• MeSH
• farmaceutická technologie MeSH
• laviny * MeSH
• prášky, zásypy, pudry MeSH
• velikost částic MeSH
• Publikační typ
• časopisecké články MeSH

Outdoor breathing trials with simulated avalanche snow are fundamental for the research of the gas exchange under avalanche snow, which supports the development of the international resuscitation guidelines. However, these studies have to face numerous problems, including unstable weather and variable snow properties. This pilot study examines a mineral material perlite as a potential snow model for studies of ventilation and gas exchange parameters. Thirteen male subjects underwent three breathing phases-into snow, wet perlite and dry perlite. The resulting trends of gas exchange parameters in all tested materials were similar and when there was a significant difference observed, the trends in the parameters for high density snow used in the study lay in between the trends in dry and wet perlite. These findings, together with its stability and accessibility year-round, make perlite a potential avalanche snow model material. Perlite seems suitable especially for simulation and preparation of breathing trials assessing gas exchange under avalanche snow, and potentially for testing of new avalanche safety equipment before their validation in real snow.The study was registered in ClinicalTrials.gov on January 22, 2018; the registration number is NCT03413878.

• MeSH
• dospělí MeSH
• dvojitá slepá metoda MeSH
• dýchání * MeSH
• kardiopulmonální resuscitace metody   MeSH
• klinické křížové studie MeSH
• laviny * MeSH
• lidé MeSH
• mladý dospělý MeSH
• oxid hlinitý * MeSH
• oxid křemičitý * MeSH
• pilotní projekty MeSH
• prospektivní studie MeSH
• sníh * MeSH
• teoretické modely MeSH
• tréninková simulace MeSH
• výměna plynů v plicích fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Geografické názvy
• Česká republika MeSH

Terrain experiments for avalanche survival research require appropriate snow conditions, which may not be available year round. To prepare these experiments and test the protocol, it might be advantageous to test them in a laboratory with a snow model. The aim of the study was to find a material that can be used to simulate snow for studying gas exchange of a person covered with avalanche snow. Three loose porous materials (perlite, wood shavings and polystyrene) were tested in two forms—dry and moisturized. Each volunteer underwent six phases of the experiment in random order (three materials, each dry and moisturized) during experimental breathing into the tested materials. Physiological parameters and fractions of oxygen and carbon dioxide in the airways were recorded continuously. All the materials selected as possible models of the avalanche snow negatively affected gas exchange during the breathing of the volunteers in a very similar extent. The time courses of the recorded parameters were very similar and were bordered from one side by the wet perlite and from the other side by the dry perlite. Therefore, other tested materials may be substituted with perlite with an appropriate water content. From all the tested materials, perlite is the best to simulate avalanche snow because of its homogeneity, reproducibility and easy manipulation.

• MeSH
• dýchání MeSH
• hyperkapnie * MeSH
• laviny * MeSH
• lidé MeSH
• respirační insuficience MeSH
• testování materiálů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

• MeSH
• horolezectví * MeSH
• kongresy jako téma MeSH
• laviny MeSH
• lidé MeSH
• omrzliny terapie   MeSH
• sportovní úrazy MeSH
• urgentní lékařství * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• zprávy MeSH

During breathing experiments in avalanche snow, measurement of CO2 is often conducted in order to monitor the volunteers or as an endpoint of the trials. From the measured CO2 curves, monitors calculate end-tidal CO2 concentrations (EtCO2). The aim of the study is to investigate, whether Datex-Ohmeda S/5 anesthesia monitor evaluates EtCO2 and other parameters of breathing gas correctly, otherwise to characterize the occurrence of the error and to find out a possible cause of error. Data from a real experiment aimed at investigation of work of breathing into snow in the presence and absence of an artificial air pocket were used to study precision of the monitor. The data were evaluated in Matlab environment. The analysis found that the average error of EtCO2 evaluation occurred in 39% and in 30 % of the total experimental time of breathing with and without the air pocket respectively (range from 13% to 93% of time). Breathing experiments with simulated snow were conducted in order to find the cause of the error. The error occurs immediately after a significant increase of CO2 in the breathing circuit as a consequence of expired gas rebreathing and is independent on other breathing parameters related to a change in breathing pattern. The experiment confirmed that a newer model CARESCAPE B650 monitor is prone to this error as well. The last experiment conducted with a standard anesthesia machine but with removed CO2 absorbing soda lime confirmed, that the error occurs even in a standard clinical setup, which might cause a wrong diagnoses or might harm a volunteer or a patient.

