Acute Mountain Sickness
Conditions
Keywords
positive end expiratory pressure, acute mountain sickness, prevention, high altitude
Brief summary
The study is examining if an over-the-counter device (Theravent) worn while sleeping can reduce acute mountain sickness upon awakening in a high altitude trekking population.
Detailed description
The specific aim of this study is to evaluate if an inexpensive and disposable end-expiratory pressure device can prevent acute mountain sickness (AMS). AMS is a common disorder found in 25-75% of hikers and trekkers in N. America and Europe who expediently ascend high altitude (\>8,000 ft). This environmental malady is insidious in onset and prevention is necessary not just to limit progression to severe or fatal disease, but also to limit physiologic deterioration in those who seek enjoyment or employment at high altitudes. One of the hallmarks of both healthy and sick individuals sleeping at high altitude is an oscillating pattern of respiration marked by periods of hyperventilation alternating with apnea or hypopnea. This distressing periodic breathing pattern leads to a feeling of suffocation, prevents restful sleep, and the hypoxic events may well worsen ensuing AMS. Prior studies have found positive end-expiratory pressure (PEEP) an effective non-pharmacologic method to prevent nocturnal desaturations and decreasing both AMS incidence and severity. Traditionally, PEEP devices are cumbersome and expensive, and while showing promising efficacy, are limited by both cost and portability as a useful non-pharmacologic option for AMS prophylaxis. The SLEEP-AID methodology is designed to prospectively enroll participants, randomized in a double blind placebo-controlled fashion to either the intervention \[Theravent (Ventus Medical) which is single use, inexpensive, and very small\] or a visually identical sham placebo group, and gather physiologic data to accurately reflect sleep patterns of high altitude travelers and objective as well as subjective outcomes of the intervention. The benefit of this approach will be to provide definitive data in a large and diverse cross section of a real hiking population that is generalizable to the majority of tens of millions of hikers, climbers, and high altitude tourists in the United States, Europe, Asia, and South America.
Interventions
DEVICETheravent
nasal EPAP device
DEVICEControl
Sham device without EPAP
Sponsors
University of Utah
Stanford University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* ages 18-65 * Lake Louise Score (LLS) of \< 3 * Have not taken NSAIDs, acetazolamide, or corticosteroids in the prior week * Have not traveled above 4200 m in the prior week. * First night in Pheriche or Dingboche
Exclusion criteria
* Unable to read the consent form * Taken NSAIDs, acetazolamide, or corticosteroids in the week prior to study enrollment. * Hazardous medical conditions which precludes the ability to tolerate the experimental device. * Pregnancy or suspected pregnancy. * Participants who are younger than 18 years of age and more than 65. * Travel to or above 4200m in the preceding week. * Diagnosis of AMS upon enrollment (LLS ≥3 with symptoms of headache) * Previously diagnosed obstructive sleep apnea * Current symptoms of nasal congestion, rhinorrhea, sinusitis, upper respiratory infection, asthma, COPD exacerbation, pneumonia, bronchitis, or other disease of the respiratory tract.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of Acute Mountain Sickness | Approximately 10 hours | Acute mountain sickness will be measured by Lake Louise Criteria and diagnosed as LLC \> or = to 3 with presence of a headache. Study participants will be followed approximately for 10 hours, from when they go to sleep until awakening the next morning. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Nocturnal Desaturations | Approximately 10 hours | Number of nocturnal desaturations will be measured by Watch-PAT200, a wristwatch type continuous sleep cycle and pulse oximetry analyzer. Study participants will be followed approximately for 10 hours, from when they go to sleep until awakening the next morning. |
| Acute Mountain Sickness Severity | approximately 10 hours | Severity of acute mountain sickness will be evaluated by the Lake Louise Criteria (0-15 point scale) with higher scores representing more severe symptoms. Study participants will be followed approximately for 10 hours, from when they go to sleep until awakening the next morning. |
| Nocturnal Awakenings | approximately 10 hours | Number of nocturnal desaturations will be measured by Watch-PAT200, a wristwatch type continuous sleep cycle and pulse oximetry analyzer. Study participants will be followed approximately for 10 hours, from when they go to sleep until awakening the next morning. |
Countries
Nepal
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Theravent A singe use, disposable, positive end expiratory pressure device worn over the nostrils while sleeping.
