Final answer:
Oxygen therapy is prescribed for COPD patients with low blood oxygen levels to improve gas exchange and alleviate symptoms. Hyperbaric oxygen therapy is sometimes used for severe infections, while for carbon monoxide poisoning, 100 percent oxygen is administered to displace the toxic gas.
Step-by-step explanation:
Oxygen therapy is prescribed to patients with Chronic Obstructive Pulmonary Disease (COPD) when they suffer from low oxygen levels (hypoxemia). COPD leads to the destruction of alveolar walls, decreasing the surface area for gas exchange and trapping air in the lungs, causing both oxygen levels to drop and carbon dioxide levels to rise in the bloodstream. Supplemental oxygen helps improve the oxygen saturation in these patients, which can relieve symptoms of shortness of breath and fatigue. Additionally, smoking cessation can slow the worsening of COPD.
In cases where infections are severe, hyperbaric oxygen therapy might be used, where patients breathe pure oxygen at a pressure higher than atmospheric levels to increase oxygen saturation in hypoxic tissues. This enhanced oxygen concentration boosts the immune response and also helps inhibit the growth of anaerobic bacteria that could be harmful. However, this type of therapy carries rare risks such as oxygen toxicity and effects on delicate tissues.
For carbon monoxide poisoning, administering 100 percent oxygen is vital as it helps displace carbon monoxide from hemoglobin, effectively reducing its half-life in the blood and converting carboxyhemoglobin back into hemoglobin to restore the oxygen-carrying capacity of the blood. Providing carbon dioxide would not be effective and would be harmful, as it does not serve the function of displacing carbon monoxide or carrying oxygen to body tissues.