Objective:To determine whether dexmedetomidine (Dex) improves oxygenation and lung mechanics in patients with moderate chronic obstructive pulmonary disease (COPD) during lung cancer surgery.Methods:Fifty-six patients with moderate COPD were randomly allocated to a control group and a Dex group (n=28 each).In the Dex group,dexmedetomidine was given as an initial loading dose at 1.0 μg/kg lasting for 10 min followed by a maintenance dose at 0.5 μg/(kg-h) during OLV while the control group was administered an equal volume of 0.9％ saline accordingly.Results:Patients in the Dex group had a significantly higher oxygenation index (P＜0.05) and higher dynamic lung compliance at Dex-30 and Dex-60 (P＜0.05) compared with those in the control group.In the Dex group,oxygenation index in the postoperative period was significantly higher (P=0.025) and postoperative complications were lower than those in the control group.Conclusion:Dex administration may provide dinically relevant benefits by improving oxygenation index and lung mechanics,and reducing postoperative pulmonary complications in patients with moderate COPD underwent lung cancer surgery.

Objective:To investigate the value of pericoronary adipose tissue histogram parameters based on coronary CT angiography (CTA) images for the differentiation of acute coronary syndrome and stable coronary artery disease.Methods:The clinical data and CTA images of 93 patients with coronary CTA examination in Suzhou Kowloon Hospital from 2013 to 2018 were analyzed retrospectively. There were 39 patients with acute coronary syndrome (acute coronary syndrome group) and 54 patients with stable coronary artery disease (stable coronary artery disease group). A region of interest (ROI) was drawn around the stenosis of the coronary arteries, with CT attenuation ranging from-190 to -30 HU to exclude non-adipose tissue. The CT attenuation of ROI excluding non-adipose were measured and histogram analysis was performed. The obtained parameters included the mean value, median value and the 5th, 10th, 45th, 55th, 70th and 95th percentiles. The differences in histogram parameters between the two groups were compared, and then the value of each parameter in differentiating acute coronary syndrome and stable coronary artery disease was evaluated based on receiver operating characteristic (ROC) analysis. The stepwise regression of multivariate logistic regression analysis was used to identify the useful features and establish the final prediction model. The ROC curve of the final model was calculated and its value was analyzed.Results:The mean, median and the 5th, 10th, 45th, 55th,70th and 95th percentile differences between the acute coronary syndrome group and the stable coronary artery disease group were statistically significant (all P<0.05). The ROC curve for the median and the 95th percentile had the same area under curve (AUC) of 0.73. The sensitivity, specificity and AUC of the diagnostic model established by multiple logistic regression were 82.1%, 89.1% and 0.90 respectively. Conclusion:CT attenuation histogram of pericoronary adipose tissue is of high value in differentiating acute coronary syndrome from stable coronary artery disease.