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Andjelkovic, Marija, Peter Paal, Susi Kriemler, Kaste Mateikaite-Pipiriene, Alison Rosier, Beth Beidleman, Mia Derstine, Jacqueline Pichler Hefti, David Hillebrandt, Lenka Horakova, Dominique Jean, and Linda E. Keyes. Nutrition in women at high altitude: a scoping review—UIAA Medical Commission recommendations. High Alt Med Biol. 25:9–15, 2024. Background: Nutritional concerns such as food composition, energy intake, and nutrient absorption are essential for performance at high altitude and may differ between men and women. We performed a scoping review to summarize what is currently known on nutrition for women during short-term, high-altitude, physically active sojourns. Methods: The UIAA Medical Commission convened an international team to review women's health issues at high altitude and to publish updated recommendations. Pertinent literature from PubMed and Cochrane was identified by keyword search combinations (including nutrition, metabolism, energy composition, micronutrients) with additional publications found by hand search. Results: We found 7,165 articles, of which 13 original articles assessed nutritional aspects in physically active women on short-term high-altitude sojourns, with other articles found by hand search. We summarize the main findings. Conclusions: Data on women's nutrition at altitude are very limited. Reduction in energy intake plus increased energy expenditure at high altitude can lead to unbalanced nutrition, negatively influencing high-altitude adaptation and physical performance. Therefore, adequate dietary and fluid intake is essential to maintaining energy balance and hydration at high altitude in women as in men. Iron supplementation should be considered for women with iron depletion before travel. [ABSTRACT FROM AUTHOR]

Horakova, Lenka, Peter Paal, Jacqueline Pichler Hefti, Marija Andjelkovic, Beth A. Beidleman, Mia Derstine, David Hillebrandt, Dominique Jean, Kastė Mateikaitė-Pipirienė, Alison J. Rosier, Susi Kriemler, and Linda E. Keyes. Women's health at high altitude: An introduction to a 7-part series by the International Climbing and Mountaineering Federation Medical Commission. High Alt Med Biol. 24:243–246, 2023. Background: Women have been traveling to high altitude since the inception of modern mountaineering. Although there are distinct female-specific features such as menstruation and menopause relevant to adaptation to and performance at high altitude, very little data exist on women's high-altitude health. To summarize what is known to date, the Medical Commission of the International Climbing and Mountaineering Federation (UIAA) has created a series of articles on women's health, high altitude illness, and performance at high altitude. Methods: Assembling an international author team, two types of manuscripts were developed: (1) reviews on female-specific topics such as pregnancy; (2) reviews on sex differences in high-altitude related illnesses, nutrition, cold injuries, and mortality. Results: The literature search yielded 7,165 articles, with 482 studies meeting the inclusion criteria for full-text review. The authors of individual chapters reviewed these articles and performed additional hand searches. Conclusions: Some important questions on women sojourning and exercising at high altitude have been studied, but many are still awaiting a qualified and evidence-based response. Our seven reviews, to be published in future issues of this journal, summarize what is known about lowland women sojourning at high altitude, provide recommendations, and highlight knowledge gaps in high altitude women's medicine. [ABSTRACT FROM AUTHOR]

Senior physicians with a higher pre-hospital anaesthesia case volume have higher first-pass tracheal intubation success rates, shorter on-site times, and lower patient mortality rates than physicians with lower case volumes. A senior physician's skill set includes the basics of management of airway and breathing (ventilating and oxygenating the patient), circulation, disability (anaesthesia), and environment (especially maintaining core temperature). Technical rescue skills may be required to care for patients requiring pre-hospital airway management especially in hazardous environments, such as road traffic accidents, chemical incidents, terror attacks or warfare, and natural disasters. Additional important tactical skills in mass casualty situations include patient triage, prioritising, allocating resources, and making transport decisions. [ABSTRACT FROM AUTHOR]

