LATE-BREAKING ABSTRACTS XIII ISMM World Congress on Mountain Medicine 2021 June 14–16,2021 Virtual Meeting

1 ACETAZOLAMIDE CANNOT BE RECOMMENDED FOR HAPE PREVENTION AFTER RAPID AND ACTIVE ASCENT TO 4,559M

Lisa M Schiefer¹, Marc M Berger², Mahdi Sareban³, Franziska Macholz¹, Larissa Schäfer¹, Peter Schmidt¹, Magdalena M Schimke¹, Kai E Swenson⁴, Benjamin Mayer⁵, Josef Niebauer³, Annalisa Cogo⁶, Susi Kriemler⁷, Stefan Schwery⁸, Philipp A Pickerodt⁹, Peter Bärtsch¹⁰, Erik R Swenson¹¹

¹Department of Anesthesiology, Perioperative and General Critical Care Medicine, Paracelsus Medical University, Salzburg, Austria; ²Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Essen, University Duisburg‐Essen, Germany; ³University Institute of Sports Medicine, Prevention and Rehabilitation, Paracelsus Medical University, Salzburg, Austria; Research Institute of Molecular Sports Medicine and Rehabilitation, Paracelsus Medical University, Salzburg, Austria; ⁴Division of Pulmonary and Critical Care Medicine, Stanford University, Palo Alto, CA, USA; ⁵Institute of Epidemiology and Medical Biometry, University of Ulm, Germany; ⁶Biomedical Sport Studies Center, University of Ferrara, Ferrara, Italy; ⁷Epidemiology, Biostatistics and Public Health Institute, University of Zürich, Zurich, Switzerland; ⁸Hospital of Valais, Switzerland; ⁹Department of Anesthesiology and Operative Intensive Care Medicine, Campus Charité Mitte and Virchow‐Klinikum, Charité‐Universitätsmedizin Berlin, Berlin, Germany; ¹⁰Department of Internal Medicine, University of Heidelberg, Heidelberg, Germany; ¹¹Pulmonary, Critical Care and Sleep Medicine, VA Puget Sound Health Care System, University of Washington, Seattle, WA, USA

Acetazolamide prevents acute mountain sickness (AMS), and acutely blunts hypoxic pulmonary vasoconstriction (HPV). No studies have evaluated whether this effect of acetazolamide on HPV can prevent high altitude pulmonary edema (HAPE) under the stresses of alpine climbing. This prospective, randomized, placebo‐controlled, double‐blind study investigated whether acetazolamide prevents HAPE when climbing from 1,130 to 4,559m.

After legal approval by public authorities and written informed consent, 13 healthy, non‐acclimatized lowlanders with a history of HAPE ascended rapidly (<22 hours) from 1,130 to 4,559m. Study medications were started 48 hours before ascent (acetazolamide: n = 7, 250mg three times daily; placebo: n = 6, three times daily). At low altitude (LA, 423m, 2 weeks before ascent) and at high altitude (HA, 4,559m) the following measurements were made: AMS‐diagnosis by Lake Louise Score (LLS) and AMS‐C Score, HAPE‐diagnosis by chest radiography, peripheral oxygen saturation (SpO₂) by finger oximetry, systolic pulmonary artery pressure (sPAP) by echocardiography. Data given as mean ± SD; statistics: mixed model, Chi‐square test.

The incidence of HAPE was 43% with acetazolamide and 67% with placebo (p = 0.33). Following ascent to HA, sPAP increased from 25 ± 5 to 48 ± 10mmHg (p < 0.01) without a significant group difference (p_group = 0.72). SpO₂ decreased from 97 ± 1 to 71 ± 10%, with a trend toward higher SpO₂ with acetazolamide at HA between groups (p_group = 0.06). AMS scores remained lower in those on acetazolamide (LLS p_group = 0.02; AMS‐C p_group = 0.08).

