Abstract: Objective To investigate the effect of dexmedetomidine on oxygenation function in adult patients with balanced
anesthesia by propofol-fentanyl under one-lung ventilation (OLV). Methods Twenty-two patients undergoing thoracic
operation were randomly divided into the study group and control group, both receiving propofol and fentanyl balanced
anesthesia. In the study group, additional infusion of dexmedetomidine (0.3 μg/kg loading dose, 0.3 μg·kg-1·h-1 maintenance
dose) was administered, and the patients in the control group received only normal saline. Arterial blood samples were
obtained at 4 time points from each patient during anesthesia for blood gas analysis. Results In the study group, the pH values
remained stable, the oxygenation index tended to decline progressively, but the incidence of hypoxemia was low; in the control
group, the pH value and oxygenation index both declined progressively with a higher incidence of hypoxemia. Conclusion
Dexmedetomidine can better maintain the oxygenation function of OLV patients in balanced anesthesia by propofol and
fentanyl, and its mechanism may be related to the decreased dose of propofol used.