[Previous Months][Date Index][Thread Index][Join - Register][Login]
[Message Prev][Message Next][Thread Prev][Thread Next]
[IP] Clinical Decision Making: DKA on Mt. Ranier (Diabetes Spectrum)
Volume 12 Number 4, 1999, Page 198
Clinical Desicion Making
DKA on Mt. Rainier: A Case Report
Christian D. Herter, MD, CDE
The alpine environment is an unpredictable, sometimes harsh arena that
can test the stamina and endurance of any athlete. Those with type 1
diabetes face added challenges, since their metabolic response to
exertional, thermal, and barometric stressors is heavily dependent upon
exogenous insulin. This report summarizes some of the issues that face
mountaineers with diabetes.
In late July 1998, a group of experienced mountaineers, including the
author, left Seattle for Mt. Rainier, a 14,600-ft dormant stratovolcano
southwest of the Puget Sound basin. Five members of the six-person team
had successfully climbed the mountain before, and all had been active in
various alpine groups for many years.
Included in the group was A.O., a 26-year-old man who has had type 1
diabetes for 17 years and is treated with continuous subcutaneous
insulin infusion (CSII). The author, age 39, also has type 1 diabetes of
13 years' duration and wears an insulin pump. The two climbers with
diabetes self-monitored their blood glucose levels frequently and kept
in close contact with each other to check blood glucose levels and to
make sure there were no problems with the infusion equipment.
The outing organizer had chosen the most popular route for the ascent,
which would begin from a trailhead at 5,000 ft. Long climbs such as this
are usually done over several days. The first leg of the ascent would
involve 5 miles of hiking across a simple snow field to Camp Muir, at
10,000 ft. Some teams rest here for a few hours before ascending; others
take an additional day, hoping the extra time will improve their
performance at altitude.
Even with the burden of fully loaded packs in the hot sun, the initial
leg of this climb was uneventful. Although the group had intended to
stop only briefly at Camp Muir, the team leader suggested spending the
night, since most of the climbers were sleep-deprived already (many just
from trying to prepare for the trip on top of busy work schedules).
The night was calm, and everyone was well-rested by morning. Since warm
temperatures and clear skies were predicted, departure from Muir was
postponed until sunset as a safety measure. The route would cross over
highly crevassed glaciers and under unstable ice cliffs on the way to
the summit. These areas would be dangerous to negotiate as temperatures
soared under the midday sun.
Some snow bridges along the route had already fallen away from the
previous day's heat. In many of these areas, Forest Service rangers had
placed narrow ladders across the crevasses. In other places, fallen snow
bridges left fissures so vast that new routes had to be forged around
them, which added hours to the ascent time.
In addition, falling rock was a continuous threat. At this time of year,
snow and ice act like cement to keep precariously perched rocks and
boulders stable above climbers. During frosty nighttime hours, these
missiles are locked on to their loft ledges. But with warmth from the
sun, they rain down on climbing routes. Nighttime was clearly the right
time for this ascent.
After packing up camp, all the climbers roped up, checked their safety
equipment, harnesses, and accessory climbing gear, and started across
the Ingraham Glacier. On leaving base camp, A.O.'s blood glucose level
was 120 mg/dl.
During the next hour, 1,000 vertical feet were gained to Ingraham Flats,
a level and relatively crevasse-free area high on the glacier. It was
8:00 p.m., and the mountain was beginning to cool. This was a good place
to have dinner and consider the rest of the route.
The team members discussed their plans for ascending the next obstacle:
the Disappointment Cleaver. This steep nunatak, which was completely
visible from their present location, presented the most serious
rock-fall danger of the route. Only a month before, a party had been
swept off by an avalanche and falling rocks. Clearly, the challenge was
to ascend the 1,000-ft crag with just enough of the rapidly fading
daylight to see the route in hopes that the few hours of cooling out of
direct sunlight was sufficient to reduce the chances of a slide.
