When used in combination with local anesthetics, dexmedetomidine (DEX) may increase nerve block-associated analgesia for approximately 5 hours, but use of DEX may be associated with a higher risk for intraoperative hypotension and bradycardia, according to a study published in the European Journal of Anaesthesiology.
The researchers performed a systematic review that included randomized controlled trials with meta-analysis and trial sequential analysis, and assessed the quality of evidence using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. After searching MEDLINE, CENTRAL and EMBASE, they included 46 trials with 3149 total participants.
Study participants who received local anesthetics in addition perineural DEX vs alone were found to have a longer duration of analgesia (mean difference, 4.87 hours; 95% CI, 4.02-5.73 hours; P <.001; moderate-quality evidence). Participants who received DEX had an increased risk for intraoperative bradycardia cardia (risk ratio, 2.83; 95% CI, 1.50-5.33; P =.035; very low quality evidence) and for intraoperative hypotension (risk ratio, 3.42; 95% CI, 1.24-9.48; P =.002; very low quality evidence). The analgesia duration was comparable when DEX was administered via the perineural or intravenous route when combined with local anesthetics (mean difference, 0.98 hours; 95% CI, −0.12 to 2.08 hours; P =.08).
“As the perineural injection of DEX is currently off-label in peripheral regional anaesthesia, there is a need for trials focusing on adverse events following perineural DEX to better define patients at a high risk of intraoperative bradycardia or hypotension,” the researchers wrote.
Schnabel A, Reichl SU, Weibel S, et al. Efficacy and safety of dexmedetomidine in peripheral nerve blocks: a meta-analysis and trial sequential analysis. Eur J Anaesthesiol. 2018;35:1-14.