Acetazolamide led to a relative risk reduction of HAPE by 35%, but the sample size and lack of reduction in sPAP compared to placebo precludes a definite conclusion regarding efficacy for HAPE prevention.

2 STRESS DETECTION IN HEMS OPERATION WITH HEART RATE VARIABILITY

Alessandro Forti¹, Davide Marchesin², Cristina Zaetta¹, Giuseppe Battistella³, Giovanni Cipolotti¹, Hannes Gatterer ⁴, Strapazzon Giacomo⁴, Marika Falla ^4,5

¹HEMS Department, ULSS 1 Dolomiti, Pieve di Cadore (BL), ITALY; ²Anesthesia and Intensive Care, University of Padova, Padova, ITALY; ³Statistic and Epidemiology, ULSS 2 Marca Trevigiana, Treviso, ITALY; ⁴Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy; ⁵Center for Mind/Brain Sciences, CIMeC, University of Trento, Rovereto (TN), ITALY

Helicopter Emergency Medical Service (HEMS) crews are subject to various sources of environmental, physical and psychological stress. The aim of the study was to assess the relationship between subjective self‐report stress, detected through the administration of questionnaires, and objective stress, detected through heart rate variability (HRV) measurement in a sample of HEMS crew members. During all phases (i.e., winching, hovering, take‐off and landing) of helicopter emergency missions, a mini‐ECG‐Holter Faros 180 Mega (Finland) was used for HRV detection during all phases of the missions in 40 participants from the HEMS crew base of Pieve di Cadore (BL), Italy. HRV signals were analyzed with Kubios HRV software using linear methods (time and frequency domain) and non‐linear ones. Subject perception for stress was assessed using the Rapid Assessment of Stress questionnaire (RSA) and the NASA‐TLX test was used to evaluate subjective perception of workload after each mission. Data from 27 participants were analyzed (data from 13 participants were excluded due to technical reasons). HR mean, SDNN, pNN50, VLF/HF, VLF, SD1, SD2 significantly changed (p < 0.05) during different phases of flight, reflecting the alterations of the sympathetic and parasympathetic activity. Detected and perceived stress were poorly correlated (p > 0.05). This study for the first time established the sympathetic/parasympathetic activity of helicopter rescue crews during all phases of HEMS mission. Despite the poor correlation between detected and perceived stress, the comparison of subjective and surveyed data in different HEMS crews could allow to implement stress‐management policies and increase safety in the workplace.

3 SIMULATED ACUTE HYPOBARIC HYPOXIA EFFECTS ON COGNITION IN HELICOPTER EMERGENCY MEDICAL SERVICE (HEMS) PERSONNEL – A RANDOMIZED, CONTROLLED, SINGLE‐BLIND, CROSS‐OVER STUDY

Marika Falla^1,2, Katharina Hüfner³, Elisabeth M. Weiss⁴, Anna Vögele¹, Alexander Dejaco¹, Jonas Brandner³, Markus Falk¹, Michiel vanVeelen¹, Giada Nicoletto¹, Bernard Weber⁵, Hermann Brugger¹, Giacomo Strapazzon¹

¹Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy; ²Center for Mind/Brain Sciences, CIMeC, University of Trento, Rovereto (TN), Italy; ³Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital for Psychiatry II, Medical University of Innsbruck, Austria; ⁴Department of Psychology, University of Innsbruck, Austria; ⁵Department of Psychology, University of Graz, Austria

