Department of Intensive Care Medicine, Chongqing Health Centre for Women and Children, Chongqing, 120 Longshan Road, Chongqing 400013, China. Department of Emergency, Chongqing Health Centre for Women and Children, Chongqing, 120 Longshan Road, Chongqing 400013, China. Department of Intensive Care Medicine, Chongqing Health Centre for Women and Children, Chongqing, 120 Longshan Road, Chongqing 400013, China. Electronic address: yaozongzhang@vip.126.com.