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Frostbite is a common injury in high altitude medicine. Intravenous vasodilators have a proven efficacy and, recently, have been proposed as a safe outpatient treatment. Nevertheless, the lack of availability and consequently delayed application of this treatment option can result in poor clinical outcomes for patients. We present the case of a 60-year-old Chilean man with severe frostbite injuries suffered while climbing Mount Everest. The patient was initially given field treatment to the extent permitted by conditions and consensus guidelines. Unfortunately, advanced management was delayed, with iloprost administered 75 hours after the initial injury. The patient also underwent 5 days of hyperbaric and analgesic/antibiotic therapies. An early bone scan predicted a poor clinical outcome, and five of the patient's fingers, between both hands, were incompletely amputated. We present this case to exemplify the importance of advanced in-field management of frostbite injuries.

Hypothermia and frostbite occur when there is a significant decrease in central and peripheral body temperature in individuals exposed to cold windy conditions, often at high altitude or in a mountain environment. Portable hyperbaric chambers increase the barometric pressure and thereby the partial pressure of oxygen inside the chamber, and their use is a well-known treatment for altitude illness. This study aims to show that a portable hyperbaric chamber could also be used to treat hypothermia and frostbite in the field, when rescue or descent is impossible or delayed.During a European research program (SOS-MAM, Flow Pulse study) measurements were taken from 27 healthy nonacclimatized voluntary subjects (21 men, 6 women, mean age 41 ± 17) at an altitude of 3800 m (Chamonix Mountain Lab, Aiguille du Midi, France) right before and immediately after spending 1 hour in a portable hyperbaric chamber at 300 mbar. We measured digital cutaneous temperature (Tcut), digital cutaneous blood flow (Fcut), digital tissue oxygenation (TWe observed significant increases in Tchamb: 9.3°C compared with the outside temperature, Tcut: +7.5°C (±6.2°C 71%), Fcut: +58This study shows that a portable hyperbaric chamber can be used to treat frostbite and/or hypothermia in the field at altitude when descent or rescue is impossible or even simply delayed.

Brustia, Raffaele, Giulia Enrione, Bruna Catuzzo, Luca Cavoretto, Massimo Pesenti Compagnoni, Enrico Visetti, Emmanuel Cauchy, Stefanie Ziegler, and Guido Giardini. Results of a prospective observational study on mountaineering emergencies in Western Alps: mind your head. High Alt Med Biol. 17:116-121, 2016.-In the northern Italian district Valle d'Aosta district during winter and summer season the population can increase up to 170% of the resident population. A prospective monocentric observational registry was held to obtain a precise picture of seasonal mountain-related medical and traumatic major events.From 1st January 2012 to 31st December 2013 all patients admitted to the Aosta Regional Hospital Emergency Room for any event occurred above 2500 m were screened: all those affected by High Altitude Illness, Acute Illness in High Altitude, Trauma, or Cold disease were prospectively included. Activity incidence rate is expressed as the occurrence of mountain-related events per 1000 hours of mountain activity. Event Incidence rate is expressed as the occurrence of new cases per 1000 hours of mountain activity.Two hundred two patients were included during the study period. Trauma (65.1% vs. 24.6%, p 0.001) and head commotive injury (48.1% vs. 15.1%, p 0.001) were more frequent during winter compared to the summer season. High altitude illness (36.9% vs. 9.3%, p 0.001) and cold pathologies (15.1% vs. 0.1%, p 0.001) occurred more frequently in summer than in winter. Patients (51.4%) were immediately discharged from emergency room, 8.4% after a 24-hour observation period, and 30.6% required hospitalization. During summer, the event risk is 0.013 per person and 1000 hours of mountain activity, while in winter, event risk amounts to 0.005 per person and 1000 hours of mountain activity.High altitude medical events or trauma represent1% of pathologies observed in the emergency room department of a mountain district in the western Alps. Head commotive injury is the most observed mountain-related event in high altitude, in winter and during ski practice. High altitude illness and cold injuries are observed more frequently in summer, during trekking or climbing activities.

