Funding for this research was provided by:
Japan Society for the Promotion of Science (18K16544, 18K08923, 19K09414)
The Japanese Society of Anesthesiologists (2018 grant A18-3)
Received: 4 June 2019
Accepted: 22 July 2019
First Online: 1 August 2019
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board at Ohta Nishinouchi Hospital (No. 3060) on 18 June 2018. The committee waived the need for patient consent.
: Not applicable.
: The authors declare that they have no competing interests.