RT Journal Article SR Electronic T1 Reply to Dr Johnston JF Regional Anesthesia & Pain Medicine JO Reg Anesth Pain Med FD BMJ Publishing Group Ltd SP 394 OP 395 DO 10.1097/AAP.0000000000000271 VO 40 IS 4 A1 Petrar, Steven D. A1 Seltenrich, Michael E. A1 Head, Stephen J. A1 Schwarz, Stephan K. W. YR 2015 UL http://rapm.bmj.com/content/40/4/394.3.abstract AB