Elevated partial pressure of carbon dioxide refers to a higher than normal pressure of carbon dioxide in the blood, usually over 60 mmHg. It is common in patients with chronic obstructive pulmonary disease (COPD). In this type of disease, due to the decrease of pulmonary elastic retraction, the body cannot exhale the carbon dioxide produced by the body when exhaling, resulting in carbon dioxide retention, which will cause increased partial pressure of carbon dioxide. This condition is also called type II respiratory failure. When the partial pressure of carbon dioxide increases, the concentration of bicarbonate ions in the blood increases and respiratory acidosis occurs, and the patient may have deep and rapid breathing.