Forensic pathology
Types of injuries
Drowning

Author: Lindsey Harle, M.D. (see Authors page)

Revised: 12 January 2017, last major update August 2012

Copyright: (c) 2012-2017, PathologyOutlines.com, Inc.

PubMed search: drowning [title] forensic

Table of Contents
Definition / general
Cite this page: Drowning. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/forensicsdrowning.html. Accessed July 23rd, 2017.
Definition / general
Drowning should be considered as a possible cause of death when:
  • 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