Drowning is the second leading cause of mortalityafter vehicular accidentsin most countries of the world. The exact statistics of these cases in the Kingdom is unknown, but through my experience, I know that, drowning cases in children largely increase during summer in Saudi.

One of the reasons of drowning is - poor monitoring by the parents and the absence of lifeguards at public swimming pools. It is important to mention here that drowning of children is not limited to swimming pools or seas, but several cases of drowning have been reported at home in the bathtub, for instance, there is a water in the tub and an infant falls on his face and is unable to move to his side.

In this article, I would like to focus on the medical aspect of drowning, the changes that take place in the body, and the first-aid treatments for the case of drowning.

The physiological changes that take place in the body while drowning in freshwater are relatively different than drowning in salt water. However, this is concerns the specialist more; hence we will not discuss it in detail.

In both cases, the person who is drowning tries to keep the air inside his lungs and prevents water from entering. So he stops breathing entirely and resists the body's need for air. He may also become nervous and start moving rapidly, which increases the body's oxygen consumption.

This may result into respiratory failure as the rate of carbon monoxide in the blood increases causing lack of oxygen. When the carbon monoxide affects the blood, he cannot control his breathing and starts inhaling water that enters the pharynx and the upper respiratory system. This constricts the pharynx, and it locks up to protect the lungs from water. Thus, he may swallow large quantities of water that reaches the stomach.

In 10 out of 15 cases of drowning, it is seen that the pharynx remains locked to protect the lungs from water. This is called dry drowning. The possibility to rescue these people is higher than the others. However, the victim whose pharynx is not locked and allows the water to enter the lungs, goes into coma due to lack of oxygen, this case is known as wet drowning.

In cases of death due to drowning, the forensics and criminal investigators try to ascertain the possible cause of death by using this information. If there is water in the lungs, then it is evident that he was alive whilst in water. And if there is no water in the lungs then it could be due to two reasons; first is dry drowning, and second is that the body was put into the water after death.

The person who is drowning, loses consciousness when the rate of oxygen pressure in blood falls to 25-30 (normal is 80). For a drowning man to faint or go into coma, it may not take more than two minutes. Also, he cannot call for help because shouting requires pulling air into lungs, which is not possible for him. He cannot wave his hands either, what we see is involuntary movements to keep his face and mouth above the water.

Continued lack of oxygen causes the heart to completely stop (in 2-10 minute), which in turn interrupts the oxygen supply to the brain resulting in death. It takes place usually six minutes after the heart stops.

Saving a person

Saving a drowning man starts by pulling him out the water. There are specific ways to get him out of water that the lifeguards are trained to handle. The first aid treatments start after getting him on to the land. If the patient is conscious, the guard starts to speak to him and tries to calm him down, and then he calls the emergency medical service to examine the patient for any need to be hospitalized.

If the patient is unconscious and there is no sign of breathing, then it is necessary to administer CPR by a person trained as per the English-Saudi Heart Association. It is similar to theCPRmethods of heart attacks.

In this context, I would like to revisit some misconceptions of the some readers. Some people believe that turning the patient on his face, particularly children, leads to quick release of the water from the lungs. This is entirely wrong, as it does not solve the fundamental problem is respiratory failure, and delays first aid; plus there is a possibility for brain cells to die.

Also, the attempt to suck the water from the stomach does not work normally, and may cause vomiting and inhaling the contents of the stomach into the lungs, and thus increasing the inflammation of the lungs and blocking the supply of oxygen.

I ask God to bless you. 

Ahmed BaHammam, FACP, FCCP
Professor of Medicine
Director, University Sleep Disorders Center
College ofMedicine, King Saud University