title: The four Ps: place, procedure, personnel, and patient.
authors.affiliation: Department of Anesthesia and Critical Care, Pritzker School of Medicine, University of Chicago, 5841 South Maryland Avenue, MC 4028, Chicago, IL 60637, USA. Electronic address: japfelbaum@dacc.uchicago.edu.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Apfelbaum
authors.affiliation: Department of Anesthesia and Critical Care, Pritzker School of Medicine, University of Chicago, 5841 South Maryland Avenue, MC 4028, Chicago, IL 60637, USA. Electronic address: tcutter@dacc.uchicago.edu.
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Cutter
mesh_terms: D000554:Ambulatory Care Facilities / Q000458:organization & administration*; D000556:Ambulatory Surgical Procedures / Q000379:methods*; D006282:Health Personnel; D006801:Humans; D010361:Patients; D019990:Perioperative Care