1. Department of Thoracic Surgery, First Hospital of Qinhuangdao, Qinhuangdao, Hebei 066000, P.R. China
2. Department of Anesthesiology, First Hospital of Qinhuangdao, Qinhuangdao, Hebei 066000, P.R. China
3. Department of Thoracic Surgery, First Hospital of Qinhuangdao, Qinhuangdao, Hebei 066000, P.R. China
4. Department of Nursing, First Hospital of Qinhuangdao, Qinhuangdao, Hebei 066000, P.R. China