Bench-to-bedside review: the effects of hyperoxia during critical illness.
Oxygen administration is uniformly used in emergency and intensive care medicine and has life-saving potential in critical conditions. However, excessive oxygenation also has deleterious properties in various pathophysiological processes and consequently both clinical and translational studies investigating hyperoxia during critical illness have gained increasing interest. Reactive oxygen species are notorious by-products of hyperoxia and play a pivotal role in cell signaling pathways. The effects are diverse, but when the homeostatic balance is disturbed, reactive oxygen species typically conserve a vicious cycle of tissue injury, characterized by cell damage, cell death, and inflammation. The most prominent symptoms in the abundantly exposed lungs include tracheobronchitis, pulmonary edema, and respiratory failure. In addition, absorptive atelectasis results as a physiological phenomenon with increasing levels of inspiratory oxygen. Hyperoxia-induced vasoconstriction can be beneficial during vasodilatory shock, but hemodynamic changes may also impose risk when organ perfusion is impaired. In this context, oxygen may be recognized as a multifaceted agent, a modifiable risk factor, and a feasible target for intervention. Although most clinical outcomes are still under extensive investigation, careful titration of oxygen supply is warranted in order to secure adequate tissue oxygenation while preventing hyperoxic harm.
Department of Intensive Care Medicine, Leiden University Medical Center, Albinusdreef 2, Leiden, 2300 RC, The Netherlands. h.j.f.helmerhorst@lumc.nl.|Laboratory of Experimental Intensive Care and Anesthesiology, Academic Medical Center, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands. h.j.f.helmerhorst@lumc.nl.
Hendrik J F
HJ
Helmerhorst
Laboratory of Experimental Intensive Care and Anesthesiology, Academic Medical Center, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands.|Department of Intensive Care Medicine, Academic Medical Center, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands.
Marcus J
MJ
Schultz
Department of Intensive Care Medicine, Onze Lieve Vrouwe Gasthuis, Oosterpark 9, Amsterdam, 1091 AZ, The Netherlands.|TIAS School for Business and Society, Tilburg University, Warandelaan 2, Tilburg, 5000 LE, The Netherlands.
Peter H J
PH
van der Voort
Department of Intensive Care Medicine, Leiden University Medical Center, Albinusdreef 2, Leiden, 2300 RC, The Netherlands.
Evert
E
de Jonge
Department of Intensive Care Medicine, Leiden University Medical Center, Albinusdreef 2, Leiden, 2300 RC, The Netherlands.
David J
DJ
van Westerloo
D000818:Animals; D003422:Critical Care; D016638:Critical Illness / Q000628:therapy*; D006801:Humans; D018496:Hyperoxia / Q000150:complications* / Q000209:etiology / Q000503:physiopathology; D010102:Oxygen Inhalation Therapy / Q000009:adverse effects; D019990:Perioperative Care