Papers by Mathieu Pasquier
Wilderness & Environmental Medicine, Dec 1, 2016
We read the article by Grasegger et al 1 regarding the radar-based RECCO Rescue System with great... more We read the article by Grasegger et al 1 regarding the radar-based RECCO Rescue System with great interest, in particular because we faced a very similar situation this past winter. A 39-year-old woman was completely buried by an avalanche while skiing off-piste in the Swiss Alps. She was neither equipped with an avalanche transceiver nor a RECCO reflector. The ski patrollers, alerted by her companion, detected a signal after a 5-minute search using the RECCO Rescue System that was later assumed to come from the victim's mobile phone. She was extricated from a depth of 80 cm after a 30-minute burial. She was uninjured, and a scarf covering both her nose and mouth probably prevented asphyxia from snow inhalation. The advantages and limitations of the RECCO Rescue System are well described by Grasegger et al 1 in their article. However, we would like to add 2 further comments. The first comment pertains to the analysis of the survival rate of completely buried avalanche victims located with the RECCO Rescue System. Grasegger et al 1 suggest that the vicinity of the accident sites to the patrolled ski areas may explain the high survival rate. Although vicinity certainly plays a role, we think that this apparently high survival rate should be interpreted cautiously. The reported cases represent a case series, without explicit selection criteria, and may be prone to a selection bias originating from 2 distinct sources. The first may be selection by the manufacturer of cases with a good outcome. The second, importantly, is the potential selection bias by those reporting cases to the manufacturer. A careful analysis of the case series seems to support this hypothesis. In the first category of victims found via the RECCO Rescue System within 1 hour of burial time, 9 of 11 (82%) were found not to have experienced cardiac arrest. This high survival rate is very unusual, as usually only one third of victims survive after a 30-minute burial time. 2 The second category of cases is represented by those found 1 or several days later using the RECCO Rescue System, all of whom died. Here again, the potential for a selection bias is high, as such dramatic cases are also certainly prone to being reported.
Wilderness & Environmental Medicine, Mar 1, 2012
Objective.-Esophageal temperature is the gold standard for in-the-field temperature monitoring in... more Objective.-Esophageal temperature is the gold standard for in-the-field temperature monitoring in hypothermic victims with cardiac arrest. For practical reasons, some mountain rescue teams use homemade esophageal thermometers to measure esophageal temperature; these consist of nonmedical inside/outside temperature monitoring instruments that have been modified to allow for esophageal insertion. We planned a study to determine the accuracy of such thermometers. Methods.-Two of the same model of digital cabled indoor/outdoor thermometer were modified and tested in comparison with a reference thermometer. The thermometers were tested in a water bath at different temperatures between 10°C and 35.2°C. Three hundred measurements were taken with each thermometer. Results.-Our experimental study showed that both homemade thermometers provided a good correlation and a clinically acceptable agreement in comparison with the reference thermometer. Measurements were within 0.5°C in comparison with the reference thermometer 97.5% of the time. Conclusions.-The homemade thermometers performed well in vitro, in comparison with a reference thermometer. However, because these devices in their original form are not designed for clinical use, their use should be restricted to situations when the use of a conventional esophageal thermometer is impossible.
High Altitude Medicine & Biology, Dec 1, 2017
Pasquier, Mathieu, Louis Marxer, Hervé Duplain, Vincent Frochaux, Florence Selz, Pierre Métraille... more Pasquier, Mathieu, Louis Marxer, Hervé Duplain, Vincent Frochaux, Florence Selz, Pierre Métrailler, Grégoire Zen Ruffinen, and Olivier Hugli. Indications and outcomes of helicopter rescue missions in alpine mountain huts: A retrospective study. High Alt Med Biol 18:355-362, 2017. AIMS This retrospective study describes the rescue indications and outcome of patients rescued by helicopter from mountain huts in the Swiss Alps. The hospital course and operational data were also studied. RESULTS Among 14,872 helicopter rescue missions undertaken during the 10-year study period, 309 (2.1%) were performed from mountain huts at a mean altitude of 2794 ± 459 m. The mean age of the patients was 43 ± 16 and 66% were male. Thirty-four percent of the patients had a National Advisory Committee for Aeronautics score ≥3. Most (89%) patients were transported to hospital and only 12 (3.9%) patients had to stay more than 48 hours. Hospital diagnoses were extremely varied. Trauma accounted for 50% and altitude diseases for 7% of the cases. A winching procedure was performed 18 times and 19 missions included a night flight. CONCLUSIONS Helicopter rescue missions in mountain huts are a small part of all rescue missions. Our study provides a better understanding of medical emergencies arising in mountain huts. The diagnoses encountered are extremely varied in their type and severity. Hut keepers should be prepared for these situations as they will often have to act as first responders in the case of medical problems.
