Ken Zafren, MD FAAEM FACEP FAWM

All Publications

• The STAR Data Reporting Guidelines for Clinical High Altitude Research HIGH ALTITUDE MEDICINE & BIOLOGY Maeder, M., Brugger, H., Pun, M., Strapazzon, G., Dal Cappello, T., Maggiorini, M., Hackett, P., Baertsch, P., Swenson, E. R., Zafren, K., STAR Core Grp, STAR Delphi Expert Grp 2018; 19 (1): 7?14

  Abstract

  Brodmann Maeder, Monika, Hermann Brugger, Matiram Pun, Giacomo Strapazzon, Tomas Dal Cappello, Marco Maggiorini, Peter Hackett, Peter Baärtsch, Erik R. Swenson, Ken Zafren (STAR Core Group), and the STAR Delphi Expert Group. The STARdata reporting guidelines for clinical high altitude research. High AltMedBiol. 19:7-14, 2018.The goal of the STAR (STrengthening Altitude Research) initiative was to produce a uniform set of key elements for research and reporting in clinical high-altitude (HA) medicine. The STAR initiative was inspired by research on treatment of cardiac arrest, in which the establishment of the Utstein Style, a uniform data reporting protocol, substantially contributed to improving data reporting and subsequently the quality of scientific evidence.The STAR core group used the Delphi method, in which a group of experts reaches a consensus over multiple rounds using a formal method. We selected experts in the field of clinical HA medicine based on their scientific credentials and identified an initial set of parameters for evaluation by the experts.Of 51 experts in HA research who were identified initially, 21 experts completed both rounds. The experts identified 42 key parameters in 5 categories (setting, individual factors, acute mountain sickness and HA cerebral edema, HA pulmonary edema, and treatment) that were considered essential for research and reporting in clinical HA research. An additional 47 supplemental parameters were identified that should be reported depending on the nature of the research.The STAR initiative, using the Delphi method, identified a set of key parameters essential for research and reporting in clinical HA medicine.

  View details for PubMedID 29596018

  View details for PubMedCentralID PMC5905862

• High altitude illness in pilgrims after rapid ascent to 4380 M TRAVEL MEDICINE AND INFECTIOUS DISEASE Zafren, K., Pun, M., Regmi, N., Bashyal, G., Acharya, B., Gautam, S., Jamarkattel, S., Lamichhane, S. R., Acharya, S., Basnyat, B. 2017; 16: 31-34

  Abstract

  The goal of the study was to characterize high altitude illness in Nepali pilgrims.We kept standardized records at the Himalayan Rescue Association (HRA) Temporary Health Camp at Gosainkund Lake (4380 m) in the Nepal Himalaya during the annual Janai Purnima Festival in 2014. Records included rate of ascent and Lake Louise Score (LLS). We defined High Altitude Headache (HAH) as headache alone or LLS = 2. Acute Mountain Sickness (AMS) was LLS?3. High Altitude Cerebral Edema (HACE) was AMS with ataxia or altered mental status.An estimated 10,000 pilgrims ascended rapidly, most in 1-2 days, from Dhunche (1960 m) to Gosainkund Lake (4380 m). We saw 769 patients, of whom 86 had HAH. There were 226 patients with AMS, including 11 patients with HACE. We treated patients with HACE using dexamethasone and supplemental oxygen prior to rapid descent. Each patient with HACE descended carried by a porter. There were no fatalities due to HACE. There were no cases of High Altitude Pulmonary Edema (HAPE).HAH and AMS were common in pilgrims ascending rapidly to 4380 m. There were 11 cases of HACE, treated with dexamethasone, supplemental oxygen and descent. There were no fatalities.

  View details for DOI 10.1016/j.tmaid.2017.03.002

  View details for PubMedID 28285976

• Delayed and intermittent CPR for severe accidental hypothermia RESUSCITATION Gordon, L., Paal, P., Ellerton, J. A., Brugger, H., Peek, G. J., Zafren, K. 2015; 90: 46-49

  Abstract

  Cardiac arrest (CA) in patients with severe accidental hypothermia (core temperature <28 °C) differs from CA in normothermic patients. Maintaining CPR throughout the prehospital period may be impossible, particularly during difficult evacuations. We have developed guidelines for rescuers who are evacuating and treating severely hypothermic CA patients.A literature search was performed. The authors used the findings to develop guidelines.Full neurological recovery is possible even with prolonged CA if the brain was already severely hypothermic before CA occurred. Data from surgery during deep hypothermic CA and prehospital case reports underline the feasibility of delayed and intermittent CPR in patients who have arrested due to severe hypothermia.Continuous CPR is recommended for CA due to primary severe hypothermia. Mechanical chest-compression devices should be used when available and CPR-interruptions avoided. Only if this is not possible should CPR be delayed or performed intermittently. Based on the available data, a patient with a core temperature <28 °C or unknown with unequivocal hypothermic CA, evidence supports alternating 5 min CPR and ?5 min without CPR. With core temperature <20 °C, evidence supports alternating 5 min CPR and ?10 min without CPR.

  View details for DOI 10.1016/j.resuscitation.2015.02.017

  View details for PubMedID 25725297

• Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia: 2014 update. Wilderness & environmental medicine Zafren, K., Giesbrecht, G. G., Danzl, D. F., Brugger, H., Sagalyn, E. B., Walpoth, B., Weiss, E. A., Auerbach, P. S., McIntosh, S. E., Némethy, M., McDevitt, M., Dow, J., Schoene, R. B., Rodway, G. W., Hackett, P. H., Bennett, B. L., Grissom, C. K. 2014; 25 (4): S66-85

  Abstract

  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.

  View details for DOI 10.1016/j.wem.2014.10.010

  View details for PubMedID 25498264

• Frostbite: Prevention and Initial Management HIGH ALTITUDE MEDICINE & BIOLOGY Zafren, K. 2013; 14 (1): 9-12

  Abstract

  Frostbite is a local freezing injury that can cause tissue loss. Historically, it has been a disease of wars, but it is a hazard for anyone who ventures outdoors in cold weather. Frozen tissue is damaged both during freezing and rewarming. Frozen tissue is numb. Rewarming causes hyperemia and is often painful. Blisters and edema develop after rewarming. Hard eschar may form with healthy tissue deep to the eschar. Frostbite can be classified as superficial, without permanent tissue loss, or deep, with varying degrees of permanent tissue loss, often less than appearances suggest. It can be difficult to predict the amount of tissue loss at the time of presentation and early in the subsequent course. Prevention is better than treatment. It may be advisable not to rewarm frozen extremities in the field, but spontaneous thawing is often unavoidable. Extremities that have thawed should be protected from refreezing at all costs. Once in a protected environment, extremities that are still frozen should be rapidly thawed in warm water. Therapy with aspirin or ibuprofen may be helpful, but evidence is limited. Thrombolytic treatment within the first 24 hours after rewarming seems to be beneficial in some cases of severe frostbite. Prostacyclin therapy is very promising.

  View details for DOI 10.1089/ham.2012.1114

  View details for PubMedID 23537254

• D-Dimer Is Not Elevated in Asymptomatic High Altitude Climbers after Descent to 5340 m: The Mount Everest Deep Venous Thrombosis Study (Ev-DVT) HIGH ALTITUDE MEDICINE & BIOLOGY Zafren, K., Feldman, J., Becker, R. J., Williams, S. R., Weiss, E. A., Deloughery, T. 2011; 12 (3): 223-227

  Abstract

  We performed this study to determine the prevalence of elevated D-dimer, a marker for deep venous thrombosis (DVT), in asymptomatic high altitude climbers. On-site personnel enrolled a convenience sample of climbers at Mt. Everest Base Camp (Nepal), elevation 5340?m (17,500?ft), during a single spring climbing season. Subjects were enrolled after descent to base camp from higher elevation. The subjects completed a questionnaire to evaluate their risk factors for DVT. We then performed a D-dimer test in asymptomatic individuals. If the D-dimer test was negative, DVT was considered ruled out. Ultrasound was available to perform lower-extremity compression ultrasounds to evaluate for DVT in case the D-dimer was positive. We enrolled 76 high altitude climbers. None had a positive D-dimer test. The absence of positive D-dimer tests suggests a low prevalence of DVT in asymptomatic high altitude climbers.

