Oxygen therapy and toxicity

Oxygen (O-2) supplementation increases the O-2 content of blood, increases the partial pressure of oxygen (PO2) in the capillary blood, and improves tissue delivery of O-2. In addition to improving tissue oxygenation, the administration of O-2 may improve the function of O-2-dependent cellular systems, such as the cytochrome P-450 system, which is important to drug and toxin metabolism; nitric oxide synthase, which regulates vasodilation; and host defense systems. Improved tissue oxygenation is also beneficial for wound healing. Given the important contributions that supplemental O-2 can make, it is no wonder that O-2 is one of the most common drugs administered in the emergency and intensive care settings.