The Effect of Dexmedetomidine on Oxygenation and Intrapulmonary Shunt during One Lung Ventilation

Background: The effect of intravenously administered dexmedetomidine on oxygenation during one-lung ventilation has not been studied. The hypothesis of this prospective, randomized study was that dexmedetomidine would be associated with an improvement in oxygenation during onelung ventilation. The secondary outcome was the change in the intrapulmonary shunt. Materials and Methods: Thirty patients undergoing one-lung ventilation were included. Patients in Group D (n = 15) received a bolus dose of 1 μg∙kg−1 dexmedetomidine at 10 min after induction of anaesthesia followed by an infusion of 0.4 μg∙kg−1∙hr−1 that was stopped at the end of the surgery, and those in the control group(Group C, n = 15) were given saline at the same dosage. Vital signs, PaO2, and pulmonary shunting (Qs/Qt) were compared. Results: During one-lung ventilation, the PaO2 in Group D increased significantly and Qs/Qt significantly decreased compared to Group C (PaO2, 203.7 ± 42.3 mmHg vs. 173 ± 37.6 mmHg [P = 0.04] and Qs/Qt 19.8% ± 4.5% vs. 31% ± 2.4% [P < 0.0001], Group D and Group C, respectively). Conclusion: Intravenous administration of dexmedetomidine achieved an improvement in oxygenation during one-lung ventilation. This was associated with a decrease in pulmonary shunt. Use of intraoperative dexmedetomidine during thoracic surgery can be suggested.