Arterial blood gas analysis at 4559 m

SubjectsPaO2 mmHgPaCO2 mmHgPA–aO2 mmHg
No AMS1439.6±4.530.0±3.67.9±3.7
Mild AMS1937.6±4.330.7±4.09.3±4.3
Moderate–severe AMS1033.9±4.0*31.1±2.812.5±4.5*

Analysis of arterial blood obtained from a femoral artery a few hours after arrival at the Margherita hut (Monte Rosa, Italy) in subjects with no acute mountain sickness (AMS), mild AMS (score 2–3 points according to Hackett et al. [103]), moderate-to-severe AMS (>3 points) or high-altitude pulmonary oedema (HAPE) (verified using chest radiography). PaO2: arterial oxygen tension; PaCO2: arterial carbon dioxide tension; PA–aO2: alveolar–arterial oxygen tension difference. *: p<0.05, compared with mild and no AMS; ***: p<0.001, compared with all groups. Data from [32].