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Q:
I am 79 years old and healthy. I have not
been diving in several years and would
like to get back into it. Are there any
recommendations, prohibitions or limitations for a
diver my age?
A:
Please note that DAN® is not a regulatory
agency and does not set standards or
guidelines for participation in diving. Any
age or fitness limitations you encounter would
come from training agencies or dive operations, not
DAN. The responsibility for the decision of whether
or not to dive is generally that of the individual
and his or her physician. This decision, however,
should be based on the most current diving medical
information available.
Many people in their 70s and 80s continue to dive,
although their diving style may change over time.
The key to safe diving is physical fitness, not age. Or
as some people glibly state, “It’s not the age but the
mileage that counts.” An athletic, physically fit senior
citizen may be a better candidate for diving than a
25-year-old in poor physical condition. But that same
person will never match the physical capabilities of an
athletic 25-year-old. All tissues — blood vessels, heart,
lungs, muscles, etc. — age.
A thorough cardiac workup and stress test are
prudent and probably the first priorities. Many
cardiologists familiar with dive medicine recommend
a cardiac stress test targeting a score of 13 metabolic
equivalents (METs), while others recommend a
minimum of 10 METs. Either level is rigorous exercise.
While most diving is relaxing, a strong current, a
long surface swim or rescuing a buddy (or oneself ) all
require a high level of exercise tolerance.
Awareness of underlying medical issues is of
practical use. The basic aches of arthritis could be
confused with decompression sickness, so conservative
profiles are recommended for anyone who deals with
this issue. Also, diving in locations with reasonable
access to medical care is prudent. Anyone can have a
medical or diving emergency, and age makes medical
emergencies more likely. A minor issue that occurs
within reasonable access to medical care can be
handled easily. The same issue can be much more
problematic on a remote island or liveaboard hours or
days from medical care.
— Frances Smith, EMT-P, DMT
Q:
I know nitrogen is not metabolized by the
body, and I’ve read that tech divers are facing
issues with helium bends. Is the size of the
molecules relevant? Heliummolecules are smaller
and lighter than oxygen molecules, while nitrogen
molecules are larger. Some people are filling their
car tires with nitrogen
because it supposedly
leaks out of the tire
more slowly than air.
A:
There are times
when size
matters and
times when it is a red
herring. This is one
of those cases where
it’s a little bit of both.
Nitrogen is a slightly
larger molecule than
RESEARCH, EDUCATION & MEDICINE
FROM THE MEDICAL LINE
54
|
SPRING 2016
Aging and Diving
DAN MEDICS AND RESEARCHERS
ANSWER YOUR QUESTIONS
ABOUT DIVE MEDICINE.
STEPHEN FRINK
STEPHEN FRINK