Resuscitation, Aug 1, 2019
Aims: Our goals were to describe and analyse the medical management and clinical course of avalan... more Aims: Our goals were to describe and analyse the medical management and clinical course of avalanche victims in cardiac arrest (CA), focusing on adherence to international recommendations on avalanche victims in CA regarding critical decisions. We retrospectively included all avalanche victims with CA from 1st January 2004 to 1st June 2016 in a single physician-staffed alpine helicopter emergency medical service. Data regarding cardiopulmonary resuscitation (CPR), transportation to hospital whilst undergoing CPR, and extracorporeal life support rewarming (ECLSR) for patients still in CA at hospital admission were abstracted from the prehospital and medical health records. Results: Sixty-six victims were included in this study; 31 (47%) were declared dead on scene. Of the remaining 35 victims, 7 (20%) had prehospital return of spontaneous circulation (ROSC), 28 (80%) were transported whilst undergoing CPR, 3 had hospital ROSC and 7 (28%) of the 25 patients with persistent CA at hospital underwent ECLSR. The medical management comprised 126 documented critical decisions, corresponding to guidelines in 117 (93%) decisions. None of the 66 studied patients survived to hospital discharge, and 7 (11%) were organ donors. The management of avalanche victims in CA respect current guidelines regarding the critical decisions, but no patient survived in this sample. The presence of a few cases with incorrect management and potential undertreatment suggests some room for improvement.
Air Medical Journal, Nov 1, 2013
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, Jun 6, 2019
Background: The Swiss staging model for hypothermia uses clinical indicators to stage hypothermia... more Background: The Swiss staging model for hypothermia uses clinical indicators to stage hypothermia and guide the management of hypothermic patients. The proposed temperature range for clinical stage 1 is < 35-32 °C, for stage 2 is < 32-28 °C, for stage 3 is < 28-24 °C, and for stage 4 is below 24 °C. Our previous study using 183 case reports from the literature showed that the measured temperature only corresponded to the clinical stage in the Swiss staging model in approximately 50% of cases. This study, however, included few patients with moderate hypothermia. We aimed to expand this database by adding cases of hypothermic patients admitted to hospital to perform a more comprehensive evaluation of the staging model. Methods: We retrospectively included patients aged ≥18 y admitted to hospital between 1. 1.1994 and 15.7.2016 with a core temperature below 35 °C. We added the cases identified through our previously published literature review to estimate the percentage of those patients who were correctly classified and compare the theoretical with the observed temperature ranges for each clinical stage. Results: We included 305 cases (122 patients from the hospital sampling and the 183 previously published). Using the theoretically derived temperature ranges for clinical stages resulted in 185/305 (61%) patients being assigned to the correct temperature range. Temperature was overestimated using the clinical stage in 55/305 cases (18%) and underestimated in 65/305 cases (21%); important overlaps in temperature existed among the four stage groups. The optimal temperature thresholds for discriminating between the four stages (32.1 °C, 27.5 °C, and 24.1 °C) were close to those proposed historically (32 °C, 28 °C, and 24 °C). Conclusions: Our results provide further evidence of the relationship between the clinical state of patients and their temperature. The historical proposed temperature thresholds were almost optimal for discriminating between the different stages. Adding overlapping temperature ranges for each clinical stage might help clinicians to make appropriate decisions when using clinical signs to infer temperature. An update of the Swiss staging model for hypothermia including our methodology and findings could positively impact clinical care and future research.