Purpose: The aim of this study is to explore the physiological vascular adaptation to exposure to high altitude and to test the hypothesis that its impairment might play a role in the pathophysiology of acute mountain sickness (AMS). Methods: 34 healthy volunteers (age 38±11years, 13 women) were studied at the sea-level and after passive ascent to 3842 m (Aguille du Midi, France). Blood pressure (BP), O2 saturation (SO2), endothelial function (flow-mediated dilation, FMD), carotid distensibility coefficient (DC), carotid-femoral pulse wave velocity (PWV), peak systolic velocity in the middle cerebral artery (MCA-PSV) were performed at sea level (T0) and after 4-h hypobaric hypoxia (T1). AMS was defined as a Lake-Louise Score>5 after 24-h hypobaric hypoxia (T2). Results: At T2 12 individuals developed AMS (AMS+). AMS+ had a greater SO2 worsening at T1 as compared to AMS- (AMS+: 97.2±1.2 to 79.3±5.8%; AMS-: 97.3±1.2 to 83.1 ± 5.7%, p=0.03), with similar heart rate increase and unchanged BP. FMD was significantly reduced in AMS+ (5.75±3.01 to 3.27±1.87%, p=0.04), but not in AMS- (4.74±2.47 to 4.02±2.36%). Mean carotid diameter was increased at T1 in both groups. DC tended to be increased in AMS- but not in AMS+, while PWV was unchanged. MCA-PSV was increased in AMS-, but not in AMS+. Conclusions: In healthy asymptomatic individuals exposed to high altitude, conduit artery endothelial function is preserved in the cerebral district vasodilatation, increased elasticity and blood flow occurs. This compensatory response is early blunted in AMS+, before symptoms onset, thus suggesting a pathogenetic role.

Despite advances in outdoor clothing and medical management of frostbite, individuals still experience catastrophic amputations. This is a particular risk for those in austere environments, due to resource limitations and delayed definitive treatment. The emerging best therapies for severe frostbite are thrombolytics and iloprost. However, they must be started within 24 hours after rewarming for recombinant tissue plasminogen activator (rt-PA) and within 48 hours for iloprost. Evacuation of individuals experiencing frostbite from remote environments within 24 to 48 hours is often impossible. To date, use of these agents has been confined to hospitals, thus depriving most individuals in the austere environment of the best treatment. We propose that thrombolytics and iloprost be considered for field treatment to maximize chances for recovery and reduce amputations. Given the small but potentially serious risk of complications, rt-PA should only be used for grade 4 frostbite where amputation is inevitable, and within 24 hours of rewarming. Prostacyclin has less risk and can be used for grades 2 to 4 frostbite within 48 hours of rewarming. Until more field experience is reported with these agents, their use should probably be restricted to experienced physicians. Other modalities, such as local nerve blocks and improving oxygenation at high altitude may also be considered. We submit that it remains possible to improve frostbite outcomes despite delayed evacuation using resource-limited treatment strategies. We present 2 cases of frostbite treated with rt-PA at K2 basecamp to illustrate feasibility and important considerations.

We report a retrospective study of the prognostic value of 2-phase technetium 99m bone scanning performed in 92 patients who presented to Chamonix Hospital with severe frostbite of the extremities in the past 12 years. The results of this study show that an initial bone scan (as early as day 3) has excellent specificity in evaluating the severity of frostbite injury. There was a direct correlation between the demarcation zone of uptake in the phalanges and the eventual level of amputation (positive predictive value, 0.84). A second scan on approximately day 7 was even more sensitive and informative. A strong correlation existed between positive uptake and eventual healing (negative predictive value, 0.99). This study showed that (99m)Tc bone scanning in the first few days after frostbite injury indicates the level of amputation in severe frostbite in more than 84% of cases. We propose an algorithm based on the results of this study that can be used to evaluate new medical and surgical management of frostbite injury.

This study tested the hypothesis that a prolonged decrease in arterial oxygen pressure in resting or contracting skeletal muscles alters their ability to develop force through an impairment of energy-dependent metabolic processes and also through an alteration of electrophysiological events. The experiment was conducted during a 32-day simulated ascent of Mt. Everest (8848 m altitude) (Everest III Comex '97), which also allowed testing of the effects of re-oxygenation on muscle function. Maximal voluntary contractions (MVCs) of the flexor digitorum, and static handgrips sustained at 60% of MVC, were performed by eight subjects before the ascent (control), then during the stays at simulated altitudes of 5000 m, 6000 m and 7000 m, and finally 1 day after the return to 0 m. The evoked muscle compound action potential (M-wave) was recorded at rest and during the manoeuvres at 60% of MVC. The changes in median frequency of electromyographic (EMG) power spectra were also studied during the contraction at 60% of MVC. In four individuals, transient re-oxygenation during the ascent allowed us to test the reversibility of hypoxia-induced MVC and M-wave changes. At rest, a significant decrease in M-wave amplitude was noted at 5000 m. This effect was associated with a prolonged M-wave conduction time at 6000 m and an increased M-wave duration at 7000 m, and persisted after the return to 0 m. Re-oxygenation did not modify the changes in M-wave characteristics. A significant decrease in MVC was measured only during the ascent (-10 to -24%) in the non-dominant forearm of subjects who underwent re-oxygenation; this intervention slightly improved muscle strength at 6000 m and 7000 m. During the ascent and after the return to 0 m, there was a significant reduction of the median frequency decrease throughout contraction at 60% of MVC compared with the EMG changes measured before the ascent. It is concluded that prolonged exposure to hypoxia slows the propagation of myopotentials and alters sensorimotor control during sustained effort. Re-oxygenation did not affect the hypoxia-induced EMG changes and had a modest influence on muscle strength.