The supine position in unconscious patients resulted in the tongue falling back because of the loss of muscle tension which obstructed the upper airway. The head reclination opened the airway, however unexperienced rescuers faced difficulties in performing bagvalve-mask ventilation as it was hard to detect the optimal head position for opening the airway. The bag-valve-mask ventilation could be optimized if it indicated an optimized head angle to the rescuer. A digital sensor was attached to the face mask for measuring the degree of head reclination. Moreover, the face mask was equipped with an airway trainer and sealed via adhesive tape. The airway trainer was connected to a test lung and ventilated through pressure-controlled standard anesthesia machine (Pmax = 10 mbar, Positive End Expiratory Pressure (PEEP) = 0 mbar, f = 12/min). The head of airway manikin was tilted to 42 degrees starting from neutral position with a gradient of 2 degrees. The primary endpoint was the correlation of preset angles and digitally measured head position angles via the mask. In addition, the tidal and minute volumes were evaluated based on the head reclination. The preset and the digitally measured head position angles depicted correlation (R2 = 0.9895855684; p < 0.001). The tidal volume was 150 mL in head position angle of <10 degrees, 200 mL at 18 degrees, 450 mL at 25 degrees, and it levelled with about 500 mL at 30 degrees. In conclusion, digital head position angle was measured to detect the correct head position. A signal in the face mask could indicate the optimized head position to the first respondents or inexperienced rescuers in emergency ventilation. [ABSTRACT FROM AUTHOR]

Mateikaitė-Pipirienė, Kastė, Dominique Jean, Peter Paal, Lenka Horakova, Susi Kriemler, Alison J. Rosier, Marija Andjelkovic, Beth A. Beidleman, Mia Derstine, Jacqueline Pichler Hefti, David Hillebrandt, and Linda E. Keyes for the UIAA MedCom writing group on Women's Health in the Mountains. Menopause and high altitude: A scoping review—UIAA Medical Commission Recommendations. High Alt Med Biol. 25:1–8, 2024. Background: Older people are an important fraction of mountain travelers and climbers, many of them postmenopausal women. The aim of this work was to review health issues that older and postmenopausal women may experience at high altitude, including susceptibility to high-altitude illness. Methods: We performed a scoping review for the UIAA Medical Commission series on Women's Health in the mountains. We searched PubMed and Cochrane libraries and performed an additional manual search. The primary search focused on articles assessing lowland women sojourning at high altitude. Results: We screened 7,165 potential articles. The search revealed three relevant articles, and the manual search another seven articles and one abstract. Seven assessed menopausal low-altitude residents during a high-altitude sojourn or performing hypoxic tests. Four assessed high-altitude residents. We summarize the results of these 11 studies. Conclusions: Data are limited on the effects of high altitude on postmenopausal women. The effects of short-term, high-altitude exposure on menopause symptoms are unknown. Menopause has minimal effect on the physiological responses to hypoxia in physically fit women and does not increase the risk of acute mountain sickness. Postmenopausal women have an increased risk of urinary tract infections, which may be exacerbated during mountain travel. More research is needed on the physiology and performance of older women at high altitude. [ABSTRACT FROM AUTHOR]

Humankind has always been exploring and discovering new worlds. Both space and deep undersea environments have several natural challenges. Explorers have always faced medical challenges, but nowadays, most of the old challenges are preventable and treatable. Both time and gravity issues have led medical scientists to search for new answers and solutions not only for non-critical diseases, but also for critical incidents, which require immediate life-saving action. In this issue of Acta Anaesthesiologica Scandinavica Warnecke et al present a study on airway management in microgravity. The authors concluded that securing the airway was faster with either a laryngeal mask or a laryngeal tube compared to tracheal intubation. Studies conducted in special circumstances are often criticized for the small number of included patients as well as for multiple confounders. These "limitations" often represent the overall challenges in working or making research in these circumstances. Confounders are not additional or exceptional but the reality in these environments. If patients are encountered and treated in special circumstances, the procedures and protocols used should not only be adapted from in-hospital ones. Instead, they should be critically evaluated and studied using the environment and methods closest to that special circumstance. Thus, we encourage researchers to raise further questions: Have we evaluated our protocols and procedures in the special circumstances and patient subgroups we encounter in our real-life? [ABSTRACT FROM AUTHOR]

