In fresh water drownings inhaled water is immediately absorbed into the blood causing hemodilution. The diluted blood quickly leads to heart failure due to ventricular fibrillation, a condition simply described as shivering of the heart, or anoxia (oxygen starvation).
Drowning may result in an acute asphyxial cardiac arrest, which emanates from hypoxemia that precedes the development of ischemia. This scenario results from initial cessation of gas exchange followed by worsening hypoxia and eventual cardiac arrest. Hypoxemia is the overriding insult.
A lack of oxygen or chemical changes in the lungs may cause the heart to stop beating. This cardiac arrest stops the flow of blood and thus stops the transport of oxygen to the brain.
“Finally, the heart will slow down because it hasn't got any oxygen. Usually, they've been unconscious for three to five minutes in the water.” It takes an average of two minutes for someone drowning to become unconscious. That's about the same time as it takes to brush your teeth (properly).
Drowning quickly causes respiratory and cardiac arrest from hypoxemia, while survivors can sustain pulmonary, neurologic, cardiovascular, and other injuries.
Most studies on near drowning report complications such as cardiopulmonary arrest, multiorgan failure, pulmonary oedema, pneumonia and hypoxic brain injury. Other reports highlight rarer haematological complications including haemolysis and coagulopathy (Layon & Modell, 2009.
Water can also damage the lungs, causing acute respiratory distress syndrome or pulmonary edema. Drowning might cause multisystem organ failure, damage the heart, kidneys and/or liver. The amount of organ damage varies depending on the individual, their submersion time and the water's temperature.
The events that result in drowning can be divided into the following sequence: (i) struggle to keep the airway clear of the water, (ii) initial submersion and breath-holding, (iii) aspiration of water, (iv) unconsciousness, (v) cardio-respiratory arrest and (vi) death – inability to revive.
When the brain is deprived of oxygen, brain cells can begin to die within five minutes. Most drowning victims who suffer oxygen deprivation sustain permanent neurological and psychological damage.
Even a weighted body will normally float to the surface after three or four days, exposing it to sea birds and buffeting from the waves. Putrefaction and scavenging creatures will dismember the corpse in a week or two and the bones will sink to the seabed.
Drowning, by definition, is the submersion in a liquid resulting in respiratory impairment. This respiratory impairment will then lead to cessation of the heart resulting in cardiopulmonary arrest.
“Most drowning victims will have sustained cardiac arrest secondary to hypoxia. In these patients, compression-only CPR is likely to be ineffective and should be avoided. The first and most important treatment of the drowning victim is the immediate provision of ventilation.
The events that result in drowning can be divided into the following sequence: (i) struggle to keep the airway clear of the water, (ii) initial submersion and breath-holding, (iii) aspiration of water, (iv) unconsciousness, (v) cardio-respiratory arrest and (vi) death – inability to revive.
Drowning is usually classified as a mechanism of injury and drowning victims are considered trauma patients.
Autopsy findings:
May see bloody froth in the airway, water in the stomach, cerebral edema, petrous or mastoid hemorrhage. "Washerwoman" changes of the hands (shriveling of the skin) develop when submerged in water for several hours; occurs regardless of whether the person died in the water.
Physicians believe that brain damage begins to occur after about five minutes of oxygen deprivation. “If you can rescue a child before that and restore their breathing with CPR, and get their breathing back, usually the children will recover,” Dr. Goodman says. “After five minutes, there will be brain damage.
Nearly 40% of drownings treated in emergency departments require hospitalization or transfer for further care (compared with 10% for all unintentional injuries). Drowning injuries can cause brain damage and other serious outcomes, including long-term disability.
Saving someone who is drowning is more difficult and dangerous than many people think (heck, even realizing someone is drowning is hard — the signs don't look like you think they would.) A person who's drowning can be panicked and clutch, kick, and grab at you as you try to rescue them, dragging you both underwater.
While distress and panic may sometimes take place beforehand, drowning itself is quick and often silent. A person close to the point of drowning is unable to keep their mouth above water long enough to breathe properly and is unable to shout.
Give five initial rescue breaths, and then continue with cycles of 30 compressions and two rescue breaths.
Those who are comatosed and resuscitated with CPR often develop severe brain injury and hypoxic encephalopathy. At least 10-30% of children with brain damage require long term rehabilitation. Hypothermia can protect the brain in some children. Other risks of drowning include aspiration, ARDs, and death.
Organs such as the brain, lungs and kidneys are mainly affected by drowning accidents. Treatment of pulmonary complications depend on the lung injury that was incurred during aspiration and also the bacteria that was aspirated[25].
Many factors may influence the pathophysiologic sequence of events in submersion injury and affect the chance of survival, including age, water temperature, duration and degree of hypothermia, the diving reflex, and the effectiveness of resuscitative efforts.
Fluid in the lungs—Near-drowning victims whose larynxes relaxed or who inadvertently aspirated water will have excess fluid in their lungs. Pneumonia—Many victims who have aspirated water are at risk of developing pneumonia, a serious illness that requires medical supervision and immediate treatment.