Drowning
More than 4,000 Americans die from drowning
each year. About 15,000 are revived and survive.
The most common causes of drowning are swim-
ming, boating, and scuba diving accidents.
Though a person may struggle in the water for an
extended time, the threshold for remaining sub-
merged is only about three minutes, after which
the BRAINcan no longer function and the person
loses CONSCIOUSNESS.
When the head goes under the water a
sequence of physiologic changes are activated,
sometimes called the diving REFLEX, that alter the
body’s cardiovascular system to reserve BLOODand
the oxygen it carries to maintain the body’s vital
functions. The HEART RATEslows, BLOOD PRESSURE
decreases, peripheral blood vessels constrict, blood
supply to vital organs increases, and body temper-
ature drops. These changes rapidly slow METABO-
LISM(the rate at which the body uses energy),
significantly cutting the body’s need for oxygen,
which is one of the two fuel sources for cells (the
other being GLUCOSE) throughout the body and the
only fuel source for brain cells. When water
enters the airway, the larynx severely spasms,
closing off the TRACHEA. This laryngeal SPASMreflex
is so intense that most people who die of drown-
ing die from asphyxiation (lack of oxygen). In
only about 10 percent of drownings does water
enter the LUNGS.
The urge to save someone who is drowning is
so strong that many would-be rescuers rush to
jump into the water. However, water rescues are
difficult. A person who is still struggling will often
fight with the rescuer as a survival reaction, even
to the extent of pushing the rescuer under the
water. All too often the outcome is two drownings
rather than a rescue. An unconscious drowning
victim is easier to pull from the water, though
nonetheless there is great risk for the rescuer who
does not know water rescue techniques. Being a
strong swimmer is not enough. Public pools,
water parks, and swimming beaches typically
have lifeguards and rescue equipment. Poles, res-
cue flotation rings, and other devices can allow a
first responder to begin helping a drowning victim
while waiting for trained rescue personnel to
reach the scene.cold water drowning Drowning that occurs
when the water temperature is below 50ºF. Sur-
vival is somewhat higher with cold water drown-
ing because the cold temperature of the water
seems to further depress METABOLISM, dramatically
lowering the body’s oxygen needs. Though in
general a person who has been submerged in cold
water for longer than 10 minutes has a poor
chance for revival, some people have survived
being under frigid water for 40 minutes. Rescue
experts recommend initiating resuscitation efforts
for all cold water drownings.
Site and situation assessmentImportant aspects
of the situation include the type of water (pool,
lake, river), how long the person has been under
water, and whether other injuries are possible.
SPINAL CORD INJURYor head injury is likely when
diving into the water, for example.
Responder personal protection measuresEssen-
tial responder personal protection items include
latex or latex-style gloves and a resuscitation
shield.
First response actionsWhen the person is still in
the water and is conscious, the responder should
use items such as ropes, poles, and flotation devices
to attempt to help the person rather than jumping
into the water, unless the responder has training in
water rescues. RESCUE BREATHING or CARDIOPUL-368