Ojective To evaluate the influence of dexmedetomidine on transforming growth factor(TGF)-β1/Smad signaling pathways in patients with lung injury associated with one lung ventilation during thoracoscopic surgery.
Methods A total of 886 undergoing pulmonary lobectomy, 444 males and 442 females, aged 40-65 years, BMI 20-24 kg/m2, falling into ASA physical status Ⅰ-Ⅱ．They were randomly divided into two groups using random number table method: dexmedetomidine group (group D) and control group (group C), 443 for each group. In group D, loading dose dexmedetomidine was injected intravenously in 10 min before anesthesia induction with 1.0 μg/kg, injection rate was adjusted in 0.3 μg·kg-1·h-1 until 30 min before the end of operation. Equal volume of normal saline was given in group C. 2 ml arterial and venous blood were collected at immediate one lung ventilation (T0), 15 min (T1), 30 min (T1), 60 min (T3) of one-lung ventilation, and 1 h after recovery of two-lung ventilation (T4), the oxygenation index (OI) and Qs/Qt were calculated by the blood gas analysis. Lung tissue was observed by HE staining. The ratio of wet and dry lung weight (W/D) and the lung physical injury score were calculated. Western blot method was used to detect TGF-β1, Smad2, Smad3, IL-6, and TNF-α in lung tissue. The incidence of pneumonia, atelectasis and respiratory failure within 48 h after operation were recorded, and the postoperative hospitalization was recorded as well.
Results Compared with group C, in group D, OI were significantly increased, Qs/Qt were significantly decreased at T1-T4(P < 0.05), and the expression of TGF-β1, Smad2, Smad3, IL-6, and TNF-α were significantly down-regulated (P < 0.05), the pathologic score were significantly decreased (P < 0.05), the ratio of wet/dry lung weight, the incidence of postoperative pneumonia and atelectasis were significantly decreased (P < 0.05), and the postoperative hospital stay was significantly shortened in group D (P < 0.05).
Conclusion Dexmedetomidine can reduce the expression of TGF-β1, Smad2, Smad3, IL-6, and TNF-α in lung tissue of patients undergoing thoracoscopic loggectomy, so as to reduce acute lung injury. |
