Search

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]

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]

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]

Background: Few data exist on the likelihood of surviving sudden cardiac arrest in the mountains. The aim of this study was to analyze the epidemiology and outcomes of patients suffering sudden cardiac arrest and undergoing cardiopulmonary resuscitation (CPR) with automated external defibrillator (AED) in the Austrian mountains. Materials and Methods: We analyzed all cardiac arrest cases in the Austrian mountains reported in the nationwide Austrian Alpine Police database from October 26, 2005, to December 31, 2015. To obtain information on outcomes, these patient data were manually merged with patient data from the main Austrian referral center for mountain emergencies, Innsbruck Medical University Hospital. Results: Overall, 781 cases of sudden cardiac arrest in the Austrian mountains were recorded. In 136 cases (17%), CPR with AED was attempted. The most frequent activities at the time of sudden cardiac arrest were hiking (n = 63, 46%) and skiing or snowboarding (n = 44, 32%). In the nationwide Austrian Alpine Police database, only 4 (3%) patients survived, whereas in the Innsbruck Medical University Hospital database, there were seven survivors who received CPR and AED. All survivors had received immediate CPR with an AED. Five patients had good neurological outcome (cerebral performance category 1–2). Conclusions: In the Austrian mountains, CPR was attempted in less than 20% of sudden cardiac arrest cases. The few that survived had received immediate CPR with an AED. To better understand the circumstances and outcome of sudden cardiac arrest in the mountains, out-of hospital and in-hospital data should be linked. [ABSTRACT FROM AUTHOR]