Getting to the base of the cleaver required passing over the upper
Ingraham Glacier, which had become extensively crevassed. The climbers
first had to cross two Forest Service ladders, which was challenging
while wearing climbing crampons. The apparently bottomless abyss bridged
by these flimsy contrivances managed to raise the resting heart rate of
even the most seasoned member of the group.
Once at the base of the cleaver, the expedition was challenged by highly
exposed, sometimes ice-covered rock. For the next 1,000 ft, careful
attention to the route was the rule. In several places where the rock
was too broken or dangerous to climb, the route detoured on to very
steep snow slopes thought to be less risky than the unstable volcanic
pumice. The going was slow, but strong. As the last vestiges of dusk
gave way to a night sky filled with summer constellations, the group
arrived at the top of the cleaver and rested.
A.O., normally of a calm temperament, began fiercely cursing. One of the
members of his rope team required more time than the others during the
last pitch, and he was incensed about it. He also mentioned some nausea,
but felt it was related to the less-than-conventional dinner he had
consumed earlier: freeze-dried vegetarian chili and slightly wilted
turkey and cheese bagels.
The others were a bit surprised by his demeanor but felt that the
exertion of the last hour could certainly have resulted in some
hypoglycemia. We suggested monitoring blood glucose and took time for a
It was now after 10:00 p.m., and the group was considerably ahead of
schedule. At the current pace, the summit was only 56 hours away. We
all enjoyed the extended break, taking some time to argue over the names
of the brighter stars and taking turns searching for satellites
streaking over our frosty perch.
The next pitch would carry the group through the upper Ingraham ice
fall, an area where the normally smooth constitution of this glacier was
broken into house-sized chunks of ice and rubble. With headlamps
lighting the way, the team roped up and set out again, planning another
stop with the next 1,000 ft of vertical gain.
A.O. led the second rope. Normally strong and practically inexhaustible,
he was now having more trouble maintaining the moderate pace set by our
leader. As the group began winding through the upper crevasse fields,
A.O. signaled that he required a rest stop, and further, that his nausea
was worsening by the minute. He emphatically denied any other symptoms,
just nausea and disabling fatigue.
As minutes passed, it became apparent that he required more attention.
For the team to congregate in such a dangerous area, anchors needed to
be placed and ropes managed carefully. A.O. was found lying on his back,
somnolent, and hyperventilating. The group's two physicians made an
assessment in the field. This could represent acute mountain sickness
(AMS) or a metabolic abnormality resulting from A.O.'s diabetes. The
other members of the group were anxious for a diagnosis, since they were
beginning to chill in the cold wind of this high altitude.
A.O. was asked about his last blood glucose reading. The initial value
of 120 mg/dl, taken as the group left Camp Muir, was the last that had
been done. He reported that his glucose meter would not operate at
temperatures encountered on the mountain. He had attempted readings both
at Ingraham Flats and at the top of the Cleaver, but the device would
not run samples, despite A.O. warming test strips and the meter itself
using his axillae. The strips could not be interpreted visually, so he
had been trying to estimate his insulin needs with no confirmatory data.
The author always carries back-up strips, which can be read visually. A
quick sampling showed that A.O.'s current blood glucose was >600 mg/dl.
This confirmed that he was suffering from acute insulin deficiency
rather than AMS.
Because the last blood glucose reading was in the normal range just 6
hours earlier, the decision was made to administer intravenous insulin.
Inspection of A.O.'s insulin pump infusion site showed quite a bit of
surrounding erythema, so members of the team performed a site change.
Since the infusion reservoir and tubing appeared unaffected, these,
along with the insulin from the reservoir, were not changed.
A.O. was clearly too ill to proceed. He started vomiting shortly after
the new infusion site had been placed. The climb leader decided that it
was unwise to continue with a member of the group in such a medically
unstable state, and ordered the team to retreat to a lower, safer area
to wait out the night.
When A.O. was able to walk, the group slowly retraced their tracks to
the top of Disappointment Cleaver, at 12,400 ft. There, they dug
trenches for protection from the wind and kept a close watch over A.O.,
checking blood glucose levels frequently. The leader had hoped that A.O.
would be well enough by morning to down-climb the treacherous cleaver.
