1. Department of Anesthesia
2. Southwest Hospital
3. the Third Military Medical University
4. Chongqing 400038
5. China
6. Institute of Respiratory Disease
7. Xinqiao Hospital
8. Chongqing 400037
9. Université P. Sabatier Toulouse III and CNRS
10. LBCMCP
11. 31062 Toulouse Cedex 9
12. France