Peripheral nerve block has an anti-inflammatory effect that is confirmed in animal studies, while inconclusive in human studies. Dexmedetomidine (DEX), a highly selective α2-adenoceptor agonist, has a potent anti-inflammatory effect. The aim of this study was to evaluate the effect of DEX added to ropivacaine for femoral nerve block (FNB) on local inflammatory response after total knee arthroplasty (TKA). Sixty patients scheduled for TKA were randomized into two equal groups in a prospective randomized study. They were all treated with FNB preoperatively. In group R, 20 ml of 0.5% ropivacaine was injected for the block; in group RD, 20 ml of 0.5% ropivacaine plus 1 μg/kg DEX was administered. Visual analog pain scale (VAS), the circumference of the operated knee and the IL-6 and PGE2 concentration in joint fluid were evaluated. Adverse events such as hypotension, bradycardia and hypoxia were recorded. VAS was lower in group RD for 12h to 48h after surgery (p < 0.03). Knee circumference was smaller in group RD at each time point after surgery (p < 0.05). PGE2 in joint fluid in group RD were lower at 6h, 12h, 24h and 48h after surgery (p<0.02), IL-6 were lower at 12h, 24h and 48h after surgery (p<0.03). Adverse events were not seen. Adding 1μg/kg dexmedetomidine to ropivacaine for femoral nerve block had a significantly inhibitory effect on local inflammatory response and showed superior postoperative pain control to ropivacaine alone after TKA.
PMID: 28106354 [Pubmed - Publisher]