No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Adaptación al aire enrarecido de las simas y cuevas. Estudio de laboratorio
Abstract
Introducción y objetivos: En el macizo del Garraf (Barcelona) las simas tienen una atmósfera con disminución de oxígeno y aumento de CO2 respecto a la normalidad. Para valorar el nivel de riesgo en la exploración de estas cavidades estudiamos a 19 espeleólogos (14 hombres y 5 mujeres) al realizar un ejercicio controlado, en una atmósfera hipercápnica, hipóxica y normobárica (15,2 ± 0,8% de O2 y 19.049 ± 299 ppmv de CO2). Métodos: El estudio se realizó en laboratorio mediante ergometría. Se realizaron 2 tests, uno en atmósfera normal (NN) y otro idéntico realizado en ambiente confinado (tienda de hipoxia), con aire enrarecido (HH). Se monitorizaron los siguientes parámetros: electrocardiograma, frecuencia cardíaca, saturación de oxígeno de la hemoglobina, lactato, glucemia capilar y presión arterial final. Resultados: Los voluntarios presentaron diferente sintomatología durante la prueba con aire enrarecido: sensación de calor (100%), mareo (47%), cefalea (3%), prurito ocular (21%), temblor en las manos (16%), extrasístoles (16,5%), respuesta hipertónica de la presión arterial (26%), taquicardia (158,5 ± 15,9 latidos/min en aire enrarecido frente a 148,7 ± 15,7 latidos/min en aire normal; p < 0,0002). Todos presentaron una disminución de la saturación de oxígeno (93,4 ± 3,4% en aire enrarecido frente a 97,7 ± 9,92% en aire normal; p < 0,00004). Discusión: Se observó una gran variabilidad individual en los síntomas y parámetros estudiados. En vista de los resultados, se recomienda no sobrepasar el umbral de 45.000 ppmv de CO2 en exploración espeleológica. Asimismo es conveniente una revisión médica de aptitud
... 2. Diferencias y similitudes con estudios previos: no se conocen estudios previos en ambiente confinado de origen natural, como son muchas simas del entorno mediterráneo. Hay que mencionar nuestro propio estudio, con voluntarios en ambiente reconstruido en tienda de entrenamiento 11 . También el estudio en medio laboral con maniquí en cámara de simulación 20 . ...
Estudio de la adaptación fisiológica en personas respirando aire enrarecido en una sima.
... El asmá tico debe prever có mo solucionar una crisis en cualquier situació n. Para que disfrute de su viaje es de suma importancia que evalú e el estado de su asma antes de salir y piense en la medicació n que debe y puede llevar, que averigü e si podrá adquirirla en el lugar adonde va, que se informe de los lugares de socorro o habitados má s cercanos, de la disponibilidad de medios para supervisar un traslado urgente (no necesariamente por una crisis de asma), etc. En la tabla 7 figuran los aspectos que se deben considerar cuando se viaja a lugares poco habitados 45 , así como las situaciones que requieren una evacuació n a un hospital. ...
Asthma is a highly prevalent chronic disease which, if not properly controlled, can limit the patient's activities and lifestyle. In recent decades, owing to the diffusion of educational materials, the application of clinical guidelines and, most importantly, the availability of effective pharmacological treatment, most patients with asthma are now able to lead normal lives. Significant social changes have also taken place during the same period, including more widespread pursuit of sporting activities and tourism. As a result of these changes, individuals with asthma can now participate in certain activities that were inconceivable for these patients only a few years ago, including winter sports, underwater activities, air flight, and travel to remote places with unusual environmental conditions (deserts, high mountain environments, and tropical regions). In spite of the publication of several studies on this subject, our understanding of the effects of these situations on patients with asthma is still limited. The Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) has decided to publish these recommendations based on the available evidence and expert opinion in order to provide information on this topic to both doctors and patients and to avert potentially dangerous situations that could endanger the lives of these patients.
Introduction: Due to the mandatory use of a mask in the context of the COVID-19 pandemic, and the authorization to do outdoor sports in Catalonia, we set out to evaluate the physiological impact of the hypoxia and hypercapnia generated by the mask during aerobic exercise.