High Altitude Medicine & Biology, Mar 1, 2012
T hree alpinists were climbing in the western European Alps at 3500 m (11,483 ft) when a snowstor... more T hree alpinists were climbing in the western European Alps at 3500 m (11,483 ft) when a snowstorm prevented further ascent, and external aid had to be called in the evening. A terrestrial rescue team together with an emergency physician (GZR) was dispatched, as weather conditions precluded any helicopter intervention. The alpinists were reached after 12 hours of difficult rescue team progression in poor conditions [external temperature -15°C (5°F), moderate snowfall, and winds of up to 50 km h -1 (30 miles h -1 )]. The alpinists were physically exhausted, and a 51-year-old, previously healthy man complained of frostbite injuries to both hands. A closed, uninhabited mountain refuge (3100 m, 10,170 ft) was reached after a 2-hour walk, and the decision was made to rest overnight due to safety considerations. Both hands showed frostbite of all distal phalanges with numbness, paleness, and cyanosis of the finger tips. Re-warming was begun in a 40°C (104°F) water bath with povidone-iodine, which caused intolerable pain after about 10 min. The physician decided to perform a bilateral regional anesthesia with wrist blocks. The area was disinfected, and the nerve block was performed as described by Chandran et al. ( ) with three injections of 5 mL of 0.5% ropivacaine for the median, ulnar, and radial nerves, about 3-4 cm proximally to the wrist. Pain in both hands was completely relieved within 10 min. Hyperemia in both hands developed, following both water bath re-warming and wrist blocks. A sterile bandage was applied, and systemic analgesia was initiated orally with acetaminophen and an NSAID (dexketoprofen), in anticipation of the end of the effect of the block, which followed about 2 h later and brought moderate pain. Six hours after arrival in the mountain refuge, improved weather conditions enabled descent to an altitude of 2400 m (7874 ft) where helicopter evacuation to a regional hospital was possible. After 24 hours of hospitalization (Fig. ), the patient was discharged and followed on an outpatient basis. After transient loss of a nail and superficial skin, the fingers recovered within 8 weeks. A mild cold intolerance persisted.
International Journal of Environmental Research and Public Health, Sep 11, 2021
Decisions in the management and rescue of avalanche victims are complex and must be made in diffi... more Decisions in the management and rescue of avalanche victims are complex and must be made in difficult, sometimes dangerous, environments. Our goal was to identify indicators for quality measurement in the management and rescue of avalanche victims. The International Commission for Mountain Emergency Medicine (ICAR MedCom) convened a group of internal and external experts. We used brainstorming and a five-round modified nominal group technique to identify the most relevant quality indicators (QIs) according to the National Quality Forum Measure Evaluation Criteria. Using a consensus process, we identified a set of 23 QIs to measure the quality of the management and rescue of avalanche victims. These QIs may be a valuable tool for continuous quality improvement. They allow objective feedback to rescuers regarding clinical performance and identify areas that should be the foci of further quality improvement efforts in avalanche rescue.
Resuscitation, Apr 1, 2017
Resuscitation, Jun 1, 2019
Aim: Evidence of existing guidelines for the on-site triage of avalanche victims is limited and a... more Aim: 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 extracorporeal life support (ECLS) resources more appropriately while increasing the proportion of survivors among rewarmed victims. Methods: 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. Results: 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 cutoffs 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 inhospital triage, larger datasets are needed to include additional parameters.
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, Feb 17, 2016
Background: Core body temperature is used to stage and guide the management of hypothermic patien... more Background: Core body temperature is used to stage and guide the management of hypothermic patients, however obtaining accurate measurements of core temperature is challenging, especially in the pre-hospital context. The Swiss staging model for hypothermia uses clinical indicators to stage hypothermia. The proposed temperature range for clinical stage 1 is <35-32 °C (95-90 °F), for stage 2, <32-28 °C (<90-82 °F) for stage 3, <28-24 °C (<82-75 °F), and for stage 4 below 24 °C (75 °F). However, the evidence relating these temperature ranges to the clinical stages needs to be strengthened. Methods: Medline was used to retrieve data on as many cases of accidental hypothermia (core body temperature <35 °C (95 °F)) as possible. Cases of therapeutic or neonatal hypothermia and those with confounders or insufficient data were excluded. To evaluate the Swiss staging model for hypothermia, we estimated the percentage of those patients who were correctly classified and compared the theoretical with the observed ranges of temperatures for each clinical stage. The number of rescue collapses was also recorded. Results: We analysed 183 cases; the median temperature for the sample was 25.2 °C (IQR 22-28). 95 of the 183 patients (51.9 %; 95 % CI = 44.7 %-59.2 %) were correctly classified, while the temperature was overestimated in 36 patients (19.7 %; 95 % CI = 13.9 %-25.4 %). We observed important overlaps among the four stage groups with respect to core temperature, the lowest observed temperature being 28.1 °C for Stage 1, 22 °C for Stage 2, 19.3 °C for Stage 3, and 13.7 °C for stage 4. Predicting core body temperature using clinical indicators is a difficult task. Despite the inherent limitations of our study, it increases the strength of the evidence linking the clinical hypothermia stage to core temperature. Decreasing the thresholds of temperatures distinguishing the different stages would allow a reduction in the number of cases where body temperature is overestimated, avoiding some potentially negative consequences for the management of hypothermic patients.
Introduction: Whereas the use of helicopters as a rapid means toreach victims and to bring them t... more Introduction: Whereas the use of helicopters as a rapid means toreach victims and to bring them to a secure place is well-recognized,very few data are available about the value of winching physicians toprovide medical care for the victims directly on-site. We sought to studythe medical aspects of alpine helicopter rescue operations involving thewinching of an emergency physician to the victim.Methods: We retrospectively reviewed the medical reports of a singlehelicopter-based emergency medical service. Data from 1 January 2003to 31 December 2008 were analyzed. Cases with emergency callindicating that the victim was deceased were excluded. Data includedthe category (trauma or illnesses), and severity (NACA score) of theinjuries, along with the main medical procedures performed on site.Results: 9879 rescue missions were conducted between 1 January2003 and 31 December 2008. The 921 (9.3%) missions involvingwinching of the emergency physician were analysed. 840 (91%)patients suffered from trauma-related injuries. The cases of the 81 (9%)people presenting with medical emergencies were, when compared tothe trauma victims, significantly more severe according to the NACAindex (p <0.001). Overall, 246 (27%) patients had a severe injury orillness, namely, a potential or overt vital threat (NACA score between4-6, table 1). A total of 478 (52%) patients required administration ofmajor analgesics: fentanyl (443 patients; 48%), ketamine (42 patients;5%) or morphine (7 patients; 1%). The mean dose of fentanyl was 188micrograms (range 25-750, SD 127). Major medical interventions wereperformed 72 times on 39 (4%) patients (table 2).Conclusions: The severity of the patients' injuries or illnesses alongwith the high proportion of medical procedures performed directlyon-site validate emergency physician winching for advanced life supportprocedures and analgesia.
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, Jul 4, 2018
Background: Avalanche rescues mostly rely on helicopter emergency medical services (HEMS) and inc... more Background: Avalanche rescues mostly rely on helicopter emergency medical services (HEMS) and include technical rescue and complex medical situations under difficult conditions. The adequacy of avalanche victim management has been shown to be unexpectedly low, suggesting the need for quality improvement. We analyse the technical rescue and medical competency requirements of HEMS crewmembers for avalanche rescue missions, as well as their clinical exposure. The study aims to identify areas that should be the focus of future quality improvement efforts. Methods: This 15-year retrospective study of avalanche rescue by the Swiss HEMS Rega includes all missions where at least one patient had been caught by an avalanche, found within 24 h of the alarm being raised, and transported. Results: Our analyses included 422 missions (596 patients). Crews were frequently confronted with technical rescue aspects, including winching (29%) and patient location and extrication (48%), as well as multiple casualty accidents (32%). Forty-seven percent of the patients suffered potential or overt vital threat; 29% were in cardiac arrest. The on-site medical management of the victims required a large array of basic and advanced medical skills. Clinical exposure was low, as 56% of the physicians were involved in only one avalanche rescue mission over the study period. Conclusions: Our data provide a solid baseline measure and valuable starting point for improving our understanding of the challenges encountered during avalanche rescue missions. We further suggest QI interventions, that might be immediately useful for HEMS operating under similar settings. A coordinated approach using a consensus process to determine quality indicators and a minimal dataset for the specific setting of avalanche rescue would be the logical next step.
High Altitude Medicine & Biology, 2021
Background: Clinical indicators are used to stage hypothermia and to guide management of hypother... more Background: Clinical indicators are used to stage hypothermia and to guide management of hypothermic patients. We sought to better characterize the influence of hypothermia on vital signs, including level of consciousness, by studying cases of patients suffering from accidental hypothermia. Materials and Methods: We retrospectively included patients aged ‡18 years admitted to the hospital with a core temperature below 35°C. We identified the cases from a literature review and from a retrospective case series of hypothermic patients admitted to the hospital between 1994 and 2016. Patients who experienced cardiac arrest, as well as those with potential confounders such as concomitant diseases or intoxications, were excluded. Relationships between core temperature and heart rate, systolic blood pressure, respiratory rate, and level of consciousness were explored via correlations and regression. Results: Of the 305 cases reviewed, 216 met the criteria for inclusion. The mean temperature was 29.7°C -4.2°C (range 19.3°C-34.9°C). The relationships between temperature and each of the four vital signs were generally linear and significantly positive, with Spearman correlations for respiratory rate, heart rate, systolic blood pressure, and Glasgow Coma Score (GCS) of 0.29 ( p = 0.024), 0.44 ( p < 0.001), 0.47 ( p < 0.001), and 0.78 ( p < 0.001), respectively. Based on linear regression, the mean decrease of a vital sign associated with a 1°C decrease of temperature was estimated to be 0.50 minute -1 for respiratory rate, 2.54 minutes -1 for heart rate, 4.36 mmHg for systolic blood pressure, and 0.88 for GCS. Conclusions: There is a significant positive correlation between core temperature and heart rate, systolic blood pressure, respiratory rate, and GCS. The relationship between vital signs and temperature is generally linear. This knowledge might help clinicians make appropriate decisions when determining whether the clinical condition of a patient should be attributed to hypothermia. This could enhance clinical care and help to guide future research.
International Journal of Environmental Research and Public Health, 2022
Accidental hypothermia is an unintentional drop of core temperature below 35 °C. Annually, thousa... more Accidental hypothermia is an unintentional drop of core temperature below 35 °C. Annually, thousands die of primary hypothermia and an unknown number die of secondary hypothermia worldwide. Hypothermia can be expected in emergency patients in the prehospital phase. Injured and intoxicated patients cool quickly even in subtropical regions. Preventive measures are important to avoid hypothermia or cooling in ill or injured patients. Diagnosis and assessment of the risk of cardiac arrest are based on clinical signs and core temperature measurement when available. Hypothermic patients with risk factors for imminent cardiac arrest (temperature < 30 °C in young and healthy patients and <32 °C in elderly persons, or patients with multiple comorbidities), ventricular dysrhythmias, or systolic blood pressure < 90 mmHg) and hypothermic patients who are already in cardiac arrest, should be transferred directly to an extracorporeal life support (ECLS) centre. If a hypothermic patient a...
Introduction: Medical helicopter services provide several advantages,like the ability to perform ... more Introduction: Medical helicopter services provide several advantages,like the ability to perform air searches for lost victims, a rapid method ofshuttling rescue personnel and equipment to the victim, and the deliveryof early on-site advance medical care. When landing is not possible, therescuers can also be directly winched to the victim. As outdoor activitiesare increasing, few data are available about the type of accidentsleading to a rescue operation involving the use of the winch. We soughtto study the epidemiology and accidentology of such rescues.Methods: We retrospectively reviewed the medical reports of a singlehelicopter-based emergency medical service. Data from 1 January 2003to 31 December 2008 were analyzed. Cases with emergency callindicating that the victim was deceased were excluded. Data includedthe age and gender of the patients, the type of patients activitypreceeding the injury, the mecanism of injury, and the type of lesions(main diagnosis).Results: 9879 rescue ...