  View details for DOI 10.1089/ham.2010.1101

  View details for PubMedID 21962065

• Acetazolamide fails to decrease pulmonary artery pressure at high altitude in partially acclimatized humans HIGH ALTITUDE MEDICINE & BIOLOGY Basnyat, B., Hargrove, J., Holck, P. S., Srivastav, S., Alekh, K., Ghimire, L. V., Pandey, K., Griffiths, A., Shankar, R., Kaul, K., Paudyal, A., Stasiuk, D., Basnyat, R., Davis, C., Southard, A., Robinson, C., Shandley, T., Johnson, D. W., Zafren, K., Williams, S., Weiss, E. A., Farrar, J. J., Swenson, E. R. 2008; 9 (3): 209-216

  Abstract

  In this randomized, double-blind placebo controlled trial our objectives were to determine if acetazolamide is capable of preventing high altitude pulmonary edema (HAPE) in trekkers traveling between 4250 m (Pheriche)\4350 m (Dingboche) and 5000 m (Lobuje) in Nepal; to determine if acetazolamide decreases pulmonary artery systolic pressures (PASP) at high altitude; and to determine if there is an association with PASP and signs and symptoms of HAPE. Participants received either acetazolamide 250 mg PO BID or placebo at Pheriche\Dingboche and were reassessed in Lobuje. The Lake Louise Consensus Criteria were used for the diagnosis of HAPE, and cardiac ultrasonography was used to measure the velocity of tricuspid regurgitation and estimate PASP. Complete measurements were performed on 339 of the 364 subjects (164 in the placebo group, 175 in the acetazolamide group). No cases of HAPE were observed in either study group nor were differences in the signs and symptoms of HAPE found between the two groups. Mean PASP values did not differ significantly between the acetazolamide and placebo groups (31.3 and 32.6 mmHg, respectively). An increasing number of signs and symptoms of HAPE was associated with elevated PASP (p < 0.01). The efficacy of acetazolamide against acute mountain sickness, however, was significant with a 21.9% incidence in the placebo group compared to 10.2 % in the acetazolamide group (p < 0.01). Given the lack of cases of HAPE in either group, we can draw no conclusions about the efficacy of acetazolamide in preventing HAPE, but the absence of effect on PASP suggests that any effect may be minor possibly owing to partial acclimatization during the trek up to 4200 m.

  View details for DOI 10.1089/ham.2007.1073

  View details for Web of Science ID 000259759600004

  View details for PubMedID 18800957

• Lightning injuries: prevention and on-site treatment in mountains and remote areas - Official guidelines of the International Commission for Mountain Emergency Medicine and the Medical Commission of the International Mountaineering and Climbing Federation (ICAR and UIAA MEDCOM) RESUSCITATION Zafren, K., Durrer, B., Herry, J. P., Brugger, H. 2005; 65 (3): 369-372

  Abstract

  Lightning is a hazard during outdoor activities, especially for hikers and mountaineers. Specific preventive measures include staying off ridges and summits, and away from single trees. If possible, stay close to a wall but keeping a distance of at least 1m away from the wall. All metal objects (carabiners, crampons, ice-axe, ski poles, etc.) should be removed and stored away safely. Lightning currents can follow wet ropes. To prevent blunt trauma the helmet should not be removed. Move as quickly as possible away from wire ropes and iron ladders. The crouch position should be adopted immediately if there is a sensation of hair "standing on end". Crackling noises or a visible glow indicate an imminent lightning strike. Rescue of lightning victims may be hazardous. Airborne helicopters can be struck by lightning with disastrous effects. It is prudent to wait until the danger of further strikes has passed. Treatment of lightning victims is based upon the ABCs - (Assessment) airway, breathing and circulation. Victims who are not breathing can often be resuscitated and should be helped first. Respiratory arrest may be prolonged, but the prognosis can be excellent if breathing is supported. Standard Advanced Life Support (ALS), if necessary, should be given at the scene.

  View details for DOI 10.1016/j.resuscitation.2004.12.014

  View details for PubMedID 15919576

• Guidelines for the management of head injuries in remote and rural Alaska. Alaska medicine Sacco, F., Zafren, K., Brown, K., Cohen, T., COOPES, B. J., Godersky, J., Hudson, D., Hyams, S., Ingraham, D., Levy, M., Ma, W., Martinez, P., Montano, W., Mithun, J., O'Malley, J., O'Neill, K., Powers, D., Smith, L. 2004; 46 (3): 58-62

  Abstract

  Numerous recommendations on the initial evaluation and treatment of the head injured patient have been proposed over the last several years. Most assume there is readily available access to computed tomography and neurosurgical specialists. Many clinicians in Alaska must evaluate and begin treatment of head injured patients in circumstances quite different from this. Vast distances, severe weather and limited medical evacuation capability are factors that come into play while caring for these patients. The current medicolegal climate also contributes to clinician anxiety over missing rare but potentially serious injuries. These guidelines developed by Alaska clinicians from multiple specialties are meant to assist clinicians dealing with this very common problem and represent a reasonable approach to these patients in remote and rural Alaska.

  View details for PubMedID 15839596

• Thrombotic complications at altitude WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2004; 15 (2): 155-155

  View details for Web of Science ID 000222041200015

  View details for PubMedID 15228070

• Trends in the workload of the two high altitude aid posts in the Nepal Himalayas JOURNAL OF TRAVEL MEDICINE Basnyat, B., Savard, G. K., Zafren, K. 1999; 6 (4): 217-222

  Abstract

  Acute mountain sickness (AMS), High altitude pulmonary edema (HAPE) and High Altitude Cerebral Edema (HACE) are well known problems in the high altitude region of the Nepal Himalayas. To assess the proportion of AMS, HAPE, and HACE from 1983 to 1995 in the Himalaya Rescue Association (HRA) aid posts' patients at the Everest (Pheriche 4,243 m) and Annapurna (Manang 3,499 m) regions, the two most popular trekking areas in the Himalayas. A retrospective study was conducted at the HRA medical aid posts in Manang (3,499 m) and Pheriche (4,243 m) in the Himalayas, where 4,655 trekkers (tourists, mostly Caucasians) and 4,792 Nepalis (mostly porters and villagers) were seen at the two high-altitude clinics from 1983 to 1995, for a variety of medical problems, including AMS.The number of trekking permits issued for entering the two most popular regions in the Himalayas was calculated and referenced to the proportion of trekkers with medical conditions. Well established guidelines like the Lake Louise Diagnostic Criteria were used in the assessment of AMS, HAPE and HACE. Linear regression analyses were performed on data collected from the two aid posts to determine the effect of time on each variable. For comparison between the aid posts, angular transformation (arcsine) and analysis of variance (ANOVA) were performed on all proportional (incidence) data.Approximately 20% of all visitors (Nepali plus trekkers) who visited the higher Pheriche aid post were diagnosed with AMS compared to around 6% at the lower Manang aid post. There was a linear increase over time in the number of trekkers entering the Everest (r=0.904, p<.001) and the Annapurna (r=0.887, p<.001) regions. The proportion of trekker patients with any medical condition visiting the two HRA aid posts at Manang and Pheriche, expressed as a function of the total number of trekkers entering the Everest and Annapurna regions, was not significantly different between Pheriche (average 4%) and Manang (average 1%). However, the proportion of AMS, HAPE and HACE in patients (Nepali plus trekkers) to the aid posts was greater in those visiting the higher Pheriche aid post compared to the lower Manang aid post (f=56.74, n=13; p<. 001). Importantly, only the proportion of AMS (r=0.568; p<.05) and not HAPE or HACE increased over time in Pheriche, alongside an unchanged proportion of trekker patients, amongst all Pheriche aid post patients. There was no increase of AMS, HAPE or HACE in Manang.HAPE and HACE are the life-threatening forms of AMS and although there is a linear increase of trekkers entering the Himalayas in Nepal, the findings revealed that HAPE and HACE have not increased over time. One possible explanation may be that awareness drives by organizations like the Himalayan Rescue Association may be effective in preventing the severe forms of AMS.

  View details for Web of Science ID 000084359600001

  View details for PubMedID 10575168

• Images - Chilblains (pernio) WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 1999; 10 (1): 25-26

  View details for Web of Science ID 000079896900007

  View details for PubMedID 10347676

• Gamow bag for high-altitude cerebral oedema LANCET Zafren, K. 1998; 352 (9124): 325-326

  View details for Web of Science ID 000074974500065

  View details for PubMedID 9690443

• Hyponatremia in a cold environment WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 1998; 9 (1): 54-55

  View details for Web of Science ID 000080104600010

  View details for PubMedID 11990182

• High-altitude medicine. Emergency medicine clinics of North America Zafren, K., Honigman, B. 1997; 15 (1): 191-222

  Abstract

  This article discusses prevention, recognition, and treatment of altitude illnesses, especially acute mountain sickness, high-altitude pulmonary edema, and high-altitude cerebral edema. Physicians advising travelers and trekkers who will be visiting high-altitude areas will find an organized approach to giving pretravel advice. Physicians practicing in or visiting high-altitude areas will find guidelines for diagnosis and treatment. This article also addresses the issue of patients with underlying diseases who wish to travel to high-altitude destinations.

