Near drowning fresh water sea water or cold

Near drowning: fresh water, sea water or cold water – is there any difference? Goran Popić Pulmonary Division, Dpt of Medicine, General Hospital, Pula

Near drowning is the survival of a drowning event and can lead to serious secondary complications including death.

Near drowning salvage at the moment of birth: At birth the airways are filled with fluid. n Release of compression after passage through the birth canal causes air to be sucked in. n Large force is necessary during the first inspiration to overcome the surface tension. n After that – large quantities of surfactant are released by the pneumocytes II. n

The principal physiologic consequences of immersion are persistent hypoxemia and resultant ischemic acidosis. A surprising degree of hypoxia can exsist without clinical signs.

Near drowning causes lung tissue hypoxia and sequential changes as in: high altitude pulmonary edema n “mechanical” (strangulation etc. ) causes of pulmonary edema n avalanche victims n acute lung injury / ARDS n

Question: Near drowning in fresh water (hypotonic). . . and the meaning of → surfactant destruction? n serum electrolyte imbalances? n hemolysis? n Answer: UNIMPORTANT ! (in terms of management)

Question: Near drowning in sea water (hyperosmolar). . . and the meaning of → fluid exudation into the alveoli? n surfactant washout? n hyperosmolar injury of the epithelium? n serum electrolytic changes? n Answer: UNIMPORTANT ! (in terms of management)

Question: Near drowning in cold water? Definition: cold water = less than 21˚ C Answers: - Bad: difficult swimming (muscular weakness), impaired judgement, core hypothermia and VF - Good: hypothermia and neuroprotection, the mammalian diving reflex

The mammalian diving reflex is triggered by cold water contacting the face (ophthalmic division of the trigeminal nerve) and causes: Apnea n Bradycardia n Peripheral vasoconstriction n Thoracic blood shift and filling up alveoli with plasma n

Near drowning in cold water, prognosis: Age of victim – the younger the better n Water temperature – the colder the better n Victim’s struggle – the more the worse n Note: if a person has been under water for LESS THAN ONE HOUR, full resuscitative efforts should be employed

General Hospital, Pula: 46 consecutive cases of near drowning victims, retrospective review: n n n n 78% males 75% swimmers 72% tourists In some cases - incapatitation arising from alcohol, heart attack, seizure, stroke In others – barotrauma or blackout on ascent from deep dive No signs of atelectasis seen on the x-rays Two deaths in hospital

Treatment of near drowning victims, some important points: n n n Immediate on site CPR is the key to increase the chance of survival. DO NOT DO any specific maneuvers (Heimlich) to expel water from the lungs. ED observation for 8 hours to screen for those requiring hospital admission. Arterial blood gas analysis and chest x-rays are the most reliable parameters. Warning of any pyrexial illness after discharge (secondary pulmonary infection).