Effects of dexmedetomidine on inflammatory responses in lung tissues during one-lung ventilation in patients undergoing esophageal cancer resection

Objective To evaluate the effects of dexmedetomidine on inflammatory responses in lung tissues during one-lung ventilation (OLV) in patients undergoing esophageal cancer resection. Methods Forty American Society of Anesthesiologists physical statusⅠor Ⅱ patients, aged 25-65 yr, with body mass index of 18-25 kg/m2, scheduled for elective radical resection of esophageal cancer, were divided into 2 groups (n=20 each) using a random number table: dexmedetomidine group (group D) and control group (group C). Dexmedetomidine was infused intravenously in a loading dose of 0.6 μg/kg over 10 min before induction of anesthesia, followed by an infusion of 0.4 μg·kg-1·h-1 until 30 min before the end of operation in group D, and the equal volume of normal saline was given instead in group C. After intubation (T1), at 30, 60 and 90 min of OLV (T2-4), and at 30 min after restoration of two-lung ventilation (T5), blood samples were taken from the internal jugular vein.Broncho-alveolar lavage fluid (BALF) in ventilated lung was collected at T1-4.The concentrations of tumor necrosis factor-alpha (TNF-α), interleukin-6(IL) and IL-10 in plasma and BALF were determined by enzyme-linked immunosorbent assay. Results Compared with group C, the plasma concentrations of TNF-α at T5 and IL-6 at T4, 5 were significantly decreased, the plasma concentration of IL-10 was increased at T4, 5, and the concentration of TNF-α in BALF at T4 and concentration of IL-6 in BALF at T3, 4 were decreased, and the concentration of IL-10 in BALF was increased at T4 in group D (P<0.05). Conclusion Dexmedetomidine can significantly ameliorate the inflammatory responses in lung tissues during OLV, thus reducing systemic inflammatory responses in patients undergoing esophageal cancer resection. Key words: Dexmedetomidine; Respiration, artificial; Inflammation