  View details for PubMedID 9056576

• Treatment of high-altitude pulmonary edema by bed rest and supplemental oxygen WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Reeves, J. T., Schoene, R. 1996; 7 (2): 127-132

  Abstract

  We evaluated the safety and efficacy of treating high-altitude pulmonary edema (HAPE) by bed rest and supplemental oxygen at moderate altitudes. We also characterized clinical parameters in HAPE before and after treatment.Case series.Two primary care centers at about 9,200 feet (2,800 meters) above sea level.All patients aged 16-69 years who had been diagnosed with HAPE and were treated with bed rest and supplemental oxygen. Patients were seen on a follow-up visit. Interventions: Selected patients were treated with bed rest and supplemental oxygen rather than hospital admission or descent.Patients were considered improved on follow-up if room air arterial oxygen saturation was increased by 10 percentage points or if their symptoms had improved.Of 58 patients with confirmed HAPE, 25 (43%) were treated by bed rest and supplemental oxygen and were seen on return visits to the clinic. All of the treated patients improved at the return visit. Systolic blood pressure, heart rate, respiratory rate, and temperature decreased significantly between the first visit and the return visit. Oxygen saturation improved between visits.Some patients with HAPE at moderate altitudes where medical facilities are available can be safely treated with bed rest and oxygen without descent.

  View details for Web of Science ID A1996XU76000004

  View details for PubMedID 11990106

• SEASONAL-VARIATION IN BAROMETRIC-PRESSURE AND TEMPERATURE IN SUMMIT-COUNTY - EFFECT ON ALTITUDE ILLNESS 8th International Hypoxia Symposium Reeves, J. T., Wagner, J., Zafren, K., Honigman, B., SCHOENE, R. B. CHARLES S HOUSTON. 1993: 275?281

  View details for Web of Science ID A1993BZ66T00027

• MORE ON TETRACYCLINE AND TICKS NEW ENGLAND JOURNAL OF MEDICINE Zafren, K. 1983; 308 (7): 403-404

  View details for Web of Science ID A1983QB71800029

  View details for PubMedID 6823249

• Sunscreen for Adventure Travel: Use Sun Protection Factor (SPF) 50 or Higher. Journal of travel medicine Zafren, K. 2020

  View details for DOI 10.1093/jtm/taaa048

  View details for PubMedID 32299101

• Data and methods to calculate cut-off values for serum potassium and core temperature at hospital admission for extracorporeal rewarming of avalanche victims in cardiac arrest. Data in brief Falk, M., Brugger, H., Bouzat, P., Pasquier, M., Mair, P., Fieler, J., Darocha, T., Blancher, M., de Riedmatten, M., Paal, P., Strapazzon, G., Zafren, K., Brodmann Maeder, M. 2020; 28: 104913

  Abstract

  The data and estimation methods presented in this article are associated with the research article, "Cut-off values of serum potassium and core temperature at hospital admission for extracorporeal rewarming of avalanche victims in cardiac arrest: a retrospective multi-centre study" [1]. In this article we estimate recommended cut-off values for in-hospital triage with respect to extracorporeal rewarming. With only 6 survivors of 103 patients collected over a period of 20 years the ability to estimate reliable threshold values is limited. In addition, because the number of avalanche victims is also limited, a significantly larger dataset is unlikely to be obtained. We have therefore adapted two non-parametric estimation methods (bootstrapping and exact binomial distribution) to our specific needs and performed a simulations to confirm validity and reliability.

  View details for DOI 10.1016/j.dib.2019.104913

  View details for PubMedID 31890782

  View details for PubMedCentralID PMC6926115

• Wilderness Medical Society Clinical Practice Guidelines forthe Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2019 Update. Wilderness & environmental medicine Dow, J., Giesbrecht, G. G., Danzl, D. F., Brugger, H., Sagalyn, E. B., Walpoth, B., Auerbach, P. S., McIntosh, S. E., Nemethy, M., McDevitt, M., Schoene, R. B., Rodway, G. W., Hackett, P. H., Zafren, K., Bennett, B. L., Grissom, C. K. 2019

  Abstract

  To provide guidance to clinicians, the Wilderness Medical Society 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 a balance between benefits and risks/burdens according to 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 the 2019 update of the Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2014 Update.

  View details for DOI 10.1016/j.wem.2019.10.002

  View details for PubMedID 31740369

• Emergency Airways After Himalayan Black Bear Attacks in Bhutan. Wilderness & environmental medicine Mize, C. H., Dorji, L., Zafren, K. 2019

  Abstract

  INTRODUCTION: Although bear attacks on humans are uncommon, the incidence has slowly risen as human populations increasingly encroach on wilderness habitat. In the Kingdom of Bhutan, Himalayan black bear attacks occur regularly. Bears preferentially attack the face, often causing injuries that require surgical airway management. We sought to determine how often patients injured by Himalayan black bears required airway management during initial resuscitation.METHODS: We conducted a retrospective review of emergency department and admission records of the 3 referral hospitals in Bhutan. We identified all victims of bear attacks in Bhutan who received emergency airway management, including surgical airway management during the period from August 2013 to December 2017.RESULTS: There were 21 patients who were treated for injuries from bear attacks during the study period. Of these, 12 required emergency airway management. Three patients who required emergency airways (2 intubations, 1 surgical airway) were attacked near a regional referral hospital and received care at that hospital. The remaining 9 patients received care from the helicopter emergency medical services (HEMS) retrieval team (1 intubation, 8 surgical airways).CONCLUSIONS: The use of highly trained HEMS critical care retrieval teams may improve outcomes in critically injured patients who require time-critical airway management in remote areas. Countries such as Bhutan with populations far from emergency and critical care might benefit from the establishment of HEMS critical care retrieval services. HEMS teams providing care while retrieving patients from austere environments should be expert in emergency airway management.

  View details for DOI 10.1016/j.wem.2019.08.003

  View details for PubMedID 31672511

• Pediatric High Altitude Cerebral Edema in the Nepal Himalayas. Wilderness & environmental medicine Church, B. J., Basnyat, B., Mattingly, B., Zafren, K. 2019

  Abstract

  High altitude cerebral edema (HACE) is a rare complication of ascent to altitudes of over 2500 m (8200 ft). We are not aware of a previously published case report of HACE in a patient under the age of 18 y. We report on 2 cases of suspected HACE in 2 patients, aged 12 and 16 y, who presented to the Manang Himalayan Rescue Association clinic at 3500 m. The 16-y-old patient presented with severe headache, vomiting, and ataxia after rapid ascent to 3800 m. The 12-y-old patient presented with severe headache, vomiting, visual disturbances, and ataxia at 4500 m, which began to resolve with descent to the clinic at 3500 m. Our cases suggest that HACE can occur in children and adolescents. Because there are no specific guidelines for treatment of acute mountain sickness or HACE in patients under the age of 18 y, we recommend treatment as for adults: oxygen, immediate descent, and dexamethasone. Simulated descent in a portable hyperbaric chamber can be used if oxygen is not available and if actual descent is not possible.

