Efficacy of Dexmedetomidine as an Adjuvant to Local Anesthetics in Peribulbar Block: A Meta-analysis With Trial-Sequential Analysis

Purpose

To assess the role of dexmedetomidine as an adjuvant to local anesthetics (LA) in enhancing the duration and quality of peribulbar blocks for ophthalmic surgeries.

Design

Systematic review with meta-analysis and trial sequential analysis.

Methods

We systematically searched MEDLINE, Embase, and Cochrane for randomized controlled trials involving adult patients undergoing ophthalmic surgery under peribulbar block, comparing LA alone vs LA + dexmedetomidine. Risk ratios (RR) and mean differences (MD) with 95% confidence intervals were computed using a random-effects model. Sensitivity and trial-sequential analyses were performed to assess inconsistencies and weight type I and II errors, and estimate the required information size of the samples for all end points.

Results

Sixteen randomized controlled trials (1220 patients) were included. Compared with LA alone, dexmedetomidine was associated with prolonged (1) motor block duration (MD: 65.01 minutes, P < .001), (2) sensory block duration (MD: 81.94 minutes, P < .001), (3) reduced intraocular pressure (MD: –2.6 mm Hg, P < .001), and (4) decreased need for supplemental injections (RR: 0.44, P = .007). In addition, dexmedetomidine showed (5) longer time to analgesic request (MD: 97.15 minutes, P < .001) and (6) increased surgeon satisfaction (RR: 1.52, P = .01). Sensitivity analyses and trial-sequential analyses were consistent across all end points, and the required information size was achieved for most end points, indicating that pooled analyses were reliable and sample sizes were sufficient.

Conclusions

Compared with LA alone, dexmedetomidine significantly prolonged sensory and motor block duration and the time to the first analgesic request; moreover, it decreased intraocular pressure and the need for supplemental injections, while increasing surgeon satisfaction.