title: In reply.
authors.affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, USA. Electronic address: eriley@stanford.edu.
authors.forename: E T
authors.initials: ET
authors.lastname: Riley
authors.affiliation: Department of Anesthesiology, UNC Medical Center, Chapel Hill, USA.
authors.forename: C P
authors.initials: CP
authors.lastname: McKenzie
authors.affiliation: Department of Anesthesiology, UNC Medical Center,, Chapel Hill, USA.
authors.forename: B
authors.initials: B
authors.lastname: Cobb
authors.affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, , Stanford, USA.
authors.forename: B
authors.initials: B
authors.lastname: Carvalho