If not, he would need evacuation by Search and Rescue. At 2:00 a.m.,
A.O.'s blood glucose had dropped to 50 mg/dl, and he required treatment
for hypoglycemia, but felt considerably better.
By morning, A.O. felt as though he had completely recovered. His waking
blood glucose was around 180 mg/dl, the nausea had resolved, and he had
managed to consume an additional 2 liters of water. He dosed 2 U of
insulin through the pump to cover his hyperglycemia, then joined the
group for the tricky descent.
A.O. actually led for most of the route back to Camp Muir. As the team
began packing up in preparation for the final trip back to the
trailhead, however, he noticed recurring nausea and fatigue. He had
taken no snack after the bolus on the Cleaver. A blood glucose check
showed a surprising level of 345 mg/dl.
At this point, his tubing and reservoir were replaced and filled with
insulin from the author's emergency supply, but the infusion site was
retained. There was rapid return to his normal level of near-euglycemia,
and he was able to finish the hike.
Though this medical emergency cost members of his team the summit, A.O.
received outstanding support and medical attention from everyone. He
hiked back to the parking area without incident, and he continued his
involvement in back-country activities.
Consideration of the incident suggested a causal relationship. The
second day of this expedition was spent largely in the hot sun of Camp
Muir. A.O. wore his insulin pump in an area exposed to direct sunlight
most of the day. Since insulin is quite temperature-sensitive,1,2 the
resulting heat probably diminished its potency. Evidence for this is
suggested by his rapid recovery when emergency insulin that had been
protected from the heat was administered by syringe.
This theory of bad insulin seems even more likely when taking into
consideration the relatively rapid return of hyperglycemia when, after
switching infusion sites, A.O. connected his infusion system to the
needle using the older insulin. When he replaced the infusion reservoir
and filled it with the emergency insulin while retaining the previous
infusion site, normal glycemia resulted.
Five Extra Essentials
All enthusiasts of the alpine environment will agree that preparedness
is an important part of any expedition. The famous Ten Essentials is a
list of items that should be taken along by anyone heading into the
wilderness, regardless of the duration of stay. Extra clothing, extra
food, flashlight, and first aid kit are among the most important items
on the list.
Outdoor adventurers with diabetes are at risk from more than the
elements. They face possible metabolic consequences of too much or too
little insulin, so monitoring and safety become life-or-death matters.
Since even the tiniest unforeseen problem can result in disaster, an
addendum to the famous Ten is suggested below:
•Extra insulin. This should be packed to prevent freezing or exposure to
the heat. •Extra supplies. More syringes and more alcohol swabs. A.O.,
who uses CSII, brought along enough equipment for several complete site
changes. •Back-up monitoring supplies. Certain meters are more tolerant
of temperature extremes, but even these can fail at high altitude. To be
sure, pack an extra alternate method, such as ChemStrips bG, which can
be interpreted visually. •Injectable glucagon. This should be kept in an
easily accessible area of the pack, not exposed to excessive heat or
cold, and all other members of the group should be familiar with its
use. •Willingness to communicate. Talk to your teammates when there is a
problem. The earlier they know, the better the chance you will all make
the summit safely.
If A.O. had carried along some visual strips, he might have been aware
of the problem with his insulin before becoming ill. With that kind of
advanced warning, this group may not have had to turn back.
1Volkin DB, Klibanov AM: Thermal destruction processes in proteins
involving cystine residues. J Biol Chem 262:2945-50, 1987.
2Amaya J, Lee TC, Chichester CO: Biological inactivation of proteins by
the Maillard reaction: effect of mild heat on the tertiary structure of
insulin. J Agric Food Chem 24:465-67, 1976.
Christian D. Herter, MD, CDE, is an assistant professor of family
medicine at the University of Washington Medical Center in Seattle.
for HELP or to subscribe/unsubscribe, contact: HELP@insulin-pumpers.org
send a DONATION http://www.Insulin-Pumpers.org/donate.shtml