Christiansen CB, et al. - Among 60 consenting, healthy volunteers, researchers examined how common peroneal nerve block duration was influenced by the use of ropivacaine 0.2%. Participants were examined for duration of sensory block, defined by insensitivity to a cold stimulus, as well as for duration of motor block following randomization to one of five volumes of ropivacaine 0.2% (2.5, 5.0, 10, 15 or 20 ml) administered by ultrasound-guided, catheter-based injection (at 10 ml.min^-1) near the common peroneal nerve. They evaluated outcomes every hour from onset of block to complete remission. They noted a remarkable variance in block durations between groups. In regression analysis, a progressively smaller impact of volume on block duration was observed with increasing volume, reaching a threshold volume above which there was no effect on nerve block duration (10 ml for sensory block and 15 ml for motor block). Overall, a ceiling impact of increasing volume of ropivacaine 0.2% on both sensory and motor block duration of the common peroneal nerve was seen.