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Ismm news 10/1998: october case discussion

ISMM News 10/1998: October Case Discussion OCTOBER CASE DISCUSSION
International Society for Mountain Medicine Newsletter, 8 (4): 14- (Oct 1998)
Question 2. A patient complains of serious insomnia when he goes above 2000m.
He has lived and worked at 2500m and cannot sleep very well. He now has a job at
2500-3500m for 6 months and is very concerned to find a way to deal with the
insomnia. What do you think is going on and what would you advise?
Brownie Schoene, USA
How long has he been at altitude before? Could be Cheyne-stokes respiration to
which he may be particularly vulnerable, but at that altitude you'd expect it to go
away with acclimatization. I'd probably try acetazolamide initially for the first week
or so (125mg qds) and stop it. If it works, that would be great. If it doesn't, then I'd
try some sleep med - dealers choice.
Stephen Bezrushka, USA
I would be flexible, and try and see if he has any obvious causes for the insomnia,
sleep apnea, etc. If not, then if he is flexible, and can try it out, see how he does, and
if problematic, leave. He could try Acetazolamide for a few days upon arrival, and
see if it helps.
John Severinghaus, USA
Simple enough to try Diamox and see if it works. If not, he may need a sleep study at
sea level to see if he obstructs and if so, get nasal CPAP.
Buddha Basnyat, Nepal
I would try to 125 mg diamox before supper for a couple of days and If that did not
work I would try something like temazepam or even low flow oxygen if that were
possible and not too cumbersome. As at regular altitudes for insomnia I would stay
away from caffeine and Alcohol and try relaxation techniques.
John West, USA
Many people have insomnia at high altitude probably related, in part, to the periodic
breathing. Although 2000 m is rather low for that, if does occur.
Depending on how seriously he wants to pursue this, he might consider oxygen-enriching the bedroom. We now have an oxygen-enriched room at the WhiteMountain Research Station facility at 3800 m and I have never slept better in mylife. Plenty of oxygen and nice low density air to breathe! The oxygen concentrationis increased to 24% that is equivalent to reducing the altitude by 900 m.
A double blind study showed that the oxygen enrichment greatly reduced the degreeof periodic breathing. In addition the subjects who slept in the oxygen-enrichedatmosphere reported that they slept better, and had a lower AMS score in themorning than when they slept in ambient air.
For each person in the room, this degree of oxygen enrichment can be obtained by ISMM News 10/1998: October Case Discussion one AirSep New Life oxygen concentrator, costing about $1,200 and consuming 350watts. The room needs to be reasonably well sealed and there should be a doubledoor to provide a small air lock. I could give him more information if he is seriouslyinterested.
Erik Swenson, USA
This sounds like a bad case of periodic breathing with sleep fragmentation. Both
could be treated with Diamox, or even temazepam, which Dubowitz (BMJ 1998;
316:587) showed at Everest Base Camp was quite effective at improving sleep
quality without surprisingly causing any deterioration in nocturnal oxygenation.
Either drug could be taken for several days until he adapts to the new altitude.
James Milledge, UK
Insomnia, even at the lowish altitude of 2000 m is not uncommon. Patients
frequently over-estimate the time they spend awake, tossing and turning. I would
first advise the patient that, a, it is not uncommon and b, is not serious. I would
encourage him that in all probability after two to three weeks at 2500 - 3500 m he
will have acclimatized and the insomnia will lessen. I would explain that on arrival
at altitude he might well have periodic breathing which will disturb his sleep but that
at that altitude it should disappear after two or three weeks. If his arrival at altitude is
abrupt, e.g. by air, I would give him some acetazolamide for the first 3-5 days.
Finally, since we now know that 10 mg of temazepam improves sleep without
causing desaturation from respiratory depression, I would prescribe him a 10 day
course to be started if he finds the problem is severe. I would advise him not to take
sleeping tablets for longer than that.
Charles Houston, USA
If this man had trouble sleeping even after living at 2500 meters it's unlikely that
Diamox or any other similar drug will help - but it might be tried. I suspect some
other cause should be investigated: certainly the Hypoxic ventilatory response, and
cardio-pulmonary condition too. We aren't given any medical history. My vote would
be against sleeping pills because they do tend to depress ventilation. Benadryl or
generic might help and is not habit forming. But look for the cause first. I don't
believe anything will be found, but I don't believe he should go to live at 2500 m or
higher.
David Murdoch, New Zealand
I am assuming this man has no other medical history of note. Periodic breathing is
the most likely cause of this person's poor sleep at high altitude, and a good clinical
history should support this. This should improve with acclimatization, but until this
occurs I would try acetazolamide 125-250 mg at night. If this does not work a
sedative such as temazepam would be worth a try.
Tom Hornbein, USA
Smell like periodic breathing of altitude-maybe. How old is the guy? Obese? etc. In
other words does he have a problem with sleep disordered breathing at sea level that
might be exacerbated at altitude? Some anecdotes with an aging trekking-high
altitude climbing population that SDB and altitude may not be easily miscible and
Diamox might not help.
