title: Volumetric capnography: lessons from the past and current clinical applications.
abstract: Dead space is an important component of ventilation-perfusion abnormalities. Measurement of dead space has diagnostic, prognostic and therapeutic applications. In the intensive care unit (ICU) dead space measurement can be used to guide therapy for patients with acute respiratory distress syndrome (ARDS); in the emergency department it can guide thrombolytic therapy for pulmonary embolism; in peri-operative patients it can indicate the success of recruitment maneuvers. A newly available technique called volumetric capnography (Vcap) allows measurement of physiological and alveolar dead space on a regular basis at the bedside. We discuss the components of dead space, explain important differences between the Bohr and Enghoff approaches, discuss the clinical significance of arterial to end-tidal CO2 gradient and finally summarize potential clinical indications for Vcap measurements in the emergency room, operating room and ICU.
authors.affiliation: Department of Critical Care Medicine, University of McGill, Montreal, Quebec, Canada.|Department of General Intensive Care, University Hospital of Liege, Liege, Belgium.
authors.forename: Sara
authors.initials: S
authors.lastname: Verscheure
authors.affiliation: Department of General Intensive Care, University Hospital of Liege, Liege, Belgium.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Massion
authors.affiliation: Department of Emergency Medicine, Cliniques universitaire Saint-Luc, Université Catholique de Louvain, Brussels, Belgium.
authors.forename: Franck
authors.initials: F
authors.lastname: Verschuren
authors.affiliation: Department of General Intensive Care, University Hospital of Liege, Liege, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Damas
authors.affiliation: Department of Critical Care Medicine, University of McGill, Montreal, Quebec, Canada. sheldon.magder@mcgill.ca.
authors.forename: Sheldon
authors.initials: S
authors.lastname: Magder
mesh_terms: D019296:Capnography / Q000379:methods* / Q000592:standards* / Q000639:trends; D006801:Humans; D007362:Intensive Care Units / Q000458:organization & administration; D011655:Pulmonary Embolism / Q000175:diagnosis; D012121:Respiration, Artificial / Q000379:methods / Q000592:standards; D012126:Respiratory Dead Space / Q000502:physiology*; D012128:Respiratory Distress Syndrome / Q000175:diagnosis / Q000401:mortality / Q000628:therapy; D015912:Thrombolytic Therapy; D014692:Ventilation-Perfusion Ratio / Q000502:physiology; D015300:Ventilator Weaning / Q000639:trends