Iloprost With and Without rt-PA: Treatment of 131 Cases of Severe Frostbite Emmanuel Cauchy; Eric Chetaille; Emmanuel Pham; Hugo Nespoulet; Pascal Zellner; Francois Becker; Peter Hackett IFREMMONT (Institut de Formation et de Recherche en Medecine de Montagne), Hopital de Chamonix, Chamonix, France, Institute for Altitude Medicine, Telluride, CO, USA Introduction.—Both rt-PA and iloprost (prostacyclin) are effective treatments for severe frostbite, but it is unclear if using them in combination is more effective. Objective.—To evaluate combined treatment with rt-PA and iloprost in severe frostbite, compared with other therapies. Methods.—Retrospective case review of 131 patients with severe frostbite. Patients without contraindication or severe trauma were managed with rapid rewarming (381C bath water immersion þ aspirin IV [250mg] þ buflomedil IV [400 mg, alphalytic vasodilator] during 1 hour. Then 41 patients received daily treatment of aspirin and buflomedil (TT-A); 58 received aspirin and IV iloprost 2 ng/6 h (prostacyclin) (TT-B); and 20 received aspirin, IV tPA (100 mg, first day only) and iloprost (TT-C). Twelve patients did not receive any treatment (TT-D). The final level of amputation was measured 3 to 8 days later on bone scanning. Results.—For grade 3 frostbite, 100% of the patients required amputation in TT-D (4 of 4 patients), as did 62.5% with TT-A (10 of 16 patients), 4.9% with TT-B (2 of 41 patients) (P o .01), and 27.3% with TT-C (3 of 11 patients) (P o .03). For grade 4, 100% needed amputation in TT-D (3 of 3 patients), 100% in TT-A (4 of 4 patients), 66.7% TT-B (4 of 6 patients) (P o .001) and 44.4% with TT-C (4 of 9 patients) (P o 0.03). Of 407 digits, 183 frozen fingers lead to 22 amputations (TT-A 49%, TT-B 0%, TT-C 2%, TT-D 49%), and 224 frozen toes lead to 25 amputations (TT-A 34%, TT-B 0%; TT-C 4%, TT-D 62%). Analysis showed that tPA was effective up to 12 hours and iloprost up to 48 hours. Conclusion.—The efficacy of iloprost was significantly higher than buflomedil or no treatment. The addition of rt-PA to prostacycline seems to improve the prognosis only of stage 4 frostbite and only when the delay between rewarming and treatment was less than 12 hours.

Objective Previous frostbite classifications were mainly based on retrospective diagnosis and, most of the time, could not be used to predict the final outcome of the lesions and especially the probability of an amputation and its level. The aim of this study was to suggest a new classification at day 0 based mainly on the topography of the lesions and on early bone scan results, which are more convenient and accurate in predicting the final outcome of frostbites. Methods The retrospective study of the clinical histories of 70 patients hospitalized at Chamonix Hospital (Mont-Blanc Massif) from 1985 to 1999 for severe frostbite injuries of the extremities has allowed us to classify the aspects of the initial lesions on day 0 and to compare them with final outcomes. Results A strong correlation was found between the extent of the lesion and the outcome of each finger or toe. When the initial lesion was on the distal phalanx, the probability of bone amputation was around 1% for the digit, 31% for the middle phalanx, 67% for the proximal phalanx, 98% for the metacarpal/metatarsal, and 100% for the carpal/tarsal. Conclusions Based on these clinical results and on the results of bone scans (previously validated), a new classification of frostbite severity at day 0 is proposed. Four degrees of severity are defined: first degree, leading to recovery; second degree, leading to soft tissue amputation; third degree, leading to bone amputation, and fourth degree, leading to large amputation with systemic effects.