Methods: 46 adolescent competitive athletes (35 women, 11 men) were evaluated. Measurements were taken of ambient air, at rest intra-mask, and during a stress test intra-mask. The concentration of O2 and CO2 intra-mask and the O2 Saturation were evaluated.
Results: The O2 of ambient air in the laboratory: 20.9%; Basal intra-mask O2: 18.0 ± 0.7% and intra-mask O2 during exercise: 17.4 ± 0.6% (p <0.0001). The CO2 was: 0.05 ± 0.01% environmental; baseline intra-mask: 1.31 ± 0.5%, and during exercise intra-mask: 1.76 ± 0.6% (p <0.0001). Baseline O2 saturation with mask was 98.4 ± 0.6% and immediately after exercise was 97.1 ± 2.8% (p <0.03). During the exercise intra-mask, 30% of the young athletes exceeded 2% of CO2 and 22% breathed oxygen with a concentration lower than 17%.
Conclusions: The use of masks generate hypercapnic hypoxia during exercise. One third of the subjects exceed the CO2 threshold of 2%.
Introduction: Due to the mandatory use of a mask, and the authorization to do outdoor sports in Catalonia, we try to assess the physiological impact of the hypercapnia hypoxia generated by the masks during aerobic sports practice.
Methods: Eight subjects (2 women) were assessed at baseline with and without a mask, and then a 21-flex test was performed following the Ruffier protocol with a mask. Control of HR (heart rate), concentration of O2 and CO2 inside the mask and SatO2. The test was carried out in ambient air in squares in the city of Barcelona.
Results: A decrease in O2 was recorded comparing the three conditions, baseline 20.9%, baseline mask 18.3%, post-exercise 17.8% (p <0.001). An increase in CO2 in the three preconditions (464, 14162, 17000 ppm; p <0.001). Basal saturation O2 was 97.6 ± 1.5% and post exercise 92.1 ± 4.12% (p 0.02).
Conclusions: The use of masks in athletes causes hypoxic and hypercapnic breathing, being more evident in effort. The use of masks during a short exercise with an intensity around 6-8 METS, decreases O2 by 3.7% and increases the CO2 concentration by 20%.
Asthma is a highly prevalent chronic disease which, if not properly controlled, can limit the patient's activities and lifestyle. In recent decades, owing to the diffusion of educational materials, the application of clinical guidelines and, most importantly, the availability of effective pharmacological treatment, most patients with asthma are now able to lead normal lives. Significant social changes have also taken place during the same period, including more widespread pursuit of sporting activities and tourism. As a result of these changes, individuals with asthma can now participate in certain activities that were inconceivable for these patients only a few years ago, including winter sports, underwater activities, air flight, and travel to remote places with unusual environmental conditions (deserts, high mountain environments, and tropical regions). In spite of the publication of several studies on this subject, our understanding of the effects of these situations on patients with asthma is still limited. The Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) has decided to publish these recommendations based on the available evidence and expert opinion in order to provide information on this topic to both doctors and patients and to avert potentially dangerous situations that could endanger the lives of these patients.
Des mesures en continu et des profils de teneurs en CO2 dans les cavités karstiques de l’Ardèche (Aven d’Orgnac, Grotte Chauvet) et des Pyrénées (Grottes de Gargas et de Niaux, Gouffre d’Esparros) ont montré : i) que les teneurs en CO2 présentent de fortes et parfois brutales variations saisonnières, ii) que les profils de CO2 dans l’espace sont fortement dépendants de la géométrie de la cavité qui se comporte souvent comme un système compartimenté.
