title: The difficulty of measuring the measurable.
authors.affiliation: Intensive Care Unit Department of Intensive Care Medicine Ente Ospedaliero Cantonale Ospedale San Giovanni Bellinzona, Switzerland andreas.perren@eoc.ch.
authors.forename: Andreas
authors.initials: A
authors.lastname: Perren
authors.affiliation: Intensive Care Unit Department of Intensive Care Medicine Ente Ospedaliero Cantonale Ospedale Civico Lugano, Switzerland.
authors.forename: Paolo
authors.initials: P
authors.lastname: Merlani
mesh_terms: D001827:Body Height; D001837:Body Weights and Measures / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D012121:Respiration, Artificial