Rojas GA, Pérez NJ

Language: Spanish
References: 14
Page: 14-17
PDF size: 157.47 Kb.

ABSTRACT

Peak Expiratory Flow in healthy people increases proportionally to the altitude above sea level. The explanation for this phenomenon is controversial, but the most accepted is based on the Poiseuille equation of laminar flow, where air density appears in the denominator. On the other hand, spirometric results obtained by several authors also differ. We consider that the phenomenon must have a biologically dependent factor, and the opportunity to investigate this hypothesis appeared when the Asociacion alpina de Mexico successfully climbed the Broad Peak of the Himalayas, which is 8047 m above sea level. Material and methods. A member of this expedition was equipped with a portable, fixed orifice spirometer in order to self-measure his Peak Expiratory Flow (PEF) at different altitudes above sea level. Results: PEF increased from the measurement obtained in Mexico City, to its maximum value at the camp, 5100 m above sea level. Between this point and the summit, 8047 m above sea level, PEF no longer increased. During the descent, the PEF mirrored the ascending behavior, since it showed no important changes until the camp at 5100 m above sea level, after which it gradually decreased. Discussion and conclusions. Up to 5000 m above sea level, PEF is influenced by gas density, but above this altitude, the low partial pressure of inspired oxygen probably limits the PEF, because the energy requirement for this maneuver is not covered.

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