L’évolution temporelle des teneurs en CO2 de l’air de la cavité est compatible avec un fonctionnement aérodynamique où se succèdent des phases de confinement avec des teneurs en CO2 qui tendent vers une valeur plafond, et des phases de déconfinement où les teneurs s’effondrent atteignant parfois celles de l’air extérieur. Les périodes de fortes teneurs peuvent être interprétées comme une mise à l’équilibre de l’air des cavités (conduits de grande taille) avec l’air issu du réseau fissural qui transite dans la zone d’infiltration des karsts en écoulement diphasique. Les teneurs isotopiques en 13C indiquent un CO2 d’origine biogénique; toutefois les teneurs identifiées dans les sols (rarement au dessus de 2%) ne sont pas suffisantes pour expliquer certaines teneurs mesurées sous terre (localement jusqu’à 4%). Une des hypothèses examinées explique la différence entre les valeurs mesurées dans l’air des sols et dans l’atmosphère des cavités par l’oxydation de matière organique durant son transit vers la profondeur; le déficit en O2, égal en %vol. à l’enrichissement en CO2, est un argument fort dans ce sens.
Les cavités karstiques se comportent ainsi comme des drains pour l’air issu du réseau fissural, les teneurs sont expliquées a tout moment par un mélange entre l’air extérieur (ventilation par les conduits) et l’air produit par le réseau fissural. Le fonctionnement aérodynamique des cavités nous apparaît être un paramètre directeur du concrétionnement en grotte, en effet l’existence de gradient en CO2 reste la condition essentielle du dépôt de carbonate de calcium.
A survey of CO 2 concentrations in the atmosphere of the Aven
d'Orgnac shows that aerodynamic transfer can be a major process in karst
system dynamics. The local meteorological conditions and the geometry of
the cavity govern exchanges between the cave atmosphere and the
exterior. Air enriched with biogenic CO 2 is transferred
through the microfissural network by diphasic infiltration from soil to
caves where it is continuously produced from rock walls. Analysis of the
aerodynamic emptying of confined zones and direct flow measurement give
a mean CO 2 production per surface unit of the cave rock
wall.
Pulmonary function, acid-base balance, renal electrolyte excretion, hematology, biorhythms and psychomotor test results were studied in six men during 30 days of exposure to a PICO2 of 14 torr (FICO2 = 0.02) with pre- and postexposure periods on air. Alveolar and arterial PCO2 increased and remained constant throughout the CO2 exposure (delta PACO2 = delta PACO2 = 2.5 torr); the rise in expiratory minute volume (delta VE = 60%) was related to the increased tidal volume. Oxygen uptake and carbon dioxide output increased about 10% because of the ventilatory work overload. Physiological dead space increased 8% without an alveolar-arterial PCO2 difference. Respiratory acidosis was mild (delta pH approximately or equal to 0.01) and the renal response was slight. There was no variation in plasma electrolytes, except a slight decrease in potassium. Red blood cell count decreased, showing a confinement effect. Adaptation to exercise was slightly impaired. Results of electrobiological and psychomotor tests and biorhythm evaluations showed no variation; application of these findings to CO2 exposure limits is discussed.
Twelve male volunteers inspired concentrations of carbon dioxide in oxygen ranging from 7% to 14% for periods of 10– 20 minutes. Respiratory minute volume, arterial pressure, heart rate, and plasma concentrations of epinephrine, norepinephrine and 17-OH corticosteroids were increased in every subject during hypercarbia. Abnormal cardiac rhythm was infrequently observed. Following substitution of oxygen for the carbon dioxide-oxygen mixture, the altered measurements returned to normal over a period of roughly 10 minutes. Neither marked hypotension nor cardiac arrhythmia was observed after correction of hypercarbia.
Submitted on January 8, 1960
More on bad air in cave American Caving Accidents
- W Mixon
Mixon W. More on bad air in cave. American Caving Accidents; NSS News, April 2000. p. 2.
Cent anys d'espeleologia a Catalunya
- Jm Miñarro
Miñarro JM. Cent anys d'espeleologia a Catalunya (1897-1997).
Map-Hiking Guidebook Scale 1:25.000. Bar-celona: Alpina
- Massís Del
Massís del Garraf. Map-Hiking Guidebook Scale 1:25.000. Bar-celona: Alpina.
Federació Catalana d'Espeleologia
- Barcelona
Barcelona: Federació Catalana d'Espeleologia; 2000. p. 12-37.
Preventive aspects of submarine medicine. Under-sea Biomedical Research
- Ke Schaefer
Schaefer KE. Preventive aspects of submarine medicine. Under-sea Biomedical Research. 1979;6:246.