To the Editor: Many alternatives have been proposed for the treatment of frostbite: hemodilution, platelet-aggregation inhibitors, low-molecular-weight heparin, alpha-adrenergic vasodilators, calcium-channel inhibitors, nonsteroidal antiinflammatory agents, prostacyclin analogues, fibrinolytic agents, and hyperbaric oxygen. None have been assessed in prospective randomized trials. Small retrospective studies1–3 suggest the efficacy of thrombolysis or prostacyclin analogues against spasm and thrombosis. Between 1996 and 2008, we randomly assigned 47 patients (44 men and 3 women) with severe frostbite to one of three treatment regimens in an open-label study. Severe frostbite was defined as having at least one digit (finger or toe) with frostbite stage 3 . . .

During Operation Everest III (Comex '97), to assess the consequences of altitude-induced hypoxia, eight volunteers were decompressed in a hypobaric chamber, with a decompression profile simulating the climb of Mount Everest. Cardiac function was assessed using a combination of M-mode and two-dimensional echocardiography, with continuous and pulsed Doppler at 5,000, 7,000, and 8,000 m as well as 2 d after return to sea level (RSL). On simulated ascent to altitude, aortic and left atrial diameters, left ventricular (LV) diameters, and right ventricular (RV) end-systolic diameter fell regularly. Heart rate (HR) increased at all altitudes accompanied by a decrease in stroke volume; in total, cardiac output (Q) remained unchanged. LV filling was assessed on transmitral and pulmonary venous flow profiles. Mitral peak E velocity decreased, peak A velocity increased, and E/A ratio decreased. Pulmonary venous flow velocities showed a decreased peak D velocity, a decreased peak S velocity, and a reduction of the D/S ratio. Systolic pulmonary arterial pressure (Ppa) showed a progressive and constant increase, as seen on the elevation of the right ventricular/right atrial (RV/RA) gradient pressure from 19.0 +/- 2.4 mm Hg at sea level up to 40.1 +/- 3.3 mm Hg at 8,000 m (p < 0.05), and remained elevated 2 d after recompression to sea level (SL) (not significant). In conclusion, this study confirmed the elevation of pulmonary pressures and the preservation of LV contractility secondary to altitude-induced hypoxia. It demonstrated a modification of the LV filling pattern, with a decreased early filling and a greater contribution of the atrial contraction, without elevation of LV end-diastolic pressure.

Because of its peculiar geographic location beneath Mont-Blanc, the Chamonix Hospital plays an important role in the management of mountaineering- and skiing-related traumatic injuries. The authors, thanks to the study of 5200 mountain rescue medical reports, set out to explain the different aspects of this activity: epidemiology, specific equipment, care in the field, reception and primary survey, dispatching, common therapeutic attitudes, progress, and results. In the dangerous environment of the high mountains, emphasis is put on the physicians' experience, allowing an early evacuation in the best conditions to the hospital. Diagnosis at the scene of the accident is very basic, and the initial treatment is based on immobilization, analgesia, and sedating. In the case of resuscitation, only the vital maneuvers are performed; these actions are carried on during the short flight and improved in the crash rooms. Finally, different specific pathologies are mentioned, including cold- or heat-related injuries, exhaustion, lightning strikes, and mountain sickness.

Acute mountain sickness (AMS) affects over 70% of subjects who ascend over 4000 m. There is no predictive test for sensitive subjects before their ascent. There seems to be a correlation between dynamic cerebral autoregulation and susceptibility to AMS. This track could be considered a preventive test. Under the Franco-Italian European project ALCOTRA - RESAMONT 2, IFREMMONT wanted to undertake an observational study: CervO2, to assess the individual variability of the vascular reactivity. This study also looks at a pathophysiological hypothesis of neurological disorders in altitude: the micro gas embolism. Our task was to develop the protocol. We then saw 120 subjects in pre-inclusion visits and we chose to include 96 of these subjects. The experiment took place in three phases with three subjects each time: first phase in control in plain, then in hypobaric hypoxia of altitude after a rapid rise to the Aiguille du Midi and then after 18 hours at altitude. We studied Lake Louise's scores, cerebral vasoreactivity by transcranial ultrasonography, we were looking for patent foramen ovale and evaluation of pulmonary artery pressure. And for 1 in 3 we made a holter transcranial doppler recording. After the premature ending of the study 58 subjects were explored, it's relative success since it is the largest cohort on this subject. The results may highlight a significant difference in cerebral vasoreactivity exploitable as a marker of AMS. The Aiguille du Midi is an exceptional natural laboratory and can now be used for other studies.; Le mal aigu des montagnes (MAM) touche plus de 70% des sujets qui monte à plus de 4000 m. Il n'y a pas de test prédictif pour détecter les sujets sensibles avant leur ascension. Il semble exister une corrélation entre l'autorégulation de la vasoréactivité cérébrale et une susceptibilité au MAM. Cette piste permet d'envisager un test préventif. Dans le cadre du projet européen franco-italien ALCOTRA - RESAMONT 2, l'IFREMMONT a voulu réaliser une étude observationnelle : CervO2, visant à évaluer les variabilités individuelles de cette vasoréactivité. Cette étude se penche aussi sur une hypothèse physiopathologique des troubles neurologiques d'altitude : le micro embolisme gazeux. Notre travail a consisté à élaborer le protocole puis nous avons vu 120 sujets en visite de pré-inclusion et nous avons choisi 96 sujets à inclure. L'expérimentation se déroulait en 3 phases par groupe de 3 sujets : en plaine, puis en hypoxie hypobarique d'altitude après une montée rapide à l'Aiguille du Midi et après 18 heures en altitude. Nous avons étudié les scores de Lake Louise, la vasoréactivité cérébrale au doppler transcrânien, la recherche de foramen ovale perméable et l'évaluation de la tension artérielle pulmonaire. Pour un sujet sur 3, nous avons réalisé un enregistrement au holter transcrânien. À l'arrêt prématuré de l'étude 58 sujets ont été explorés, une relative réussite puisque c'est la plus grande cohorte sur ce sujet. L'analyse des résultats pourrait mettre en évidence une différence significative de vasoréactivité cérébrale exploitable comme marqueur de MAM. L'Aiguille du Midi est laboratoire naturel exceptionnel où pourront désormais être réalisées d'autres études.

