Nearly 80% of people who die from drowning are male. Drug and alcohol are involved in half of adolescent and adult deaths associated with water recreation. Trauma from water recreation is secondary to dives, falls, and horseplay. And failure to wear a personal floatation device (PFD), while boating, results in a staggering 88% of drowning deaths.

Drowning – The Lungs

The lungs are the organ system that is primarily involved in drowning pathophysiology. During the drowning process, the victims become panicked, which causes an increase in respiratory rate. At some point, victims are thrust underwater and have to hold their breath. Victims inhale water into their lungs, causing pulmonary damage. They become very hypoxemic, which will then cause secondary organ damage. The heart becomes ischemic, and neurological injury can result.

Arrhythmias – Irregular Heartbeats

Heart arrhythmias, or irregular heartbeats, are a common problem after drowning but are not usually caused by electrolyte disturbances such as high calcium, high magnesium, or high sodium, as the volume of aspirated water is rarely enough to disturb plasma electrolytes. The arrhythmias are typically secondary to severe hypoxemia that causes an ischemia in the cardiac conduction system.

Hypoxia

Hypoxia (lack of oxygen) causes injury and inflammation in the brain that can lead to cerebral oedema and increased intracranial pressure. This process can occur after a relatively short period of hypoxia, which is why oxygenation is so important in the management of submersion injury. After resuscitating patients, it is important to monitor them for further neurologic deterioration, as reperfusion injury can occur.

Drowning itself is quick and silent, although it may be preceded by distress, which is more visible. Generally, in the early stages of drowning, very little water enters the lungs. A small amount of water entering the trachea can cause a muscle spasm that seals the airway and prevents the passage of both air and water until unconsciousness occurs.

This means a person drowning is unable to shout or call for help or seek attention, as they cannot get enough air. The instinctive drowning response is the final set of autonomic reactions in the 20 to 60 seconds before sinking underwater. To the untrained eye, it can look like calm, safe behaviour. Persons trained in rescue learn to recognize drowning people by watching for these movements.

Rescue

A drowning person may grab the rescuer, submerging the rescuer in the process. Thus, it is advised that the rescuer approach with a buoyant object, or from behind, twisting the victim’s arm on their back to restrict movement. If the rescuer does get pushed underwater, they should dive downwards to escape the victim.

The priority is then to transport the victim to the water's edge in preparation for removal from the water. The victim is turned onto their back with a secure grip used to tow from behind. If the person is cooperative, they may be towed in a similar fashion and held at the armpits. If the person is unconscious, they may be pulled in a similar way and held at the chin and cheeks, ensuring that the mouth and nose are well above the water.

Since drowning is mainly an oxygenation problem, rescue breaths should be started immediately. Even before chest compression. The sooner you can get air into the lungs, the better. The European Resuscitation Council recommends that five (5) rescue breaths be initiated instead of two (2) breaths when starting CPR. Most patients with respiratory arrest will respond after the first few rescue breaths.

Prevention

Prevention is more important than any action one can take after a submersion incident has occurred. Alcohol should be avoided when participating in or supervising water activities. Everyone on a boat should always wear approved personal flotation devices that will support the person’s head above water, even if the person becomes unconscious. Camp far enough away from water so that people, especially children, do not accidentally wander into the water.