Undoubtedly you will see a child with a “near drowning” if you work in the ED during the summer. Most children are fine, even those that received some back blows, mouth to mouth or some semblance of bystander rescue maneuvers. Asymptomatic children (no respiratory symptoms) can be safely discharged home. Those that are having difficulty breathing or other symptoms should receive appropriate respiratory support and be followed closely clinically and with chest x-rays when the situation changes. All symptomatic children should be admitted to the hospital.
A recent post on the PEM fellows blog by Angela Lumba-Brown, MD addressed a common misconception surrounding the concept of the so-called “dry drowning.” Every summer this issue seems to make its way around Facebook and even written up in USA Today. Theoretically, when a child (or mammal for that matter) goes under water you will have forceful glottic closure/laryngospasm. This is a protective response that prevents water from rushing into the lungs. The release of that pressure can lead to a condition akin to post obstructive pulmonary edema (POPE) where the sudden change of pressure leads to an influx of fluids into the lungs. Additionally, the laryngospasm can be so forceful that resultant bronchospasm also occurs, leading to impaired ventilation and subsequently oxygenation. Even a small amount of water dribbling unexpectedly into the larynx can cause this automatic reaction. This glottic closure is why most of the water goes into the stomach, and thus many submersion victims vomit quite a bit of pool water.
Generally, the aforementioned physiologic changes and deleterious aftereffects occur fast and patients are very sick very fast. What gets parents so riled up is that the media and some medical experts note that kids can have a submersion event, and then 24 to 48 hours later experience a “dry-drowning” where the initial spasm leads to very delayed impairments in ventilation due to transudative edema and/or bronchospasm. Though there are news reports and social network conversations on the matter every summer the existing research is not surprisingly, thin.
Dr. Lumba-Brown notes that:
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.
The rest of the evidence is on animals. Take from that what you will. Nevertheless she also notes that:
The conclusions from the limited data available supports that laryngospasm associated with immersion injuries can result in life threatening complications in the acute setting.
So, in short, if something bad is gonna happen it will be noticeable right away. Symptoms can worsen, but they’ll be present upon initial evaluation.