Q:
After some recent dives, some of my toes were
really sore. Within a few hours they looked
bruised and were extremely painful; I could
hardly walk. It took several days for the bruising and
pain to go away. Could this have been decompression
sickness (DCS)?
A:
This was unlikely to have been DCS due to the
location and the symptoms you described. DCS
symptoms are not known to isolate in specific
digits. Your presentation suggests a condition known as
reactive hyperemia, which may result after a period of
reduced blood flow to an area of the body. When circulation
is fully restored following constriction, the blood vessels
dilate and may become engorged with blood. This can
cause discoloration ranging from dark red to the bruised
appearance you described as well as intense pain.
If fin straps are too tight or a diver forces his foot into the
foot pocket too firmly, a steady mechanical pressure on the
blood vessels may result. This is colloquially known as “fin
foot.” Colder water may also contribute to the constriction
of the blood vessels, further reducing blood flow to the area.
Usually this condition does not require medical intervention
other than pain management. Staying off the affected foot as
much as possible, elevating it and applying warm compresses
will typically improve comfort. Ensure proper fit of your
booties and fins, and don’t overtighten heel straps.
—
Marty McCafferty, EMT-P, DMT
Q:
I have some tanks in my garage that are filled
to 3,000 psi, and I have not used them in many
months. Is there any hazard to breathing the air
in these tanks after a prolonged period? Does the air in
them need to be replaced after a certain amount of time?
A:
We’re not aware of any studies that address this
issue specifically. To comply with recommended
safety guidelines, all scuba cylinders should be
visually inspected annually. The gas in the cylinder is
replaced in the course of the visual inspection. Experts
have discussed whether air in a cylinder can actually “go
bad,” but without any data, arguments for or against using
the air after a prolonged period are purely speculative.
There is no clear mechanism to explain why the air would
not be suitable for use, and any theoretical risk is avoided
by the annual inspection.
—
Marty McCafferty, EMT-P, DMT
RESEARCH, EDUCATION & MEDICINE
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F R O M T H E M E D I C A L L I N E
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FALL 2012
Sore Toes: DCS or Fin Foot?
DAN® medics answer your questions about dive medicine.
STEPHEN FRINK
STEPHEN FRINK