Supportive measures attempt to improve oxygen delivery to body cells. A patent airway, adequate ventilation, and supplemental oxygen are important prerequisites. Once oxygen is delivered to the alveolar/capillary interface, it must diffuse into the blood and be carried by adequate numbers of red blood cells. Hemoglobin in the red blood cells must bind with oxygen to carry it to the tissues; yet, the hemoglobin must release the oxygen to the cells in the peripheral capillaries. Cells must be able to use oxygen to produce energy and restore normal cellular function. Restoration of cellular function is a complex sequence that cannot be achieved with a single therapeutic intervention. The supportive management of the shock patient requires many different drugs and therapies to maintain tissue perfusion and to restore normal cellular function.