Many alternatives have been proposed for the treatment of frostbites. None has been assessed in prospective randomized trials. Conventionnal treatment often associates rapid rewarming, aspirin and alpha-adrenergic vasodilatators but have disappointing results in severe frostbites cases. The physiopathology incites to study two treatments : one based on the use of a prostacyclin analogue (iloprost) and the other based on thrombolytic therapy with rt-PA. Between 1996 and 2008 we randomly assigned 47 patients suffering, after rapid rewarming protocol, from at least one lesion concerning more than the whole distal phalanx. Each received for 8 days a treatment by aspirin associated with buflomedil, or with iloprost, or with iloprost + rt-PA. The risk of amputation in the buflomedil group was 60%. It was significantly lower in the iloprost group (0%) and iloprost + rt-PA group (19%). (p< ; 0,001 and p< ; 0,03 respectively, by Fisher's exact test). Those results were confirmed when frostbitten digits were studied independently, according to the severity (stages 3 and 4), the amount of time since rewarming ≤12h, ≤24h or ≤48h and the localization of the frosbite (feet or hands). However, our results do not rule out a possible positive effect of rt-PA when associated with iloprost. On the basis of these results, we recommend that in the treatment of severe frostbite a combination of aspirin and prostacyclin should be used. The addition of rt-PA should be considered on a case-by-case basis, depending on the severity of injury (at least stage 4 frostbite), the presence of any medical or traumatic contraindications, and the amount of time passed since rewarming.; De nombreux traitements ont été proposés dans la prise en charge des gelures. Aucun n'a fait la preuve de son efficacité au cours d'études prospectives randomisées. Les traitements conventionnels associent réchauffement rapide, aspirine et vasodilatateurs périphériques mais donnent des résultats décevants pour les gelures graves. La physiopathologie incite à considérer deux traitements basés l'un sur un analogue de la prostacycline (iloprost), l'autre sur l'utilisation d'un thrombolytique (rt-PA). Nous avons réalisé une étude prospective contrôlée de 1996 à 2008 aux Hôpitaux du Pays du Mont Blanc, portant sur 47 patients présentant, après protocole de réchauffement rapide, une gelure dépassant l'IPD. Chacun a bénéficié d'un traitement par aspirine associé soit au buflomédil, soit à l'iloprost, soit à l'iloprost et au rt-PA. Le risque d'amputation dans le groupe traité par buflomédil est de 60%. Il est significativement inférieur dans les groupes iloprost (0%) et iloprost + rt-PA (19%) (p< ; 0,001 et < ; 0,03 test de Fisher). Ces résultats sont confirmés si l'on considère séparément chaque gelure selon sa gravité, pour des délais de prise en charge ≤12h, ≤24h, ou ≤48h, et selon la localisation au pied ou à la main. Nos résultats ne nous permettent cependant pas de confirmer ou d'infirmer un effet additif du rt-PA lorsqu'il est associé à l'iloprost. Nous recommandons donc de traiter tous les patients victimes de gelures graves par l'association aspirine + iloprost. L'adjonction de rt-PA doit être discutée collégialement au cas par cas pour les lésions dépassant la MP, pris en charge dans les 48h maximum et dans le strict respect des contrindications médicales et traumatiques.