Wilderness Medical Society Clinical Practice Guidelines for the Prevention, Diagnosis, and Treatment of Acute Altitude Illness: 2024 Update.

To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for prevention, diagnosis, and treatment of acute mountain sickness, high altitude cerebral edema, and high altitude pulmonary edema. Recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches for managing each form of acute altitude illness that incorporate these recommendations as well as recommendations on how to approach high altitude travel following COVID-19 infection. This is an updated version of the original WMS Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness published in Wilderness & Environmental Medicine in 2010 and the subsequently updated WMS Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness published in 2014 and 2019.

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2019 Update.

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the guidelines published in 2014.

Wilderness Medical Society practice guidelines for the prevention and treatment of acute altitude illness: 2014 update.

To provide guidance to clinicians about best practices, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for prevention and treatment of acute mountain sickness, high altitude cerebral edema, and high altitude pulmonary edema. These guidelines present the main prophylactic and therapeutic modalities for each disorder and provide recommendations about their role in disease management. Recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches to prevention and management of each disorder that incorporate these recommendations. This is an updated version of the original WMS Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness published in Wilderness & Environmental Medicine 2010;21(2):146-155.

Wilderness Medical Society practice guidelines for the prevention and treatment of frostbite: 2014 update.

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for the prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the original guidelines published in Wilderness & Environmental Medicine 2011;22(2):156-166.

Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia: 2014 update.

To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is an updated version of the original Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia published in Wilderness & Environmental Medicine 2014;25(4):425-445.

Oral Coenzyme Q10 supplementation does not prevent cardiac alterations during a high altitude trek to everest base cAMP.

Exposure to high altitude is associated with sustained, but reversible, changes in cardiac mass, diastolic function, and high-energy phosphate metabolism. Whilst the underlying mechanisms remain elusive, tissue hypoxia increases generation of reactive oxygen species (ROS), which can stabilize hypoxia-inducible factor (HIF) transcription factors, bringing about transcriptional changes that suppress oxidative phosphorylation and activate autophagy. We therefore investigated whether oral supplementation with an antioxidant, Coenzyme Q10, prevented the cardiac perturbations associated with altitude exposure. Twenty-three volunteers (10 male, 13 female, 46±3 years) were recruited from the 2009 Caudwell Xtreme Everest Research Treks and studied before, and within 48 h of return from, a 17-day trek to Everest Base Camp, with subjects receiving either no intervention (controls) or 300 mg Coenzyme Q10 per day throughout altitude exposure. Cardiac magnetic resonance imaging and echocardiography were used to assess cardiac morphology and function. Following altitude exposure, body mass fell by 3 kg in all subjects (p<0.001), associated with a loss of body fat and a fall in BMI. Post-trek, left ventricular mass had decreased by 11% in controls (p<0.05) and by 16% in Coenzyme Q10-treated subjects (p<0.001), whereas mitral inflow E/A had decreased by 18% in controls (p<0.05) and by 21% in Coenzyme Q10-treated subjects (p<0.05). Coenzyme Q10 supplementation did not, therefore, prevent the loss of left ventricular mass or change in diastolic function that occurred following a trek to Everest Base Camp.

Wilderness Medical Society practice guidelines for the prevention and treatment of frostbite.

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for the prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens for each modality according to methodology stipulated by the American College of Chest Physicians.

Wilderness Medical Society consensus guidelines for the prevention and treatment of acute altitude illness.

To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the prevention and treatment of acute mountain sickness (AMS), high altitude cerebral edema (HACE), and high altitude pulmonary edema (HAPE). These guidelines present the main prophylactic and therapeutic modalities for each disorder and provide recommendations for their roles in disease management. Recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches to the prevention and management of each disorder that incorporate these recommendations.

Supplemental oxygen and hyperbaric treatment at high altitude: cardiac and respiratory response.

INTRODUCTION: The most effective treatment for high altitude sickness is prompt descent. However, rapid descent is sometimes impossible and alternative solutions are desirable. Supplemental oxygen at ambient pressure and hyperbaric oxygen in a hyperbaric tent have both been demonstrated to improve symptoms and increase arterial oxygenation (SaO2) in those with high altitude sickness; however, their use in combination has not previously been described in a controlled study. METHODS AND RESULTS: In this feasibility study, the SaO2 of six healthy, well-acclimatized participants rose from 76.5 to 97.5% at 4900 m and 72.5 to 96.0% at 5700 m following the administration of oxygen via a nasal demand circuit (33 ml of oxygen per pulse) inside a hyperbaric tent (107 mmHg above ambient barometric pressure) (p < 0.05). This contrasted with an increase in SaO2 to 89.5% at 4900 m and 86.3% at 5700 m with only supplemental oxygen and an increase in SaO2 to 92.8% (4900 m) and 90.5% (5700 m) with only hyperbaric exposure. In addition, combining treatments also resulted in an increase in tidal volume (29.0 and 31.0%) and minute ventilation (12.0 and 23.0%) together with a fall in heart rate (15.0 and 17.0%) at 4900 and 5700 m, respectively. No significant differences in heart rate, tidal volume, minute ventilation, SaO2, or respiratory rate were seen when hyperbaric treatment and supplemental oxygen were directly compared. CONCLUSIONS: In healthy, well-acclimatized subjects the combination of hyperbaric exposure and supplemental oxygen has a noteworthy effect on physiological parameters at high altitude. Awareness of this knowledge may enhance the treatment of patients with life-threatening high altitude sickness.

Supplemental oxygen effects on ventilation in acclimatized subjects exercising at 5700 m altitude.

INTRODUCTION: This study examines the effect of supplemental oxygen on acclimatized mountaineers at high altitude during rest and submaximal exercise. METHODS: Three healthy, acclimatized participants undertook nine periods of data collection lasting 10 min each over 2 consecutive days at 5700 m. These occurred at rest and exercise (40 and 80 W), breathing ambient air or supplemental oxygen (2 and 4 L m min') through an open-circuit breathing system. RESULTS: As minute ventilation increased during exercise, the fraction of inspired oxygen (FIO2) fell from 0.31 at rest to 0.23 with 2 L x min(-1) of oxygen and from 0.36 to 0.26 with 4 L x min(-1). Oxygen at both flow rates resulted in a significant increase in the arterial blood saturation of oxygen (SaO2) (Rest: 79% to 96% to 97%; 40 W: 80% to 95% to 97%; 80 W: 76% to 94% to 98%) and reduction in respiratory rate (RR) (Rest: 28 to 22 to 24; 40 W: 36 to 25 to 25; 80 W: 41 to 26 to 26). Tidal volume (VT, ml x s(-1)) was found to increase with the addition of oxygen (Rest: 959 to 844 to 969; 40 W: 1393 to 1834 to 1851; 80 W: 1558 to 2105 to 2215) and resulted in a non-significant reduction in minute ventilation (VE, L) (Rest: 25 to 17 to 21; 40 W: 46 to 45 to 43; 80 W: 61 to 51 to 53). No significant changes in heart rate were observed when oxygen was used (Rest: 78 to 62 to 71; 40 W: 90 to 91 to 96; 80 W: 105 to 102 to 101). CONCLUSION: An open-circuit breathing system may increase SaO2 and reduce RR in acclimatized mountaineers during rest and sub-maximal exercise at 5700 m, though further research is needed to confirm this.