Drowning is technically defined as the physical filling of the lungs with massive amounts of liquid like water. Statistics have shown that it is possible for people to drown in as little as 2 inches of water. Infants may drown in a bathtub while pre-school children are likely to drown in a swimming pool.
Drowning victims may conveniently be classified under one of the four classifications, these are: the asymptomatic victims, the symptomatic victims, victims in arrest, and dead victims. Asymptomatic victims does not exhibit any signs and symptoms when brought to the emergency room. They are the class that underwent a very brief immersion episode or those who are immediately resuscitated at the site of the accident.
The symptomatic subgroup will present clinically with anxiety, altered vital signs, altered state of consciousness , dyspnea, coughing with wheezing, and vomiting. Victims in cardiopulmonary arrest will present with apnea, asystole, fibrillation, and immersion syndrome. However, victims who are obviously dead are usually wheeled in the emergency room with long standing apnea, asystole with nomothermia, dependent lividity, rigor mortis, and no central nervous system reflexes.
The management of drowning victim is largely centered on the state of hypoxemia. Patients who are grossly asymptomatic are attached to pulse oximeter for close monitoring while arterial blood gases are taken to determine the extent of hypoxemia and metabolic acidosis. Blood tests like complete blood count, glucose levels, cardiac enzymes, and liver enzymes are taken to determine organ impairment after drowning.
Renal function test through serum creatinine determination establishes the extent of renal damage during metabolic acidosis states. Chest radiography demonstrates water aspiration, atelectasis, and pulmonary edema in patients after drowning. Electrocardiography (ECG) is routinely performed to spot arrhythmias and bradycardias after a drowning incident .
Best prognostic outcomes in post drowning patients are directly influenced by the conduct of pre- hospital care by the bystanders . Patient must immediately be referred to an emergency service facility to conduct patients to the nearest tertiary hospital. Drowning victims are immediately removed from the water and initial cardiopulmonary resuscitation must be initiated. Patients who are hypoxemic (PO2 below 70) are intubated in the emergency room to increase blood oxygenation. Volume depletion brought about by the pulmonary edema is treated with an intravenous isotonic crystalloid solution.
A nasogastric tube is sometimes attached to drain fluids from the stomach. Patients with respiratory failure due to drowning are given surfactant therapy to improve ventilation and blood oxygenation . It is imperative to treat physiologic imbalances like electrolyte imbalance, hypoglycemia, seizures, and bronchospasms as soon as they are detected in the hospital setting.
Drowned patients who are coherent, alert, or mildly obtunded when brought to the emergency room department have a better prognosis. Patients who are grossly comatose and unresponsive with delayed attempts for cardiopulmonary resuscitation carry a very poor prognosis. Studies have shown that 35% to 65% of these cases die in the emergency room. Although those who survive has a very high likelihood of sustaining neurologic sequelae in the future in up to 60% of cases. In general, 35% of water immersion injury in children are fatal.
Accidents are the leading cause of drowning among toddlers between the ages 1 to 4 years old. Patients with organic diseases like seizure disorders, stroke, coronary conditions, and hypoglycemia are more prone to drowning. Adults who have taken in too much alcohol and sedatives are likely to drown while swimming in a body of water. Swimmers may also drown when a sudden cardiac arrhythmia strikes during the activity. Secondary drowning can occur if the lungs produce excessive liquids as a reaction to a gas or liquid irritants impairing the gas exchange.
According to the World Health Organization (WHO), drowning represents the third leading cause of accidental death worldwide. There are approximately 372,000 drowning deaths occurring worldwide annually. Male children with access to water facilities are more prone to drowning than their female counterparts. On the average, there are 10 deaths per day due to drowning in the United States .
There is a bimodal distribution in the drowning victim incidence, the first peak is observed on the toddler years and the second peak is seen among adolescents below 14 years of age. Drowning usually occurs on weekends during summer time because of the increased water-related activities for children. British statistics elaborate that 10% of the drowning incidences occur domestically in bathtubs, water buckets, and garden ponds .
The pathophysiology of drowning revolves in the propagation of tissue hypoxemia and metabolic acidosis that happens during the event. Primary damage of the cerebral tissues stems out from the initial hypoxemia during the event, although secondary cerebral hypoxemia may also occur in drowning especially when complications like cardiac arrhythmia and pulmonary edema sets in. The initial phase of drowning is characterized by severe laryngospasm due to the initial water irritation of the oropharyngeal area. The hypoxemia ensues when the air is no longer passing through the neck area causing carbon dioxide retention to the blood. The progressive carbon dioxide retention causes the laryngospasm to relax that makes the patient automatically gasp and hyperventilate.
This motion underwater causes more water fluids to rush in the lung air spaces aggravating the hypoxemic states. Water in the lungs must actively be ventilated in because victims that are already dead could not accumulate water in the pulmonary spaces even when thrown in the water post-mortem . The active aspiration of water reaching a level of approximately 22 ml per kilogram body weight can already alter electrolyte balance and cause significant hyponatremia especially in drowning children. In 10 to 20% of cases, cardiac arrest ensues just a few minutes after severe laryngospasm, causing deaths referred to clinically as “dry drowning”. Patients who survive drowning may develop infections of the air spaces like the nasal sinuses, the lungs, and the central nervous system with unusual bacteria like Naegleria sp., Pseudallescheria boydii, Balamuthia, and Aeromonas spp. .
Accidental drowning can actively be prevented by installing barriers to water hazards in the domestic setting. Teaching children how to swim greatly reduces the risk for drowning among school age children. Effective policies on safe boating, ferrying, and shipping prevents untoward maritime accidents that may lead to massive drowning.
Drowning is clinically defined as death due to asphyxia after submersion to a large amount of liquid within a period of 24 hours . Drowning is considered as a serious public concern for it represents a major cause of disability and death especially among children . Patients who survive drowning sustain permanent neurologic deficits in one-third of cases. The immediate threats associated with drowning are the untoward effects it has on the cardiovascular and nervous system. Community education is the best way to prevent unnecessary morbidity and mortality linked with drowning.