Many people with<unk><unk><unk>  disease have a low partial pressure of<unk>  in the blood and high partial pressure of carbon dioxide. Treatment with supplemental<unk>  may improve their well-being; alternatively, in some this can lead to the adverse<unk>  of elevating the carbon dioxide content in the blood (hypercapnia) to levels that may become toxic. With normal lung function, a stimulation to take another breath occurs when a patient has a slight rise in PaCO2. The slight rise in PaCO2 stimulates the respiratory centre in the brain, creating the impulse to take another breath. In some patients with a<unk> ally high level of PaCO2, such as those with COPD, the stimulus and drive to breathe is caused by a decrease in PaO2. This is called a hypoxic drive. Thus, when<unk>  is administered to patients with known CO2 retention, patients need to be watched for signs of hypoventilation, a decreased level of consciousness, and apnea.
Effect of oxygen on chronic obstructive pulmonary disease
Effects of high altitude on humans
Airway resistance
Central neurogenic hyperventilation
Pathophysiology of asthma
Pathophysiology of acute respiratory distress syndrome
Intermittent hypoxic training
Aspirin exacerbated respiratory disease