Ventilation with positive end-expiratory pressure (PEEP) may result in decreased venous return to the heart and therefore decrease cardiac output. We evaluated the influence of PEEP ventilation on arterial blood pressure in the field in 296 posttraumatic intubated patients being treated by a helicopter emergency medical service in a retrospective cohort study. Initial systolic blood pressure on the scene, upon hospital admission and their mean difference were compared between patients being ventilated with no/low PEEP (0–0.3 kPa) and moderate PEEP (0.3–1 kPa). In a subgroup analysis of initially hemodynamic unstable patients (systolic blood pressure < 80 mmHg), systolic blood pressure was compared between patients being ventilated with no/low or moderate PEEP Further, the mean difference between initial systolic blood pressure and upon hospital admission was correlated with the chosen PEEP. Systolic arterial blood pressure of patients being ventilated with no/low PEEP improved from 105 ± 36 mmHg to 112 ± 38 mmHg, and that of patients being ventilated with moderate PEEP improved from 105 ± 38 mmHg to 119 ± 27 mmHg. In initially unstable patients being ventilated with no/low PEEP systolic blood pressure improved from initially 55 ± 36 mmHg to 78 ± 30 mmHg upon hospital admission, and in those being ventilated with moderate PEEP, the systolic blood pressure improved from 43 ± 38 mmHg to 91 ± 27 mmHg. There was no significant correlation between the chosen PEEP and the mean difference of systolic blood pressure (Pearson's correlation, r = 0.07, P = 0.17). Ventilation with moderate PEEP has no adverse effect on arterial systolic blood pressure in this cohort of trauma patients requiring mechanical ventilation. Initially unstable patients being ventilated with moderate PEEP tend to be hemodynamically more stable. [ABSTRACT FROM AUTHOR]

Purpose: Despite continuous improvement in minimally invasive surgery (MIS) and growing evidence for its superiority in procedures in various organ systems, a routinely application in patients with acute bowel obstruction (ABO) cannot be seen to date. Besides very general explanations for this attitude, not much is known about the decision process in a particular patient. This retrospective study aims at investigating surgeon- and patient-specific factors for or against MIS in acute bowel obstruction. Methods: A retrospective analysis of all patients undergoing either MIS or open surgery (OS) for ABO at a single center between 2009 and 2017 was performed. All available preoperative parameters were included in the analysis and subdivided into patient- (age, gender, BMI, previous abdominal procedures, inflammatory process, ASA score, bowel dilatation) and surgeon-specific (time of patient admission, senior surgeon performed the procedure or taught the case, availability of a surgical resident or junior doctor as assisting surgeon) factors. Statistical analysis was performed to reveal their influence on the surgeon's decision for or against MIS. Results: Of 106 patients requiring surgical intervention, 57 were treated by OS (53.77%) and 49 by MIS (46.23%). Patients with a higher ASA score (ASA III) and a bowel width of ≥ 3.8 cm in preoperative radiologic imaging were more likely to undergo OS (p < 0.01). Also, a late admission time to the hospital (x̄ = 14.78 h) was associated with OS (p = 0.01). Concerning previous abdominal surgical interventions, patients with prior appendectomy rather were assigned to MIS (p < 0.01) whereas those with prior colectomy to OS (p < 0.01). Conclusions: The choice of procedure in patients with bowel obstruction is a highly individualized decision. Whereas scientifically proven parameters, such as high age and BMI, had no influence on the decision process, impaired general health condition (ASA score), high bowel width, previous surgical intervention, and a late admission time influenced the decision process towards open surgery. Trial registration: Retrospectively registered with the German Clinical Trials Register: DRKS00021600. [ABSTRACT FROM AUTHOR]

