Drowning

Drowning is the process of respiratory impairment due to submersion in liquid, most commonly a body of water. It is the leading cause of unintentional injury death among children under the age of five in the US and the third leading cause of unintentional injury death for all age groups worldwide. Risk factors include poor safety (especially inadequate supervision of children), inability to swim, intoxication (e.g., with alcohol), and preexisting medical conditions associated with seizures, cramps, loss of consciousness, and/or poor neuromuscular control (e.g., epilepsy, diabetes mellitus, cardiovascular disease, Parkinson disease). Urgent rescue and first aid, especially basic life support in unresponsive individuals, are fundamental to the prevention of injury and death. Rescued individuals, including those who are responsive, should receive prompt medical evaluation, including assessment of neurological and pulmonary function (e.g., dyspnea, apnea, cough, wheezing, impaired consciousness), past medical history, history of substance use, the type of liquid involved (e.g., fresh water or salt water), and the amount of liquid aspirated. Complications of drowning, e.g., ARDS and cardiac arrest, may occur days or even weeks after the event.

• Peak age: children < 5 years ^[1]
• Leading cause of unintentional injury death in children ages 1–4. ^[2]
  • Second leading cause of unintentional injury death in children ages 5–14 after motor vehicle crashes
  • Third leading cause of unintentional injury death worldwide
• There are approximately 4000 unintentional drowning deaths in the US each year. ^[3]
• ♂ > ♀ ^[4]

Epidemiological data refers to the US, unless otherwise specified.

• Inability to swim
• Poor safety, esp. inadequate supervision of children; , access to open bodies of water , not wearing life jackets during water activities such as boating, and risky behavior
• Use of recreational or prescription drugs that may impair consciousness, awareness, and/or motor function (e.g., alcohol, SSRIs, benzodiazepines)
• Hypothermia or hyperthermia (while swimming or bathing)
• Medical conditions associated with seizures, cramps, loss of consciousness, and/or poor neuromuscular control (e.g., epilepsy, cardiovascular disease, preexisting injuries, diabetes mellitus, Parkinson disease).
• Living in areas prone to natural disasters such as floods and storms.

• Submersion → panic → holding of breath → activation of the inspiratory reflex within 1–2 minutes → aspiration of liquid or laryngospasm → hypoxemia → organ hypoxia (especially cerebral and cardiac) → possible injury or death

Features of drowning injury ^[5][6]

• Impaired consciousness, loss of consciousness
• Hypothermia
• Pulmonary
  • Dyspnea/apnea
  • Cyanosis
  • Pulmonary edema
  • White or pink froth from nostrils and/or mouth
• Cardiovascular
  • Hypotension
  • Cardiac arrest
  • Cardiac arrhythmias
• SCUBA diving injuries
  • Barotrauma
  • Air embolism

Postmortem features of drowning ^[7]

• Pulmonary findings
  • Pleural effusion
  • Pulmonary edema
  • Paltauf spots: bright red spots of ∼ 1 cm in size, which occur due to capillary hemorrhage of the pleura
• Gastrointestinal findings: Wischnewsky spots (gastric mucosal petechial hemorrhages associated with hypothermia)
• External findings
  • White or pink froth cone over nostrils and/or mouth
  • Pallor and wrinkling of the palms, soles, fingers, and toes
  • Prone body position: back upwards, head and extremities dangling downwards
  • Travel abrasions and lacerations on the forehead, backs of the hands, knees, and dorsum of the feet

• Clinical evaluation: For further information, see “ABCDE approach.”
• Physical examination
  • Auscultation of the lung: rales indicate pulmonary edema
  • Neurological examination: pupillary reflex, Glasgow coma scale
• Laboratory studies: ABG (to detect metabolic and/or respiratory acidosis)
• Imaging: x-ray chest (to confirm the diagnosis of pulmonary edema)

• Acute interventions ^[8]
  • Safe rescue: Rescuers should not put their lives at risk to save a drowning person.
  • Immediate resuscitation in unresponsive patients (for further information see “Basic life support”)
• Emergency department management
  • Supplementation of O₂ ^[9]
    • Via nasal cannula or noninvasive positive pressure ventilation: in patients without neurological deterioration and with an SpO₂ > 90%
    • Via endotracheal tube: in patients with signs of neurological deterioration or an SpO₂ < 90%
    • Oxygen saturation should be between 92–96%.
  • Advanced cardiac life support
  • Management of hypothermia
    • Removal of wet clothing
    • Rewarming in case of hypothermia (see “Management of hypothermia” for more information)
  • For asymptomatic individuals and those with mild symptoms: monitoring for 8 hours (due to risk of delayed symptoms)

Rescuers should not put their lives at risk to save a drowning person.

In unresponsive patients, CPR should be performed immediately after rescue for resuscitation to be successful.

• ARDS
• Pulmonary edema
• Pneumothorax
• Acute tubular necrosis (due to hypoxemia)
• Brain death
• Elevated intracranial pressure
• Infection (e.g., pneumonia, meningitis)
• Cardiac arrest

We list the most important complications. The selection is not exhaustive.

• Factors associated with poor outcome (see “Complications” above) include:
  • Submersion lasting > 5 min
  • CPR delayed > 10 min
  • Glasgow Coma Scale < 5 upon presentation

• Swimming education
• Safety equipment (e.g., life jackets)
• Water rescue training
• Water safety signs posted at potential sites of drowning
• Rescue equipment and personnel (e.g., lifeguards) at recreational swimming locations (e.g., pools, beaches)
• Avoidance of alcohol and drug consumption before swimming
• Installing barriers around potential water hazards (e.g., pools, wells, waterfronts)
• Close supervision of children around water (e.g., during bathing as well as swimming)