title: Does hyperoxia enhance susceptibility to secondary pulmonary infection in the ICU?
abstract: Hyperoxia is common practice in the acute management of circulatory shock, and observational studies report that it is present in more than 50 % of mechanically ventilated patients during the first 24 h after intensive care unit (ICU) admission. On the other hand, "oxygen toxicity" due to the increased formation of reactive oxygen species limits its use due to serious deleterious side effects. However, formation of reactive oxygen species to boost bacterial killing is one of the body's anti-microbial auto-defense mechanisms and, hence, O2 has been referred to as an antibiotic. Consequently, hyperoxia during the peri-operative period has been advocated for surgical patients in order to reduce surgical site infection. However, there is ample evidence that long-term exposure to hyperoxia impaired bacterial phagocytosis and thereby aggravated both bacterial burden and dissemination. Moreover, a recent retrospective study identified the number of days with hyperoxia, defined as a PaO2 > 120 mmHg only, as an independent risk factor of ventilator-associated pneumonia in patients needing mechanical ventilation for more than 48 h. Since so far the optimal oxygenation target is unknown for ICU patients, "conservative" O2 therapy represents the treatment of choice to avoid exposure to both hypoxemia and excess hyperoxemia.
authors.affiliation: Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung, Universitätsklinikum, Helmholtzstrasse 8/1, Ulm, Germany.|Klinik für Anästhesiologie, Abteilung Klinische Anästhesiologie, Universitätsklinikum, Albert-Einstein-Allee 23, Ulm, Germany.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Nußbaum
authors.affiliation: Klinik für Anästhesiologie, Abteilung Klinische Anästhesiologie, Universitätsklinikum, Albert-Einstein-Allee 23, Ulm, Germany. peter.radermacher@uni-ulm.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Radermacher
authors.affiliation: Département de Réanimation Médicale et de Médecine Hyperbare, Centre Hospitalier Universitaire, 4 rue Larrey, Angers, France.|Laboratoire de Biologie Neurovasculaire et Mitochondriale Intégrée, CNRS UMR 6214 - INSERM U1083, Université Angers, PRES L'UNAM, Angers, 49933, Cedex 9, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Asfar
authors.affiliation: Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung, Universitätsklinikum, Helmholtzstrasse 8/1, Ulm, Germany.|Klinik für Anästhesiologie, Abteilung Klinische Anästhesiologie, Universitätsklinikum, Albert-Einstein-Allee 23, Ulm, Germany.
authors.forename: Clair
authors.initials: C
authors.lastname: Hartmann
mesh_terms: D060085:Coinfection / Q000209:etiology* / Q000503:physiopathology; D004198:Disease Susceptibility; D006801:Humans; D018496:Hyperoxia / Q000150:complications* / Q000209:etiology; D007362:Intensive Care Units / Q000458:organization & administration; D008168:Lung / Q000382:microbiology / Q000503:physiopathology; D010100:Oxygen / Q000008:administration & dosage* / Q000627:therapeutic use / Q000633:toxicity; D010102:Oxygen Inhalation Therapy / Q000009:adverse effects; D010587:Phagocytosis / Q000187:drug effects / Q000502:physiology; D053717:Pneumonia, Ventilator-Associated / Q000209:etiology / Q000503:physiopathology; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000494:pharmacology / Q000627:therapeutic use; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods; D012141:Respiratory Tract Infections / Q000209:etiology* / Q000503:physiopathology; D012307:Risk Factors
chemical_list: D017382:Reactive Oxygen Species; D010100:Oxygen
keywords: Antibiotic; Catecholamine; Hyperoxia; Mechanical ventilation; Phagocytosis; Sedation; Ventilator-associated pneumonia