Resuscitation, 2021
Clinical staging of accidental hypothermia is used to guide out-of-hospital treatment and transpo... more Clinical staging of accidental hypothermia is used to guide out-of-hospital treatment and transport decisions. Most clinical systems utilize core temperature, by measurement or estimation, to stage hypothermia, despite the challenge of obtaining accurate field measurements. Recent studies have demonstrated that field estimation of core temperature is imprecise. We propose a revision of the original Swiss Staging system. The revised system uses the risk of cardiac arrest, instead of core temperature, to determine the staging level. Our revised system simplifies assessment by using the level of responsiveness, based on the AVPU scale, and by removing shivering as a stage-defining sign.
High Altitude Medicine & Biology, 2017
Pasquier, Mathieu, Louis Marxer, Hervé Duplain, Vincent Frochaux, Florence Selz, Pierre Métraille... more Pasquier, Mathieu, Louis Marxer, Hervé Duplain, Vincent Frochaux, Florence Selz, Pierre Métrailler, Grégoire Zen Ruffinen, and Olivier Hugli. Indications and outcomes of helicopter rescue missions in alpine mountain huts: A retrospective study. High Alt Med Biol 18:355-362, 2017. AIMS This retrospective study describes the rescue indications and outcome of patients rescued by helicopter from mountain huts in the Swiss Alps. The hospital course and operational data were also studied. RESULTS Among 14,872 helicopter rescue missions undertaken during the 10-year study period, 309 (2.1%) were performed from mountain huts at a mean altitude of 2794 ± 459 m. The mean age of the patients was 43 ± 16 and 66% were male. Thirty-four percent of the patients had a National Advisory Committee for Aeronautics score ≥3. Most (89%) patients were transported to hospital and only 12 (3.9%) patients had to stay more than 48 hours. Hospital diagnoses were extremely varied. Trauma accounted for 50% and altitude diseases for 7% of the cases. A winching procedure was performed 18 times and 19 missions included a night flight. CONCLUSIONS Helicopter rescue missions in mountain huts are a small part of all rescue missions. Our study provides a better understanding of medical emergencies arising in mountain huts. The diagnoses encountered are extremely varied in their type and severity. Hut keepers should be prepared for these situations as they will often have to act as first responders in the case of medical problems.
Resuscitation, 2019
Aims: Our goals were to describe and analyse the medical management and clinical course of avalan... more Aims: Our goals were to describe and analyse the medical management and clinical course of avalanche victims in cardiac arrest (CA), focusing on adherence to international recommendations on avalanche victims in CA regarding critical decisions. We retrospectively included all avalanche victims with CA from 1st January 2004 to 1st June 2016 in a single physician-staffed alpine helicopter emergency medical service. Data regarding cardiopulmonary resuscitation (CPR), transportation to hospital whilst undergoing CPR, and extracorporeal life support rewarming (ECLSR) for patients still in CA at hospital admission were abstracted from the prehospital and medical health records. Results: Sixty-six victims were included in this study; 31 (47%) were declared dead on scene. Of the remaining 35 victims, 7 (20%) had prehospital return of spontaneous circulation (ROSC), 28 (80%) were transported whilst undergoing CPR, 3 had hospital ROSC and 7 (28%) of the 25 patients with persistent CA at hospital underwent ECLSR. The medical management comprised 126 documented critical decisions, corresponding to guidelines in 117 (93%) decisions. None of the 66 studied patients survived to hospital discharge, and 7 (11%) were organ donors. The management of avalanche victims in CA respect current guidelines regarding the critical decisions, but no patient survived in this sample. The presence of a few cases with incorrect management and potential undertreatment suggests some room for improvement.
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Papers by Mathieu Pasquier