This cardiac arrest stops the flow of blood and thus stops the transport of oxygen to the brain. Cardiac arrest used to be the traditional point of death, but at this point, there is still a chance of recovery. The brain cannot survive long without oxygen, and the continued lack of oxygen in the blood, combined with the cardiac arrest, will lead to the deterioration of brain cells, causing first brain damage and eventually brain death from which recovery is generally considered impossible. The brain will die after approximately six minutes without oxygen at normal body temperature, but hypothermia of the central nervous system may prolong this.The extent of central nervous system injury to a large extent determines the survival and long term consequences of drowning, In the case of children, most survivors are found within 2 minutes of immersion, and most fatalities are found after 10 minutes or more. Water aspiration
If water enters the airways of a conscious person, the person will try to cough up the water or swallow it, often inhaling more water involuntarily. When water enters the larynx or trachea, both conscious and unconscious people experience laryngospasm, in which the vocal cords constrict, sealing the airway. This prevents water from entering the lungs. Because of this laryngospasm, in the initial phase of drowning, water generally enters the stomach, and very little water enters the lungs. Though laryngospasm prevents water from entering the lungs, it also interferes with breathing.
These lung injuries can be contributed by water aspiration and also irritants present in the water such as microbial pathogens leading to complications such as lung infection that can develop in adult respiratory disease syndrome later on in life. Some literature suggests that occurrences of drowning can lead to acute kidney injury from lack of blood flow and oxygenation due to shock and global hypoxia. These kidney injury can cause irreversible damage to the kidneys and may require long-term treatment such as renal replacement therapy. Infant Risk
Children are overrepresented in drowning statistics, with children aged 0–4 years old having the highest number of deaths due to unintentional downing. In 2019 alone 32,070 children between the ages 1–4 years old died as a result of unintentional drowning, equating to an age-adjusted fatality of 6.04 per 100,000 children. Infants are particularly vulnerable because while their mobility develops quickly, their perception concerning their ability for locomotion between surfaces develops slower. An infant can have full control of their movements, but simply wont recognize that water does not provide the same support for crawling as hardwood floors would. An infant’s capacity for movement needs to be met with an appropriate perception of surfaces of support (and avoidance of surfaces that do not support locomotion) to avoid drowning. By crawling and interacting with their environment, infants learn to distinguish surfaces offering support for locomotion from those that do not, and their perception of surface characteristics will improve, as well as their perception of falls risk, over several weeks.