Authors: Maagaard M et al.
BMJ Journals Regional Anesthesia & Pain Medicine Vol 50 Issue 4
Summary
This systematic review with meta-analysis and trial sequential analysis evaluated whether combining dexamethasone and dexmedetomidine as adjuncts to peripheral nerve blocks prolongs analgesia compared with placebo or either adjunct alone. Although both agents are commonly used to extend block duration, the incremental benefit of combining them has remained uncertain.
The authors identified nine randomized controlled trials comprising 14 eligible comparisons in adult surgical patients receiving peripheral nerve blocks. Comparators included placebo, dexamethasone alone, and dexmedetomidine alone. The primary outcome was duration of analgesia. Methodologic rigor was assessed using risk of bias-2, GRADE, and trial sequential analysis.
Compared with placebo, the combination of dexamethasone and dexmedetomidine significantly prolonged analgesia by several hours. The combination also extended analgesia when compared with dexmedetomidine alone. However, when compared with dexamethasone alone, the duration of analgesia was similar, with no clinically meaningful difference. Overall certainty of evidence was graded as moderate, largely due to high risk of bias across many included trials.
These findings suggest that while adding both agents is superior to placebo and dexmedetomidine alone, dexamethasone appears to be the dominant contributor to prolonging analgesia. The routine addition of dexmedetomidine to dexamethasone may not provide additional benefit if the primary goal is extending block duration.
Key Points
Combining dexamethasone and dexmedetomidine prolongs analgesia compared with placebo.
The combination provides longer analgesia than dexmedetomidine alone.
Analgesia duration with the combination is similar to dexamethasone alone.
Most included trials had a high risk of bias, resulting in moderate certainty of evidence.
Dexamethasone alone appears sufficient when the primary goal is prolonging block duration.
Thank you BMJ Journals Regional Anesthesia & Pain Medicine for allowing us to review and summarize this important systematic review on peripheral nerve block adjuncts.