The effect of acute exposure to hypobaric hypoxia (HH) and its impact on the cognitive performance of helicopter emergency medical service (HEMS) personnel, including physicians, paramedics, winch operators and mountain rescuers is unexplored. We sought to evaluate the effect of HH on selected cognitive domain in HEMS crew members. A randomized, controlled, single‐blind, cross‐over study design was performed in an environmental chamber (terraXcube) to induce HH in 48 healthy HEMS crew members. Participants performed three different cognitive tests before the ascent, after 5 min at altitude, and after simulated cardiopulmonary resuscitation at altitude of 200, 3000 and 5000 m asl. The Balloon Analogue Risk Task (BART) was used to evaluate the risky decision making, the digit symbol substitution test (DSST) to evaluate the processing speed and the psychomotor vigilance (PVT) that include measurement of reaction time (RT) to evaluate the sustained attention. Data were analyzed using a linear mixed model. Mean reaction time (RT) was significantly slower (p < 0.05) at HH (5000m asl) but there were no independent effects of HH on the other parameters of the PVT (number of lapses, false start, performance score), BART or DSST. This finding suggests that except for a reduced psychomotor speed there is no significant reduction in high level cognitive performance in HEMS crew members during mountain rescue operations up to 5000 m asl, in the absence of cold/heat and wind, for at least 30 minutes after arrival at altitude.

4 AN ARTIFICIAL AIR POCKET DEVICE REDUCES INSPIRED LEVEL OF CARBON DIOXIDE IN PARTICIPANTS COMPLETELY BURIED IN AVALANCHE DEBRIS: AN EXPERIMENTAL, RANDOMIZED CROSSOVER STUDY

Giacomo Strapazzon MD PhD^1,2, Sandro Malacrida PhD¹, Enrica Governo MD³, Tomas Dal Cappello¹, Simon Rauch MD PhD¹, Margherita Urgesi MD¹, Simona Mrakic‐Sposta PhD⁴, Alessandra Vezzoli PhD⁴, Marika Falla MD PhD^1,5, Alberto Cabarle², Martin Palma¹, Luca Cavoretto³, Enrico Visetti⁶, Guido Giardini MD³, Hermann Brugger MD¹, Federico Prato MD⁷

¹Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy; ²Corpo Nazionale Soccorso Alpino e Speleologico, CNSAS, Milano, Italy; ³Mountain Medicine Center, Azienda Sanitaria Valle d'Aosta, Aosta, Italy; ⁴Institute of Clinical Physiology ‐ National Research Council IFC ‐ CNR, Milano, Italy; ⁵CIMeC ‐ Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy; ⁶Department of Anesthesia and Intensive Care, Gruppo Policlinico di Monza, Monza, Italy; ⁷Anesthesia and Intesive Care Unit, Azienda Sanitaria Locale di Biella, Biella, Italy

Completely buried avalanche patients die mostly within 35 min generally due to acute asphyxiation. The use an artificial air pocket device (AAPD) could prolong survival. The aim of the study was to evaluate the influence of AAPD on the development of hypoxia and hypercapnia in completely buried participants. In an experimental, randomized, crossover study, thirteen healthy participants breathed in a mouthpiece connected to a tubing system integrated in a backpack: the tube was blinded connected either to a 1 L artificial air pocket or to the AAPD (Ferrino Airsafe^®). Participants were buried under avalanche debris until peripheral oxygen saturation (SpO₂) dropped below 84% (or up to 60 minutes); vital signs, O₂ and CO₂ concentrations, and the inspired fraction of O₂ (FiO₂) and CO₂ (FiCO₂) were continuously monitored. Survival curves showed a difference between the tests in the artificial air pocket vs. in the AAPD tests for SpO₂<84% (log‐rank test, p < 0.05), burial time increased in each participant in the latter. Despite the longer duration of the tests with the AAPD, the delta (difference between end and beginning of the test) of O₂ and CO₂ concentration at the output point did not differ when compared to levels into the 1 L air pocket (Wilcoxon signed‐rank test, p ≥ 0.05), but the increase of FiO₂ and the reduction of FiCO₂ at three min were different (Wilcoxon signed‐rank test, p < 0.05). AAPD effects can prolong survival of completely buried avalanche patients with patent airway and allow intervention of emergency care providers despite a small air pocket.