Introduction: Interindividual collisions while skiing or snowboarding occur regularly, they can be associated with severe injuries.Objective: To elucidate causes of accidents, injury patterns and potential risk factors for injury severity in interindividual collisions of skiers and snowboarders.Material and Methods: Retrospective analysis of the Austrian Registry for Mountain Accidents within a 13-year timeframe (2005-2018) with regard to on- or off-piste collisions of skiers and snowboarders.Results: A total of 30,503 collisions, involving 52,430 (85.9%) skiers and 8,576 (14.1%) snowboarders were analysed. Denominators are lacking, since total numbers of skiers and snowboarders were not available. Compared to skiers, snowboarders were younger (23 vs. 42 years; p<0.001), predominantly male (77.4% vs. 61.0%; p<0.001) and less often severely injured (46.8% vs. 26.2%; p<0.001). Most accidents occurred on slopes (>95%). Collisions involving two snowboarders occurred proportionally more often in terrain parks (4.1% of 1,664 injured snowboarders; p<0.001) and while one victim was standing or sitting (9.7%; p<0.001). Contusions/strains/sprains were most prevalent (>23%), as were head injuries (>12%). In skiers, chest, shoulder, hip, thigh and knee injuries occurred more often, leading to fractures, dislocations, concussions and internal injuries more frequently. In snowboarders, spine/back, elbow, forearm, wrist and lower leg injuries were more prevalent. Female gender and standing or sitting prior to the accident was a risk factor for being more severely injured in collisions involving i) two skiers (OR: 4.02 (3.79-4.26) and 3.91 (3.26-4.68)), ii) a skier and a snowboarder (OR: 4.50 (3.95-5.14) and 11.49 (8.04-16.41)) or iii) two snowboarders (OR: 2.85 (2.12-3.84) and 12.47 (6.17-25.20)). Wearing a helmet increased the risk when two skiers collided (OR: 1.10 (1.03-1.17)). In skier vs. snowboarder collisions, the skier had a higher risk of being injured more severely (OR: 7.93 (6.98-9.01)).Conclusions: In interindividual collisions of skiers and snowboarders, injury patterns and preceding causes differ substantially. Skiers are more likely to be severely injured. Awareness of an increased risk of injury should be raised particularly while standing or sitting on the slope. [ABSTRACT FROM AUTHOR]

Zafren, Ken, Raimund Lechner, Peter Paal, Hermann Brugger, Giles Peek, and Tomasz Darocha. Induced hypothermia as cold as 3°C in humans: Forgotten cases rediscovered. High Alt Med Biol. 23:105–113.—The lowest temperature from which humans can be successfully rewarmed from accidental hypothermia is unknown. The lowest published core temperature with survival from accidental hypothermia is 11.8°C. We recently reported a rediscovered case series of patients in whom profound hypothermia was induced for surgery. The patient in this case series with the lowest core temperature, 4.2°C, survived neurologically intact. We subsequently rediscovered several additional case series of induced hypothermia to core temperatures below 11.8°C. In one case series, at least one patient was cooled to 3°C. We do not know if any patient survived cooling to 3°C. As in the previous case series, the authors of the additional reports presented physiological data at various core temperatures, showing wide variations in individual responses to hypothermia. These data add to our understanding of the physiology of profound hypothermia. Although induced hypothermia for surgery differs from accidental hypothermia, survival from very low temperatures in induced hypothermia provides evidence that humans with accidental hypothermia can be resuscitated successfully from temperatures much lower than 11.8°C. We continue to advise against using core temperature alone to decide if a hypothermic patient in cardiac arrest has a chance of survival. [ABSTRACT FROM AUTHOR]

