Objective To evaluate the effects of midazolam intravenous drip combined with lidocaine via nebulization on patients during mechanical ventilation in intensive care unit ( ICU) . Methods 60 thoracic patients required postoperative mechanical ventilation in ICUwere randomized into 2 groups. The patients in therapeutic group received lidocaine 1 mg/kg via nebulization and midazolam intravenous drip 0. 1 mg·kg- 1·h- 1 . The patients in control group received 0. 9% NaCl 1 mg/kg via nebulization andmidazolam0. 1 mg·kg- 1 ·h- 1 . According to the scale of Ramsay, the additional midazolam and fentanyl were injected to maintain sedation and inhibit cough in both groups. During ventilation, calm score, the number and the severity of cough, the mean arterial pressure ( MAP) , heart rate ( HR) , and the consumption of midazolam and fentanyl were record. Results The number and severity of cough, the scale of MAP and HR in the therapeutic group were all significant lower than those in the control group ( P lt; 0. 05) . Theconsumption of midazolam and fentanyl in the therapeutic group were also significantly lower than that in the control group ( P lt; 0. 05) .Conclusion Midazolam intravenous drip combined with lidocaine via nebulization can reduce the side effects and requirement of sedative and opioids drug in ICU patients undergoing mechanical ventilation.