It’s a familiar sight – a
stationary rib displaying a dive flag (either a red rectangle with a white
diagonal stripe or a blue-and-white double-tailed pennant, the A or Alpha
flag). Hopefully you will recognise these, know that there is a diver in the
vicinity and keep your distance.
But what if one of the divers is
in difficulty and needs help? Maybe the rib’s engine has failed and won’t
start. They cannot get the diver to shore quickly for the necessary emergency
aid he needs. How could you help? You might be the only boat in the area and
his life could be in your hands.
Understanding
breathing air at depth
The air we breathe consists of
approx 79% nitrogen and 21% oxygen. Our bodies use the oxygen, but the nitrogen
is inert (our body doesn’t use it). A diver’s compressed air in the scuba tank
is essentially the same. The filling process filters the air to remove chemical
impurities and most of the moisture, which can damage the scuba tanks. The
nitrogen, however, though inert at the surface, changes as it is breathed in
under pressure and at depths approaching 30 metres can have an intoxicating
effect which intensifies as you go deeper.
Problems
Contaminated Air
Very occasionally there is a
problem with the compressor or the filtering system, and the diver’s air
becomes contaminated, maybe with carbon monoxide or oil vapour. This sometimes
tastes and smells bad, but it can also be odourless and tasteless, and more
difficult to recognise. A diver breathing contaminated air may be suffering
from headaches, nausea, dizziness or even unconsciousness. Physical signs could
be cherry-red lips and fingernail beds. Initial treatment is simply to get them
to breathe plenty of fresh air, but oxygen should be given if it is available.
Then make sure that they have medical attention as soon as possible.
Nitrogen Narcosis
Divers suffering from reaction to
nitrogen behave as though intoxicated, with impaired judgement and coordination,
and a disregard for safety. It affects people differently, and can combine with
drugs or alcohol to affect people at lower depths. Fortunately the symptoms
diminish when the diver nears the surface, with no after effects, so it is not
in itself dangerous. The danger occurs because of the impaired judgement and
coordination of the
diver.
Decompression Sickness (DCS, also
known as the bends or diver’ disease)
This is a dangerous condition
arising from dissolved gases coming out of solution. The deeper the diver goes
and the longer he stays down, the more excess nitrogen his body will absorb.
When he ascends the nitrogen can’t stay dissolved so it begins to come out of
solution, forming bubbles in the blood vessels and tissues. To counteract this,
the diver must stop at regular intervals to allow decompression to occur. If he
ascends too quickly he will be in danger of developing DCS. The signs and
symptoms can vary depending on where these bubbles form, but can include
paralysis, shock, weakness, dizziness, numbness, tingling, skin rashes and itching,
difficulty breathing and pain in the joints and limbs. Severe cases can result
in unconsciousness and even death. The symptoms can come on gradually and are
sometimes intermittent, usually manifesting themselves anywhere from 15 minutes
to 12 hours after a dive.
Anyone thought to be suffering
from DCS should seek medical help immediately, as they may need specialist
treatment in a decompression chamber where the diver is put back under pressure
to help the body absorb the gas bubbles in the tissues. This will take time so
first aid may need to be administered which includes drying and rewarming the
diver, lying him down and giving oxygen if it is available. He should be
monitored carefully to prevent or treat shock, and if he stops breathing or has
no pulse, rescue breathing and CPR may have to be used. If vomiting occurs he
should be moved to the recovery position (on his side). It might be beneficial
to give fluids as this helps reduce dehydration, but no drugs should be given
as they may mask the symptoms. He should be kept in a horizontal position until
he arrives at an emergency care facility. The faster treatment begins, the less
risk there will be of permanent residual symptoms. Even if no symptoms present
themselves initially, if there is the slightest danger that a diver has stayed
down for too long, or ascended too quickly, medical assistance should be sought.
To conclude – the chances are
that you will never find yourself in a position where you have to give a diver
first aid. In most cases his colleagues in the dive boat will be more than
capable and knowledgeable. You never know, however, what can happen at sea and
a little knowledge might just enable you to give someone assistance or even
save their life.
Author – Dee White