Theravent: nasal EPAP device | 115 |
| Control A visibly identical sham device that does not provide positive end expiratory pressure.
Control: Sham device without EPAP | 104 |
| Total | 219 |
Baseline characteristics
| Characteristic | Theravent | Control | Total |
|---|---|---|---|
| Age, Continuous | 39 years STANDARD_DEVIATION 6 | 37 years STANDARD_DEVIATION 8 | 38 years STANDARD_DEVIATION 7 |
| Region of Enrollment Nepal | 115 participants | 104 participants | 219 participants |
| Sex: Female, Male Female | 32 Participants | 31 Participants | 63 Participants |
| Sex: Female, Male Male | 83 Participants | 73 Participants | 156 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 104 | 0 / 115 |
| serious Total, serious adverse events | 0 / 104 | 0 / 115 |
Outcome results
Primary
Incidence of Acute Mountain Sickness
Acute mountain sickness will be measured by Lake Louise Criteria and diagnosed as LLC \> or = to 3 with presence of a headache. Study participants will be followed approximately for 10 hours, from when they go to sleep until awakening the next morning.
Time frame: Approximately 10 hours
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Control | Incidence of Acute Mountain Sickness | 18 Participants |
| Theravent | Incidence of Acute Mountain Sickness | 16 Participants |
Secondary
Acute Mountain Sickness Severity
Severity of acute mountain sickness will be evaluated by the Lake Louise Criteria (0-15 point scale) with higher scores representing more severe symptoms. Study participants will be followed approximately for 10 hours, from when they go to sleep until awakening the next morning.
Time frame: approximately 10 hours
Population: Severity
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Control | Acute Mountain Sickness Severity | Fatigue severity | 0.15 unit on a scale |
| Control | Acute Mountain Sickness Severity | Sleep severity | 1.11 unit on a scale |
| Control | Acute Mountain Sickness Severity | Dizziness severity | 0.15 unit on a scale |
| Control | Acute Mountain Sickness Severity | Gastrointestinal symptoms severity | 0.11 unit on a scale |
| Control | Acute Mountain Sickness Severity | Headache severity | 0.46 unit on a scale |
| Theravent | Acute Mountain Sickness Severity | Gastrointestinal symptoms severity | 0.058 unit on a scale |
| Theravent | Acute Mountain Sickness Severity | Headache severity | 0.26 unit on a scale |
| Theravent | Acute Mountain Sickness Severity | Fatigue severity | 0.20 unit on a scale |
| Theravent | Acute Mountain Sickness Severity | Dizziness severity | 0.049 unit on a scale |
| Theravent | Acute Mountain Sickness Severity | Sleep severity | 1.13 unit on a scale |
Secondary
Nocturnal Awakenings
Number of nocturnal desaturations will be measured by Watch-PAT200, a wristwatch type continuous sleep cycle and pulse oximetry analyzer. Study participants will be followed approximately for 10 hours, from when they go to sleep until awakening the next morning.
Time frame: approximately 10 hours
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Control | Nocturnal Awakenings | 11 Number of events |
| Theravent | Nocturnal Awakenings | 13 Number of events |
Secondary
Number of Nocturnal Desaturations
Number of nocturnal desaturations will be measured by Watch-PAT200, a wristwatch type continuous sleep cycle and pulse oximetry analyzer. Study participants will be followed approximately for 10 hours, from when they go to sleep until awakening the next morning.
Time frame: Approximately 10 hours
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control | Number of Nocturnal Desaturations | 270 Number of events | Standard Deviation 226 |
| Theravent | Number of Nocturnal Desaturations | 214 Number of events | Standard Deviation 183 |