Submersion Injuries
Adam Cheng
Introduction
Drowning: death within 24 hours of a submersion incident
Near-drowning: survival for at least 24 hours following a submersion incident
Near-drowning 2-20 times more common than drowning
> 50% of drowning and near-drowning occur in children < 4 years of age
Second leading cause of accidental death in children
Risk Factors for Near-Drowning
Young age, particularly < 4 years
Child maltreatment and neglect
Alcohol intoxication: 40-50% of near-drowning associated with alcohol use
Drug abuse
Seizure disorder: 4- to 5-fold increased risk
Cardiac disorder: prior history of arrhythmias
Risk-taking behavior
Residential swimming pool: most drownings < age 4
Close proximity to rivers, lakes, canals, beaches: mostly adolescents
Pathophysiology
Final common event: hypoxemia
Dry drowning: water does not enter the lungs due to laryngospasm, but anoxia develops because of persistent laryngospasm
Wet drowning can be divided into two categories, with different pathophysiologic consequences: fresh water and sea water drowning
 Figure 52.1 Sequence of Events |
Fresh Water Near-Drowning
Hypotonic fresh water dilutes pulmonary surfactant and results in atelectasis and hypoxemia from ventilation-perfusion mismatch and intrapulmonary shunting
Hyponatremia and hypokalemia occur in 15% of cases: hypotonic fresh water is rapidly reabsorbed into the systemic circulation from alveoli
Hemolysis and hyperkalemia: large amounts of fresh water are aspirated, leading to hypotonic plasma and RBC hemolysis
Sea Water Near-Drowning
Pulmonary edema: hypertonic sea water attracts fluid into alveoli
Hypoxemia from shunting as fluid-filled alveoli continue to be perfused
Intravascular hypovolemia may occur
Electrolyte imbalances are uncommon
Table 52.1 Organ Systems Affected in Near-Drowning | ||||||||||
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