What is the normal range for arterial carbon dioxide partial pressure?
The normal value of arterial blood carbon dioxide partial pressure is generally 35-45mmHg. Below 35mmHg indicates respiratory alkalosis, and above 45mmHg indicates respiratory acidosis. Respiratory alkalosis is excessive ventilation, with excessive exhalation of carbon dioxide, which can be seen in physiologically overly excited young women and clinically known as hysteria. Pathologically, it can be seen in mild to moderate asthma attacks, early pneumonia, pulmonary embolism, and other diseases. Generally, no excessive intervention is required, and oxygen therapy or increased ineffective dead space ventilation can be given. Respiratory acidosis is caused by various causes of pulmonary ventilation dysfunction, resulting in the inability to smoothly exhale carbon dioxide. The most common patients are those with chronic obstructive pulmonary disease stage IV, and generally require invasive and non-invasive ventilator-assisted ventilation treatment.
PCO2 is an important indicator of respiratory acid-base balance disorders. Due to excessive ventilation and excessive excretion of CO2, its value is below normal, indicating respiratory alkalosis. Due to insufficient ventilation, insufficient excretion of CO2 and retention in the body, its value is higher than normal, indicating respiratory acidosis. In metabolic acidosis, due to the compensatory reaction of deepening and accelerating respiration, the patient's PCO2 value may decrease below normal. In metabolic alkalosis, the PCO2 value may rise above normal. Decreased PCO2: indicates excessive ventilation, which is clinically rare and mainly seen in excessive alveolar ventilation and excessive exhalation of carbon dioxide, such as some pneumonia, pulmonary infarction, asthma, etc., which can cause respiratory alkalosis. Increased PCO2: seen in upper airway obstruction, insufficient alveolar ventilation, respiratory dysfunction, and accumulation of carbon dioxide in the body caused by various reasons, such as chronic bronchitis, pulmonary emphysema, pulmonary edema, pulmonary heart disease, large-area atelectasis, severe asthma attacks, chest wall and pleural diseases, etc., can all cause respiratory acidosis.
