Received: 20 November 2020
Accepted: 16 April 2021
First Online: 27 April 2021
: The study protocol was approved by the Institutional Review Board of Shanghai Children’s Medical Center (approval number: SCMCIRB-K2020049–1) and was registered with the Chinese Clinical Trial Registry (ChiCTR-2000033368). The anaesthesiologists involved in the study obtained written informed consent from the parents or their guardians after explaining the study protocol to them.
: Not applicable.
: The authors declare that they have no competing interests.