• MeSH
• dospělí MeSH
• dýchání MeSH
• hyperkapnie * patofyziologie   MeSH
• laviny MeSH
• lidé MeSH
• mladý dospělý MeSH
• oxid uhličitý analýza   MeSH
• sníh MeSH
• výzkum MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• práce podpořená grantem MeSH

Presence of an air pocket and its size play an important role in survival of victims buried in the avalanche snow. Even small air pockets facilitate breathing. We hypothesize that the size of the air pocket significantly affects the airflow resistance and work of breathing. The aims of the study are (1) to investigate the effect of the presence of an air pocket on gas exchange and work of breathing in subjects breathing into the simulated avalanche snow and (2) to test whether it is possible to breathe with no air pocket. The prospective interventional double-blinded study involved 12 male volunteers, from which 10 completed the whole protocol. Each volunteer underwent two phases of the experiment in a random order: phase "AP"--breathing into the snow with a one-liter air pocket, and phase "NP"--breathing into the snow with no air pocket. Physiological parameters, fractions of oxygen and carbon dioxide in the airways and work of breathing expressed as pressure-time product were recorded continuously. The main finding of the study is that it is possible to breath in the avalanche snow even with no air pocket (0 L volume), but breathing under this condition is associated with significantly increased work of breathing. The significant differences were initially observed for end-tidal values of the respiratory gases (EtO2 and EtCO2) and peripheral oxygen saturation (SpO2) between AP and NP phases, whereas significant differences in inspiratory fractions occurred much later (for FIO2) or never (for FICO2). The limiting factor in no air pocket conditions is excessive increase in work of breathing that induces increase in metabolism accompanied by higher oxygen consumption and carbon dioxide production. The presence of even a small air pocket reduces significantly the work of breathing.

• MeSH
• asfyxie patofyziologie   prevence a kontrola   MeSH
• dechová práce fyziologie   MeSH
• dechový objem fyziologie   MeSH
• dospělí MeSH
• dvojitá slepá metoda MeSH
• hyperkapnie patofyziologie   MeSH
• hypoxie patofyziologie   MeSH
• inspirační rezervní objem fyziologie   MeSH
• katastrofy * MeSH
• klinické křížové studie MeSH
• kyslík fyziologie   MeSH
• laviny * MeSH
• lidé MeSH
• monitorování fyziologických funkcí MeSH
• oxid uhličitý fyziologie   MeSH
• sníh MeSH
• zdraví dobrovolníci pro lékařské studie MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH

AIM: Asphyxia is the primary cause of death among avalanche victims. Avalanche airbags can lower mortality by directly reducing grade of burial, the single most important factor for survival. This study aims to provide an updated perspective on the effectiveness of this safety device. METHODS: A retrospective analysis of avalanche accidents involving at least one airbag user between 1994 and 2012 in Austria, Canada, France, Norway, Slovakia, Switzerland and the United States. A multivariate analysis was used to calculate adjusted absolute risk reduction and estimate the effectiveness of airbags on grade of burial and mortality. A univariate analysis was used to examine causes of non-deployment. RESULTS: Binomial linear regression models showed main effects for airbag use, avalanche size and injuries on critical burial, and for grade of burial, injuries and avalanche size on mortality. The adjusted risk of critical burial is 47% with non-inflated airbags and 20% with inflated airbags. The adjusted mortality is 44% for critically buried victims and 3% for non-critically buried victims. The adjusted absolute mortality reduction for inflated airbags is -11 percentage points (22% to 11%; 95% confidence interval: -4 to -18 percentage points) and adjusted risk ratio is 0.51 (95% confidence interval: 0.29 to 0.72). Overall non-inflation rate is 20%, 60% of which is attributed to deployment failure by the user. CONCLUSION: Although the impact on survival is smaller than previously reported, these results confirm the effectiveness of airbags. Non-deployment remains the most considerable limitation to effectiveness. Development of standardized data collection protocols is encouraged to facilitate further research.

• MeSH
• airbagy * MeSH
• asfyxie mortalita   prevence a kontrola   MeSH
• laviny * MeSH
• lidé MeSH
• multivariační analýza MeSH
• retrospektivní studie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH

• MeSH
• laviny MeSH
• lidé MeSH
• pomoc v nouzi MeSH
• psi MeSH
• roční období MeSH
• úrazy a nehody statistika a číselné údaje   MeSH
• urgentní zdravotnické služby MeSH
• záchranná práce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• psi MeSH
• zvířata MeSH

• MeSH
• asfyxie MeSH
• financování organizované MeSH
• hyperkapnie MeSH
• hypotermie MeSH
• hypoxie MeSH
• laviny klasifikace   mortalita   MeSH
• lidé MeSH
• přežití fyziologie   MeSH
• statistika jako téma MeSH
• výzkum MeSH
• Check Tag
• lidé MeSH

• Klíčová slova
• zdravotnická záchranná služba, třídění, zástava oběhu,
• MeSH
• časové faktory MeSH
• dospělí MeSH
• financování organizované MeSH
• horolezectví zranění   MeSH
• hypotermie diagnóza   ošetřování   terapie   MeSH
• laviny MeSH
• lidé MeSH
• medicína katastrof metody   organizace a řízení   MeSH
• medicína v divočině metody   organizace a řízení   MeSH
• mimotělní oběh metody   přístrojové vybavení   využití   MeSH
• polytrauma MeSH
• první pomoc metody   ošetřování   MeSH
• sportovní úrazy diagnóza   ošetřování   terapie   MeSH
• sporty na sněhu zranění   MeSH
• srdeční zástava diagnóza   komplikace   terapie   MeSH
• tělesná teplota MeSH
• třídění pacientů metody   využití   MeSH
• urgentní zdravotnické služby metody   organizace a řízení   využití   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• kazuistiky MeSH