  View details for DOI 10.1016/j.wem.2019.05.003

  View details for PubMedID 31301992

• Successful Field Rewarming of a Patient with Apparent Moderate Hypothermia Using a Hypothermia Wrap and a Chemical Heat Blanket WILDERNESS & ENVIRONMENTAL MEDICINE Phillips, D., Bowman, J., Zafren, K. 2019; 30 (2): 199?202

  View details for DOI 10.1016/j.wem.2019.01.001

  View details for Web of Science ID 000472986100014

• Cut-off values of serum potassium and core temperature at hospital admission for extracorporeal rewarming of avalanche victims in cardiac arrest: A retrospective multi-centre study RESUSCITATION Brugger, H., Bouzat, P., Pasquier, M., Mair, P., Fieler, J., Darocha, T., Blancher, M., de Riedmatten, M., Falk, M., Paal, P., Strapazzon, G., Zafren, K., Maeder, M. 2019; 139: 222?29

  View details for DOI 10.1016/j.resuscitation.2019.04.025

  View details for Web of Science ID 000470076000029

• Successful Field Rewarming of a Patient with Apparent Moderate Hypothermia Using a Hypothermia Wrap and a Chemical Heat Blanket. Wilderness & environmental medicine Phillips, D., Bowman, J., Zafren, K. 2019

  Abstract

  Hypothermia is a common problem encountered by search and rescue teams. Although mildly hypothermic patients can be rewarmed in the field and can then self-evacuate, the Wilderness Medical Society hypothermia guidelines suggest that a moderately hypothermic patient in the wilderness requires warming in a medical facility. The Hypothermia Prevention and Management Kit, developed by the US military, consists of a chemical heat blanket (CHB) and a heat-reflective shell. We present a case in which a hypothermia wrap and the CHB from a Hypothermia Prevention and Management Kit were used successfully to rewarm a patient with apparent moderate hypothermia in the field. We are unaware of previous reports of successful field rewarming of a patient with moderate hypothermia. We believe the use of the CHB in conjunction with a hypothermia wrap made field rewarming possible. We recommend that a CHB, along with the components of a hypothermia wrap, be carried by search and rescue teams when a hypothermic patient might be encountered. Although there were no documented core temperatures, we believe this case is consistent with the hypothesis that if a hypothermic patient who is found lying down and shivering is allowed to stand or walk before insulation is applied and before there has been an additional period of 30 min during which the patient continues to shiver, there may be increased afterdrop with deleterious results.

  View details for PubMedID 30824366

• Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness: 2019 Update. Wilderness & environmental medicine Luks, A. M., Auerbach, P. S., Freer, L., Grissom, C. K., Keyes, L. E., McIntosh, S. E., Rodway, G. W., Schoene, R. B., Zafren, K., Hackett, P. H. 2019

  Abstract

  To provide guidance to clinicians about best preventive and therapeutic practices, the Wilderness Medical Society (WMS) 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. 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 to prevention and management of each form of acute altitude illness 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 2010 and subsequently updated as the WMS Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness in 2014.

  View details for DOI 10.1016/j.wem.2019.04.006

  View details for PubMedID 31248818

• Helicopter Critical Care Retrieval in a Developing Country: A Trauma Case Series from Bhutan. High altitude medicine & biology Mize, C. H., Evers, E. S., Dorji, L., Zafren, K. 2019

  Abstract

  Mize, Charles Haviland, Egmond Samir Evers, Lhab Dorji, and Ken Zafren. Helicopter critical care retrieval in a developing country: A trauma case series from Bhutan. High Alt Med Biol. 00:000-000, 2019. Background: The care of victims of traumatic injuries requires an organized system to achieve the best outcomes. Dispatch of specialist physicians, paramedics, and nurses to the patient by helicopter can reduce mortality. Countries in the developing world share the challenge of providing timely medical care to trauma victims, while facing others such as a higher trauma burden, poor infrastructure, inadequate government resources, organizational constraints, a lack of technical expertise, and prohibitive costs. These challenges can severely limit the provision of critical prehospital trauma care. Methods: We reviewed the prehospital trauma database to identify victims of trauma who required aeromedical evacuation as determined by the national triage system of Bhutan during the 4-month period after the establishment of the national Bhutan Emergency Aeromedical Retrieval (BEAR) team. We collected the patients' age and gender, description of injuries, mechanism of injury, interventions undertaken by the critical care retrieval team, and patient outcomes (alive vs. dead). Results: During the first 4 months of service, BEAR cared for 16 trauma patients. Fourteen patients survived to hospital discharge; two died after hospitalization. No patient died on scene or during transport. The team successfully treated several challenging casualties, including a patient gored by a water buffalo leading to traumatic cardiac arrest with successful resuscitation, victims of a compressed gas cylinder explosion, a bear mauling, and a penetrating arrow injury to the head. The team performed a variety of critical care interventions, including induction and maintenance of anesthesia, orotracheal intubation, mechanical ventilation, tube thoracostomy, administration of blood products, and successful management of traumatic cardiac arrest. Conclusion: A critical care helicopter retrieval team can deliver trauma care in a developing country, such as Bhutan, with favorable outcomes at low cost.

  View details for DOI 10.1089/ham.2019.0019

  View details for PubMedID 31460794

• Prehospital administration of surfactant to a premature neonate in respiratory distress. Scandinavian journal of trauma, resuscitation and emergency medicine Mize, C. H., Dorji, L., Zafren, K. 2019; 27 (1): 95

  Abstract

  The population of the Kingdom of Bhutan is scattered in small villages throughout the eastern Himalaya. Infants born prematurely in villages have no access to neonatal intensive care until they are transported to the national referral hospital, a process that once took hours, if not days. After the introduction of a helicopter critical-care retrieval team, we were able to send a trained team to a remote location that successfully administered surfactant and initiated critical care to a premature, extreme low birth weight infant in severe respiratory distress in the first hour of life. Although the infant was in shock and in a near-arrest state at the time the team arrived, he made an excellent recovery after resuscitation by the team.

  View details for DOI 10.1186/s13049-019-0664-9

  View details for PubMedID 31665094

• Cut-off values of serum potassium and core temperature at hospital admission for extracorporeal rewarming of avalanche victims in cardiac arrest: A retrospective multi-centre study. Resuscitation Brugger, H., Bouzat, P., Pasquier, M., Mair, P., Fieler, J., Darocha, T., Blancher, M., de Riedmatten, M., Falk, M., Paal, P., Strapazzon, G., Zafren, K., Brodmann Maeder, M. 2019

  Abstract

  Evidence of existing guidelines for the on-site triage of avalanche victims is limited and adherence suboptimal. This study attempted to find reliable cut-off values for the identification of hypothermic avalanche victims with reversible out-of-hospital cardiac arrest (OHCA) at hospital admission. This may enable hospitals to allocate ECLS resources more appropriately while increasing the proportion of survivors among rewarmed victims.All avalanche victims with OHCA admitted to seven centres in Europe capable of ECLS from 1995 to 2016 were included. Optimal cut-off values, for parameters identified by logistic regression, were determined by means of bootstrapping and exact binomial distribution and served to calculate sensitivity, rate of overtriage, positive and negative predictive values, and receiver operating curves.In total, 103 avalanche victims with OHCA were included. Of the 103 patients 61 (58%) were rewarmed by ECLS. Six (10%) of the rewarmed patients survived whilst 55 (90%) died. We obtained optimal cut-off values of 7?mmol/L for serum potassium and 30?°C for core temperature.For in-hospital triage of avalanche victims admitted with OHCA, serum potassium accurately predicts survival. The combination of the cut-offs 7?mmol/L for serum potassium and 30?°C for core temperature achieved the lowest overtriage rate (47%) and the highest positive predictive value (19%), with a sensitivity of 100% for survivors. The presence of vital signs at extrication is strongly associated with survival. For further optimisation of in-hospital triage, larger datasets are needed to include additional parameters.

  View details for PubMedID 31022496

• Wilderness Mass Casualty Incident (MCI): Rescue Chain After Avalanche at Everest Base Camp (EBC) In 2015 WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Brants, A., Tabner, K., Nyberg, A., Pun, M., Basnyat, B., Maeder, M. 2018; 29 (3): 401?10

  View details for DOI 10.1016/j.wem.2018.03.007

  View details for Web of Science ID 000445975900017

• Reported Resuscitation of a Hypothermic Avalanche Victim With Assisted Ventilation in 1939. Wilderness & environmental medicine Zafren, K., Atkins, D., Brugger, H. 2018; 29 (2): 275?77

  Abstract

  We present a historical case of a 12-year-old boy who survived a reported avalanche burial in 1939 in the Upper Peninsula of Michigan. The boy was completely buried for at least 3 h, head down, at a depth of about 1 m. He was extricated without signs of life and likely hypothermic by his father, who took him to his home. There, the father performed assisted ventilation for 3 hours using the Schafer method, a historical method of artificial ventilation, without any specific rewarming efforts. The boy recovered neurologically intact. This case illustrates the importance of attempting resuscitation, possibly prolonged, of victims of hypothermia, even those who are apparently dead.

