Summer is here, and with it, the fun of swimming! While every parent knows the necessity of vigilant supervision whenever children are near water, there are some dangers that can go undetected simply because they are not well-enough known. It is common knowledge that drowning is a leading cause of death among children, but how many of us know that children can suffer the effects of drowning hours after having been swimming due to water inhalation? Or that a sudden inrush of water into one's mouth can cause the larynx to spasm and snap shut resulting in asphyxiation? Or that jumping into extremely cold water can result in cardiac arrest? There is growing concern surrounding these incidences and knowing how to prevent such tragedies starts with understanding what to look for.
Recently there have been well-publicized, terrifying reports of children who have "drown" hours after returning home from a day spent swimming. It bears clarifying that while these are often reported as "dry" drownings because the child was not physically in the water at the time of death, such incidences would more accurately be described as "delayed (or secondary)" drownings. That said, while there is a difference between "dry" and "delayed" drowning, both can lead to respiratory arrest and can culminate in cardiac arrest and brain death.
The main difference between "dry" drowning and "delayed" drowning is the presence or absence of water in the victim's lungs. True "dry" drowning deaths do not involve the presence of any liquid in the lungs. Conversely, "delayed" drownings are marked by the presence of some (usually small) amount of liquid in the lungs.
Though not completely understood, "dry" drownings are thought to be caused by: 1. a sudden rush of water into the throat that causes the airway to snap shut (a condition known as a laryngospasm), resulting in asphyxiation, and/or 2. the shock of sudden entry into extremely cold water that causes the heart to stop.
While the incidence of "delayed" drowning (where liquid is present in the lungs) is relatively rare, true "dry" drownings account for ten to fifteen percent of all drowning deaths. Considering that approximately 4,000 people drown in the U.S. each year, that means "dry" drowning kills approximately 400-600 U.S. victims annually. "Dry" drowning poses a significant enough mortality risk that those who swim (or supervise swimmers) should know what can be done to decrease the chance of its happening to them or their loved ones.
To help prevent "dry" drowning, swimmers should keep their mouths closed when jumping or diving into water, thereby protecting the larynx from a sudden inrush of water that could cause it to spasm and cut off the airway. Also, do not dive or jump into extremely cold water; instead enter cold water gradually. Those who have a history of heart or respiratory problems should avoid entering very cold water at all, even if they plan to go slowly.
Unlike "dry" drowning, "delayed" drowning takes longer to occur and can be treated if caught early. A "delayed" drowning episode (where blood is not being properly oxygenated within the body due to a respiratory intake of liquid) is marked by the following indicators: persistent coughing, shortness of breath, painful or shallow breathing, pain in chest, change in mood, change in mental status, and/or lethargy. Other signs of poorly oxygenated blood include increased agitation when lying flat, sweaty skin, or skin color changes such as paleness or blue/grayish cast.
Remember, children's bodies cannot compensate for very long without proper oxygenation and "crash" rapidly once these signs are present, so quick action is imperative. "Delayed" drowning usually occurs within 1 to 24 hours after an incident of respiratory intake of liquid. If it is caught early, it can be treated by supplying oxygen to the lungs. Call 911 or rush immediately to the emergency room if there are signs or symptoms indicating risk of a "delayed" drowning episode.