Mythbusting Dry Drowning

 

 

OLYMPUS DIGITAL CAMERA

 

It’s 10am on a Monday. You walk into the room of a 7 year old boy and his mother. His mother is very concerned that her son, who was swimming in the pool all weekend, may now be “dry drowning.” She read about dry drowning in a parenting magazine and became concerned when she noticed he was “lethargic” this morning and only wanted to lay on the couch and watch cartoons. You ask about respiratory symptoms and, now that you mention it, her son has a DRY cough.  As a matter of fact, now she is really concerned because SHE has a dry cough too — and could you check her out while she’s there? You look at the child; he’s tan from his weekend in the sun and is eating a popsicle without any difficulty.  In fact, he winks at you and asks for another.

What exactly is dry drowning and is the boy with a cough doing it before your very eyes? Do you need to observe him and for how long?  Does he need a chest X-ray at 4 hours post pool time?  You pull out your mobile device and type “dry drowning.” The first search engine result is an article from Web MD that reads,  “With dry drowning, water never reaches the lungs. Instead, breathing in water causes your child’s vocal chords to spasm and close up after he’s already left the pool, ocean, or lake.” Essentially this piece describes laryngospasm following irritation from the water at the larynx.

Web MD’s definition of dry drowning is in contrast to ChildrensMD’s definition  (the 2nd search result), “Sometime within the next 24 hours their lungs start a massive inflammatory reaction to the water they inhaled into their lungs. Sometimes they need a ventilator to breathe for them, and drugs to keep their blood pressure up. But the worst cases of dry drowning are the children I never see, the ones who were put to bed and never wake up in the morning.” Never. wake. up.  Now you understand why your patient’s mother, as well as other parents, would have serious concerns!

The third search result is a Wikipedia topic…not sure if the 7th CNN result will be any better.

As pediatric emergency medicine providers, we will see many concerned caregivers this summer – how can we best respond to them and with what evidence? The term “dry drowning” is conspicuously absent from a PubMed search, however the following research articles describe the term.

In a 2001 study from Pediatric Clinics of North America, the authors state, “Dry drownings” probably do not exist; if there is no water in the lungs at autopsy, the victim probably was not alive when he or she entered the water.”

However, shortly thereafter in 2003, both Circulation and Resuscitation published “Recommended guidelines for uniform reporting of data from drowning: the Utstein Style,” and discussed dry drowning. In this guideline, the authors cite animal studies from the 1940s to support that “10% to 15% of drowning victims may die with no significant aspiration of liquid ‘dry-drowning’… by lethal hypoxia secondary to reflex laryngospasm from liquid penetration into the naso- and oropharyngeal airways [that results in] vagovagal cardiac inhibition or sudden cardiac arrest, pulmonary reflexes, or absorption of aspirated liquid into the bloodstream.” These 2animal studies* support that laryngospasm is generally limited to 1.5 to 2 minutes after the onset of submersion making complications of laryngospasm the actual cause of death.

More recently, a 2014 study from the American Journal of Forensic Medical Pathology supported  that death in adults can occur following significant aspiration of liquid, by mechanisms such as profound hypoxia during laryngospasm, pulmonary reflexes, or vagally mediated cardiac arrest.

Regarding children, in a 2014, 16 year retrospective pediatric study of immersion related deaths, authors reported that 82% occurred in children younger than 4 years of age with 70% occurring at home and 91% of these deaths being associated with lack of direct supervision. The article succinctly points out that none of these deaths were attributed to dry drowning.

070805-N-7446H-003 ATSUGI, Japan (Aug. 5, 2007) - A volunteer lifeguard stands watch as kids participate in a 50-meter swim during the 21st Annual Three F Cup Japanese-American Friendship Triathlon. This is the first time Naval Air Facility Atsugi has hosted the event, which was relocated from Sagami General Depot. U.S. Navy photo by Mass Communication Specialist 2nd Class Derek J. Hurder (RELEASED)

The conclusions from the limited data available supports that laryngospasm associated with immersion injuries can result in life threatening complications in the acute setting.  After a normal exam on your patient and a little bit of time to explore your other differentials, you reassure your patient’s mother with the literature on your side. However, you don’t say good-bye just yet.  The previously described 2014 pediatric study provided you with some parting words of wisdom and perhaps the most important take home message of the summer pool season – the vast majority of pediatric drowning deaths are associated with lack of supervision.

 

Angela Lumba-Brown MD, FAAP

Angela Lumba-Brown MD, FAAP

Clinical Assistant Professor Pediatric Emergency Medicine at Stanford University School of Medicine
Angela's research focus is in pediatric traumatic brain injury and recent research has been in therapeutic intervention for concussion. She the director of PEMNetwork.
Angela Lumba-Brown MD, FAAP