Near-drowning: fresh, salt, and cold water immersion.

Near-drowning and immersion hypothermia are important, preventable causes of mortality and morbidity. The most important consequences of an immersion accident are hypoxia and its effects on the cardiovascular system and the CNS. The mammalian diving reflex and hypothermia may offer some protection to the CNS despite prolonged hypoxia. The initial management of a nearly drowned victim must be focused on reversal of hypoxemia and acidosis. Prompt and effective on-site CPR is of paramount importance in ensuring optimal survival. The presence of immersion hypothermia must be recognized. Hypothermic patients should be managed according to the severity and the duration of hypothermia. Active external rewarming is adequate for acute and mild hypothermia, whereas active core rewarming may be necessary for chronic and severe hypothermia.