title: It is hard to get a grip on it. Reply.
authors.affiliation: Department of Anesthesiology and Critical Care, University of New Mexico School of Medicine, Albuquerque, NM 87131,USA. Electronic address: ngerstein@gmail.com.
authors.forename: Neal Stuart
authors.initials: NS
authors.lastname: Gerstein
authors.affiliation: Department of Anesthesiology and Critical Care, University of New Mexico School of Medicine, Albuquerque, NM 87131,USA.
authors.forename: Timothy Randal
authors.initials: TR
authors.lastname: Petersen
authors.affiliation: Department of Anesthesiology and Critical Care, University of New Mexico School of Medicine, Albuquerque, NM 87131,USA.
authors.forename: Isaac
authors.initials: I
authors.lastname: Tawil
authors.affiliation: Department of Anesthesiology and Critical Care, University of New Mexico School of Medicine, Albuquerque, NM 87131,USA.
authors.forename: Darren Alan
authors.initials: DA
authors.lastname: Braude
mesh_terms: D002983:Clinical Competence; D005260:Female; D006801:Humans; D008297:Male; D008397:Masks; D012121:Respiration, Artificial / Q000592:standards*