Objective: To evaluate the analgesia effect of para vertebral nerve block (PVB) post Methods: Sixty patients undergoing simple nephrectomy (age 35-65 years old, both genders, weight 45-80 kg, ASA grade I or II) were randomly divided into two groups using the table of random numbers: the control group and the PVB group, with 30 patients in each For both groups, patients were given intravenous infusion of 2% ropivacaine 250 ml post operation and intravenous morphine patient-controlled Six, 12, 24 and 48 hours post operation, blood gas analysis was conducted and VAS scores under quiet and exercising conditions were The cumulative morphine usage and cases of complications were calculated at 48 hours post Results: Compared with control group, PVB group had a significant higher PaO2 and lower PaCO There were significant differences in VAS scores under exercising condition while no difference under quiet condition between two In PVB group, the cumulative morphine usage decreased, there were fewer cases of nausea, vomiting, pruritus and orthostatic hypotension, and the first flatus time post operation was shortened (P<05) Conclusions PVB analgesia post nephrectomy may reduce the usage of morphine and the incidence of 问题:CEA的英文全称未给出,故翻译时未采用此缩写。方法中未说明PVB何时及如何实施。吗啡辅助镇痛没查到有assist的翻译,一般就直接说patient controlled analgesia,或其后加pump。