  View details for PubMedID 29599095

• International Commission for Mountain Emergency Medicine Consensus Guidelines for On-Site Management and Transport of Patients in Canyoning Incidents WILDERNESS & ENVIRONMENTAL MEDICINE Strapazzon, G., Reisten, O., Argenone, F., Zafren, K., Zen-Ruffinen, G., Larsen, G. L., Soteras, I. 2018; 29 (2): 252?65

  Abstract

  Canyoning is a recreational activity that has increased in popularity in the last decade in Europe and North America, resulting in up to 40% of the total search and rescue costs in some geographic locations. The International Commission for Mountain Emergency Medicine convened an expert panel to develop recommendations for on-site management and transport of patients in canyoning incidents. The goal of the current review is to provide guidance to healthcare providers and canyoning rescue professionals about best practices for rescue and medical treatment through the evaluation of the existing best evidence, focusing on the unique combination of remoteness, water exposure, limited on-site patient management options, and technically challenging terrain. Recommendations are graded on the basis of quality of supporting evidence according to the classification scheme of the American College of Chest Physicians.

  View details for PubMedID 29422373

• Management of Multi-Casualty Incidents in Mountain Rescue: Evidence-Based Guidelines of the International Commission for Mountain Emergency Medicine (ICAR MEDCOM) HIGH ALTITUDE MEDICINE & BIOLOGY Blancher, M., Albasini, F., Elsensohn, F., Zafren, K., Hoelzl, N., McLaughlin, K., Wheeler, A. R., Roy, S., Brugger, H., Greene, M., Paal, P. 2018

  Abstract

  Blancher, Marc, François Albasini, Fidel Elsensohn, Ken Zafren, Natalie Hölzl, Kyle McLaughlin, Albert R. Wheeler III, Steven Roy, Hermann Brugger, Mike Greene, and Peter Paal. Management of multi-casualty incidents in mountain rescue. High Alt Med Biol. 00:000-000, 2018.Multi-Casualty Incidents (MCI) occur in mountain areas. Little is known about the incidence and character of such events, and the kind of rescue response. Therefore, the International Commission for Mountain Emergency Medicine (ICAR MEDCOM) set out to provide recommendations for the management of MCI in mountain areas.Details of MCI occurring in mountain areas related to mountaineering activities and involving organized mountain rescue were collected. A literature search using (1) PubMed, (2) national mountain rescue registries, and (3) lay press articles on the internet was performed. The results were analyzed with respect to specific aspects of mountain rescue.We identified 198 MCIs that have occurred in mountain areas since 1956: 137 avalanches, 38 ski lift accidents, and 23 other events, including lightning injuries, landslides, volcanic eruptions, lost groups of people, and water-related accidents.General knowledge on MCI management is required. Due to specific aspects of triage and management, the approach to MCIs may differ between those in mountain areas and those in urban settings.Mountain rescue teams should be prepared to manage MCIs. Knowledge should be reviewed and training performed regularly. Cooperation between terrestrial rescue services, avalanche safety authorities, and helicopter crews is critical to successful management of MCIs in mountain areas.

  View details for PubMedID 29446647

• In Response to Ibuprofen vs Acetaminophen in AMS Prevention by Kanaan et al Reply WILDERNESS & ENVIRONMENTAL MEDICINE Kanaan, N. C., Peterson, A. L., Pun, M., Thapa, G. B., Tiwari, A., Basyal, B., Holck, P. S., Starling, J., Freeman, T. F., Gehner, J. R., Keyes, L., Levin, D. R., O'Leary, C. J., Stuart, K. E., Velgersdyk, J. L., Zafren, K., Basnyat, B. 2017; 28 (4): 385?87

  View details for PubMedID 29110912

• Yarsagumba Fungus: Health Problems in the Himalayan Gold Rush WILDERNESS & ENVIRONMENTAL MEDICINE Koirala, P., Pandit, B., Phuyal, P., Zafren, K. 2017; 28 (3): 267?70

  Abstract

  Seasonal migration of people in search of Yarsagumba fungus creates a population of collectors that faces hardship and health risks in austere high-altitude settings.In 2016, our 4-person team performed a 2-day health-needs survey of people collecting Yarsagumba fungus near the village of Yak Kharka (4020 m) in the Manang District of Nepal.There were approximately 800 people, both male and female, from age 10 to over 60, collecting Yarsagumba fungus. They had paid high prices for permits, hoping to recoup the cost and make a profit by selling specimens of Yarsagumba, but the fungus seemed scarce in 2016, resulting in a bleak economic forecast. Most collectors were living in austere conditions, walking long hours to the collection areas early in the morning and returning in the late afternoon. Most were subsisting on 1 daily meal. Health problems, including acute mountain sickness as well as respiratory and gastrointestinal illnesses, were common. Yarsagumba has become harder to find in recent years, increasing hardships and risk of injury. Medical care was almost nonexistent.As abundance decreases and demand increases, there is increasing pressure on collectors to find Yarsagumba. The collectors are an economically disadvantaged population who live in austere conditions at high altitude with poor shelter and sanitation, strenuous work, and limited availability of food. Health care resources are very limited. There are significant risks of illness, injury, and death. Targeted efforts by government entities and nongovernmental organizations might be beneficial in meeting the health needs.

  View details for PubMedID 28716290

• Prophylactic Acetaminophen or Ibuprofen Result in Equivalent Acute Mountain Sickness Incidence at High Altitude: A Prospective Randomized Trial. Wilderness & environmental medicine Kanaan, N. C., Peterson, A. L., Pun, M., Holck, P. S., Starling, J., Basyal, B., Freeman, T. F., Gehner, J. R., Keyes, L., Levin, D. R., O'Leary, C. J., Stuart, K. E., Thapa, G. B., Tiwari, A., Velgersdyk, J. L., Zafren, K., Basnyat, B. 2017

  Abstract

  Recent trials have demonstrated the usefulness of ibuprofen in the prevention of acute mountain sickness (AMS), yet the proposed anti-inflammatory mechanism remains unconfirmed. Acetaminophen and ibuprofen were tested for AMS prevention. We hypothesized that a greater clinical effect would be seen from ibuprofen due to its anti-inflammatory effects compared with acetaminophen's mechanism of possible symptom reduction by predominantly mediating nociception in the brain.A double-blind, randomized trial was conducted testing acetaminophen vs ibuprofen for the prevention of AMS. A total of 332 non-Nepali participants were recruited at Pheriche (4371 m) and Dingboche (4410 m) on the Everest Base Camp trek. The participants were randomized to either acetaminophen 1000 mg or ibuprofen 600 mg 3 times a day until they reached Lobuche (4940 m), where they were reassessed. The primary outcome was AMS incidence measured by the Lake Louise Questionnaire score.Data from 225 participants who met inclusion criteria were analyzed. Twenty-five participants (22.1%) in the acetaminophen group and 18 (16.1%) in the ibuprofen group developed AMS (P = .235). The combined AMS incidence was 19.1% (43 participants), 14 percentage points lower than the expected AMS incidence of untreated trekkers in prior studies at this location, suggesting that both interventions reduced the incidence of AMS.We found little evidence of any difference between acetaminophen and ibuprofen groups in AMS incidence. This suggests that AMS prevention may be multifactorial, affected by anti-inflammatory inhibition of the arachidonic-acid pathway as well as other analgesic mechanisms that mediate nociception. Additional study is needed.

  View details for DOI 10.1016/j.wem.2016.12.011

  View details for PubMedID 28479001

• Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia EMERGENCY MEDICINE CLINICS OF NORTH AMERICA Zafren, K. 2017; 35 (2): 261-?

  Abstract

  Accidental hypothermia is an unintentional drop in core temperature to 35°C or below. Core temperature is best measured by esophageal probe. If core temperature cannot be measured, the degree should be estimated using clinical signs. Treatment is to protect from further heat loss, minimize afterdrop, and prevent cardiovascular collapse during rescue and resuscitation. The patient should be handled gently, kept horizontal, insulated, and actively rewarmed. Active rewarming is also beneficial in mild hypothermia but passive rewarming usually suffices. Cardiopulmonary resuscitation should be performed if there are no contraindications to resuscitation. CPR may be delayed or intermittent.

  View details for DOI 10.1016/j.emc.2017.01.003

  View details for PubMedID 28411927

• Wilderness Medical Society Practice Guidelines for Prevention and Management of Avalanche and Nonavalanche Snow Burial Accidents. Wilderness & environmental medicine Van Tilburg, C., Grissom, C. K., Zafren, K., McIntosh, S., Radwin, M. I., Paal, P., Haegeli, P., Smith, W. W., Wheeler, A. R., Weber, D., Tremper, B., Brugger, H. 2017; 28 (1): 23-42

  Abstract

  To provide guidance to clinicians and avalanche professionals about best practices, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the prevention, rescue, and medical management of avalanche and nonavalanche snow burial victims. Recommendations are graded on the basis of quality of supporting evidence according to the classification scheme of the American College of Chest Physicians.

