1 Department of Respiration, Jinan Central Hospital Affiliated to Shandong University, 105 JieFang Rd, Ji'nan, 250013, Shandong, China.
2 Department of Surgery, Qilu Hospital, Shandong University, Ji'nan, 250012, Shandong, China.
3 Department of General Surgery, The Fourth People's Hospital of Ji'nan, The Second Affiliated Hospital of Tai Shan Medical College, Ji'nan, 250031, China.
4 Department of Critical Care Medicine, Qilu Hospital, Shandong University, Ji'nan, 250012, Shandong, China.
5 Department of Respiration, Jinan Central Hospital Affiliated to Shandong University, 105 JieFang Rd, Ji'nan, 250013, Shandong, China. respirat@163.com.