Dexmedetomidine with different concentrations added to local anesthetics in erector spinae plane block: a meta-analysis of randomized controlled trials

Background Dexmedetomidine has been used as a perineural local anesthetic (LA) adjuvant to facilitate the potency of erector spinal plane block (ESPB). This quantitative review aimed to evaluate whether perineural dexmedetomidine for ESPB can improve the effects of analgesia compared to LA alone. Methods Randomized controlled trials (RCTs) that investigated the addition of dexmedetomidine to LA compared to LA alone in ESPB were included. The pain scores, duration of sensory block, the time to first analgesia requirement, postoperative morphine consumption, rescue analgesia, and dexmedetomidine-related side effects were analyzed and combined using random-effects models. Results A total of 823 patients from 13 RCTs were analyzed. Dexmedetomidine was used at the concentration of 0.5 μg/kg in three trials and 1 μg/kg in nine trials, and both in one trial. Both concentrations of dexmedetomidine perineurally administrated significantly reduced the rest VAS scores postoperatively at 12 h (0.5 μg/kg dexmedetomidine: MD = −0.86; 95% CI: −1.59 to −0.12; p = 0.02; 1 μg/kg dexmedetomidine: MD = −0.49; 95% CI: −0.83 to −0.16; p = 0.004), and 24 h (0.5 μg/kg dexmedetomidine: MD = −0.43; 95% CI: −0.74 to −0.13; p = 0.005; 1 μg/kg dexmedetomidine: MD = −0.62; 95% CI: −0.84 to −0.41; p 0.00001). Both concentrations of dexmedetomidine added in LAs improved the dynamic VAS scores postoperatively at 12 h (0.5 μg/kg dexmedetomidine: MD = −0.55; 95% CI: −0.95 to −0.15; p = 0.007; 1 μg/kg dexmedetomidine: MD = −0.66; 95% CI: −1.05 to −0.28; p = 0.0006) and 24 h (0.5 μg/kg dexmedetomidine: MD = −0.52; 95% CI: −0.94 to −0.10; p = 0.01; 1 μg/kg dexmedetomidine: MD = −0.46; 95% CI: −0.75 to −0.16; p = 0.002). Furthermore, perineural dexmedetomidine prolonged the duration of the sensory block and the time to first analgesia requirement, reduced postoperative morphine consumption, and lowered the incidence of rescue analgesia and chronic pain. Conclusion The meta-analysis showed that using perineural dexmedetomidine at either 0.5 μg/kg or 1 μg/kg doses in ESPB can effectively and safely enhance pain relief. Systematic review registration PROSPERO (CRD42023424532: https://www.crd.york.ac.uk/PROSPERO/ ).