  View details for DOI 10.1016/j.wem.2016.10.004

  View details for PubMedID 28257714

• Mountain Medicine and Technical Rescue (Book Review) HIGH ALTITUDE MEDICINE & BIOLOGY Book Review Authored by: Zafren, K. 2017; 18 (1): 82?83

  View details for PubMedID 28112542

• Subtle Cognitive Dysfunction in Resolving High Altitude Cerebral Edema Revealed by a Clock Drawing Test WILDERNESS & ENVIRONMENTAL MEDICINE Quigley, I., Zafren, K. 2016; 27 (2): 256-258

  Abstract

  High altitude cerebral edema (HACE) is a life-threatening condition that can affect people who ascend to altitudes above 2500 m. Altered mental status and the presence of ataxia distinguishes HACE from acute mountain sickness (AMS). We describe a patient with subtle cognitive dysfunction, likely due to HACE that had not fully resolved. When he initially presented, the patient appeared to have normal mental status and was not ataxic. The diagnosis of HACE was missed initially but was made when further history became available. Cognitive dysfunction was then diagnosed based on abnormal performance of a clock drawing test. A formal mental status examination, using a clock drawing test, may be helpful in assessing whether a patient at high altitude with apparently normal mental status and with normal gait has HACE.

  View details for PubMedID 26874815

• The Great Earthquake in Nepal-A Personal View WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2016; 27 (1): 171?75

  View details for PubMedID 26596240

• Hypothermia Evidence, Afterdrop, and Guidelines WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Giesbrecht, G. G., Danzl, D. F., Bragger, H., Sagalyn, E. B., Walpoth, B., Weiss, E. A., Auerbach, P. S., McIntosh, S. E., Nemethy, M., McDevitt, M., Dow, J., Schoene, R. B., Rodway, G. W., Hackett, P. H., Bennett, B. L., Grissom, C. K. 2015; 26 (3): 439?41

  View details for PubMedID 25840910

• A Pain in the Neck. Clay shoveler's fracture due to cervical spine trauma. Wilderness & environmental medicine Koirala, P., Wolpin, S., Phuyal, P., Basnyat, B., Zafren, K. 2015; 26 (3): 430-432

  View details for DOI 10.1016/j.wem.2015.03.003

  View details for PubMedID 25858233

• An Itchy Situation WILDERNESS & ENVIRONMENTAL MEDICINE Phuyal, P., Koirala, P., Basnyat, B., Zafren, K. 2015; 26 (1): 89?90

  View details for PubMedID 25443760

• Cold Injuries IOC MANUAL OF EMERGENCY SPORTS MEDICINE Zafren, K., Giesbrecht, G., McDonagh, D., McDonagh, D., Zideman, D. 2015: 220?27

  View details for Web of Science ID 000457080500026

• Wilderness Medical Society practice guidelines for the prevention and treatment of acute altitude illness: 2014 update. Wilderness & environmental medicine Luks, A. M., McIntosh, S. E., Grissom, C. K., Auerbach, P. S., Rodway, G. W., Schoene, R. B., Zafren, K., Hackett, P. H. 2014; 25 (4): S4-14

  Abstract

  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.

  View details for DOI 10.1016/j.wem.2014.06.017

  View details for PubMedID 25498261

• Wilderness Medical Society practice guidelines for basic wound management in the austere environment: 2014 update. Wilderness & environmental medicine Quinn, R. H., Wedmore, I., Johnson, E. L., Islas, A. A., Anglim, A., Zafren, K., Bitter, C., Mazzorana, V. 2014; 25 (4): S118-33

  Abstract

  In an effort to produce best-practice guidelines for wound management in the austere environment, the Wilderness Medical Society convened an expert panel charged with the development of evidence-based guidelines for the management of wounds sustained in an austere (dangerous or compromised) environment. Recommendations are made about several parameters related to wound management. These recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks or burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians. This is an updated version of the original guidelines published in Wilderness & Environmental Medicine 2014;25(3):295-310.

  View details for DOI 10.1016/j.wem.2014.08.015

  View details for PubMedID 25498257

• Wilderness medical society practice guidelines for the prevention and treatment of acute altitude illness: 2014 update. Wilderness & environmental medicine Luks, A. M., McIntosh, S. E., Grissom, C. K., Auerbach, P. S., Rodway, G. W., Schoene, R. B., Zafren, K., Hackett, P. H. 2014; 25 (4): S4-S14

  Abstract

  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.

  View details for DOI 10.1016/j.wem.2014.06.017

  View details for PubMedID 25498261

• Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2014 Update. Wilderness & environmental medicine Zafren, K., Giesbrecht, G. G., Danzl, D. F., Brugger, H., Sagalyn, E. B., Walpoth, B., Weiss, E. A., Auerbach, P. S., McIntosh, S. E., Némethy, M., McDevitt, M., Dow, J., Schoene, R. B., Rodway, G. W., Hackett, P. H., Bennett, B. L., Grissom, C. K. 2014; 25 (4): S66-85

  View details for DOI 10.1016/j.wem.2014.10.010

  View details for PubMedID 25498264

• Wilderness Medical Society Practice Guidelines for Basic Wound Management in the Austere Environment WILDERNESS & ENVIRONMENTAL MEDICINE Quinn, R. H., Wedmore, I., Johnson, E., Islas, A., Anglim, A., Zafren, K., Bitter, C., Mazzorana, V. 2014; 25 (3): 295-310

  Abstract

  In an effort to produce best-practice guidelines for wound management in the austere environment, the Wilderness Medical Society convened an expert panel charged with the development of evidence-based guidelines for the management of wounds sustained in an austere (dangerous or compromised) environment. Recommendations are made about several parameters related to wound management. These recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks or burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians.

  View details for PubMedID 24931588

• Spine Protection in the Austere Environment WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Smith, W. R., Johnson, D. E., Kovacs, T. 2014; 25 (3): 364?66

  View details for PubMedID 24931589

• Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Giesbrecht, G. G., Danzl, D. F., Brugger, H., Sagalyn, E. B., Walpoth, B., Weiss, E. A., Auerbach, P. S., McIntosh, S. E., Nemethy, M., McDevitt, M., Dow, J., Schoene, R. B., Rodway, G. W., Hackett, P. H., Bennett, B. L., Grissom, C. K. 2014; 25 (4): 425-445

  Abstract

  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.

  View details for PubMedID 25443771

• Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Lightning Injuries: 2014 Update WILDERNESS & ENVIRONMENTAL MEDICINE Davis, C., Engeln, A., Johnson, E. L., McIntosh, S. E., Zafren, K., Islas, A. A., McStay, C., Smith, W. R., Cushing, T. 2014; 25 (4): S86-S95

  Abstract

  To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the treatment and prevention of lightning injuries. These guidelines include a review of the epidemiology of lightning and recommendations for the prevention of lightning strikes, along with treatment recommendations organized by organ system. Recommendations are graded on the basis of the quality of supporting evidence according to criteria put forth by the American College of Chest Physicians. This is an updated version of the original WMS Practice Guidelines for Prevention and Treatment of Lightning Injuries published in Wilderness & Environmental Medicine 2012;23(3):260-269.

  View details for DOI 10.1016/j.wem.2014.05.004

  View details for PubMedID 25498265

• Prevention of high altitude illness TRAVEL MEDICINE AND INFECTIOUS DISEASE Zafren, K. 2014; 12 (1): 29?39

  Abstract

  High altitude illness - Acute Mountain Sickness (AMS), High Altitude Cerebral Edema (HACE) and High Altitude Pulmonary Edema (HAPE) - can be prevented or limited in severity by gradual ascent and by pharmacologic methods. The decision whether to use pharmacologic prophylaxis depends on the ascent rate and an individual's previous history of altitude illness. This review discusses risk stratification to determine whether to use pharmacologic prophylaxis and recommends specific drugs, especially acetazolamide, dexamethasone and nifedipine. This review also evaluates non-recommended drugs. In addition, this review suggests non-pharmacologic methods of decreasing the risk of severe altitude illness. There are also brief sections on how to decrease sleep disturbance at high altitude, travel to high altitude for patients with pre-existing illness and advice for travelers ascending to high altitude.

