Evaluation of motor block of the lower legs in continuous lumbar epidural infusion of ropivacaine
Yamaguchi, S.; Kitamura, J.; Yamamoto, K.
Masui. Japanese Journal of Anesthesiology 61(6): 583-587
2012
ISSN/ISBN: 0021-4892 PMID: 22746019 Document Number: 663870
Continuous epidural infusion of ropivacaine is commonly used for postoperative analgesia because of its motor-sparing properties. But there are a few patients whose motor block of the lower legs is prolonged. The aim of this study is to investigate the effect of low density ropivacaine regarding motor block of the lower legs when administered continuously into the lumbar epidural space. All patients were randomly divided into following three groups. Ropivacaine 0.2% was administered after spinal anesthesia (0.2%S group, n=24). Ropivacaine 0.2% was administered after epidural anesthesia (0.2%E group, n=37). Ropivacaine 0.1% was administered after epidural anesthesia (0.1%E group, n=20). We measured the effect of motor block of the lower legs by Bromage scale after postoperative 7 and 19 hours. The motor block was significantly stronger and the duration was more prolonged in order of 0.2%S group, 0.2%E group, and 0.1%E group. For avoiding prolongation of motor block of the lower legs in continuous lumbar epidural infusion for postoperative analgesia, 0.1% ropivacaine would be better than 0.2%. We should pay attention to the fact that the use of ropivacaine after spinal anesthesia prolongs and increases motor block of the lower legs.