sympatholytic and anti-inflammatory effects of ropivacaine and bupivacaine after infraclavicular block in arterio venous fistula surgery

Background: various mechanisms have been suggested for analgesic effects of drugs used in infra-clavicular block and each has contributed to pain relief. objectives: the aim of this study was to compare the degree of sympathetic block and measure tumor necrosis factor (tnf)-alpha, interleukin (il)-6, and il-1 levels before and after infra-clavicular block with ropivacaine and bupivacaine in patients undergoing arterio venous fistula (avf) surgery. methods: forty-eight patients undergoing avf surgery were randomly divided to two groups, undergoing infra-clavicular block with ropivacaine and bupivacaine. the bupivacaine group was blocked with 30 ml of 0.5% bupivacaine and in the ropivacaine group, the blockage was done with 30 ml of 0.5% ropivacaine. infra-clavicular block was carried out by ultrasound in a vertical manner. blood samples were taken before the block and one hour after the block to measure il-1, il-6, and tnf-alpha. data were analyzed by covariance analysis and correlation t-test. results: t-correlation analysisshowedthat in both ropivacaineandbupivacaine groups, the tnf-alpha, il-6, andil-1 levels decreased after the block. also, the increase in arterial diameter was significantly greater in ropivacaine group. conclusions: the present study showed that peripheral block with any single drug could reduce pre-inflammatory factors. on the other hand, ropivacaine significantly increased the diameter of the artery compared to the bupivacaine group.