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Contact with DAN
The diver experienced some difficulty driving due to the
reduced sensation and strength in her hands. Thinking
her symptoms resulted from being cold, she spent more
than an hour immersing her hands in warm water, but
she noted no change in her symptoms. Concerned that
she might have decompression sickness (DCS), she called
DAN®. The diver and the DAN medic discussed her
dive profiles, breathing gas and any potential issues that
might have occurred on either dive. The discussion then
turned to the symptoms: their time of onset, character
and evolution. During the conversation two important
pieces of information surfaced. First, her wrist seals
were well used, meaning the chances were very low that
constriction had impeded normal circulation. Second, the
diver had a history of similar symptoms.
The Complication
The diver reported a history of carpal-tunnel syndrome.
Upon reflection she noted her present symptoms were
essentially identical to those she had before. Once
carpal-tunnel symptoms became a likely explanation, the
medic sought to determine whether some activity during
the dive could have aggravated the condition. The diver
explained that she made the dives to familiarize herself
with the use of a new camera housing in the marine
environment. She confirmed she had an appropriate
amount of weight for ballast, but she realized she did
not have the weight positioned for proper trim. The
housing tended to float with the lens side up, which
required her to flex her wrists to bring the camera into
a usable position. The DAN medic encouraged her to be
evaluated at the local hospital’s emergency department
that day.
Discussion
There are no tests or imaging methods such as X-ray,
CT scan or MRI that can diagnose DCS. The diagnosis
of DCS is typically reached by a process of elimination.
This can be more difficult when a preexisting condition
mimics the symptoms of DCS. Three primary factors are
associated with the diagnosis: provocative dive profiles,
proximity of symptom onset to diving and symptoms
consistent with DCS. Let’s review this case with these
criteria in mind.
The diver’s profiles (85 feet for 22 minutes on air;
60-minute surface interval; 55 feet for 40 minutes on air)
were not particularly aggressive, but DCS cannot be ruled
out based on this exposure alone. The actual onset time
of the symptoms is somewhat unclear due to the fact that
the diver’s hands were so cold. However, the symptom
onset was well within 24 hours, the timeframe within
which DCS symptoms are expected to occur. Eighty
percent of all DCS symptoms present within the first 12
hours following a dive.
Regarding the specific location of her symptoms, there
are no documented cases of DCS in which symptoms
occurred in both hands and nowhere else. Some might
argue that a preexisting musculoskeletal condition could
predispose the individual to an increased risk of DCS
in the affected area. There is some evidence that this is
a possibility, but no such predisposition is statistically
apparent; the case data about DCS do not support the
idea that previously injured areas of the body are prone to
DCS. DAN’s recommendation that the diver seek medical
evaluation was to ensure review of all other possible signs
and symptoms.
The Conclusion
The diver chose to wait until the next morning so a
physician familiar with her condition could evaluate
her. Her symptoms had improved slightly overnight and
remained localized in her hands. The diver did not report
any new symptoms. A physical evaluation determined that
the reduced sensation originated at the heels of the hands
and extended into the index, middle and ring fingers of
both hands. The fifth (little) fingers were unaffected.
Based on this verified presentation and the manner
in which the diver repeatedly flexed her wrists during
the dives, the doctor suggested that the symptoms were
consistent with an aggravation of the diver’s existing
carpal-tunnel syndrome. The doctor spoke with one of
DAN’s consulting dive physicians. After reviewing the
profiles, the time of symptom onset, the character and
progression of the symptoms and, ultimately, the objective
physical findings, both doctors agreed that DCS was
unlikely, and hyperbaric treatment was not recommended.
There is no substitute for a physical examination in
person. A diagnosis cannot be made over the phone or
based solely on signs and symptoms that appear in a
particular list. None of the signs or symptoms listed for
DCS is exclusive or unique to DCS; all factors need to
be considered in their proper context. While one of the
essential goals in the management of DCS is prompt
initiation of treatment in a hyperbaric chamber, this
should not supersede a thorough medical evaluation.
Medical examinations that occur prior to treatment have
not been associated with negative clinical outcomes, and
they may uncover other important causes of symptoms
that were erroneously associated with diving.
If a diver develops symptoms following a dive, encourage
prompt evaluation by a medical professional, and do not
hesitate to contact us via the DAN Emergency Hotline
(+1-919-684-9111).
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