Effects of Changes in Ventilatory Pattern during Altitude Acclimatization
The frequent occurrence of periodic breathing (PB) during sleep in sojourners to high altitude has been well documented1–6. PB is thought to be most pronounced during the first few nights at altitude and to diminish over time as the process of acclimatization takes its course4. However, in recent studies conducted at extreme altitudes3, 5, 6, it was found that PB and recurrent apneas persisted even after the subjects tested had been at the altitudes in question for more than 3 weeks. Weil et al.2 reported the common occurrence of “undulating respirations of varying amplitude but without true apnea” in long-term high-altitude residents. Thus, it is probably safe to conclude that there is a tendency for the regularization of breathing pattern with altitude acclimatization, although in some individuals PB is never completely eliminated.
KeywordsBreathing Pattern Periodic Breathing Tidal Breathing Ventilatory Pattern Pressure Cost
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- 2.Weil, J.V., M.H. Kryger and C.H. Scoggin. Sleep and breathing at high altitude. In: Sleep Apnea Syndromes, ed. C. Guilleminault and W.C. Dement, New York: Alan R. Liss, 1978, pp. 119–135.Google Scholar
- 6.Anholm, J.D., A.C.P. Powles, R. Downey III, CS. Houston, J.R. Sutton, M.H. Bonnet and A. Cymerman. Operation Everest II: Arterial oxygen saturation and sleep at extreme simulated altitude. Am. Rev. Respir. Dis. (in press).Google Scholar
- 8.Khoo, M.C.K. The noninvasive estimation of cardiopulmonary parameters. Ph.D. Dissertation, Boston, MA, 1981.Google Scholar
- 11.Milic-Emili, J. Work of breathing. In: The Lung: Scientific Foundations, ed. R.G. Crystal, J.B. West et al., pp.1065–1075, Raven Press, New York, 1991.Google Scholar