5 NEPALESE DIPLOMA IN MOUNTAIN MEDICINE: AN EXPERIENCE OF A DECADE OF MOUNTAIN MEDICINE EDUCATION IN NEPAL AND THE FUTURE CHALLENGES

Sushil Pant¹, MBBS, DiMM; Maniraj Neupane², MBBS, PhD, DiMM; Suzy Stokes³, MBChB, FRCEM, FIMC, FAWM, DiMM

¹Mountain Medicine Society of Nepal; Internal Medicine, Montefiore New Rochelle Hospital/Albert Einstein College of Medicine; ²Mountain Medicine Society of Nepal; Pulmonary and Critical Care, National Institutes of Health; ³British Mountain Medicine Society; Emergency Department, Oxford University Hospitals, Oxford, United Kingdom; Thames Valley Air Ambulance, Oxford, United Kingdom

In recent years, high altitude medicine training has gained popularity with well‐established courses in European and other western countries. Here, we present our experience of conducting the International Climbing and Mountaineering Federation, International Commission for Alpine Rescue, and International Society of Mountain Medicine (UIAA/ICAR/ISMM) basic diploma in mountain medicine course in Nepal by the Mountain Medicine Society of Nepal (MMSN). Since 2010, MMSN has conducted six Nepalese Diploma in Mountain Medicine (NepDiMM) courses using lectures, group discussions, clinical scenarios, and hands‐on training in Kathmandu and the Himalayan glaciers. We assessed medical knowledge using essays and multiple choice questions, and practical knowledge using clinical scenarios and skill demonstrations. In a decade, NepDiMM has trained 104 doctors. Of the 38 Nepalese doctors trained, 5 were female and 18 were practicing in Nepal. High altitude medicine was taught by medical instructors from Nepal, the UK, the US and other European countries. Winter skills were solely taught by Nepalese Sherpa mountain guides after first 3 seasons. Our graduates have worked at high altitude aid posts including Everest ER, major trail races, and as advisors for local expedition companies. NepDiMM was instrumental in the development of mountain medicine and rescue in Nepal. The major challenges for future are development of local instructors and continued professional development of faculties. In a decade of mountain medicine education in Nepal, NepDiMM has built a good foundation for future courses. However, local faculty development remains a major challenge and requires a strong commitment from the stakeholders in Nepal.

6 TRANSCRIPTION FACTORS REGULATION IN HUMAN PERIPHERAL WHITE BLOOD CELLS DURING HYPOBARIC HYPOXIA EXPOSURE: AN IN‐VIVO EXPERIMENTAL STUDY

*Sandro Malacrida^1,4, Alessandra Giannella², Giulio Ceolotto², Carlo Reggiani⁴, Alessandra Vezzoli³, Simona Mrakic‐Sposta³, Sarah Moretti³, Rachel Turner¹, Marika Falla⁵, Hermann Brugger¹ and Giacomo Strapazzon¹.

¹Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy; ²Department of Medicine‐DIMED, Campus Biomedico Pietro D'Abano, University of Padova, Padova, Italy; ³Institute of Bioimaging and Molecular Physiology, National Council of Research, Segrate (Milan), Italy; ⁴Department of Biomedical Sciences, University of Padova, Padova, Italy; ⁵Department of Neurology, General Hospital of Bolzano, Bolzano, Italy

High altitude is a natural laboratory, within which the clinical study of human physiological response to hypobaric hypoxia (HH) is possible. Failure in the response results in progressive hypoxemia, inflammation, and increased oxidative stress (OxS). Thus, investigating temporal changes in transcription factors (TFs) HIF‐1α, HIF‐2α, NF‐κB and NRF2 mRNA levels, relative to OxS and inflammatory markers, may reveal human molecular response to hypoxia. Biological samples from 15 healthy participants were collected at baseline and after passive ascent to 3830m (24h and 72h). Gene expression was assessed by qPCR and ROS generation was determined by EPR spectroscopy. Oxidative damage and cytokine levels were estimated by immuno or enzymatic methods. The effect of HH exposure on gene expression was evaluated by analysis of variance for repeated measures of ΔCt for gene mRNA levels. All p‐value less than 0.05 were considered statistically significant. Hypoxia transiently enhanced HIF‐1α mRNA levels over time reaching a peak after 24h. Whereas, HIF‐2α and NRF2 mRNA levels increased overtime. In contrast, the NF‐κB mRNA levels remained unchanged. Plasma levels of IL‐1β and IL‐6 also remained within normal ranges. ROS production rate and markers of OxS damage were significantly increased over time. The analysis of TF‐gene expression suggests that HIF‐1α is a lead TF during sub‐acute HH exposure. The prolongation of the HH exposure led to a switch between HIF‐1α and HIF‐2α/NRF2, suggesting the activation of new pathways. These results provide new insights regarding the temporal regulation of TFs, inflammatory state, and ROS homeostasis involved in human hypoxic response.

