viernes, 12 de octubre de 2018

What is Dry Drowning?

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By Lois Zoppi, BAReviewed by Karolina Brzozowska, M.Sc.

There are a number of causes of drowning leading to disruption of the respiratory system and preventing the distribution of oxygen around the body, resulting in hypoxia and cardiac arrest.

Contrary to historical definitions and popular belief, drowning is a process that does not always result in death, as it can be interrupted, and cases of drowning can vary in severity. Cases where the victim is rescued and the drowning process is interrupted are referred to as nonfatal drowning, while terminal cases are termed fatal drowning.

Typically, the causes of drowning include:

Water in the lungs
Disruption of the surfactant (substance that prevents small airways from sticking together)
Laryngospasm (obstructing the airways at the vocal chords)
Pulmonary edema (lungs filling with fluid due to cardiac arrest or damaged lung tissue, among other causes)

Laryngospasm occurs in less than two percent of drowning cases and is incorrectly thought to protect the airways.

Drowning is a largely preventable cause of death and is one of the most common causes of death in children. Those who have been rescued from drowning present few symptoms thereafter and usually fully recover within four to eight hours of the incident.

Dry Drowning

Dry drowning, sometimes called secondary drowning, is not a medically accepted diagnosis and is a controversial term in the medical field, as the symptoms of drowning and dry drowning are the same. Therefore, no clinical distinction can be made between the two. Historically, the term ‘dry drowning’ was used to describe cases in which the deceased found in the water had no water in the lungs at autopsy.

There is a lot of misinformation spread by mainstream media outlets about alleged cases of dry drowning, with most cases having alternative, medically recognized sources.

Many health organisations, disease control and prevention centers, care providers and aquatics institutes strongly discourage the use of modifiers to categorize drowning cases.

The following terms are not to be used to describe or categorize drowning:

Near drowning (used to describe patients who survive the drowning process)
Wet drowning
Dry drowning
Passive drowning
Saltwater or freshwater drowning (there were once distinctions between drowning in different types of water, which have since been proved false)
Secondary drowning (used to describe patients who worsen after water exposure)

Secondary Drowning

Secondary drowning, like dry drowning, is not a medically accepted term. In the past it was used to describe patients whose symptoms worsened due to pulmonary edema from aspirating small amounts of water. Again, it is not an accepted term due to the presence of alternative clinical causes of drowning.

Delayed Symptoms of Drowning

After an incident in water, it’s advised to stay vigilant for the next 24 hours. Since patients may not present symptoms of drowning immediately afterwards, it is advised that they seek immediate medical attention if any of the following symptoms are present at a later stage:

Difficulty breathing
Shortness of breath
Coughing
Discomfort in the chest
Foam in the mouth

Patients are advised to seek medical attention even they feel normal after leaving the water, but begin to show symptoms more than eight hours after the incident. Other diagnoses at this point should be considered, such as:

Spontaneous pneumothorax
Chemical pneumonitis
Bacterial or viral pneumonia
Head injuries
Chest trauma
Asthma
Acute respiratory distress

All of these have been mistakenly termed as delayed, dry or secondary drowning.

Incidence Rates

A global report by the World Health Organisation stated that drowning claims the lives of 372,000 people worldwide every year. It is also a leading cause of death in children between the ages of 1 and 14.

Treatment

Prevention is the best measure in avoiding all nonfatal and fatal cases of drowning. If prevention methods should fail and the drowning process begins, the most important course of action is to reverse cerebral hypoxia by providing oxygen to the brain.

Summary

Dry drowning is not a medically accepted term for diagnosing drowning. In reality, drowning is a process with varying severity, and is not synonymous with death as commonly believed and reinforced by the media.

Cases of fatal drowning are caused by a number of complications stemming from aspiration of water including hypoxemia, apnea, and cardiac arrest.

Prevention is the most important course of action in all cases of nonfatal and fatal drowning, with methods including supervision, swimming lessons, provision of floatation equipment, as well as consistent and accurate use and distribution of terminology relating to water safety and drowning.