title: Letter to the Editor.
authors.affiliation: Department Anesthesiology, Leiden University Medical Centre, Leiden, The Netherlands l.j.s.m.teppema@lumc.nl.
authors.forename: Luc J
authors.initials: LJ
authors.lastname: Teppema
authors.affiliation: Department Anesthesiology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Remco R
authors.initials: RR
authors.lastname: Berendsen