Drowning: A Diagnosis of Exclusion

With warmer weather approaching (or already arrived, depending on your location), it’s a good opportunity to review investigation of drowning deaths in forensic pathology. Drowning is the leading cause of deaths for children between the ages of 1 and 4 in the United States, but it can affect any age group.

Drowning is a diagnosis of exclusion – there are no pathognomonic signs of drowning, and a complete autopsy is required to rule out competing causes of death. Keeping an open mind during the investigation is the first step – discovering a body in water doesn’t automatically mean the cause of death is drowning. The body of a homicide victim may be disposed of in water as an attempt to destroy evidence, or someone may die of a cardiac arrythmia while they happen to be swimming.

The questions to answer in possible drowning deaths are much like those when faced with a body found after a fire (see “The Basics of Deaths by Fire” from February 23, 2023). Was the person alive when their body entered the water? And if they were, did they die from drowning – or did they die of another cause, and then become submerged?

Autopsies of drowned individuals commonly reveal findings supportive of, but not specific for, drowning. The lungs are typically over-expanded and edematous, and foamy fluid may be in the airways. A “foam cone” may protrude from the nostrils and/or mouth. Pulmonary effusions can be present, and the petrous ridges at the base of the skull may show red-purple discoloration due to vascular congestion and hemorrhage. The stomach and sphenoid sinus may contain large amounts of watery fluid. Wrinkling and pallor of the skin of the hands and feet (formerly called “washerwoman’s hands”) is often identified but doesn’t necessarily indicate drowning as it can occur with pre-mortem or post-mortem submersion.

A posterior neck dissection is necessary in most drownings to rule out high cervical spine injuries, which are often overlooked without this special autopsy technique. This type of trauma can be seen in divers or jumpers who strike head-first in shallow bodies of water and may cause death by itself or contribute to the decedent’s inability to self-extricate from the water. Pathologists also need to be aware that post-mortem injuries can happen as the body is passively carried by currents and bumps into rocks or other debris, known as “travel abrasions”.

The body of water is another consideration. It would be highly unlikely for a neurologically alert teenager or adult to drown in a bathtub, whereas an infant could easily drown if left unsupervised. In contrast, it may take a river or ocean with strong currents to overpower experienced swimmers. Personal medical history is important, as well – an adult with epilepsy could drown even in shallow water if they experience a seizure. The temperature of the water can also play a role. Cold water can trigger cardiac arrhythmias, contribute to fatigue of skeletal muscles, or incite hypothermia leading to a loss of consciousness. Toxicology testing is an important ancillary test in drowning deaths to provide context and may reveal intoxications that help explain someone’s inability to remove themselves from the water. Alcohol can contribute to the impairment of physical coordination and/or increase risk-taking behaviors, and has been associated with up to 70% of water recreation-associated deaths.

If the autopsy doesn’t show any indicators of drowning but reveals potentially lethal natural disease (such as severe coronary artery stenosis), then it’s likely the person died while they happened to be in the water and not because they were in the water. In every situation, though, the autopsy findings must be correlated with the decedent’s history, the results of scene investigation, and toxicology testing before a final diagnosis can be rendered. In this way, autopsies of water-associated deaths highlight the importance of context and investigation in forensic pathology.

Figure 1. A classic example of the “foam cone” seen at autopsy in instances of drowning. This finding results from marked pulmonary edema, and isn’t specific for drowning – it can be seen in many other conditions including opiate overdoses and heart disease.

Figure 2. Foamy fluid in the trachea and mainstem bronchi can be seen in any condition that causes pulmonary edema, and also is not specific for drowning.

Figure3. Wrinkling and paleness of the hands and feet is often seen in bodies recovered from water, whether or not the cause of death was actually drowning.

References

Armstrong EJ, Erskine KL. Investigation of drowning deaths: a practical review. Academic Forensic Pathology, Jan 2018.
Centers for Disease Control and Prevention, National Center for Injury Prevention and Control. Drowning Prevention. <https://www.cdc.gov/drowning/facts/index.html> Accessed 6/21/2023.