Why should arterial puncture be performed with no exposure to air?

Arterial puncture should be performed with no exposure to air primarily to avoid the escape of gas from the liquid. When blood is drawn from an artery, it contains dissolved gases such as oxygen and carbon dioxide, which are critical for assessing gas exchange in the body. If exposed to air, these gases can escape from the liquid, potentially altering the results of blood gas analyses. Such changes can misrepresent a patient’s respiratory status and lead to inappropriate medical decisions.

While maintaining sterility and preventing contamination are important in phlebotomy, these concerns are typically more related to venous punctures or maintaining the integrity of the sample rather than the specific consequences of gas escape. Accurate blood pressure readings are not directly related to air exposure during arterial puncture and are influenced by other factors, such as the technique and equipment used. Therefore, the primary concern in arterial puncture is to ensure that the blood gases remain undisturbed and representative of the patient's physiological condition.