1 From the Department of Anaesthesiology, The Second Hospital of Anhui Medical University, and Key Laboratory of Anaesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, Anhui, China (JH, YZ) and Department of Anaesthesia and Perioperative Care and Centre for Cerebrovascular Research, University of California, San Francisco, San Francisco, California, USA (MM).