A 22-year-old man dives into a cold river and is pulled out within two minutes, dead. Resuscitation fails. Autopsy shows no water in the airways, no froth, lungs of normal weight, and no diatoms in distant organs. Which mechanism best explains this death?

• A Laryngeal oedema from aspiration of river silt
• B Haemoconcentration and ventricular fibrillation from hypertonic water
• C Vagal inhibition of the heart triggered by sudden cold water contact (immersion syndrome) ✓
• D Delayed secondary drowning from surfactant washout

Explanation

Immersion syndrome, also called dry drowning or cold water shock, is death from vagally mediated cardiac arrest or arrhythmia when cold water strikes the skin, larynx or external auditory meatus, often in an intoxicated individual. Because little or no water is aspirated, the autopsy is essentially negative apart from nonspecific asphyxial signs. Surfactant washout describes secondary drowning, which is delayed and would show pulmonary findings, and hypertonic haemoconcentration applies to salt-water aspiration.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.