ORIGINAL ARTICLE   Free access

Minerva Anestesiologica 2017 June;83(6):590-7

DOI: 10.23736/S0375-9393.17.11430-6

Copyright © 2017 EDIZIONI MINERVA MEDICA

language: English

Adding dexmedetomidine to ropivacaine for femoral nerve block inhibits local inflammatory response

Jing LI ¹ ✉, Hanghui WANG ², Buhuai DONG ¹, Jianbing MA ², Xucai WU ¹

¹ Department of Anesthesiology, Honghui Hospital, Xi’an Jiaotong University, Xi’an, China; ² Department of Orthopedics, Honghui Hospital, Xi’an Jiaotong University, Xi’an, China

BACKGROUND: 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).
METHODS: 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 were injected for the block; in group RD, 20 mL of 0.5% ropivacaine plus 1 µg/kg DEX were administered. Visual Analog Scale (VAS), the circumference of the operated knee, and the concentration of interleukin-6 (IL-6) and prostaglandin E2 (PGE2) in joint fluid were evaluated. Adverse events such as hypotension, bradycardia and hypoxia were recorded.
RESULTS: VAS was lower in group RD for 12 to 48 hours 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 was lower at 6, 12, 24, and 48 hours after surgery (P<0.02), IL-6 was lower at 12, 24, and 48 hours after surgery (P<0.03). No adverse events were observed.
CONCLUSIONS: Adding 1 µg/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.

KEY WORDS: Dexmedetomidine - Inflammation - Knee replacement arthroplasty - Nerve block - Dinoprostone - Interleukin-6