Woyke, Simon, Anja Hütter, Christopher Rugg, Willi Tröger, Bernd Wallner, Mathias Ströhle, and Peter Paal. Sex differences in mountain bike accidents in Austria from 2006 to 2018: a retrospective analysis. High Alt Med Biol. 25:89–93, 2024. Introduction: Mountain biking is becoming increasingly popular, and mountain bike (MTB) accidents are on the rise. The aim of this study was to assess sex differences in mountain biking accidents in the Austrian Alps. Methods: This retrospective study includes all MTB accidents in Austria from 2006 to 2018. Data were collected by Alpine Police officers and recorded in a national digital registry. Results: The accidents involved 5,095 mountain bikers (81% men and 19% women). The number of MTB accidents rose markedly from 208 in 2006 to 725 in 2018. Men wore a helmet more often than did women (95% vs. 92%; p = 0.001). The most common injury category was "wound/bleeding" for both sexes (men 40% and women 41%). Women were more frequently transported by helicopter or terrestrially (p > 0.001). Conclusion: In the Austrian Alps, the number of MTB accidents more than tripled between 2006 and 2018. Women were involved in only one fifth of all accidents. Sex differences in MTB accidents include (1) women wearing helmets less often, (2) women being less frequently injured, (3) women suffering fewer serious injuries, and (4) women being more frequently transported by helicopter or terrestrially, while men more often did not require transportation. [ABSTRACT FROM AUTHOR]

Lugnet, Viktor, Miles McDonough, Les Gordon, Mercedes Galindez, Nicolas Mena Reyes, Alison Sheets, Ken Zafren, and Peter Paal. Termination of cardiopulmonary resuscitation in mountain rescue: a scoping review and ICAR MedCom 2023 recommendations. High Alt Med Biol. 24:274–286, 2023. Background: In 2012, the International Commission for Mountain Emergency Medicine (ICAR MedCom) published recommendations for termination of cardiopulmonary resuscitation (CPR) in mountain rescue. New developments have necessitated an update. This is the 2023 update for termination of CPR in mountain rescue. Methods: For this scoping review, we searched the PubMed and Cochrane libraries, updated the recommendations, and obtained consensus approval within the writing group and the ICAR MedCom. Results: We screened a total of 9,102 articles, of which 120 articles met the inclusion criteria. We developed 17 recommendations graded according to the strength of recommendation and level of evidence. Conclusions: Most of the recommendations from 2012 are still valid. We made minor changes regarding the safety of rescuers and responses to primary or traumatic cardiac arrest. The criteria for termination of CPR remain unchanged. The principal changes include updated recommendations for mechanical chest compression, point of care ultrasound (POCUS), extracorporeal life support (ECLS) for hypothermia, the effects of water temperature in drowning, and the use of burial times in avalanche rescue. [ABSTRACT FROM AUTHOR]

Pichler Hefti, Jacqueline, Dominique Jean, Alison Rosier, Mia Derstine, David Hillebrandt, Lenka Horakova, Linda E. Keyes, Kastė Mateikaitė-Pipirienė, Peter Paal, Marija Andjelkovic, Beth Beidlemann, and Susi Kriemler. High-altitude pulmonary edema in women: a scoping review—UIAA Medical Commission Recommendations. High Alt Med Biol. 24:268–273, 2023. Background: High-altitude pulmonary edema (HAPE) can occur >2,500–3,000 m asl and is a life-threatening medical condition. This scoping review aims to summarize the current data on sex differences in HAPE. Methods: The International Climbing and Mountaineering Federation (UIAA) Medical Commission convened an international author team to review women's health issues at high altitude. Pertinent literature from PubMed and Cochrane was identified by keyword search combinations (including HAPE), with additional publications found by hand search. The primary search focus was for original articles that included minimum one woman and at least a rudimentary subgroup analysis. Results: The literature search yielded 7,165 articles, 416 of which were relevant for HAPE, and 7 of which were ultimately included here. Six were case series, consistently reporting a lower HAPE prevalence in women. The one retrospective case–control study reported male HAPE prevalence at 10/100,000 and female at 0.74/100,000. No studies were identified that directly compared sex differences in the prevalence of HAPE. No published data was found for topics other than epidemiology. Conclusions: Few studies and associated methodological limitations allow few conclusions to be drawn. Incidence of HAPE may be lower in women than in men. We speculate that besides physiological aspects, behavioral differences may contribute to this potential sex difference. [ABSTRACT FROM AUTHOR]

