title: It is hard to get a grip on it.
authors.affiliation: University of Washington, Harborview Medical Center, Seattle, WA 98104, USA. Electronic address: joffea@uw.edu.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Joffe
authors.affiliation: University of Wisconsin School of Medicine and Public Health, Madison, WI 53792,USA.
authors.forename: Richard E
authors.initials: RE
authors.lastname: Galgon
mesh_terms: D002983:Clinical Competence; D005260:Female; D006801:Humans; D008297:Male; D008397:Masks; D012121:Respiration, Artificial / Q000592:standards*