Effets physiologiques chez l'homme du confinement de longue durée en atmosphère enrichie en dioxyde de carbone
- Radziszewski E L Giacomoni
- Guillerm
Radziszewski E, Giacomoni L, Guillerm R. Effets physiologiques chez l'homme du confinement de longue durée en atmosphère enrichie en dioxyde de carbone. Proceedings of a colloquium on Space and Sea. Marseille, France, 24-27 Novembre 1987, ESA SP-280 edit., Mars 1988. p. 19-23.
Le CO 2 dans l'atmosphère des grottes
- Bourges F D Hulst
- A Mangin
Bourges F, d'Hulst D, Mangin A. Le CO 2 dans l'atmosphère des grottes, sa place dans la dynamique des systèmes karstiques. Par F. Bourges, D. d'Hulst et A. Mangin. Communication à la Réu-nion des Sciences de la Terre de Brest du 31 mars au 3 avril 1998.
Perfil fisiològic i càrregues de tre-ball en espeleologia
- Balcells M Ja Prat
- Yzaguirre
Balcells M, Prat JA, Yzaguirre I. Perfil fisiològic i càrregues de tre-ball en espeleologia. Apunts. 1986;23:217-24.
Hypoxia — An invisible enemy. Guidelines for exerci-se tests, by the Working Group on Exercise Tests and Rehabili-tation of the French Society of Cardiology
- Bounhoure Jp
- Broustet Jp
- P Cahen
- Lesbre Jp
- B Letac
- Mallion
- Jm
Bounhoure JP, Broustet JP, Cahen P, Lesbre JP, Letac B, Mallion JM, et al. Hypoxia — An invisible enemy. Guidelines for exerci-se tests, by the Working Group on Exercise Tests and Rehabili-tation of the French Society of Cardiology. Arch Mal Coeur Vaiss. 1979;72 Spec 3:30.
Cave science topics: CO2 in caves
- James
James J, Dyson J. Cave science topics: CO 2 in caves. Caving In-ternational. 1981;13:54-9.
Evaluation of carbon dioxide and oxygen data in atmospheres using the Gibbs Triangle and Cave Air Index
- Ejm Halbert
Halbert EJM. Evaluation of carbon dioxide and oxygen data in
atmospheres using the Gibbs Triangle and Cave Air Index. Printed in Helictite. Journal of Australasian Cave Research. 1982;20:
60-8.
Bad air in de cavities of the Garraf Mountain. EspeleoCat. Federació Catalana d'Espeleologia
- I Yzaguirre
- R Cano
- G Burgos
- A Sanmartí
Yzaguirre I, Cano R, Burgos G, Sanmartí A. Bad air in de cavities of the Garraf Mountain. EspeleoCat. Federació Catalana
d'Espeleologia. 2007;5:53-5.
Radon and CO 2 as markers of cave atmosphere dynamics: evidence and pitfalls in underground confinement; application to cave conservation
- F Bourges
- A Mangin
- D Hulst
Bourges F, Mangin A, d'Hulst D. Radon and CO 2 as markers of
cave atmosphere dynamics: evidence and pitfalls in underground
confinement; application to cave conservation. Communication
au colloque Climate Changes: the Karst Record III. Montpellier
(France), 11-14 de mayo de 2003.
Evaluation of carbon dioxide and oxygen data in atmospheres using the Gibbs Triangle and Cave Air Index. Printed in Helictite
- Halbert
Radon and CO2 as markers of cave atmosphere dynamics: evidence and pitfalls in underground confinement; application to cave conservation
- Bourges
Cent anys d’espeleologia a Catalunya (1897-1997)
- Miñarro
Effets physiologiques chez l’homme du confinement de longue durée en atmosphère enrichie en dioxyde de carbone
- Radziszewski
Bad air in de cavities of the Garraf Mountain. EspeleoCat
- Yzaguirre
Preventive aspects of submarine medicine
- Schaefer
More on bad air in cave
- Mixon
Perfil fisiològic i càrregues de treball en espeleologia
- Balcells