PaCO2 stands for partial pressure of carbon dioxide in arterial blood.
It is a measurement often used to assess a person’s respiratory status.
PaCO2 levels can provide important information about the efficiency of carbon dioxide exchange in the lungs.
Normal PaCO2 levels fall within a range of 35 to 45 millimeters of mercury (mmHg).
Higher levels of PaCO2, known as hypercapnia or hypercarbia, can indicate respiratory acidosis, which means that the body is retaining too much carbon dioxide.
This can be caused by conditions such as asthma, obstructive lung disease, or hypoventilation.
Lower levels of PaCO2, known as hypocapnia, can indicate respiratory alkalosis, which means that the body is eliminating too much carbon dioxide.
Conditions such as anxiety, hyperventilation, or pulmonary embolism can lead to hypocapnia.
PaCO2 is the major physiological regulator of cerebral vascular tone, and hypercapnia increases cerebral blood blood flow by up to 2 mL per hundred grams of brain tissue for each increase of 1 mmHg in the PaCO2.