Anaesthesia
-
Randomized Controlled Trial
The effects of perineural dexmedetomidine on the pharmacodynamic profile of femoral nerve block: a dose-finding randomised, controlled, double-blind study.
This randomised, controlled, double-blind study investigated the effects of different doses of perineural dexmedetomidine on the pharmacodynamic profile of femoral nerve block in patients undergoing arthroscopic knee surgery. Ultrasound-guided femoral nerve block was performed before general anaesthesia using 25 ml of bupivacaine 0.5% combined with normal saline in the control group, and 25 μg, 50 μg or 75 μg of dexmedetomidine in three treatment groups (n = 15 for each group). All patients received a standard general anaesthetic and multimodal postoperative analgesic regimen. ⋯ The total 24-h postoperative morphine consumption was 7.6 (5.1) mg in the control group, and 6.5 (3.5), 3.9 (3.4), 1.8 (2.6) in the 25 μg, 50 μg and 75 μg treatment groups, respectively. Postoperative morphine consumption was significantly higher in the control group compared with the 50 μg (p = 0.045) and the 75 μg (p = 0.001) treatment groups. The best analgesic profile was achieved at the 75 μg dose, but this was associated with increased risk of hypotension.