  View details for PubMedID 24393671

• Wilderness Medical Society Practice Guidelines for Basic Wound Management in the Austere Environment: 2014 Update WILDERNESS & ENVIRONMENTAL MEDICINE Quinn, R. H., Wedmore, I., Johnson, E. L., Islas, A. A., Anglim, A., Zafren, K., Bitter, C., Mazzorana, V. 2014; 25 (4): S118-S133

  Abstract

  In an effort to produce best-practice guidelines for wound management in the austere environment, the Wilderness Medical Society convened an expert panel charged with the development of evidence-based guidelines for the management of wounds sustained in an austere (dangerous or compromised) environment. Recommendations are made about several parameters related to wound management. These recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks or burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians. This is an updated version of the original guidelines published in Wilderness & Environmental Medicine 2014;25(3):295-310.

  View details for DOI 10.1016/j.wem.2014.08.015

  View details for Web of Science ID 000346949400012

  View details for PubMedID 25498257

• Resuscitation of avalanche victims: Evidence-based guidelines of the international commission for mountain emergency medicine (ICAR MEDCOM) Intended for physicians and other advanced life support personnel RESUSCITATION Brugger, H., Durrer, B., Elsensohn, F., Paal, P., Strapazzon, G., Winterberger, E., Zafren, K., Boyd, J. 2013; 84 (5): 539-546

  Abstract

  In North America and Europe ?150 persons are killed by avalanches every year.The International Commission for Mountain Emergency Medicine (ICAR MEDCOM) systematically developed evidence-based guidelines and an algorithm for the management of avalanche victims using a worksheet of 27 Population Intervention Comparator Outcome questions. Classification of recommendations and level of evidence are ranked using the American Heart Association system.If lethal injuries are excluded and the body is not frozen, the rescue strategy is governed by the duration of snow burial and, if not available, by the victim's core-temperature. If burial time ?35 min (or core-temperature ?32 °C) rapid extrication and standard ALS is important. If burial time >35 min and core-temperature <32 °C, treatment of hypothermia including gentle extrication, full body insulation, ECG and core-temperature monitoring is recommended, and advanced airway management if appropriate. Unresponsive patients presenting with vital signs should be transported to a hospital capable of active external and minimally invasive rewarming such as forced air rewarming. Patients with cardiac instability or in cardiac arrest (with a patent airway) should be transported to a hospital for extracorporeal membrane oxygenation or cardiopulmonary bypass rewarming. Patients in cardiac arrest should receive uninterrupted CPR; with asystole, CPR may be terminated (or withheld) if a patient is lethally injured or completely frozen, the airway is blocked and duration of burial >35 min, serum potassium >12 mmol L(-1), risk to the rescuers is unacceptably high or a valid do-not-resuscitate order exists. Management should include spinal precautions and other trauma care as indicated.

  View details for DOI 10.1016/j.resuscitation.2012.10.020

  View details for Web of Science ID 000320996600008

  View details for PubMedID 23123559

• "Performance enhancing" drugs at high altitude. Wilderness & environmental medicine Zafren, K., Berghold, F., Hillebrandt, D. 2013; 24 (2): 173?74

  View details for DOI 10.1016/j.wem.2012.11.012

  View details for PubMedID 23434166

• Prophylaxis for Acute Mountain Sickness ANNALS OF EMERGENCY MEDICINE Zafen, K. 2012; 60 (5): 671-672

  View details for DOI 10.1016/j.annemergmed.2012.05.017

  View details for Web of Science ID 000310928800026

  View details for PubMedID 23089097

• Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Lightning Injuries WILDERNESS & ENVIRONMENTAL MEDICINE Davis, C., Engeln, A., Johnson, E., McIntosh, S. E., Zafren, K., Islas, A. A., McStay, C., Smith, W. '., Cushing, T. 2012; 23 (3): 260-269

  Abstract

  To provide guidance to clinicians about best practices, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the treatment and prevention of lightning injuries. These guidelines include a review of the epidemiology of lightning strikes and recommendations for the prevention of lightning strikes, along with treatment recommendations organized by organ system. Recommendations are graded based on the quality of supporting evidence according to criteria put forth by the American College of Chest Physicians.

  View details for Web of Science ID 000308284600013

  View details for PubMedID 22854068

• Public Access Defibrillation ANNALS OF EMERGENCY MEDICINE Zafren, K. 2012; 59 (6): 558-558

  View details for DOI 10.1016/j.annemergmed.2011.11.044

  View details for Web of Science ID 000305302300026

  View details for PubMedID 22626023

• Does Ibuprofen Prevent Acute Mountain Sickness? WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2012; 23 (4): 297-299

  View details for Web of Science ID 000311914700001

  View details for PubMedID 23158203

• Prediction of Acute Mountain Sickness by Pulse Oximetry: What Are the Right Questions? WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2012; 23 (4): 377-378

  View details for Web of Science ID 000311914700017

  View details for PubMedID 22981487

• Accident on Mt Kenya WILDERNESS & ENVIRONMENTAL MEDICINE Oelz, O., Zafren, K. 2011; 22 (1): 87?90

  View details for DOI 10.1016/j.wem.2010.09.009

  View details for Web of Science ID 000288342900015

  View details for PubMedID 21377126

• In Response to "Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Frostbite" WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2011; 22 (4): 364-365

  View details for Web of Science ID 000297966300014

  View details for PubMedID 21982756

• In Response to Bradford Washburn's 1962 NEJM Article "Frostbite: What It Is-How To Prevent It-Emergency Treatment"-Historical Background and Commentary WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2011; 22 (4): 366-368

  View details for Web of Science ID 000297966300016

  View details for PubMedID 22000546

• Prospective, Double-Blind, Randomized, Placebo-Controlled Comparison of Acetazolamide Versus Ibuprofen for Prophylaxis Against High Altitude Headache: The Headache Evaluation at Altitude Trial (HEAT) WILDERNESS & ENVIRONMENTAL MEDICINE Gertsch, J. H., Lipman, G. S., Holck, P. S., Merritt, A., Mulcahy, A., Fisher, R. S., Basnyat, B., Allison, E., Hanzelka, K., Hazan, A., Meyers, Z., Odegaard, J., Pook, B., Thompson, M., Slomovic, B., Wahlberg, H., Wilshaw, V., Weiss, E. A., Zafren, K. 2010; 21 (3): 236-243

  Abstract

  High altitude headache (HAH) is the most common neurological complaint at altitude and the defining component of acute mountain sickness (AMS). However, there is a paucity of literature concerning its prevention. Toward this end, we initiated a prospective, double-blind, randomized, placebo-controlled trial in the Nepal Himalaya designed to compare the effectiveness of ibuprofen and acetazolamide for the prevention of HAH.Three hundred forty-three healthy western trekkers were recruited at altitudes of 4280 m and 4358 m and assigned to receive ibuprofen 600 mg, acetazolamide 85 mg, or placebo 3 times daily before continued ascent to 4928 m. Outcome measures included headache incidence and severity, AMS incidence and severity on the Lake Louise AMS Questionnaire (LLQ), and visual analog scale (VAS).Two hundred sixty-five of 343 subjects completed the trial. HAH incidence was similar when treated with acetazolamide (27.1%) or ibuprofen (27.5%; P = .95), and both agents were significantly more effective than placebo (45.3%; P = .01). AMS incidence was similar when treated with acetazolamide (18.8%) or ibuprofen (13.7%; P = .34), and both agents were significantly more effective than placebo (28.6%; P = .03). In fully compliant participants, moderate or severe headache incidence was similar when treated with acetazolamide (3.8%) or ibuprofen (4.7%; P = .79), and both agents were significantly more effective than placebo (13.5%; P = .03).Ibuprofen and acetazolamide were similarly effective in preventing HAH. Ibuprofen was similar to acetazolamide in preventing symptoms of AMS, an interesting finding that implies a potentially new approach to prevention of cerebral forms of acute altitude illness.

  View details for Web of Science ID 000282163300007

  View details for PubMedID 20832701

• Avalanche Triage: Are Two Birds in the Bush Better Than One in the Hand? WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2010; 21 (3): 273-274

  View details for Web of Science ID 000282163300016

  View details for PubMedID 20832710

• Wilderness Medical Society Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness WILDERNESS & ENVIRONMENTAL MEDICINE Luks, A. M., McIntosh, S. E., Grissom, C. K., Auerbach, P. S., Rodway, G. W., Schoene, R. B., Zafren, K., Hackett, P. H. 2010; 21 (2): 146-155

  Abstract

  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.

