title: Reply to Cantrell and Nordt.
authors.affiliation: a Department of Emergency Medicine , Queen's University , Kingston , Ontario , Canada.
authors.forename: R Mason
authors.initials: RM
authors.lastname: Curtis
authors.affiliation: a Department of Emergency Medicine , Queen's University , Kingston , Ontario , Canada.
authors.forename: Marco L A
authors.initials: ML
authors.lastname: Sivilotti