A reduced concentration of oxygen in the blood, hypoxemia, is common to all near-drownings. In the early stages of drowning, the person may initially gasp and aspirate small amounts of water. Hyperventilation and voluntary holding of breath may follow. The aspiration of small amounts of water triggers laryngospasm during which the trachea is sealed such that neither water nor air passes through. Hypoxemia results and asphyxia leads to relaxation of the airway, allowing water to enter and fill the lungs. This is referred to as “wet drowning”.
Drowning occurs very quickly. Within two to three minutes of submersion, most individuals are unconscious and within four to six minutes the brain begins to suffer from lack of oxygen.
Mammalian Diving Reflex
The mammalian diving reflex may allow some individuals to survive for longer periods in the water. The diving reflex may occur in young children who are suddenly submerged in cold water. This reflex slows the heartbeat, constricts peripheral arteries thereby directing more oxygenated blood to the heart and brain, and produces immediate apnoea that prevents aspiration. Respiratory and cardiac metabolism decreases, which in turn reduces the damage to organs. In some cases, children who have been submerged for extended time periods can be fully resuscitated.
Types of Drowning
- Dry Drowning
- Near Drowning
- Fresh Water Drowning
- Salt Water Drowning
- Secondary Drowning
- Muscle spasms in the area around the voice box block the airway, often due to immersion in cold water. This is known as apnoea. No water enters the lungs. Around 10% of drownings are dry drownings.
- Near drowning is the term for survival after suffocation caused by submersion in water or another fluid. Some experts exclude from this definition cases of temporary survival that end in death within 24 hours.
Fresh Water Drowning
- Only a small amount of either kind of water is needed to damage the lungs and interfere with the body's ability to breathe. If fresh water is inhaled, it passes from the lungs to the bloodstream and destroys red blood cells.
Salt Water Drowning
- If salt water is inhaled, the salt causes fluid from the body to enter the lung tissue displacing the air.
- If a tiny amount of water enters the lungs, this can cause irritation, and the fluid produced in the lungs as a result can accumulate to cause drowning up to 72 hours after immersion in water. Casualties who have suffered near drowning must always be seen by a doctor as soon as possible, even if they appear to be fine.
Hypothermia occurs when your body's control mechanisms fail to maintain a normal body temperature. Your normal core body temperature is usually right around 98.6 F. An internal body temperature of 95 F or lower signals hypothermia. This condition must always be considered in all cases of near drowning.
Alcohol can increase the onset speed of hypothermia, slowing reactions and inducing vomiting.
Check for pulse in 2 different locations if hypothermia is present, Lift prolonged immersion casualty out horizontally without them helping themselves; this will reduce the risk of post immersion collapse, Use of spinal board and cervical collar if drowning has occurred in shallow water.
Apply direct heat to patient - treat as for a patient suffering from hypothermia, Perform abdominal thrusts as this will displace water from stomach into the lungs.
Transport to Hospital
- The overall prognosis of a person experiencing near-drowning is related directly to the duration and magnitude of hypoxia. Neurological damage is the major long-term concern in treating persons experiencing near-drowning.