  View details for Web of Science ID 000279235900013

  View details for PubMedID 20591379

• Wilderness Medical Society Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness-A View From the Other Side of the Atlantic Reply WILDERNESS & ENVIRONMENTAL MEDICINE Luks, A. M., McIntosh, S. E., Grissom, C. K., Auerbach, P. S., Rodway, G. W., Schoene, R. B., Zafren, K., Hackett, P. 2010; 21 (4): 384-385

  View details for Web of Science ID 000285703700021

• Clinical Images WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Basnyat, B., Basnyat, G. 2009; 20 (1): 81-82

  View details for Web of Science ID 000264280300015

  View details for PubMedID 19364167

• Fluid management in traumatic shock: a practical approach for mountain rescue. Official recommendations of the International Commission for Mountain Emergency Medicine (ICAR MEDCOM). High altitude medicine & biology Sumann, G., Paal, P., Mair, P., Ellerton, J., Dahlberg, T., Zen-Ruffinen, G., Zafren, K., Brugger, H. 2009; 10 (1): 71-75

  Abstract

  Sumann, Günther, Peter Paal, Peter Mair, John Ellerton, Tore Dahlberg, Gregoire Zen-Ruffinen, Ken Zafren, and Hermann Brugger. Fluid management in traumatic shock: a practical approach for mountain rescue. High Alt. Med. Biol. 10:71-75, 2009.-The management of severe injuries leading to traumatic shock in mountains and remote areas is a great challenge for emergency physicians and rescuers. Traumatic brain injury may further aggravate outcome. A mountain rescue mission may face severe limitations from the terrain and required rescue technique. The mission may be characterized by a prolonged prehospital care time, where urban traumatic shock protocols may not apply. Yet optimal treatment is of utmost importance. The aim of this study is to establish scientifically supported recommendations for fluid management that are feasible for the physician or paramedic attending such an emergency. A nonsystematic literature search was performed; the results and recommendations were discussed among the authors and accepted by the International Commission for Mountain Emergency Medicine (ICAR MEDCOM). Diagnostic and therapeutic strategies are discussed, as well as limitations on therapy in mountain rescue. An algorithm for fluid resuscitation, derived from the recommendations, is presented in Fig. 1. Focused on the key criterion of traumatic brain injury, different levels of blood pressure are presented as a goal of therapy, and the practical means for achieving these are given.

  View details for DOI 10.1089/ham.2008.1067

  View details for PubMedID 19278354

• Fluid Management in Traumatic Shock: A Practical Approach for Mountain Rescue HIGH ALTITUDE MEDICINE & BIOLOGY Sumann, G., Paal, P., Mair, P., Ellerton, J., Dahlberg, T., Zen-Ruffinen, G., Zafren, K., Brugger, H. 2009; 10 (1): 71-75

  View details for DOI 10.1089/ham.2008.1067

  View details for Web of Science ID 000264087400008

• The Most Dangerous Catch: Fisherman Caught by Halibut Hook WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2009; 20 (4): 375-377

  View details for Web of Science ID 000273503700013

  View details for PubMedID 20030448

• The use of extrication devices in crevasse accidents: official statement of the International Commission for Mountain Emergency Medicine and the Terrestrial Rescue Commission of the International Commission for Alpine Rescue intended for physicians, paramedics, and mountain rescuers WILDERNESS & ENVIRONMENTAL MEDICINE Winterberger, E., Jacomet, H., Zafren, K., Ruffinen, G. Z., Jelk, B. 2008; 19 (2): 108-110

  Abstract

  Injured patients in crevasses who are suspected of having sustained spinal injuries should ideally be extricated after being immobilized in a horizontal position on a stretcher and having a cervical collar applied. Sometimes, however, horizontal stabilization is not possible, because the crevasse is too narrow, and the patient needs to be stabilized in a vertical position. In such cases an extrication device can be a useful adjunct. The Kendrick Extrication Device stabilizes the position of the body and maintains firm support of the head, neck, and torso. Therefore, the International Commission for Mountain Emergency Medicine supports the use of this device in narrow crevasses, if horizontal evacuation is not possible.

  View details for Web of Science ID 000256509600005

  View details for PubMedID 18513106

• When searches become futile WILDERNESS & ENVIRONMENTAL MEDICINE Fortini, A., Zafren, K., Sharp, F., Shimanski, C. 2008; 19 (1): 73-73

  View details for Web of Science ID 000254367000015

  View details for PubMedID 18333661

• A reference correction. Wilderness & environmental medicine Zafren, K. 2007; 18 (4): 323-?

  View details for PubMedID 18076299

• Management of blunt trauma victims with significant hemoperitoneum with normal examination AMERICAN JOURNAL OF EMERGENCY MEDICINE Zafren, K. 2003; 21 (6): 513-513

  View details for DOI 10.1016/S0735-6757(03)00172-4

  View details for Web of Science ID 000186208300023

  View details for PubMedID 14574671

• Clinical images. Wound care in the wilderness. Wilderness & environmental medicine Zafren, K. 2001; 12 (3): 201-203

  View details for PubMedID 11562020

• Effect of insurance on admission for head injury AMERICAN JOURNAL OF EMERGENCY MEDICINE Zafren, K. 2001; 19 (5): 460-460

  View details for Web of Science ID 000170970400019

  View details for PubMedID 11555813

• Warnings in the wilderness WILDERNESS & ENVIRONMENTAL MEDICINE Anonymous 2001; 12 (2): 129-133

  View details for Web of Science ID 000169377300010

  View details for PubMedID 11434489

• Poison oak dermatitis. Wilderness & environmental medicine Zafren, K. 2001; 12 (1): 39-40

  View details for PubMedID 11294555

• How useful is on-mountain sonography? WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2001; 12 (4): 230-231

  View details for Web of Science ID 000172919300002

  View details for PubMedID 11769916

• Unusual presentation of a fracture and possible early compartment syndrome. Wilderness & environmental medicine Zafren, K. 2000; 11 (3): 199-200

  View details for PubMedID 11055568

• Clinical images WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2000; 11 (4): 269-271

  View details for Web of Science ID 000166445800007

  View details for PubMedID 11199532

• Images - Erythema nodosum WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, Z., Kercher, E. 1999; 10 (3): 171-173

  View details for Web of Science ID 000083483600008

  View details for PubMedID 10560312

• Images - Answer WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 1999; 10 (2): 115-116

  View details for Web of Science ID 000081796100010

  View details for PubMedID 10442160

• Presentation of the case. Lighting injuries. Wilderness & environmental medicine Zafren, K. 1999; 10 (4): 253-255

  View details for PubMedID 10628287

• Tragedy on Ptarmigan Peak WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 1998; 9 (3): 188-190

  View details for Web of Science ID 000080104900008

  View details for PubMedID 11990189

• Migratory pain in appendicitis AMERICAN JOURNAL OF EMERGENCY MEDICINE Zafren, K. 1998; 16 (4): 437-438

  View details for Web of Science ID 000074870100035

  View details for PubMedID 9672474

• Telemedicine revisited ANNALS OF EMERGENCY MEDICINE Zafren, K. 1998; 31 (6): 790-790

  View details for Web of Science ID 000073986100022

  View details for PubMedID 9624327

• Brown recluse spider bite (necrotic arachnidism) WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 1998; 9 (4): 211-212

  View details for Web of Science ID 000079405000003

  View details for PubMedID 11990193

• Re: Prevention and Management of Cardiovascular Events during Travel. Journal of travel medicine Zafren, K. 1997; 4 (3): 152

  View details for PubMedID 9815504

• Outcome assessments and air ambulance services LANCET Zafren, K. 1996; 347 (9018): 1843-1843

  View details for Web of Science ID A1996UU46900072

  View details for PubMedID 8667965

• Warning! Long commute. Science Zafren, K. 1996; 272 (5269): 1726a-?

  View details for PubMedID 17831839

• ALTERNATIVE TRAINING IN EMERGENCY-MEDICINE AMERICAN JOURNAL OF EMERGENCY MEDICINE Zafren, K. 1993; 11 (1): 97-98

  View details for Web of Science ID A1993KL86500028

  View details for PubMedID 8447885

• BASE DEFICIT AS A DIAGNOSTIC-TEST FOR ABDOMINAL INJURY ANNALS OF EMERGENCY MEDICINE Zafren, K., Purcell, T. 1992; 21 (11): 1406-1406

  View details for Web of Science ID A1992JU81200023

  View details for PubMedID 1416343

• OPEN AND CLOSED PERITONEAL-LAVAGE ANNALS OF EMERGENCY MEDICINE Zafren, K., Purcell, T. 1992; 21 (10): 1298-1298

  View details for Web of Science ID A1992JR19600028

  View details for PubMedID 1416319