Most physical emergency situations, such as umbilical fouling, entrapment, and
equipment failure, have been mentioned in previous chapters. Those with direct
medical implications will be recounted briefly in this section, with elaboration
when necessary for a clear understanding of the problem and the solution.
A diver caught in an uncontrolled ascent must exhale
continuously to avoid arterial gas embolism. When ascending, the diver should
vent enough air to prevent the variable volume dry suit from rupturing at the
surface while maintaining positive buoyancy. Treatment of an uncontrolled ascent
is found in paragraph 21-3.6.4 for air diving.
Otitis externa (swimmer’s ear) is an infection of the ear canal
caused by repeated immersion. The water in which the dive is being performed
does not have to be contaminated with bacteria for otitis externa to occur. The first
symptom of otitis externa is an itching and/or wet feeling in the affected ear. This
feeling will progress to local pain as the external ear canal becomes swollen and
inflamed. Local lymph nodes (glands) may enlarge, making jaw movement
painful. Fever may occur in severe cases. Once otitis externa develops, the diver
should discontinue diving and be examined and treated by Diving Medical
Personnel. Unless preventive measures are taken, this condition is very likely to
occur during diving operations, causing unnecessary discomfort and restriction
from diving.
External ear prophylaxis, a technique to prevent
swimmer’s ear, should be done each morning, after each wet dive, and each evening during diving operations. External ear prophylaxis is accomplished using
a 2 percent acetic acid in aluminum acetate (e.g., Otic Domboro) solution. The
head is tilted to one side and the external ear canal gently filled with the solution,
which must remain in the canal for 5 minutes. The head is then tilted to the other
side, the solution allowed to run out and the procedure repeated for the other ear.
The 5-minute duration shall be timed with a watch. If the solution does not remain
in the ear a full 5 minutes, the effectiveness of the procedure is greatly reduced.
During prolonged diving operations, the external
ear canal may become occluded with wax (cerumen). When this happens, external
ear prophylaxis is ineffective and the occurrence of otitis externa will become
more likely. The external ear canal can be examined periodically with an otoscope
to detect the presence of ear wax. If the eardrum cannot be seen during examination,
the ear canal should be flushed gently with water, dilute hydrogen peroxide,
or sodium bicarbonate solutions to remove the excess cerumen. Never use swabs
or other instruments to remove cerumen; this is to be done only by trained medical
personnel. Otitis externa is a particular problem in saturation diving if divers do
not adhere to prophylactic measures (see paragraph 15-18.2).
Underwater trauma is different from trauma that occurs at
the surface because it may be complicated by the loss of the diver’s gas supply and
by the diver’s decompression obligation. If possible, injured divers should be
surfaced immediately and treated appropriately. If an injured diver is trapped, the
first priority is to ensure sufficient breathing gas is available, then to stabilize the
injury. At that point, a decision must be made as to whether surfacing is possible.
If the decompression obligation is great, the injury will have to be stabilized until
sufficient decompression can be accomplished. If an injured diver must be
surfaced with missed decompression, the diver must be treated as soon as possible,
realizing that the possible injury from decompression sickness may be as severe or
more severe than that from the other injuries.
These types of injuries will depend on the
geographical location and local marine plants and animals. In planning diving
operations, potential marine hazards should be identified and local experts
consulted on treatment experience and antisera availability for treating envenomization.
Treatment advice should be formalized into procedures and filed in
Appendix 5C for ready reference during operations. Suitable references on the
subject are listed in Appendix 5C.
Using unsanitized diving equipment
presents a health hazard that can be avoided easily through proper cleaning procedures.
Cleaning and disinfecting procedures vary depending on the equipment and
how it is used. Cleaning instructions for diving equipment are provided in the
appropriate equipment operations and maintenance manual and PMS maintenance
requirement cards.
