In the United State, drowning is major cause of accidental death. The number of deaths may rise to 50 per day during summer vacation weekends. Twenty five percent of drowning victims are teenagers, 20% are less than 10 years of age, 10% occur in each decade of life from age 20 to age 70,and has resulted in 5500 deaths yearly for the last four decades. In adult, 40% of the cases of adult drowning is caused by alcohol ingestion.

Hypoxemia and aspiration are the effects of drowning. The physiology effects of aspiration differ acording to whether the drownimg medium:

• Fresh water or salt water.
• Hypotonic or hypertonic.

In the fresh water, the fluid is rapidly absorbed from the alveoli, producing intravascular hypervolemia, hypotonicity, dilution of serum electrolytes, and intravascular hemolysis. Three minutes after fresh water aspiration, the intravascular volume may increase 50%. The direct injury to pulmonary surfactant results in increased surface tension and damage to the pulmonary capillary membrane that can result in a form of noncardiogenic pulmonary edema. In the later, infection can occur because debris and microorganisms in the alveoli.

In the salt water aspiration, the effects are different from fresh water aspiration. If salt water aspiration is aspirated, water into the alveoli from the vascular space, producing hypovolemia, hemoconcentration and hypertonicity.

Treatment of the near-drowning victim should be directed toward immediate restoration of ventilation,as the degree of hypoxemia and resulting damage increase rapidly. After that, the major goals are to evaluate and correct residual hypoxemia or acidosis and electrolyte abnormalities. Endotracheal intubation and ventilation can be used for the patient has aspirated significant quantities of fluid. If the circulation can be restored, metabolic acidosis will be self-correcting.

The victim is still at high risk of acute respiratory failure if aspiration occurred. Treatment is identical to that for acute respiratory failure due to nay cause- specifically, intubation and the initiation of positive pressure mechanical ventilation with supplemental O2.

The chance of neurologic damage is negligible if the victim never lost consciousness during the drowning episode. If significant intravascular hemolysis has occured, the kidney may also be affected. Dialysis may be neccessary if acute renal failure occurs (dr. rend-san)