ISPUP helps to identify the behavior of people in the process of drowning

The Instituto de Saúde Pública da Universidade do Porto (ISPUP) participated in an international study that helped to recognize the pattern of behavior of individuals experiencing drowning.

Difficulties in water, immediate disappearance, movements similar to climbing a ladder or backward circular movements with the arms extended laterally are some of the typical drowning behaviors.

The investigation, which aims to assist lifeguards and aquatic rescue professionals, concluded that there is at most a two-minute time window to identify and recognize a person in the process of drowning. After this, the individual will become submerged and unconscious. The action time is thus very short.

The study, published in the International Journal of Environmental Research and Public Health, was developed due to the need to better understand the behavior of an individual who is in the process of drowning, a term used, in this context, to describe the situation of those with difficulty breathing during the process of immersion or submersion in water.

“There is little research in this area. Every year around 300 thousand individuals die due to drowning worldwide, but few studies have explored the visible behavior of those who are drowning. Understanding this dimension is important because it will help aquatic rescue professionals to recognize a drowning event and respond as early as possible to save lives”, says the ISPUP researcher Catarina Queiroga involved in the study.

With this purpose in mind, a team of 20 international experts in the field of aquatic rescue, including the ISPUP researcher, analyzed the behavior of a group of individuals in the process of drowning, by watching videos of aquatic incidents. The images analyzed, captured mainly by means of video surveillance systems, security cameras and closed circuit, were related to private or public pools and open water.

The importance of action time

In the 23 videos analyzed by the team of experts, 24 people experienced the process of drowning and five lost consciousness. Most of the videos portrayed drowning in children or adolescents and outdoor pools had the highest number of occurrences.

Among nine of the drowned individuals, the study observed some behaviors previously described in the literature, called “Instinctive Drowning Response”. This includes a set of negative characteristics, such as the inability to call for help and to wave, the impossibility of voluntarily controlling the movements of the arms as well as the inability to perform movements horizontally or diagonally.

Positive characteristics were also observed, such as involuntary but controlled movements of extension of the arms and pressure on the surface of the water, in a vertical movement similar to that of climbing a ladder.

Surprisingly, in 19 of the 24 drowning individuals, a new behavioral pattern that had not been described in previous studies was noted. This corresponded to making backward circular movements with the arms extended laterally, in an attempt to keep their head out of the water, which experts call “backwards water milling”.

The researchers’ observations suggest that there is, at most, a two-minute time window to identify and recognize a person in the process of drowning. After this, the individual will become submerged and unconscious.

As Catarina Queiroga explains, “this time interval is the maximum limit for recognizing an individual that is drowning and initiating actions aimed at interrupting the drowning process as well as minimizing the impact of water entering the airways and the consequent hypoxia, corresponding, roughly speaking, to the period of time in which the person is still conscious”.

It is particularly important to reinforce the idea that, contrary to what is often depicted in the media, people who experience drowning do not wave or shout for help. Drowning is quick and silent.

Need for future studies

According to the ISPUP researcher, the published article will help lifeguards, aquatic rescue professionals and researchers to identify someone who is in a drowning situation and to understand the importance of being aware of these behaviors to save lives, when preventing an incident has failed.

“Given that this article showed that the visible behavior of a drowning person can vary widely and there are many aspects that are still unknown, it is necessary to increase knowledge in this area by conducting further observational studies”, she concludes.

The research entitled The Visible Behaviour of Drowning Persons: A Pilot Observational Study Using Analytic Software and a Nominal Group Technique is available HERE and was developed by an international working group of experts from various countries dedicated to studying drowning.

Image: Unsplash/Lavi Perchik

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