Исследования показывают, что абсолютно здоровый человек, висящий в
сознании, но неподвижности на верёвке, через 10-20 минут внезапно
сознание теряет. По-видимому, губительный процесс ускоряется, если
человек уже травмирован или потерял сознание, в итоге смерть может
наступить буквально через несколько минут, если его не снять с
Таким образом, время – решающий фактор: необходимо не только
добраться до пострадавшего, но и снять его с верёвки на твёрдую
землю как можно быстрее.
Harness Hang Syndrome: Fact and Fiction
there has been a lot of information and misinformation disseminated
about Harness Hang Syndrome (HHS) resulting in the impression that
some ascending systems cause HHS and others do not and that HHS is
not of general concern. To clear up this confusion, we’ll cover the
history of the testing that has been done, the results of those
tests and the conclusions obtained. HHS, the rapid loss of
consciousness followed by death due to hanging immobile in a
harness, happens in ALL harnesses and ascending systems. Someone
hanging immobile in a seat harness is a serious medical emergency
that must be dealt with immediately.
Maurice Amphoux, a doctor involved in industrial safety research in
France, performed a short series of tests in order to determine what
harnesses would be best for workers to use when working at height.
At the time, it was a standard practice for workers to use simple
waist belts even when a significant fall was possible. Dr. Amphoux
was using a parachute harness for the tests and found, much to his
surprise, that the test subjects lost consciousness after a few
minutes of hanging in the harnesses. One subject lost consciousness
in only 3.5 minutes! He performed some more tests a little later
under better controls and found that the subjects experienced
cardiac arrythmias at the time they lost consciousness. Dr. Amphoux
discontinued the tests because of concern for the safety of the
subjects. He then published his findings, trying to get the word out
about HHS. The French caving community was notified but the news was
greeted with skepticism.
the newly-formed Medical Commission of the French Federation of
Speleology (FFS) decided to do some informal HHS testing to see if
Dr. Amphoux was right. The Commission had two subjects hang immobile
in their standard caving vertigear (Frog systems) with no particular
controls. One subject lost consciousness after about 30 minutes and
the other lost consciousness after only 7 minutes! The testers were
horrified and discontinued testing out of fear for the safety of the
subjects. The Commission decided to fall back and come up with some
new protocols for the testing. After seeing what happened, the
Commission began to suspect that some fatalities that had been
formerly attributed to exposure might have actually been caused by
later, the FFS Medical Commission approached HHS testing a little
more seriously. Utilizing the facilities of the Sport Physiology Lab
at the University Hospital of Besançon, the Commission had three
volunteers in excellent physical condition participate in more HHS
testing. Using the new protocols, the subjects’ vital signs were
monitored with EEG, ECG and blood gas sampling equipment. The tests
were also videotaped.
subject was positioned as if he had been ascending (with a Frog
system) and simply stopped and became relaxed (as if completely
exhausted) with neck in hyperextension, arms dangling at his sides,
legs extended and feet in the footloop. The subject complained of
extreme discomfort from the neck position just before HHS symptoms
set in. The subject’s head was then supported to see if the HHS
symptoms could be alleviated. The symptoms did subside but then
reappeared within a couple of minutes and progressed until the
subject lost consciousness.
subject hung in the same position as the first but with his head
supported by a padded stand. HHS symptoms began to appear anyway. At
the onset of the symptoms, the testers had the subject move his legs
some. This caused the symptoms to subside. However, once the subject
became immobile again, the symptoms reappeared rapidly and
progressed until he became unconscious.
subject hung with head supported but with legs pulled up, feet even
with his butt as if he had been about to take a step up with his
Frog system. Even with the legs much higher than with the previous
two subjects, HHS symptoms appeared and the subject lost
consciousness. Further, even though this subject was lowered and
released before the symptoms got extreme, he lost consciousness
testing was done in 1986 by Jim Brinkley at the Aerospace Medical
Research Lab, Wright-Patterson Air Force Base, Ohio with better
controls that those used by the FFS Medical Commission and the
results were the same. Brinkley used Class III industrial harnesses
(very similar to a parachute harness) and found that HHS occurred
very consistently in all test subjects.
