Suffocation after submersion in water, often leading to unconsciousness and even death
- May occur at any age but most common in children and adolescents
- More common in males
- Access to unfenced water is a risk factor
- Genetics is not a significant factor
Drowning causes about 450 deaths each year in the UK and is a common cause of accidental death, particularly in children and adolescents. An even greater number have a near-drowning experience. The majority of cases of drowning are the result of water activities in a strong current or after drinking alcohol. However, young children who drown often do so in swimming pools or ponds at home. The risk of drowning can be greatly reduced by taking care around water and particularly by supervising children when they are swimming or playing in water (see Safety in and around water).
When a submerged person starts to choke, the larynx (voice box) goes into spasm, preventing water from entering the lungs but blocking normal breathing. Eventually, lack of oxygen causes loss of consciousness, and the larynx usually relaxes. If the face is submerged, water may then enter the lungs. In 1 out of 10 cases, the larynx stays closed and no water enters the lungs. This condition is known as dry drowning.
People who are drowning can often be revived by first aid. However, life-threatening complications may develop, and hospital treatment is still needed even if they have apparently recovered.
Are there complications?
Lack of oxygen can lead to brain damage and death. Even if breathing is restored, water may cause inflammation of the lining of the lungs, leading to acute respiratory distress syndrome. Debris in the lungs may cause infection and lung damage, impairing the ability of the lungs to function normally.
Inhaled water may alter blood chemistry. If fresh water is inhaled, it passes from the lungs to the bloodstream and destroys the red blood cells. If salt water is inhaled, the salt causes blood to enter the tissues of the lungs.
A drowning person can survive for longer in cold water because the body’s processes slow down. As a result, many people who have been resuscitated after a near-drowning experience may also have hypothermia.
What can I do?
Call an ambulance. Shout for a trained first-aider to help you. Only attempt to rescue a drowning person if you are sure that you can do so without putting yourself at risk.
The person will need to be brought back to land before any other measures can be taken. If the person is conscious and close to you, throw him or her an object that will float, ideally with a rope attached. Alternatively, throw in one end of a stick, pole, or even an item of clothing for the person to grasp. If the person cannot reach the object, swim out only if it is safe. Otherwise, note the position of the person and call for assistance.
Once the person is on land, ask the first-aider to assess his or her condition and, if necessary, carry out emergency measures such as resuscitation.
If the person has fallen into cold water, wrap him or her in warm, dry clothing or blankets to try to reduce the risk of hypothermia. Continue resuscitating a person who is cold because nearly drowned people can survive far longer if they have hypothermia.
Even if the person seems well, medical attention should be sought to make sure that there are no complications.
What might the doctor do?
Even if the person is conscious when first seen in hospital, he or she is likely to be admitted for observation because problems can develop in the first 24–48 hours. Treatment may range from giving oxygen to monitoring and care in an intensive therapy unit. In some cases, mechanical ventilation may be needed to ease breathing difficulties. Additional treatment depends on any complications that develop. For example, corticosteroids may be given to reduce inflammation in the lungs, and antibiotics may be administered to counter possible lung infections.
If hypothermia has developed, the person is rewarmed slowly. Body temperature needs to be slowly returned to normal before an assessment for brain damage can be carried out.
What is the prognosis?
The outlook is improved if the water is cold, the period of submersion is short, and the person is young and otherwise healthy. About 1 in 20 people who are resuscitated later die of a complication. Those who survive may have sustained some permanent brain damage.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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