Derstine, Mia, Dominique Jean, Beth A. Beidleman, Jacqueline Pichler Hefti, David Hillebrandt, Lenka Horakova, Susi Kriemler, Kasté Mateikaité–Pipiriené, Peter Paal, Alison Rosier, Marija Andjelkovic, and Linda E. Keyes. Acute mountain sickness and high altitude cerebral edema in women: A scoping review—UIAA Medical Commission recommendations. High Alt Med Biol. 24:259–267, 2023. Background: Acute mountain sickness (AMS) and high-altitude cerebral edema (HACE) are illnesses associated with rapid ascent to altitudes over 2,500 m in unacclimatized lowlanders. The aim of this scoping review is to summarize the current knowledge on sex differences in the epidemiology, pathophysiology, symptomatology, and treatment of AMS and HACE, especially in women. Methods and Results: The UIAA Medical Commission convened an international author team to review women's health issues at high altitude and to publish updated recommendations. Pertinent literature from PubMed and Cochrane was identified by keyword search combinations (including AMS, HACE, and high altitude), with additional publications found by hand search. The primary search focus was for articles assessing lowland women sojourning at high altitude. Results: The literature search yielded 7,165 articles, 37 of which were ultimately included. The majority of publications included did not find women at increased risk for AMS or HACE. There was extremely limited sex-specific data on risk factors or treatment. Conclusions: There is a limited amount of data on female-specific findings regarding AMS and HACE, with most publications addressing only prevalence or incidence with regard to sex. As such, general prevention and treatment strategies for AMS and HACE should be used regardless of sex. [ABSTRACT FROM AUTHOR]

Kriemler, Susi, Kastė Mateikaitė-Pipirienė, Alison Rosier, Linda E. Keyes, Peter Paal, Marija Andjelkovic, Beth A. Beidleman, Mia Derstine, Jacqueline Pichler Hefti, David Hillebrandt, Lenka Horakova, and Dominique Jean; for the UIAA MedCom Writing Group on Women's Health in the Mountains. Frostbite and mortality in mountaineering women: a scoping review—UIAA Medical Commission recommendations. High Alt Med Biol. 24:247–258, 2023. Background: The harsh environment of high altitudes (HA) poses many serious health risks for mountaineers, including cold injuries and death. The aim of this work was to review whether female mountaineers are at special risk for frostbite or death at HA compared with their male counterparts. Methods: The UIAA Medical Commission convened an international author team to review women's health issues at HA and to publish updated recommendations. Pertinent literature from PubMed and Cochrane was identified with additional publications found by hand search. The primary search focus was for articles assessing cold injuries and death in women mountaineers at HA. Results: We reviewed the literature and identified 20 relevant studies: 2 studies on frostbite at HA, plus 7 studies and 1 report for death at HA. An additional 10 studies about frostbite at low altitude were included. We found that female mountaineers at HA were at lower risk of death than their male counterparts, but sex differences in frostbite were inconclusive. Conclusions: The frequency of cold injuries and mortality in female mountaineers is not yet well studied, and the studies that have been published tend to lack precise exposure data. More studies and registries with sex-differentiated data are needed. [ABSTRACT FROM AUTHOR]

Most health care providers consider accidental hypothermia to be related to cold exposure or to winter conditions; thus, a patient may not be suspected of suffering from hypothermia in a warm environment or out of the winter season. Healthcare providers may be inclined to ignore temperature readings below the normal range as false and may overlook severe hypothermia (core temperature <32 °C) cases because they do not expect such a patient. Keywords: accidental hypothermia; cardiac arrest; cognitive bias; emergency medicine; heuristics; medical errors EN accidental hypothermia cardiac arrest cognitive bias emergency medicine heuristics medical errors 322 324 3 08/17/23 20230801 NES 230801 To the Editor, Accidental hypothermia is defined as the unintentional drop of the core temperature <35 °C. [Extracted from the article]

