Clinical Implications of Hyperoxia
Joseph Priestley was credited with the first discovery of oxygen, what he termed “dephlogisticated air” in 1774, noting “The feeling of it in my lungs was not sensibly different from that of common air, but I fancied that my breast felt peculiarly light and easy for some time afterwards.” Almost 250 years later, oxygen represents the most widely administered drug in modern acute hospital care, with ∼15% of all patients admitted receiving administered oxygen,1 representing over 5 million people annually in the United States alone.2 Within our specialty, we have almost universally titrated oxygen therapy to ensure avoidance of potentially injurious periods of hypoxemia. The same focus of attention has not been traditionally afforded for levels of relative hyperoxia with the assumption that excess oxygen is relatively harmless. There are emerging clinical data within a variety of arenas that suggest this assumption may not be true, and there is renewed interest in potential detrimental consequences of hyperoxia,3–6 not only with regard to lung injury but to all organ dysfunction. As the field evolves, the conceivable adoption of tighter “normoxic” parameters in a variety of settings has far-reaching implications for our discipline and has potential to significantly alter clinical practice at essentially no cost.