Serum carbon dioxide is usually the total amount of carbon dioxide in the serum and is commonly found in blood gas analysis lab results. The normal range of serum carbon dioxide is usually 23 to 31 mmol/L. If the serum carbon dioxide index is high, it usually reflects the high total amount of carbon dioxide in serum bicarbonate and carbonic acid, which is usually found in lung diseases, thoracic diseases, and foreign bodies in the airway. Because pulmonary ventilation dysfunction will lead to carbon dioxide discharge difficulties, so it will cause the serum carbon dioxide elevation, need to analyze the causative factors, and then for the primary disease treatment, improve the patient’s pulmonary ventilation function.