The restorative effect of physical activity in alpine environments on mental and physical health is well recognized. However, a risk of accidents and post-accident mental health problems is inherent to every sport. We aimed to characterize mental health in individuals following mountain sport accidents requiring professional medical management. Adult victims of mountain sport accidents treated at the hospital of the Medical University of Innsbruck (Austria) between 2018 and 2020 completed a cross-sectional survey at least 6 months following the admission (median 44 months, n = 307). Symptoms of post-traumatic stress disorder (PTSD, PCL-5), anxiety, depression, and somatization (PHQ), resilience (RS-13), sense of coherence (SOC-9L), post-traumatic growth (PTGI), and quality of life (EUROHIS-QOL), as well as sociodemographic and clinical information, were obtained from an online survey and extracted from electronic health records. Mental health outcome patterns were investigated by semi-supervised medoid clustering and modeled by machine learning. Symptoms of PTSD were observed in 19% of participants. Three comparably sized subsets of participants were identified: a (1) neutral, (2) post-traumatic growth, and (3) post-traumatic stress cluster. The post-traumatic stress cluster was characterized by high prevalence of symptoms of mental disorders, low resilience, low sense of coherence, and low quality of life as well as by younger age, the highest frequency of pre-existing mental disorders, and persisting physical health consequences of the accident. Individuals in this cluster self-reported a need for psychological or psychiatric support following the accident and more cautious behavior during mountain sports since the accident. Reliability of machine learning-based prediction of the cluster assignment based on 40 variables available during acute medical treatment of accident victims was limited. A subset of individuals show symptoms of mental health disorders including symptoms of PTSD when assessed at least 6 months after mountain sport accident. Since early identification of these vulnerable patients remains challenging, psychoeducational measures for all patients and low-threshold access to mental health support are key for a successful interdisciplinary management of victims of mountain sport accidents. [ABSTRACT FROM AUTHOR]

Severe accidental hypothermia carries high mortality and morbidity and is often treated with invasive extracorporeal methods. Continuous veno‐venous hemodiafiltration (CVVHDF) is widely available in intensive care units. We sought to provide theoretical basis for CVVHDF use in rewarming of hypothermic patients. CVVHDF system was used in the laboratory setting. Heat balance and transferred heat units were evaluated for the system without using blood. We used 5L of crystalloid solution at the temperature of approximately 25°C, placed in a thermally insulated tank (representing the "central compartment" of a hypothermic patient). Time of warming the central compartment from 24.9 to 30.0°C was assessed with different flow combinations: "blood" (central compartment fluid) 50 or 100 or 150 mL/min, dialysate solution 100 or 1500 mL/h, and substitution fluid 0 or 500 mL/h. The total circulation time was 1535 minutes. There were no differences between heat gain values on the filter depending on blood flow (P =.53) or dialysate flow (P =.2). The mean heating time for "blood" flow rates 50, 100, and 150 mL/min was 113.7 minutes (95% CI, 104.9‐122.6 minutes), 83.3 minutes (95% CI, 76.2‐90.3 minutes), and 74.7 minutes (95% CI, 62.6‐86.9 minutes), respectively (P <.01). The respective median rewarming rate for different "blood" flows was 3.6°C/h (IQR, 3.0‐4.2°C/h), 4.8 (IQR, 4.2‐5.4°C/h), and 5.4 (IQR, 4.8‐6.0°C/h), respectively (P <.01). The dialysate flow did not affect the warming rate. Based on our experimental model, CVVHDF may be used for extracorporeal rewarming, with the rewarming rates increasing achieved with higher blood flow rates. [ABSTRACT FROM AUTHOR]

Cardiopulmonary resuscitation prioritises treatment for cardiac arrests from a primary cardiac cause, which make up the majority of treated cardiac arrests. Early chest compressions and, when indicated, a defibrillation shock from a bystander give the best chance of survival with a good neurological status. Cardiac arrest can also be caused by special circumstances, such as asphyxia, trauma, pulmonary embolism, accidental hypothermia, anaphylaxis, or COVID-19, and during pregnancy or perioperatively. Cardiac arrests in these circumstances represent an increasing proportion of all treated cardiac arrests, often have a preventable cause, and require additional interventions to correct a reversible cause during resuscitation. The evidence for treating these conditions is mostly of low or very low certainty and further studies are needed. Irrespective of the cause, treatments for cardiac arrest are time sensitive and most effective when given early-every minute counts. [ABSTRACT FROM AUTHOR]

