title: [Fallacies in arterial blood gas interpretation].
abstract: The arterial blood gas analysis (ABGA) is a valuable diagnostic tool in daily clinical practice. It yields information about oxygenation, ventilation and acid-base status. ABGAs should always be interpreted within a clinical context. If a result is absolutely not compatible with a clinical situation, the probe should be repeated or prompt further differential diagnoses. A probe should be free of air bubbles and be rapidly proceeded in the laboratory. Body temperature and fraction of inspired oxygen are mandatory prerequisites for adequate interpretation. With CO-oximetry, not only oxygenated hemoglobin but also carboxihemoglobin and met-hemoglobin content can be measured in the case of a suspected intoxication. For the assessment of ventilation, PaCO2 must be interpreted in the context of PaO2, as already a "normal value" of PaCO2 may indicate severe ventilator failure in a patient with hypoxemia. A normal pH does not exclude acid-base disorders, PaCO2 and bicarbonate must also be taken into account. When FIO2 is changed, steady state conditions must be awaited before a next control especially in the case of ventilation-perfusion mismatch, e. g. in COPD, pneumonia, pulmonary embolism. In a hypoxic state, immediate application of oxygen is warranted, in hypercapnia, ventilation should be increased. In acid-base disorders, treatment of the underlying disease is most often conducive.
authors.affiliation: Ambulante Medizinische Diagnostik, Klinik für Innere Medizin, Kantonsspital Münsterlingen. robert.thurnheer@stgag.ch
authors.forename: Robert
authors.initials: R
authors.lastname: Thurnheer
mesh_terms: D001158:Arteries / Q000378:metabolism*; D016477:Artifacts; D001784:Blood Gas Analysis / Q000379:methods*; D002245:Carbon Dioxide / Q000097:blood*; D006801:Humans; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D012680:Sensitivity and Specificity
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen