic Pathology: Mechanisms of Respiratory Impairment
1. Clinical Classification
| Category | Examples/Mechanisms |
|---|---|
| Mechanical Obstruction | Suffocation (smothering, choking), hanging, Strangulation (ligature, manual). |
| Environmental/Chemical | Drowning, Carbon Monoxide poisoning, Cyanide toxicity. |
| Mechanical Compression | Traumatic asphyxia (crush injury), Postural (positional) asphyxia. |
2. General Autopsy Findings
- Petechial Hemorrhages: Small, pinpoint hemorrhages (classic in conjunctiva, eyelids, and epicardium) due to increased venous pressure and capillary rupture.
- Cyanosis: Deep blue/purple discoloration of the skin and mucous membranes.
- Visceral Congestion: Engorgement of internal organs, particularly the lungs and brain, often associated with pulmonary edema.
- Fluid Blood: Blood often remains liquid and dark due to high CO2 levels and fibrinolysis.
3. Forensic High-Yield Pearls
- Hanging vs. Strangulation: In hanging, the ligature mark is typically inverted V-shaped and non-continuous (at the site of the knot). In strangulation, the mark is usually horizontal and continuous around the neck.
- Traumatic Asphyxia: Characterized by intense cyanosis and petechiae restricted to the head, neck, and upper chest; occurs when the chest is pinned (e.g., car crush), preventing respiratory excursion.
- Drowning: Look for “foam cone” at the mouth/nostrils and diatom findings in organs (though controversial, still cited).