Mittermair, Christof, Eva Foidl, Bernd Wallner, Hermann Brugger, and Peter Paal. Extreme cooling rates in avalanche victims: case report and narrative review. High Alt Med Biol. 22: 235–240, 2021. Background: We report a 25-year-old female backcountry skier who was buried by an avalanche during ascent. A cooling rate of 8.5°C/h from burial to hospital is the fastest reported in a person with persistent circulation. Methods: A case report according to the CARE guidelines is presented. A literature search with the keywords "avalanche" AND "hypothermia" was performed and yielded 96 results, and the last update was on October 25, 2020. A narrative review complements this work. Results: A literature search revealed four avalanche patients with extreme cooling rates (>5°/h). References of included articles were searched for further relevant studies. Nineteen additional pertinent articles were included. Overall, 32 studies were included in this work. Discussion: An avalanche patient cools in different phases, and every phase may have different cooling rates: (1) during burial, (2) with postburial exposure on-site, and (3) during transport. It is important to measure the core temperature correctly, ideally with an esophageal probe. Contributing factors to fast cooling are sweating, impaired consciousness, no shivering, wearing thin monolayer clothing and head and hands uncovered, an air pocket, and development of hypercapnia, being slender. Conclusions: Rescuers should be prepared to encounter severely hypothermic subjects (<30°C) even after burials of <60 minutes. Subjects rescued from an avalanche may cool extremely fast the more contributing factors for rapid cooling exist. After avalanche burial (≥60 minutes) and unwitnessed cardiac arrest, chances of neurologically intact survival are small and depend on rapid cooling and onset of severe hypothermia (<30°C) before hypoxia-induced cardiac arrest. [ABSTRACT FROM AUTHOR]

Roy, Steven, Inigo Soteras, Alison Sheets, Richard Price, Kazue Oshiro, Simon Rauch, Don McPhalen, Maria Antonia Nerin, Giacomo Strapazzon, Myron Allen, Alistair Read, and Peter Paal. Guidelines for mountain rescue during the COVID-19 pandemic: official guidelines of the International Commission for Alpine Rescue. High Alt Med Biol. 22: 128–141, 2021. Background: In mountain rescue, uncertainty exists on the best practice to prevent coronavirus disease 2019 (COVID-19) transmission. The aim of this work was to provide a state-of-the-art overview of the challenges caused by the COVID-19 pandemic in mountain rescue. Methods: Original articles or reviews, published until December 27, 2020 in Cochrane COVID-19 Study Register, EMBASE, PubMed, and Google Scholar were included. Articles were limited to English, French, German, or Spanish with the article topic COVID-19 or other epidemics, addressing transmission, transport, rescue, or cardiopulmonary resuscitation. Results: The literature search yielded 6,190 articles. A total of 952 were duplicates and 5,238 were unique results. After exclusion of duplicates and studies that were not relevant to this work, 249 articles were considered for this work. Finally, 72 articles and other sources were included. Conclusions: Recommendations are provided for protection of the rescuer (including screening, personal protective equipment [PPE], and vaccination), protection of the patient (including general masking if low risk, specific PPE if high risk), equipment hygiene (including disinfection after every mission), use of single-use products, training and medical measures under COVID-19 precautions, and psychological wellbeing of rescuers during the COVID-19 pandemic. Adapted COVID-19 precautions for low-and-medium-income countries are also discussed. [ABSTRACT FROM AUTHOR]

In conclusion, in hypothermic CA patients with a potentially stiff chest, using POCUS, orthograde blood flow in the common carotid arteries in synchrony with chest compressions can be quickly and reliably assessed. The blood flow is indicative of the effectiveness of chest compressions and can help in the decision-making regarding continuation or termination of CPR in case of a patient with a potentially stiff chest. [Extracted from the article]