7 EVALUATION OF LEFT VENTRICULAR CONTRACTILE RESERVE DURING STRESS ECHOCARDIOGRAPHY IN NORMOBARIC NORMOXIA AND SIMULATED HYPOXIA: HEALTHY CONTROLS VS ISCHEMIC PATIENTS.

E. Salvi^1,2, L. Bastiani³, S. Mrakic‐Sposta⁴, A. Vezzoli⁴, E. Riccardi⁵, B. Catuzzo⁶, G. Giardini⁷, L. Pratali³

¹Italian Navy Medical Service, Naval Academy; Livorno, ITALY; ²University of Pisa, ITALY; ³CNR National Research Council, Institute of Clinical Physiology; Pisa, ITALY; ⁴Institute of Clinical Physiology, National Research Council (CNR), ASST Grande Ospedale Metropolitano Niguarda, Milan, ITALY.; ⁵Department of Pneumology, University of Turin, Torino, ITALY.; ⁶Mountain Medicine Center, Ospedale Regionale Umberto Parini, Aosta, Italy.; ⁷Department of Neurology, Neurophysiopathology Unit, Valle d'Aosta regional hospital; Aosta, ITALY

Aim of the study was to investigate the effects of exposure to simulated hypoxia in people with previous coronary artery disease.

Methods: 70 volunteers, 44 healthy subjects (CONTR, 57.7 ± 11.4yrs) and 26 patients with stable Coronary Artery Disease (CAD, 65.3 ± 8.0yrs), underwent stress‐echocardiography exercising both in normoxic and hypoxic condition (FiO₂ = 12.5%).

Results: Left ventricular contractility (LV_esP/V) in normoxia was reduced in CAD, both during rest (4.7 ± 2.7 vs 5.9 ± 2.5 mmHg/mL; p = 0.06) and exercise (8.4 ± 3.9 vs 10.4 ± 3.9 mmHg/mL; p = 0.04) while there was no significant difference between CAD/CONTR in hypoxia (6.3 ± 2.8 vs 6.6 ± 2.7 mmHg/mL) at rest and at exercise (8.9 ± 3.3 vs 10.0 ± 4.3 mmHg/mL). Left Ventricular Contractile Reserve (LVCR, assessed as the ratio between contractility at stress peak and at rest) showed no differences with similar reduction during hypoxic exposure (CAD = 2 CONTR = 1.9 in normoxia and CAD = 1.5 CONTR = 1.7 in hypoxia). Without differences in WMSI, ST downslope (>1mm) was more frequent in CAD (20.0% vs 4.8%; p = 0.09) in normoxia, while during hypoxic exercise downslope probability was similar between the groups (CAD = 50.0%, CONTR = 56.1%). Downslope in CONTR was commoner in subjects with higher Systolic Pulmonary Artery Pressure, SPAP (40.5 ± 9.8 vs 46.0 ± 8.8 mmHg, p = 0.07) and Right Ventricle Contractility (4.5 ± 1.3 vs 6.6 ± 3.6 mmHg/cm²; p = 0.03).

