Background

Respiration is the process of gas exchange at the cellular level. Oxygen is conducted into the lung and taken up by the blood via hemoglobin to be transported throughout the body. In the peripheral tissues, carbon dioxide is exchanged for oxygen, which is transported by the blood to the lungs, where it is exhaled. This process is essential to cellular and organism survival. Dysfunction of this process is a feature of multiple-injury patterns that can lead to increased morbidity and mortality.