“…All trials used long-acting LAs, including levobupivacaine in one trial ( 43 ), bupivacaine in three trials ( 37 , 40 , 41 ), and ropivacaine in nine trials ( 7 – 9 , 34 – 36 , 38 , 39 , 42 ). DEX was used at a concentration of 0.5 μg/kg in three trials ( 9 , 37 , 40 ), 1 μg/kg in nine trials ( 7 , 8 , 34 – 36 , 38 , 41 – 43 ), and both concentrations in one trial ( 39 ). Among them, four trials ( 7 , 34 , 38 , 43 ) also examined other adjuvants such as nalbuphine and dexamethasone, which arms were excluded from our analysis as unsuitable for the inclusion criteria.…”