Immersion, near-drowning and drowning.

“Drowning” is defined as “suffocation by submersion, especially in water”66; it continues to be the third most common cause of accidental death in the general population and, for children in many countries, the second most common cause after road accidents.75 In the USA, 40% of drowning victims are less than 4 yr old.74 In Britain, the Office of Population Census reports that child deaths from this cause continue to be the third most common cause of accidental death after road accidents and burns. “Near-drowning” is defined as “survival, at least temporarily, after suffocation by submersion in water”.65 We would challenge this definition as most dictionaries define “suffocation” as cessation of breathing leading to unconsciousness or death. However, pulmonary complications may follow aspiration of water without cessation of breathing or loss of consciousness. Thus “near-drowning” should be defined as “survival, at least temporarily, after aspiration of fluid into the lungs”. The importance of the distinction between the two definitions is that aspiration of fluid may lead to later pulmonary complications, even in those without a history of loss of consciousness, and thus care must be exercised in the management of all patients with a history of aspiration. Modell, Graves and Ketover reported68 that in dogs, aspiration of as little as 2.2 ml/kg body weight produced a decrease in 2 O a P to approximately 8 kPa (60 mm Hg) within 3 min. Pulmonary surfactant is altered locally by water in the alveoli resulting in pulmonary shunting via either fluid-filled (salt water) or atelectatic (fresh water) alveoli. Pearn78 stated that within minutes after inhalation of as little as 2.5 ml/kg body weight, the normal intrapulmonary shunt of approximately 10% may increase to as much as 75%. Even victims who are conscious, alert and outwardly clinically normal after a near-drowning incident may take several days to revert to pre-immersion values.78 After aspiration of either fresh or salt water there may be delayed outpouring of fluid into the alveoli, secondary to pulmonary parenchymal damage with transudation of protein rich fluid, so called “secondary