Abstract
Recent data demonstrate that the magnitude of the heat loss that occurs from the respiratory tract during exercise correlates with the degree of post-exertional obstruction that develops in asthmatics. Respiratory heat loss relates directly to the minute ventilation and heat capacity of the inspired gas and inversely to its water content and temperature. Because it has been shown that inhaling 100% oxygen during exercise blunts the obstructive response, we wondered if this effect could be accounted for by differing values of heat exchange with air and oxygen breathing. To examine this question, we studied 10 asthmatics by measuring multiple aspects of pulmonary mechanics before and after four bouts of exhausting leg work during which the subjects inhaled either air or oxygen conditioned to provide widely differing thermal burdens on their airways. Under all inspired gas conditions, oxygen breathing produced significantly less obstruction than air. Minute ventilation was also significantly less with oxygen as was the total heat lost. As the latter fell, so did the magnitude of the postexercise obstruction. When the differences in ventilation and respiratory heat loss between air and oxygen were eliminated by eucapnic hyperventilation, the differences in the obstructive responses also disappeared. Thus, the effects of hyperoxia on exercise-induced asthma can be accounteed for solely by alterations in heat exchange.
Full text
PDF








Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BRISCOE W. A., DUBOIS A. B. The relationship between airway resistance, airway conductance and lung volume in subjects of different age and body size. J Clin Invest. 1958 Sep;37(9):1279–1285. doi: 10.1172/JCI103715. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bar-Or O., Neuman I., Dotan R. Effects of dry and humid climates on exercise-induced asthma in children and preadolescents. J Allergy Clin Immunol. 1977 Sep;60(3):163–168. doi: 10.1016/0091-6749(77)90119-1. [DOI] [PubMed] [Google Scholar]
- Chan-Yeung M. M., Vyas M. N., Grzybowski S. Exercise-induced asthma. Am Rev Respir Dis. 1971 Dec;104(6):915–923. doi: 10.1164/arrd.1971.104.6.915. [DOI] [PubMed] [Google Scholar]
- Chen W. Y., Horton D. J. Heat and water loss from the airways and exercise-induced asthma. Respiration. 1977;34(6):305–313. doi: 10.1159/000193842. [DOI] [PubMed] [Google Scholar]
- DUBOIS A. B., BOTELHO S. Y., BEDELL G. N., MARSHALL R., COMROE J. H., Jr A rapid plethysmographic method for measuring thoracic gas volume: a comparison with a nitrogen washout method for measuring functional residual capacity in normal subjects. J Clin Invest. 1956 Mar;35(3):322–326. doi: 10.1172/JCI103281. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Deal E. C., Jr, McFadden E. R., Jr, Ingram R. H., Jr, Jaeger J. J. Hyperpnea and heat flux: initial reaction sequence in exercise-induced asthma. J Appl Physiol Respir Environ Exerc Physiol. 1979 Mar;46(3):476–483. doi: 10.1152/jappl.1979.46.3.476. [DOI] [PubMed] [Google Scholar]
- Deal E. C., Jr, McFadden E. R., Jr, Ingram R. H., Jr, Strauss R. H., Jaeger J. J. Role of respiratory heat exchange in production of exercise-induced asthma. J Appl Physiol Respir Environ Exerc Physiol. 1979 Mar;46(3):467–475. doi: 10.1152/jappl.1979.46.3.467. [DOI] [PubMed] [Google Scholar]
- Fisher H. K., Holton P., Buxton R. S., Nadel J. A. Resistance to breathing during exercise-induced asthma attacks. Am Rev Respir Dis. 1970 Jun;101(6):885–896. doi: 10.1164/arrd.1970.101.6.885. [DOI] [PubMed] [Google Scholar]
- Herxheimer H. Skin sensitivity to flour in bakers' apprentices. Lancet. 1967 Jan 14;1(7481):83–84. doi: 10.1016/s0140-6736(67)92479-8. [DOI] [PubMed] [Google Scholar]
- McFadden E. R., Jr, Ingram R. H., Jr, Haynes R. L., Wellman J. J. Predominant site of flow limitation and mechanisms of postexertional asthma. J Appl Physiol Respir Environ Exerc Physiol. 1977 May;42(5):746–752. doi: 10.1152/jappl.1977.42.5.746. [DOI] [PubMed] [Google Scholar]
- McFadden E. R., Jr, Stearns D. R., Ingram R. H., Jr, Leith D. E. Relative contributions of hypocarbia and hyperpnea as mechanisms in postexercise asthma. J Appl Physiol Respir Environ Exerc Physiol. 1977 Jan;42(1):22–27. doi: 10.1152/jappl.1977.42.1.22. [DOI] [PubMed] [Google Scholar]
- NEWHOUSE M. T., BECKLAKE M. R., MACKLEM P. T., MCGREGOR M. EFFECT OF ALTERATIONS IN END-TIDAL CO2 TENSION ON FLOW RESISTANCE. J Appl Physiol. 1964 Jul;19:745–749. doi: 10.1152/jappl.1964.19.4.745. [DOI] [PubMed] [Google Scholar]
- Schiffman P. L., Ryan A., Whipp B. J., Hansen J. E., Wasserman K. Hyperoxic attenuation of exercise-induced bronchospasm in asthmatics. J Clin Invest. 1979 Jan;63(1):30–37. doi: 10.1172/JCI109274. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Simonsson B. G., Skoogh B. E., Ekström-Jodal B. Exercise-induced airways constriction. Thorax. 1972 Mar;27(2):169–180. doi: 10.1136/thx.27.2.169. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sly R. M. Induction of increased airway obstruction by exercise or voluntary hyperventilation in asthmatic children. Ann Allergy. 1972 Dec;30(12):668–675. [PubMed] [Google Scholar]
- Strauss R. H., Ingram R. H., Jr, McFadden E. R., Jr A critical assessment of the roles of circulating hydrogen ion and lactate in the production of exercise-induced asthma. J Clin Invest. 1977 Sep;60(3):658–664. doi: 10.1172/JCI108817. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Strauss R. H., McFadden E. R., Jr, Ingram R. H., Jr, Deal E. C., Jr, Jaeger J. J. Influence of heat and humidity on the airway obstruction induced by exercise in asthma. J Clin Invest. 1978 Feb;61(2):433–440. doi: 10.1172/JCI108954. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Strauss R. H., McFadden E. R., Jr, Ingram R. H., Jr, Jaeger J. J. Enhancement of exercise-induced asthma by cold air. N Engl J Med. 1977 Oct 6;297(14):743–747. doi: 10.1056/NEJM197710062971402. [DOI] [PubMed] [Google Scholar]
- Sykes T. W., Haynes R. L., McFadden E. R., Jr On line determination of lung volumes by plethysmography and digital computer. Am Rev Respir Dis. 1977 Apr;115(4):581–585. doi: 10.1164/arrd.1977.115.4.581. [DOI] [PubMed] [Google Scholar]
