Anesthesia Technologist Practice Exam

The rationale behind purging the transfer bag in an autotransfusion system of air primarily relates to the maintenance of stable oxygen concentration in the blood contained within the bag. When air is present, it can displace the blood, leading to a decrease in the partial pressure of oxygen (PaO2) in that blood. This can result in the blood being less effective at delivering oxygen once reinfused into the patient.

By removing the air, the concentration of oxygen within the blood remains higher, which ensures that when the blood is reinfused, it has optimal oxygen-carrying capacity. This is crucial for the physiological demands of the patient, especially during surgical procedures or in cases of significant blood loss where maintaining oxygenation is vital.

Additionally, the presence of air can also increase the risk of bubbles forming, which can lead to complications if these air bubbles were to enter the patient's bloodstream, potentially causing air embolism. Thus, purging air is an essential step in ensuring the autotransfusion process is safe and effective, allowing for better patient outcomes.