ABSTRACT
AIM: The purpose of this study was to evaluate the mechanism of high altitude pulmonary edema (HAPE) and high altitude acute response (HAAR). METHODS: Pulmonary function and partial oxygen pressure were measured in 10 patients with HAAR and 6 patients with HAPE before and after bronchoalveolar lavage (BAL),10 high altitude healthy volunteers were served as control subjects. RESULTS: The partial oxygen pressure of HAAR and HAPE significantly decreased before BAL compared with control; DLCO%, DLCO/VA%, PaO_2 of HAPE increased significantly [from 76.01%?6.29%, 150.30%?15.20%, (31.73?3.01) mmHg before BAL to 103.31%?9.23%, 176.04%?16.10%, (45.31?3.56) mmHg after BAL]. The above parameters were also changed in HAAR and controls, but had no statistical significance. CONCLUSION: High concentration of proteins and cells in BAL fluid for HAPE, gas exchange impairment and PaO_2 increase after BAL suggest accumulation of protein-rich fluid and cells in the alveolar space plays a crucial role in the development of HAPE.