Abstract
A very high ventilatory response to hypoxia is believed necessary to reach extreme altitude without oxygen. Alternatively, the excessive ventilation could be counterproductive by exhausting the ventilatory reserve early on. To test these alternatives, 11 elite climbers (2004 Everest-K2 Italian Expedition) were evaluated as follows: 1) at sea level, and 2) at 5,200 m, after 15 days of acclimatisation at altitude. Resting oxygen saturation, minute ventilation, breathing rate, hypoxic ventilatory response, maximal voluntary ventilation, ventilatory reserve (at oxygen saturation=70%) and two indices of ventilatory efficiency were measured. Everest and K2 summits were reached 29 and 61 days, respectively, after the last measurement. Five climbers summited without oxygen, the other six did not, or succeeded with oxygen (two climbers). At sea level, all data were similar. At 5,200 m, the five summiters without oxygen showed lower resting minute ventilation, breathing rate and ventilatory response to hypoxia, and higher ventilatory reserve and ventilatory efficiency, compared to the other climbers. Thus, the more successful climbers had smaller responses to hypoxia during acclimatisation to 5,200 m, but, as a result, had greater available reserve for the summit. A less sensitive hypoxic response and a greater ventilatory efficiency might increase ventilatory reserve and allow sustainable ventilation in the extreme hypoxia at the summit. Copyright
| Original language | English |
|---|---|
| Pages (from-to) | 165-171 |
| Number of pages | 7 |
| Journal | European Respiratory Journal |
| Volume | 27 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 2006 |
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Keywords
- Altitude
- Hypoxia
- Ventilation
- Ventilatory control
- Ventilatory efficiency
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
Cite this
Hypoxic ventilatory response in successful extreme altitude climbers. / Bernardi, L.; Schneider, A.; Pomidori, L.; Paolucci, E.; Cogo, A.
In: European Respiratory Journal, Vol. 27, No. 1, 01.2006, p. 165-171.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Hypoxic ventilatory response in successful extreme altitude climbers
AU - Bernardi, L.
AU - Schneider, A.
AU - Pomidori, L.
AU - Paolucci, E.
AU - Cogo, A.
PY - 2006/1
Y1 - 2006/1
N2 - A very high ventilatory response to hypoxia is believed necessary to reach extreme altitude without oxygen. Alternatively, the excessive ventilation could be counterproductive by exhausting the ventilatory reserve early on. To test these alternatives, 11 elite climbers (2004 Everest-K2 Italian Expedition) were evaluated as follows: 1) at sea level, and 2) at 5,200 m, after 15 days of acclimatisation at altitude. Resting oxygen saturation, minute ventilation, breathing rate, hypoxic ventilatory response, maximal voluntary ventilation, ventilatory reserve (at oxygen saturation=70%) and two indices of ventilatory efficiency were measured. Everest and K2 summits were reached 29 and 61 days, respectively, after the last measurement. Five climbers summited without oxygen, the other six did not, or succeeded with oxygen (two climbers). At sea level, all data were similar. At 5,200 m, the five summiters without oxygen showed lower resting minute ventilation, breathing rate and ventilatory response to hypoxia, and higher ventilatory reserve and ventilatory efficiency, compared to the other climbers. Thus, the more successful climbers had smaller responses to hypoxia during acclimatisation to 5,200 m, but, as a result, had greater available reserve for the summit. A less sensitive hypoxic response and a greater ventilatory efficiency might increase ventilatory reserve and allow sustainable ventilation in the extreme hypoxia at the summit. Copyright
AB - A very high ventilatory response to hypoxia is believed necessary to reach extreme altitude without oxygen. Alternatively, the excessive ventilation could be counterproductive by exhausting the ventilatory reserve early on. To test these alternatives, 11 elite climbers (2004 Everest-K2 Italian Expedition) were evaluated as follows: 1) at sea level, and 2) at 5,200 m, after 15 days of acclimatisation at altitude. Resting oxygen saturation, minute ventilation, breathing rate, hypoxic ventilatory response, maximal voluntary ventilation, ventilatory reserve (at oxygen saturation=70%) and two indices of ventilatory efficiency were measured. Everest and K2 summits were reached 29 and 61 days, respectively, after the last measurement. Five climbers summited without oxygen, the other six did not, or succeeded with oxygen (two climbers). At sea level, all data were similar. At 5,200 m, the five summiters without oxygen showed lower resting minute ventilation, breathing rate and ventilatory response to hypoxia, and higher ventilatory reserve and ventilatory efficiency, compared to the other climbers. Thus, the more successful climbers had smaller responses to hypoxia during acclimatisation to 5,200 m, but, as a result, had greater available reserve for the summit. A less sensitive hypoxic response and a greater ventilatory efficiency might increase ventilatory reserve and allow sustainable ventilation in the extreme hypoxia at the summit. Copyright
KW - Altitude
KW - Hypoxia
KW - Ventilation
KW - Ventilatory control
KW - Ventilatory efficiency
UR - http://www.scopus.com/inward/record.url?scp=30744447965&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=30744447965&partnerID=8YFLogxK
U2 - 10.1183/09031936.06.00015805
DO - 10.1183/09031936.06.00015805
M3 - Article
C2 - 16387950
AN - SCOPUS:30744447965
VL - 27
SP - 165
EP - 171
JO - European Journal of Respiratory Diseases
JF - European Journal of Respiratory Diseases
SN - 0903-1936
IS - 1
ER -