134 Submersion Injuries
Key Points• Drowning is the second leading cause of death in children.
• Inadequate supervision is the main risk factor for drowning in children.
• Some patients with relatively mild symptoms initially can deteriorate.
• Cardiopulmonary resuscitation at the scene is the most important factor in improving survival.
• Most drowning victims should be transferred to the emergency department regardless of the initial appearance at the scene.
• The degree of hypoxia determines the outcome.
• Cervical spine immobilization is unnecessary unless trauma is suspected.
• Asymptomatic patients should be observed for at least 4 to 6 hours before being discharged.
Epidemiology
Submersion simply means going under water. To avoid confusion, especially in reporting, the International Liaison Committee on Resuscitation recommends that the following previously used terms no longer be used: dry and wet drowning, active and passive drowning, silent drowning, secondary drowning, and drowned versus near-drowned.1 In 2002, the World Congress on Drowning adopted a uniform definition of drowning: “the process resulting in primary respiratory impairment from submersion/immersion in a liquid medium.”2
Drowning is an important cause of childhood morbidity and is among the top 10 causes of mortality (Fig. 134.1). Drowning is estimated to kill 500,000 people every year worldwide. Eighty percent of these episodes take place in low-income countries and low-income groups. About 80% of drowning episodes are deemed preventable.3,4
(Adapted from National Center for Injury Prevention and Control, Centers for Disease Control and Prevention. Web-based Injury Statistics Query and Reporting System [database]. Available at http://www.cdc.gov/ncipc/wisgars/.)
Overall rates of drowning have dropped in all age groups, probably as a result of improved awareness, use of preventive measures, and other factors (Box 134.1). Inadequate supervision is the main risk factor for drowning in children. Most toddlers who drown do so in their own home pools, most infants drown in bathtubs, and adults and older children drown in fresh water. Fencing of private pools reduces the risk for drowning.5
Pathophysiology
Injuries from drowning result mainly from asphyxia and subsequent hypoxic-ischemic damage to vital organs. The event starts with panic because of air hunger and, eventually, aspiration of fluid into the hypopharynx. Reflex laryngospasm occurs but is usually brief before the victim aspirates large amounts of fluid into the lungs. Further aspiration can occur if the victim vomits and aspirates gastric contents. Aspiration is the end result of all drowning, and the old terminology of dry and wet drowning should not be used.6,7 Changes in intravascular volume, hematocrit, and electrolyte concentration as a result of aspiration are usually mild and not clinically significant. Both salt water and fresh water cause lung injury. The effect of tonicity on the intravascular compartment is minimal.8,9
