Pulmonary Division, Dpt of Medicine, General Hospital, Pula 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. Release of compression after passage through the birth canal causes air to be sucked in. Large force is necessary during the first inspiration to overcome the surface tension. After that – large quantities of surfactant are released by the pneumocytes II.

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 “mechanical” (strangulation etc.) causes of pulmonary edema avalanche victims acute lung injury / ARDS

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

Question: Near drowning in sea water (hyperosmolar) Question: Near drowning in sea water (hyperosmolar) ... and the meaning of → fluid exudation into the alveoli? surfactant washout? hyperosmolar injury of the epithelium? serum electrolytic changes? 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 Bradycardia Peripheral vasoconstriction Thoracic blood shift and filling up alveoli with plasma

Near drowning in cold water, prognosis: Age of victim – the younger the better Water temperature – the colder the better Victim’s struggle – the more the worse 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: 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: 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).