Page 97 - JSOM Spring 2026

training exercise with the partner force in Nepal (supplemen- but other symptoms persisted. Evacuation occurred 3 hours
tal Figure S1). The course of elevation gain was as follows: after the initiation of treatment and took 45 minutes to get
to Kathmandu, Nepal (4,600ft/1,400m). After arrival, the pa-
• 381ft/116m to 3,317ft/1011m, where the patient stayed for tient had prompt resolution of all symptoms except chills and
1 week cough. The patient declined visiting the Nepali hospital and in-
• Day 1: from Naya Pul (3,317ft/1011m) to Chomrong stead elected to be evaluated in the hotel by an attached medic.
(7,251ft/2,210m) The patient was started on a 10-day course of amoxicillin/
• Day 2: from Chomrong to Deurali (10,391ft/3,175m) clavulanate 875/125mg by mouth twice a day. Three days after
• Day 3: from Deurali to ABC (13,550ft/4,130m) descent, the patient had complete resolution of symptoms with
• Day 4–9 (5 days): Annapurna Base Camp with several in- no medication support or requirement for higher levels of care.
cursions to 14,500ft/4420m
Discussion
The patient reported to his Special Operations medic with a
mild cough and congestion that was worse at night, starting Predicting and treating HAPE with the logistical constraints
the second day after elevation goal, and with significant fatigue and limitations created by an austere environment make this
with exertion different from his prior exercises at similar alti- case uniquely complex. Ideally, screening would be key when
tudes. He reported having trouble catching their breath after planning an exercise or operation. However, it is difficult
walking 50m and having to stop to rest and catch his breath to identify which operators are at a higher risk of HAPE as
due to coughing fits over the previous 12 hours. Insomnia was pre-ascent physical conditioning is not predictive or protec-
8,9
also reported due to developing symptoms of orthopnea and tive. There is thought to be a genetic predisposition, but
chills. Pulse oximetry was initially 93%, measured the day of there is currently no reliable screening to evaluate the general
arrival at elevation goal, but had decreased to 76% at the time population for this. On the other hand, a European study
9
of evaluation. The patient was also tachycardic and had an concluded that individuals with a pulmonary artery systolic
elevated temperature of 101°F by oral thermometer. Physi- pressure (PASP) below 40mmHg during hypoxic conditions
cal exam was remarkable for bulging tympanic membranes, were unlikely to develop HAPE, with a negative predictive
10
oropharyngeal edema, and bilateral inspiratory crackles. Per- value of 97%, which could potentially argue in favor of
sistent productive cough was noted with yellowish sputum. echocardiographic screening for select mountaineering units.
The patient was treated conservatively with oral and nasal de- The U.S. Army Research Institute of Environmental Medicine
congestants, nonsteroidal anti-inflammatory drugs, warming, (USARIEM) has also conducted studies focused on screening
rehydration, and rest. in the form of a predictive wearable tool designed to assess an
individual’s risk of developing acute mountain sickness. 11
The day after evaluation (day 3 at elevation goal), the patient
was re-evaluated and reported worsening shortness of breath, In addition to screening and medical prevention, the inherent
tunnel vision, fatigue, and feeling like he could only take 10 risks of high-altitude illness faced by military personnel op-
steps at one time. Physical exam redemonstrated fever at erating in these environments demand adequate preventative
102°F, skin flushing, and worsened bilateral inspiratory crack- mission planning. A rapid ascent, defined as a sleeping alti-
les. Initial treatment was considered insufficient and medical tude elevation gain of more than 500m per day at elevations
2
evacuation was established as a priority. above 3,000m, without extra days of acclimatization, signifi-
cantly increases the risk of both high-altitude cerebral edema
Evacuation considerations included a 3-day hike to the nearest (HACE) and HAPE. Notably, while the patient’s prophylactic
5
vehicle with an additional 2-hour drive to the nearest treat- acetazolamide may have helped prevent the development of
ment facility. Partial descent was considered inappropriate HACE in this patient, he was not given nifedipine or tadalafil,
given the patient’s lack of mobility and risk of worsening his which can reduce the risk of HAPE development in adult pa-
9
condition with exertion. The patient was mobilized to a nearby tients. A review of the most recent standard of care consensus
“tea house” for warmth and proximity to the designated land- and standard military operating guideline handbooks, 12–15 sug-
ing zone. Prompt coordination led to evacuation via a Nepali gests it is appropriate to start nifedipine or a phosphodiester-
military rotary aircraft which arrived within 4 hours, achiev- ase type 5 (PDE-5) inhibitor as prophylaxis prior to ascent and
ing a narrow window afforded by weather and topography. continuing it at goal altitude for 2 days for individuals with a
One oxygen tank was elected to be used to reach a target SpO previous history of altitude intolerance or planned rapid as-
2
of 90%. The tank was set to 3L/min as there was only enough cent, as defined above. This patient’s planned and executed
3,9
oxygen inside to supply for 2 hours. The patient was treated altitude gain would have made him a candidate for this pro-
with nifedipine 30mg by mouth once until descent and was phylaxis, and could have prevented the significant operational
provided with an albuterol inhaler 90µg/actuation instructed disruption and emergency.
for two inhalations as needed for symptom relief. A portable
hyperbaric chamber had been part of the mission equipment Interestingly, PDE-5 inhibitors have not only been used for
and was considered at this moment pending evacuation. After treatment but have also been evaluated for their capability to
a risks and benefits analysis, the chamber was not utilized be- improve exercise performance at high altitudes. For instance, a
cause of the patient’s inability to clear his ears and concerns study published in the Annals of Internal Medicine found that
for otic barotrauma, and the risk for decompression sickness/ sildenafil reduced hypoxic pulmonary hypertension at rest and
pulmonary overinflation in the setting of a short evacuation during exercise, thereby increasing exercise capacity during se-
timeframe and the patient’s overall condition. vere hypoxia at high altitude. 16

Pulse oximetry reading, symptoms of dyspnea, and tunnel vi- When it comes to treatment, rapid decision-making is mission
sion improved with supplemental oxygen via non-rebreather, critical. Descent should always be considered early and is the

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