Conclusions: CAD and CONTR similarly increase their left ventricle contractility in response to hypoxia. ECG alterations during exercise in CONTR could be ascribed to an hyper reactivity of the right heart in response to hypoxia. By contrast, CAD seem to be less sensitive to hypoxia, perhaps for a physiological adaptation to the chronic perpetuation of ischemic/hypoxic situations.

8 VIRCHOW‐ROBIN SPACES ENLARGE DURING RECOVERY FROM HIGH ALTITUDE CEREBRAL EDEMA AND PERSIST

Steven Roy,¹; Giuseppe Barisano,²; Peter Hackett,³

¹Department of Critical Care Medicine, Cumming School of Medicine, University of Calgary, Canada; ²USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, USA; ³Altitude Research Center, Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, USA

Introduction: The glymphatic system has been proposed as potentially implicated in the pathophysiology of High Altitude Cerebral Edema (HACE). The perivascular or Virchow‐Robin spaces (VRS) are the conduits for glymphatic flow found in the human brain. We conducted a retrospective analysis of magnetic resonance (MR) images to identify VRS in patients with HACE.

Methods: We used admission and followup T2‐weighted images from patients with acute HACE to identify changes in detectable VRS over time. An expert VRS reader counted the VRS in the centrum semiovale of 28 scans using a validated scale. The spatial overlap of venous vessels (determined with susceptibility‐weighted images) with VRS was analyzed to assess if the counted VRS were periarterial or perivenular.

Results: Images were analyzed for 8 patients admitted to hospital for HACE who had an MR scan within 3 days of admission. The mean number of available scans was 3.5 over an average period of 2.2 years. The mean number of visible VRS increased 115% within days of admission and 156% within a year. All patients had increases in visualized VRS over time. Venous vessels did not overlap with visible VRS strongly suggesting the changes were periarterial.

Conclusions: We describe increases in the observable number of VRS of patients with HACE. These increases often occurred rapidly and persisted years later, suggesting a permanent alteration. To our knowledge, this is the first description of altered VRS resulting from HACE. Further investigation is required to determine possible functional significance of these findings and the mechanisms.

9 MITIGATING RISK OF COVID‐19 DURING MOUNTAIN RESCUE ‐ OFFICIAL GUIDELINES OF THE INTERNATIONAL COMMISSION FOR ALPINE RESCUE (ICAR)

Steven Roy,^1,2,3; Alison Sheets,^2,4,5; Inigo Soteras,^2,6; Giacomo Strapazzon,^2,7,8; Don McPhalen,^2,9; Maria Antonia Nerin,^2,10; Simon Rauch,^2,6,11; Richard Price,^2,12; Kazue Oshiro,^2,13,14; Myron Allen,^15,16; Alistair Read,^16,17; Peter Paal,^2,18,19,20

¹Department of Critical Care Medicine, University of Calgary, Canada; ²Medical Commission of the International Commission for Alpine Rescue (ICAR MEDCOM), Switzerland; ³International Society for Mountain Medicine; ⁴Emergency Medicine, Boulder Community Health, Boulder, Colorado, USA; ⁵University of Colorado Wilderness and Environmental Medicine Fellowship, Aurora, Colorado, USA; ⁶Emergency Medical System. Catalonia, Spain. University of Girona, Catalonia, Spain; ⁷Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy; ⁸Corpo Nazionale Soccorso Alpino e Speleologico, National Medical School (CNSAS SnaMed), Milan, Italy; ⁹Department of Surgery, University of Calgary, Canada; ¹⁰Jose Ramon Morandeira Mountain Medicine Association‐CUEMUM, Spain; ¹¹Department of Anaesthesiology and Intensive Care Medicine, F. Tappeiner Hospital, Merano, Italy; ¹²LandSAR, New Zealand; ¹³Department of Cardiovascular Medicine, Hokkaido Ohno Memorial Hospital, Sapporo, Japan; ¹⁴Director of Mountain Medicine, Research, and Survey Division, Hokkaido Ohno Memorial Hospital, Sapporo, Japan; ¹⁵National Ski Patrol, USA; ¹⁶Terrestrial Commission of the International Commission for Alpine Rescue (ICAR), Switzerland; ¹⁷Mountain Rescue, England and Wales, UK; ¹⁸Department of Anaesthesiology and Intensive Care Medicine, Hospitallers Brothers Hospital, Paracelsus Medical University Salzburg, Austria; ¹⁹Austrian Board for Mountain Safety, Innsbruck, Austria; ²⁰Austrian Society of Mountain and High Altitude Medicine, Mieming, Austria

