ABSTRACT
Objective To investigate the influence of different volumes of ropivacaine with isod-osage on diaphragmatic excursion following ultrasound-guided interscalene brachial plexus block. Methods Sixty ASA Ⅰ-Ⅱ patients scheduled for right ulnoradial fracture internal fixation removal were randomized into group A (0.5% ropivacaine 20 ml)and group B (0.75% ropivacaine 13.3 ml) (n=30,each).Diaphragmatic excursion were evaluated by M type ultrasound before,1 5 min and 30 min after drug injection. The degree and duration of sensory and motor block were recorded. Results The anesthetic effect and maintain time had no significant difference between groups;Com-pared with group A,group B had lower incidence of diaphragmatic paralysis (P <0.05).There were 28 (93%)and 22 (73%)cases of patients in group A and group B respectively showed reduction of diaphragmatic excursion more than 50% or even complete paralysis 30 min after drug injection (P <0.05).Conclusion Ultrasound-guided interscalene brachial plexus with 0.5% ropivacaine 20 ml or 0.75% ropivacaine 13.3 ml both can provide excellent block.Compared with 0.75% ropivacaine 13.3 ml,0.5% ropivacaine 20 ml is more likely to lead to diaphragmatic paralysis.