Oxygen in the ICU: Too Much of a Good Thing?

Oxygen gas was discovered and described in the 1770s by Scheele, Priestley, and Lavoisier and shortly thereafter its therapeutic potential for patients with respiratory illness was appreciated. Oxygen has become a mainstay of treatment for acutely ill patients, with emphasis frequently placed on the importance of avoiding hypoxemia. Modern clinical practice guidelines for critically ill patients generally target the normal levels for the partial pressure of arterial oxygen and the oxyhemoglobin saturation in arterial blood, which range from 89 through 100 mm Hg and 95% through 97%, respectively, depending on patient age. Here, Ferguson discusses oxygen in the ICU.