Background: In mountain rescue, uncertainty exists on the best practice to prevent COVID‐19 transmission. Regionally developed guidelines are mixed consensus and evidence based. The aim of this work is to provide a state‐of‐the‐art overview of the challenges caused by the COVID‐19 pandemic in mountain rescue and introduce recommendations for management of these challenges.

Methods: Original articles or reviews, published until December 27, 2020 in Cochrane COVID‐19 Study Register, EMBASE, PubMed and Google Scholar were included. Articles were limited to English, French, German or Spanish with the manuscript topics of COVID‐19 or other epidemics, addressing transmission, transport, rescue or CPR. The bibliographies of included articles were hand‐searched for additional articles. The resulting articles were provided to the guidelines panel for consideration. The panel used a consensus approach to develop recommendations and graded each recommendation according to predetermined criteria (GRADE guidelines).

Results: The literature search yielded 6195 articles (952 duplicates, 5243 unique results). In abstract screening, 273 studies met the inclusion criteria for full‐text review and 4971 articles did not and were excluded. Full‐text review revealed 5 additional duplicates and 18 articles failed to meet the inclusion criteria. The remaining 249 articles were included for consideration by the consensus committee.

Conclusions: This article covers several important topics pertaining to mountain rescue: specific challenges in mountain rescue related to COVID‐19, rescuer safety and infection prevention, terrestrial and airborne rescue, transportation, mountain rescue training and challenges in resource‐limited countries. Evidence‐graded recommendations are provided. Finally, knowledge gaps are identified and an outlook is given.

10 A CASE OF HAPE DEVELOPED AT RELATIVELY LOW ALTITUDE OF 2,680 M IN JAPAN ALPS.

Tomonori Harada^1,2, Takahiro Namiki¹, Takase Osawa¹, Naohiro Niimi¹, Mikio Matsumoto^1,3, Shin Aizawa^1,2

¹Nihon University School of Medicine Tokusawa Clinic, Japan; ²Department of Functional Morphology, Nihon University School of Medicine, Japan; ³Tokyo Rinkai Hospital, Japan

A 31‐year‐old man who was good in health at sea level felt decreased exercise tolerance in the second morning of Mt. Yari (3,180 m) hiking at the altitude of 2,704 m. In addition, a fever, dyspnea and expectorated pink sputum appeared at the night of same day in another hut of 2,680 m. Then, he descended through a route which usually requires 7 hours, but it took 2 days for him. He stopped our volunteer mountain clinic (1,562 m) locates on the way. The total of self‐reported Lake Louise Score at the presence was 2 (only for headache, not including 2 for sleep) and SpO₂ was 78% with heart rate of 95 bpm. Body temperature was 37.7 degreeC. Cyanosis was present but rales were not heard by auscultation. He refused the evacuation and used approximately 2 times of usual hiking time to finish the route. Chest CT revealed pulmonary edema with patchy and asymmetric ground glass opacity at a hospital (690 m). Inflammation state was also confirmed with neutrophilia (10,590/μL) and elevated CRP level (7.06 mg/dL). However, he recovered without any medications, and the CT on three days later did not show the pulmonary edema. Therefore, we diagnosed him with HAPE, based on recovery with the descending to sea level only. Although he had become similar condition at previous hiking, he did not have knowledge about HAPE.

HAPE may not be well‐known illness among Japanese hikers, and the advices are required to aware the development and prevent from the recurrence.