Objective To evaluate the effects of penehyclidine hydrochloride (PHCD) combined with high-frequency jet ventilation (HFJV) of the operated lungs on pulmonary function and inflammatory response during one-lung ventilation (OLV) in patients with chronic obstructive pulmonary disease (COPD).Methods Sixty American Society of Anesthesiologists physical status Ⅱ or Ⅲ patients of both sexes with COPD,aged 40-64 yr,with body mass index of 17-26 kg/m2,scheduled for elective video-assisted thoracoscopic surgery under general anesthesia,were divided into 4 groups (n =15 each) using a random number table method:conventional group (group C),PHCD group (group P),HFJV group (group H) and PHCD combined with HFJV group (group PH).After induction of anesthesia,the patients were intubated with a double-lumen tube and then mechanically ventilated,with inspired oxygen concentration 100％,oxygen flow rate 2 L/min,tidal volume 6-8 ml/kg,respiratory rate 10-14 breaths/min,and respiratory rate was set at 12-16 breaths/min and PETCO2 was maintained at 40-45 mmHg during OLV.PHCD 0.01 mg/kg was intravenously injected before intubation in P and PH groups.The ventilation mode was changed to OLV after beginning of skin incision in each group.Ventilation of the lung on the operated side was performed by means of HFJV (driving pressure 0.5 kg/cm2) during OLV in P and PH groups.The pneumodynamic parameters such as airway peak pressure (Ppeak),airway plateau pressure (Pplat),airway resistance (Raw) and dynamic lung compliance (Cdyn) were monitored immediately before skin incision (T1) and at 60 and 120 min of OLV (T2,3).Arterial blood samples were obtained at T2 for blood gas analysis,and oxygenation index (OI),respiratory index (RI),physiologic dead space fraction (VD/Vr)and alveolar-arterial oxygen gradiant (A-aDO2) were calculated.Venous blood samples were drawn at T3 for determination of the serum concentrations of tumor necrosis factor-alpha (TNF-α),interleukin-6 (IL-6)and IL-8 by enzyme-linked immunosorbent assay.The occurrence of pulmonary complications was recorded within 72 h after operation.Results Compared with group C,the serum concentrations of TNF-α,IL-6 and IL-8,Ppeak,Pplat,Raw,RI,VD/VT,A-aDO2 and incidence of pulmonary complications were significantly decreased,and Cdyn and OI were increased in group P and group PH (P＜0.05),and the serum concentrations of TNF-α,IL-6 and IL-8,RI,VD/VT,A-aDO2 and incidence of pulmonary complications were significantly decreased,and OI was increased in group H (P＜0.05).Compared with group P or group H,the serum concentrations of TNF-α,IL-6 and IL-8,RI,VD/VT,A-aDO2 and incidence of pulmonary complications were significantly decreased,and OI was increased in group PH (P＜0.05).Conclusion PHCD combined with HFJV of the operated lung produces better efficacy in improving respiratory function,inhibiting inflammatory responses,reducing lung injury and is more helpful in improving prognosis than either alone in the patients with COPD.