Autopsy & forensics
Types of injuries
Drowning
Author: Lindsey Harle, M.D.
Last author update: 1 August 2012
Last staff update: 5 June 2023 (update in progress)
Copyright: (c) 2012-2019, PathologyOutlines.com, Inc.
PubMed search: Drowning [title] forensic
Table of Contents
Definition / generalCite this page: Harle L. Drowning. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/forensicsdrowning.html. Accessed June 8th, 2023.
Definition / general
Drowning should be considered as a possible cause of death when:
Stages of drowning:
Freshwater versus saltwater drowning:
Near drowning: when a submerged individual survives greater than 24 hours after rescue
Survival in cold water drowning:
Autopsy findings:
- Body is recovered from a body of water, on the banks of a body of water or near a fluid filled container
- Body is found with head submerged in fluid (e.g. bathtub)
Stages of drowning:
- Voluntary breath holding until the urge to breath becomes overwhelming
- Fluid aspirated into airways / swallowed into GI tract
- Fluid aspiration ceases due to anoxic cerebral injury
- Anoxic cerebral injury becomes irreversible
Freshwater versus saltwater drowning:
- Any difference in severity of fresh versus salt water drowning is unproven
- Freshwater drowning: water denatures alveolar surfactant and rapidly passes into the bloodstream producing hemolysis
- Saltwater drowning: water dilutes alveolar surfactant; circulating plasma is drawn via osmosis into alveoli, resulting in hemoconcentration and increased blood electrolyte levels
Near drowning: when a submerged individual survives greater than 24 hours after rescue
- May show pulmonary edema, hemoglobinuria, cardiac arrhythmia, pneumonitis, fever, sepsis and sequelae of cerebral hypoxia; rapidly developing cerebral edema is a common mechanism of death
Survival in cold water drowning:
- Several reported cases of individuals surviving after prolonged immersion in cold water
- Thought to be due to the "diving reflex": cold water immersion leading to bradycardia and vasoconstriction to all major organs, with the exception of the brain and heart
Autopsy findings:
- Drowning is a diagnosis of exclusion, based on ruling out all other causes of death via complete autopsy and toxicology
- May see bloody froth in the airway, water in the stomach, cerebral edema, petrous or mastoid hemorrhage
- "Washerwoman" changes of the hands (shriveling of the skin) develop when submerged in water for several hours; occurs regardless of whether the person died in the water
- Postmortem lacerations / abrasions due to scraping along rough surfaces in the water or animal activity should not be confused with antemortem trauma
Unconfirmed tests for drowning
Diatom test:
- Diatoms are microscope algae present in bodies of water; theoretically should never be present in a human unless they inhaled water
- Look for diatoms in bone marrow
- Validity questionable because diatoms are present in soil and atmosphere, and samples are easily contaminated
- Absence of diatoms does not rule out drowning:
Paired cardiac electrolytes:
- In saltwater drowning, Na and Cl concentrations in right and left heart blood should be widely different
- Invalid if individual survived for a period of time or had significant CPR
Sphenoid sinus fluid:
- Significant fluid in sphenoid sinuses (several milliliters) is suggestive of water aspiration; not a validated test
