Fig 1.
PRISMA Flow diagram of this meta-analysis.
Fig 2.
Risk of bias summary.
Fig 3.
Forest plot displaying the results of pain response score and the results of subgroup analysis by type of postoperative analgesia.
Fig 4.
Results of meta-regression analysis.
Fig 5.
Forest plot displaying the results of postoperative analgesic consumption and the results of subgroup analysis by mean age.
Fig 6.
Forest plot displaying the results of the time of first request for postoperative analgesia.
Fig 7.
Forest plot displaying the results of incidence of PONV.