ISMM News 10/1998: October Case Discussion Simon Gibbs, UK
The chronic nature of his sleep problem at only moderate altitude makes me wonder
if he has sleep apnoea as well as the periodic respiration induced by hypoxia. I
would advise that he be questioned further and I might suggest a sleep study to make
the diagnosis.
Andy Pollard, UK
The first question to answer is why the patient gets insomnia at altitude. Insomnia is
not necessarily related to altitude and first both organic (sleep apnoea due to upper
airway obstruction perhaps worsened by the climate at altitude) and psychological
(depression, anxiety etc) should be excluded by the physician. Other environmental
causes for insomnia should also be considered (uncomfortable bed, inadequate
warmth etc). Other causes of insomnia, which might be worsened by the decrease in
oxygen levels at altitude (such as heart and lung diseases) should be excluded by the
physician.
If everything else is excluded then altitude itself could be the cause of the insomnia.
However, it is unusual for someone to fail to acclimatize at such moderate altitudeand I would expect any altitude related insomnia (periodic breathing due to pooracclimatization) to settle down after a week at the longest. An interested physicianmight be able to do a sleep study on ascent to altitude to help clarify the diagnosis.
Assuming underlying causes of insomnia have been excluded, how should altitudeinsomnia be treated? I am generally not in favour of using any drugs at altitudeexcept in emergency situations. Indeed, it would be hardto justify taking acetazolamide (diamox) or any other drug for 6 months. Its use isnot usually considered necessary until ascending over this altitude anyway. My firstchoice would be to do nothing expecting the insomnia to settle over a week or so asthe patient acclimatizes. If it does not, or it is already known that it won't, I would tryto find an interested respiratory physician to help with proving that the problem isaltitude related (a sleep study) and does not improve with time.
If the insomnia is proven to be altitude related and settles after a week or so, then ashort course of acetazolamide may speed the process of acclimatization the nexttime. Some people will not tolerate the side effects of acetazolamide and it should betested for a few days at sea level to see if it suits the patient. I would then use it forthe first week at altitude only.
Sleeping pills could be considered if oximetry is normal on a sleep study but mayaffect the patient's ability to work safely.
Dr. Ton Ricart, Spain
The information we have, rather limited, says nothing about this patient having
insomnia at sea level. He has previously lived at altitude and again he has accepted a
new job at altitude. He just complains of not sleeping very well without more serious
complications, if so he has not suffered from Acute Mountain Sickness. Insomnia
may express a chronic intolerance to altitude. Since he accepts to go back to altitude
insomnia is probably a nuisance and not a real intolerance. I think the patient may
ISMM News 10/1998: October Case Discussion benefit from explanations about what's happening and usual treatment for insomnia.
Therefore it should be interesting to think about: a) Do not prescribe hypnotic drugs that may enhance the situation by decreasingventilation and oxyhaemoglobinb) In case we find data about previous altitude intolerance I should study hypoxiatolerance and if needed I should suggest to change the job Gerald Dubowitz (Pheriche, Nepal)
Insomnia is a feature of Acute Mountain Sickness, AMS (Lake Louise score) it is
also commonly reported during sojourns to altitude in otherwise well individuals. It
is in part due to episodes of periodic breathing and desaturation. In addition it occurs
because of environmental changes such as cold and discomfort. Initially I would
enquire about his trekking programme. How fast has he trekked in previously? Can
he trek in more slowly to allow better acclimatization? Is the insomnia an early
feature which improves or does it last the duration of the sojourn at altitude?
If we have identified a good trekking profile, but he still has symptoms; has he takendiamox? If he acclimatizes well otherwise I would initially suggest a nightly dose ofdiamox e.g. 125mg nocte ( or less cf Peter Hackett) taken perhaps 3-4 hours beforebed (to initially avoid nocturesis) assuming he has no known contraindication totaking this ( e.g. sulphur allergy etc). This would be safe even if he has mild AMS(e.g. headache + one other symptom). If we are sure he is acclimatizing well and heonly has insomnia and this is not a feature of poor acclimatization or AMS he canalternatively (or additionally consider taking a low dose hypnotic). I agree withSimon Gibbs a paper in the BMJ (BMJ 1998; 316:587) in February indicated a LOWdose of temazepam a (short acting) benzodiazepine hypnotic was shown to improvesleep without a detrimental effect on oxygen saturation. This contrasts previousstudies using large doses of benzodiazpines and other hypnotics that were indeeddetrimental to nocturnal oxygenation. The result of this study clearly indicated it(temporarily) reduced episodes of periodic respiration and marked desaturations). Atthis point it is important to note that this particular study done a relatively smallnumber of individuals, none of whom scored significantly on the Lake Louise score(i.e. they did not have AMS) so there may be individuals in any given populationwho may react differently, especially if they have significant AMS. If a low dosedoes not work there is no evidence that a higher dose will be beneficial and fairlygood evidence that it may in fact be detrimental.
Content copyright 1998 ISMM Last modified 18-Nov-2002

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