RT Journal Article SR Electronic T1 Editor’s comments JF Regional Anesthesia & Pain Medicine JO Reg Anesth Pain Med FD BMJ Publishing Group Ltd SP rapm-2021-102829 DO 10.1136/rapm-2021-102829 A1 Brian D Sites A1 Matthew Davis YR 2021 UL http://rapm.bmj.com/content/early/2021/05/21/rapm-2021-102829.abstract