1. Department of Anesthesiology, Huai’an First People’s Hospital, Nanjing Medical University, Huai’an, Jiangsu, China (mainland)
2. Department of Anesthesiology, Weifang People’s Hospital, Weifang, Shandong, China (mainland)
3. Department of Anesthesiology, Huaiyin Hospital of Huaian City, Huai’an, Jiangsu, China (mainland)