DIVING

2. Dive Injuries
threatening emergencies, and identify signs and symptoms consistent with the diagnosis of DCS. DAN cannot perform
this vital on-scene function but can provide advice especially to those that do not regularly see diving related injuries or
illness.
The fact that this diver reported his dive as “uneventful and conducted in the same fashion as many times before”, may
prompt some investigation for other contributing factors like behavior before and after the dive. In this case, the diver
had a difficult time getting out of his new wetsuit and had exhausted himself in the process. Symptom onset shortly
after what he described as an extraordinary effort may be coincidental although strenuous post-dive physical activity is
known to mobilize bubbles.
It is possible that the type of forceful effort involved in getting out of his wetsuit might have involved breath holding and
increasing intrathoracic pressure in a similar fashion to what takes place while performing Valsalva-like maneuvers.
Should a patent foramen ovale (PFO) be present, this could have shunted venous gas emboli to his left atrium and
arterial circulation. During the patient’s hospitalization, the patient tested positive for a PFO. Although it is tempting to
see this PFO as the smoking gun, we cannot say this with confidence as there may be intrapulmonary shunts that were
not looked for or discovered. Furthermore, it’s well recognized that this etiology is still possible in the absence of any
abnormal right-to-left shunts. Surfacing from a dive ends the exposure to compressed gas breathing, but the unloading
of surplus gas lasts for hours and divers should avoid strenuous physical activity during that time. Following the “flying
after diving guidelines” is a possible conservative guideline to help determine when it may be safe to return to strenuous
physical activity.
Due to the geographic location where the injury took place and the availability of a 24 hour international airport in town,
the logistics for a medical evacuation were remarkably seamless. A U.S.-based air ambulance was able to make a round
trip from a major medical center in the U.S. within less than 6 hours. Many injuries take place where service providers are
not readily available, or where air traffic depends on daylight and/or good weather. None of these were an issue here.
This was a serious DCS case that had a remarkably good outcome due to a number of factors:
1. Timely recognition of unusual symptoms following a dive
2. Timely call for assistance
3. Favorable geographic location with:
• Available professional medical evaluation
• Readily available assets and conditions for Med Evac
4. Aggressive case management with prompt call for Med Evac once local medical assistance reached its limits
5. Timely definitive treatment and aftercare
6. Patient’s financial resources to cover all expenses
2.1.5 Injuries reported through MSCC
The MSCC captures just a part of diving injuries and is most likely to capture cases suspected of specific diving injuries
that require treatment in a hyperbaric chamber. It’s well recognized that the most common dive related injury is ear
barotrauma, which is reflected in MSCC data although many more cases are probably treated in primary care settings
or urgent care centers and remain unreported. In every diving report, one of our primary goals is to provide a slightly
different angle to achieve the most impact at reducing injuries discovered upon review of the many recorded cases. By
learning from both the good and bad experiences of others, we hope to continually improve the safety of diving. In this
edition, we will provide a series of memorable cases for such purpose.
2.1.5.1 Decompression Illness (DCI)
Decompression Illness includes decompression sickness (DCS) and arterial gas embolism (AGE). DCS may be caused
by free gas in tissues and circulation emerging from dissolved inert gas; AGE by gas in the arterial circulation originating
from alveolar gas in over inflated or stretched tissue within the lungs.
Distinguishing between the two conditions is not always easy but it may be important in some cases. First aid is the same
for both conditions and should not be delayed while attempting to figure out the right diagnosis. The primary concern of
44
Annual Diving Report – 2012-2015 Edition