Reiner K, et al. - Given that the difference between the effect of ropivacaine and levobupivacaine on sympathetic nerve fibers during central neuraxial blocks remains unknown, researchers tested the presumption that there is no difference in the degree of sympathectomy between the two drugs during lumbar epidural analgesia for labor pain. They included 60 healthy parturients, these subjects randomly received 10 mL of 0.125% ropivacaine + 100 mcg of fentanyl or 10 mL of 0.125% levobupivacaine + 100 mcg of fentanyl in the epidural space. Following the baseline measurement, they recorded photoplethysmography signal from the first toe of the leg at 5, 10 and 20 minutes post-delivery of epidural analgesia. With respect to sympathectomy–mediated side effects of the epidural block for labor analgesia, no difference was found between 0.125% ropivacaine and 0.125% levobupivacaine. However, the degree of sympathectomy between the two local anesthetics showed a certain difference, as per photoplethysmography findings.