Introduction
Drowning refers to death by suffocation due to immersion in water.
It may be classified as “wet”- where the victim has inhaled water or “dry”- a less common condition, but one that involves the closing of the airway due to spasms induced by water
Wet drowning could occur by either fresh or salt water.
Drowning typically accounts for a small but significant percentage of accidental deaths.
Near-drowning episodes refer to instances where rescue was successful and death prevented.
Near-drowning can be associated with
considerable disability e.g. head injury,
paralysis, and respiratory complications.
Contributory factors
- Swimming in deep waters
- Falling unexpectedly into water
- Not being able to swim
- Breath-holding swimming and diving
- Alcohol consumption
- High water temperatures
- Easy, illicit access to pools
- Inadequate pool and spa covers
- Muscle cramps or epileptic attacks developing during swimming
Pathophysiology
- Inhalation of water results in ventilation perfusion imbalance with hypoxaemia and pulmonary oedema
- Absorption of hypotonic fresh water results in collapse of the alveoli, resulting in right-to
left shunting of un-oxygenated blood - Absorption of hypertonic salt water results in alveolar oedema, but the overall effects are the same for both inhalation of fresh and salt water.
- Infection may develop subsequently and is more likely when contaminated water is inhaled
Clinical features
- If alive, patient is unconscious and not breathing
- Hypoxemia and tissue hypoxia
- Acidosis
- Hypothermia
- Pneumonia
- Acute renal failure
- Haemolysis
Complications of near-drowning
- Hypoxic brain injury with cerebral oedema (which may occur withinb24 hours)
- Cardiac arrhythmias
- Dehydration
- Acute Respiratory Distress Syndrome (ARDS)
- Acute renal failure
- Disseminated Intravascular Coagulopathy
Investigations
- Full Blood Count; ESR
- Chest radiograph
- Electrolytes, Urea and Creatinine
- Liver function tests.
- Acid base status evaluation
- Arterial blood gases
- Skull and spine radiographs
- CT Scan (if available)
Treatment objectives
- Immediate resuscitation and stabilization to prevent or minimize complications
Non-drug measures
- Airway management Immobilize the cervical spine, as trauma may be present
- Treat hypothermia vigorously
- Endotracheal intubation with mechanical ventilation and Positive End-Expiratory
- Pressure if patient is apneic or in severe respiratory distress or has oxygen-resistant hypoxemia
- Admission for observation for at least 24 hours if any of the complications are observed even if briefly
Drug treatment
- Ventilate with 100% oxygen
- Establish an intravenous infusion with 0.9% saline or lactated Ringer’s solution
- Manage pulmonary complications with the administration of 100% oxygen initially, titrated thereafter reviewing arterial blood gases
- Bronchodilators if bronchospasm is
present - Manage metabolic acidosis: give
NaHCO if pH is 3 persistently less than 7.2 - Treat cerebral oedema
- Hyperventilation
- Intravenous mannitol (1-2 g/kg every 4 hours)
- Appropriate management of pulmonary oedema
Prevention
- Teach the unskilled to stay away from water
- Teach persons not to swim beyond skill level
- Parental/caregiver supervision of children
- Diving only under suitable conditions
- Education/public awareness
- Isolation fences around outdoor pools, and locked doors for indoor pools
- Locked safety covers for spas and hot tubs