|
POOLSAFE INCIDENT REVIEWS
Two serious incidents in public swimming
pools at the end of 2006 have again highlighted the
dangers of hypoxic (breath holding) training. Both
incidents resulted in a shallow water blackout.
Thankfully a quick response by lifeguards and bystanders
in both cases lead to a positive outcome. However, the
hazards of hypoxic training cannot be understated.
Shallow water blackout is the result of a
lack of oxygen causing unconsciousness. The lungs
deprived of oxygen suck any remaining oxygen from the
blood supply causing blackout quickly and often without
warning to the victim. Swimmers often breathe rapidly
prior to submersion (hyperventilation) to lower the
level of carbon dioxide in the body which reduces the
stimulation to breath. Whilst this is an important tool
for free diving, swimmers inexperienced in this
technique often exceed basic precautionary warning signs
and rob the body of vital oxygen stores. Once submerged
and underwater, the swimmer can be hidden from the view
of lifeguards. A series of events is then triggered,
including the inhalation of water, possible convulsions
and ultimately drowning, cardiac arrest and death.
The victims of shallow water blackout at
the end of 2006 were both strong swimmers. One was a
competitive free diver and the other was an 11 year old
squad swimmer. These individuals do not fit the profile
of an “at risk” swimmer. Lifeguards are more likely
going to ignore these types of customers and rarely
appreciate how dangerous the underwater swimming
activity is. Therefore, lifeguards must be taught to
understand and appreciate that even the most talented
people in the pool can quickly and quietly kill
themselves by holding their breath. Whenever a lifeguard
sees anyone performing a dangerous activity, it must be
quickly stopped. In addition, when someone is sitting or
lying on the bottom of the pool, they must be recovered
immediately (when in doubt, pull them out).
Nevertheless, Water Safety New Zealand
(WSNZ) and New Zealand Recreation Association (NZRA) do
not believe that breath holding or hypoxic training
should be banned from public pools. Controlled breathing
and rhythmic breathing are essential for swimming and
other aquatic activities and can have positive results.
It is better that such activities are done in a
controlled environment. WSNZ and NZRA suggest that
aquatic facilities adopt the following policy in
relation to breath holding activity to minimise the risk
to pool users and lifeguards.
Shallow water blackout can be avoid by
ensuring that carbon dioxide levels in the body are
properly calibrated prior to diving and that appropriate
safety measures are in place; this can be achieved if
underwater swimmers/divers do the following:
-
Alert the lifeguard to the intended
activity
-
Do not hyperventilate prior to diving
-
Breathe normally. Allow the body to
dictate the rate of breathing to ensure carbon
dioxide levels are properly calibrated
-
Never swim alone. Dive in pairs, one
to observe, one to dive
-
Buddy pairs must both know CPR
Breath holding underwater is extremely
dangerous and should not be undertaken by children or
recreational swimmers. A seemingly innocent trick, game
or competition can quickly become deadly. Whenever a
lifeguard sees anyone performing a dangerous activity,
it must be quickly stopped.
The above suggestion is consistent with a
recommendation made to Swimming New Zealand,
New Zealand
Swim Coaches and Teachers and swimming
pool managers following a similar incident in Auckland
in April 2005. |
