Drowning

Drowning Overview

According to the World Health Organization, drowning is defined as "the process of experiencing respiratory impairment from submersion/immersion in liquid." Drowning may result in death or complete recovery. However, victims may often sustain some physical or mental injury. Most drownings occur within a short distance of safety, whether that be in the bathtub, the edge of a pool or shoreline, and may often be prevented.
Because the head is submerged, air and oxygen can't get into the lungs and the victim suffocates. The tissues and organs in the body require oxygen to function, and begin to fail within a matter of minutes if deprived of it. Without oxygen, the heart muscle can become irritable and cause the electrical system to malfunction, preventing the heart from beating. Brain damage occurs within six minutes if it lacks oxygen rich blood flow.
Who is likely to drown, when, and where?

• The World Health Organization estimates that there are 388,000 drowning deaths worldwide each year. In the Unites States, the latest yearly stastistics from the CDC reported almost 4,000 people had died from drowning.
• Drowning is the third leading cause of accidental death in the United States. For children, it is the second leading cause of accidental death in school-age children, and the number one cause of death in preschoolers.
• More than half of drowning deaths occur in swimming pools.
• One-quarter to one-third of drowning victims have had swimming lessons.
• Children less than one year of age usually drown in bathtubs because they are not coordinated or strong enough to lift themselves out of the water.
• Children aged 1-4 most often drown in swimming pools.
• As children age, the percentage that drown in natural water such as rivers, lakes, ponds, and oceans begins to increase. For those older than age 15, 65% of drownings occur in natural water.
• Alcohol is a factor in up to half of adolescent and adult drowning deaths.

Mammalian Dive Reflex
Drowning suffocation causes a lack of oxygen, resulting in death in only a few minutes. An exception to this rule appears in victims who have been suddenly and rapidly submerged into ice-cold water. Some of these victims have been reported to survive up to an hour underwater without any physical damage. This phenomenon is known as the mammalian dive reflex, which is activated when the face and body plunge into ice-cold water. The acute cooling results in the very quick slowing of body metabolism and diverts blood to the essential organs of the body, the heart, lungs, and brain. With very slow metabolism, the amount of residual oxygen in the blood stream may be enough to maintain basic organ function for many minutes.
The mammalian diving reflex is most well developed in children, and is gradually decreased with age. The drowning victim may appear dead since the heart may be beating so slow that the heart beats cannot be counted, and the blood pressure so low that it can't be detected. It is very important to begin resuscitation attempts in this situation.
The mammalian dive reflex situation does not apply to victims who have gradually cooled and developed hypothermia

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Drowning Risks

The following are drowning risks in infants and children:

• Lack of supervision in the bathtub or other body of water
• A swimming pool is a risk factor in itself. Children who have drown, have only been out of sight for less than 5 minutes.
• Lack of life jackets (personal floatation devices) on boats. Pool toys are not a substitute for a "real" life jacket.
• Child abuse or neglect

The following are drowning risks In teenagers and adults:

• Alcohol consumption. Alcohol use is a factor in half of all teenage and adult drowning deaths.
• Inability to swim
• Medical emergency in the water. This includes victims who experience a heart attack, stroke or seizure in the water. It also includes open water drowning victims who sustain an animal bite or evenomation (sting).
• Fatigue or exhaustion when swimming. The buddy system is meant to prevent drowning associated with unsupervised swimming or failing to follow water safety rules.
• Not appreciating the environment. This includes diving into shallow water and sustaining a head or neck injury, or falling into the water when walking on thin ice.
• Boating accidents
• Lack of life jackets (personal floatation devices or PFDs)
• Scuba diving accidents
•   Suicide attempts 

Drowning Symptoms

Drowning is a silent killer. Victims may not be able to call for help because they are expending all of their energy trying to breathe or keep their head above water. When water is inhaled, the upper airway or larynx (voicebox) may go into a spasm, making it difficult to cry for help.
The drowning sequence

• The victim struggles to keep his or her head above the water
• After the head submerges or drops below the water surface, breath holding occurs
• When water enters the upper airways, it causes the larynx to go into spasm
• Most often the spasm relaxes, allowing water through the larynx into the bronchial tree and the lungs. Approximately 10%-20% of drowning victims have persistent laryngeal spasm and no fluid is found in their lungs on autopsy.
• The brain stops functioning within just a few minutes without oxygen, and permanent damage occurs if there is no oxygen for more than six minutes.
• The heart muscle needs oxygen to function and deadly, irregular heart rhythms may occur with oxygen deprivation.

Signs of drowning
In real life, drowning doesn't look at all like it is depicted on television or in the movies. The victim does not flail and thrash in the water, as it appears in the movies. Instead, drowning tends to be a deceptive quieter act, and victims tend to appear lethargic.
The drowning victim often is bobbing with their head tilted back just at the waterline and the mouth wide open. There are attempts to keep rolling on to the back. The respiratory effort may be rapid but is often shallow. The eyes tend to be wide open and may hold a sense of panic. If there is a swimming effort, it is weak and uncoordinated.

When to Seek Medical Care

All drowning victims require an emergency 911 call.
Even though the majority of drowning victims are revived with first aid, all these victims require activation of the emergency medical services and evaluation by a health care professional. Complications of the drowning event may take time to develop and their presentation may first be noticed hours after the drowning episode.