Intrapulmonary Shunt and Oxygenation During One-Lung Ventilation: Influence of Dexmedetomidine Combined with Transcutaneous Acupoint Electrical Stimulation

Background: One-lung ventilation (OLV) often causes hypoxemia due to intrapulmonary shunting. This study investigated how combining dexmedetomidine with transcutaneous acupoint electrical stimulation (TAES) affects intrapulmonary shunt and oxygenation during OLV. Methods: Eighty thoracoscopic lobectomy patients were randomized into four groups: control (Group A, saline), dexmedetomidine (Group B, 1μg·kg−1 loading, 0.4μg·kg−1·h−1 maintenance), TAES (Group C, bilateral stimulation at five acupoints), and combination (Group D, both interventions). Measurements were taken at five timepoints: before anesthesia (T0), 15 min after two-lung ventilation (T1), 30 min after OLV (T2), one h after OLV (T3), and 15 min after resuming two-lung ventilation (T4). Oxygenation parameters (PaO2, OI, A-aDO2, Qs/Qt, RI) and hemodynamics were assessed. Results: During OLV (T2, T3), Groups B and C showed significantly improved oxygenation parameters compared to Group A (p<0.05), while Group D demonstrated superior improvement compared to all other groups (p<0.05). All groups experienced decreased OI and increased Qs/Qt and A-aDO2 during OLV compared to baseline, with Group A showing the most pronounced changes and Group D the least. Conclusion: Both dexmedetomidine and TAES individually improve intrapulmonary shunt and oxygenation during OLV, but their combination provides superior results compared to either intervention alone.