Abstract:Objective To investigate effect of two doses of Dexmedetomidine (Dex) on cardiac output and microcirculation in patients with mechanical ventilation after radical resection of lung cancer. Methods A total of 60 patients who were treated in the Intensive Care Unit after lung surgery were included. The patients were randomly devided into two groups with 30 people in each. Dex was infused in a dose of 0.6 μg/(kg·h) (group A) or 0.8 μg/(kg·h) (group B). The values of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), cardiac output (CO), transcutaneous oxygen pressure (TcPO2), transcutaneous carbon dioxide pressure (TcPCO2), PaO2, PaCO2 and Lac were recorded before (T0), 15 min (T1), 30 min (T2), 1 h (T3),and 2 h (T4) after continuous intravenous infusion of the drugs. Cardiovascular adverse events were recorded. Results There were significant differences in the hemodynamic indexes at different time points in both groups,the indices showed descending trends which were more obvious in the group B. However, there were no significant differences in the indexes between the two groups. There were no significant differences in PaO2,PaCO2 or TcPCO2 between the two groups at different time points. There were differeces in Lac between the two groups at different time points (p < 0.05) with an upward trend in each group. There were differeces in TcPO2 between the groups A and B at different time points (p < 0.05) and the change trends of the two groups after drug administration were different (p < 0.05). TcPO2 increased in the two groups after infusion. Conclusions In the dose of 0.6 μg/(kg·h) Dexmedetomidine infusion, hemodynamics change little while microcirculation is effectively improved in the mechanically ventilated patients after radical resection of lung cancer.