Abstract
Early desaturation during acute simulated HA exposure is significantly related to AMS development.
Aim: To study the hypoxic profile and the AMS development during the ascent from Alagna (A), 1200m, to Capanna Regina Margherita (M), 4559m, with an overnight stay in Rifugio Gnifetti (G), 3647m.
Methods: 44 (8F) subjects (age 18-67) were recruited in A, equipped with a 24-h data memory pulse oximeter (Pulsox-3Si, Minolta) and asked to fill the Lake Louise questionnaire (LL).
Results: 15 subjects (34%) showed a LL score ≥3 (AMS+). In A SpO2 data were similar but during HA exposure AMS+ group had a significantly lower SpO2: at Punta Indren (I), 3275m after a 45min cable car ascent; in G during 3h rest and the subsequent night. There was no significant difference during the 2h exercise (Ex1) to reach G.
Table 1. Spo2% mean
In G, AMS+ always spent more time with a lower SpO2.
Table 2. % of total time
As regard the ascent to M (Ex2), data of only 24 subjects are available, (5 AMS+; 19 AMS–). None of AMS- group developed AMS during the climb to M. AMS+ had a significantly lower SpO2 as compared to AMS- but the sample is too small to draw definitive conclusions.
Conclusion: AMS development is significantly related to a more severe O2 desaturation at rest and during the night; the more severe hypoxemia occurs very early at the beginning of HA exposure as already shown during hypoxia simulated test (Loeppky '08 and Burtscher '04) (*p<0,05).
- © 2011 ERS
