B-lines after ascent to high altitude by flight vs. climbing

Giacomo Strapazzon, Emily Procter, Roberto Vezzaro, Georg Hofer, Tomas Dal Cappello, Michael Pohl, Kai Schenk, Simon Rauch, Hermann Brugger


Objective: To compare the incidence of B-lines and changes in clinical parameters in participants acutely exposed to hypobaric hypoxia after ascending to high altitude by flight vs. climbing.

Study design: Cross-sectional.

Methods: Chest ultrasonography, clinical parameters (SpO2, HR and BR) and signs and symptoms of high altitude illnesses were assessed by blinded investigators in 40 participants after ascent to 3830 m. 19 participants were flown by helicopter, 14 participants slept at 3029 m the night before ascending and 7 participants climbed nonstop.

Results: The mean number of B-lines in participants who were flown by helicopter was similar to the number in participants who ascended by climbing (7.1±5.7 vs. 7.9±6.0, P=0.686). The two groups did not differ in LLS, SpO2 or BR despite that HR showed a marginally significant difference.

Conclusions: B-lines after exposure to hypobaric hypoxia seem to be independent of the physical effort to ascend. It is important to further investigate B-lines in subjects exposed to hypobaric hypoxia for work and training purposes, also in the aerospace field.


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