So what are
the symptoms of HHS? The FFS testing showed that HHS symptoms
appeared in no more than 10 minutes with healthy subjects.
Brinkley’s research showed that 6 minutes was the normal
onset time. Keep in mind that Amphoux’s tests had one fellow lose
consciousness in 3.5 minutes. HHS symptoms begin with an overall
feeling of illness (as with a flu bug) followed by excessive
sweating, nausea, dizziness and hot flashes. Testers noticed that
the subjects had obvious brain function impairment with the initial
onset of HHS that worsened very rapidly. As HHS progresses, the
symptoms worsen with difficulty in breathing, increasing heart rate,
progressively worsening cardiac arrythmias, an abrupt increase in
blood pressure followed by unconsciousness. Death would follow
within minutes if the subject were not released quickly.
HHS? No one is entirely sure. First thoughts were that pressure on
the neck from the chest harness shoulder straps might be a cause but
testing ruled that out. Some testers believed that it was the type
of seat harness, but the fact that caving harnesses, parachute
harnesses and Class III industrial harnesses all cause HHS indicates
that this is not true as well. Another theory was pulmonary
impairment, but blood gas testing ruled this out, too. Most of the
testers believe that HHS is caused by blood being trapped in the
legs so that the net result is similar to hypovolemic shock. No
blood is actually being lost, but the amount of blood available in
the torso to keep the brain and vital organs sufficiently perfused
with blood is inadequate nonetheless. There are likely some blood
chemistry problems occurring as well. Until more testing is done
with state-of-the-art equipment, no one will be absolutely certain.
However, there are some conclusions we can make now.
hanging immobile in a seat harness is the root cause of HHS.
Any caver who has done much vertical work has hung in his harness
for much longer than 10 minutes and had no problems. But he was not
immobile. As long as you are squirming around, shifting your weight
and keeping busy, HHS is not an issue. The problem occurs when a
caver, perhaps exhausted or cold, tries to ascend a pit and gets
hung up somehow. Most of the French fatalities were inexperienced
cavers who had technical trouble with their gear and were not
knowledgeable enough to correct the problem. Already tired from
caving, the cavers struggled with the gear until completely
exhausted, then HHS set in and they died.
someone hanging immobile in a harness - any harness - is a
dire medical emergency. The FFS testing showed that 10 minutes was
the usual onset time in a healthy subject. If someone is
stranded on rope underground, it’s likely that they are tired and
cold so you can expect HHS to set in much more rapidly. Cavers that
witnessed two of the French fatalities said that once the caver on
rope stopped struggling, unconsciousness and death occurred in less
than 10 minutes.
preventing HHS is the best course of action. The articles on the
testing done by the FFS were unclear as to how much effort was
needed to revive the test subjects once they lost consciousness or
what their condition was once revived. Certainly, the best thing is
to make certain that it never happens in the first place.
should never cave alone in a vertical cave.
certain that everyone on a vertical caving trip is competent.
Everyone should know how to change from ascent to descent and
who is exhausted or badly hypothermic should not be allowed to
attempt a climb. An important note here is that some of the
French fatalities occurred in pits of less than 20 meters depth
with one occurring on an 8-meter pit, so pit depth isn’t
necessarily an issue.
should not get left behind in a vertical cave as the group heads
Finally, most cavers on a vertical caving trip should know how to do
a pickoff (single rope rescue), if not everyone. If someone in the
caving group does get hung up somehow, do not allow them to struggle
for any length of time. If the stranded caver can’t correct the
problem on the first try, he probably won’t get it on the second or
third. Remember that the FFS subjects experienced progressively
worse brain function impairment as the HHS symptoms began to set in.
This means that not only is the exhausted caver getting more
exhausted, he’s also getting more stupid. Someone should be headed
up (or down) the rope to assist the stranded caver shortly after
that first attempt at correction. The would-be rescuer might be able
to simply assist and thus correct the problem. Or the rescuer may
have to pick the stranded caver off and get them back to the bottom
of the pit. Either way, knowing how to do a pickoff should be
mandatory and all the cavers on a trip should be ready to use that