3.4. Results of primary outcomes
The forest plot (Figure 3 ) reveals the network meta-analysis’ results for the primary outcomes. In terms of postoperative pain intensity, amantadine, magnesium sulphate, pregabalin, dexmedetomidine, ibuprofen, flurbiprofen plus dexmedetomidine, parecoxib, parecoxib plus dexmedetomidine and S (+)-ketamine plus methadone were associated with milder pain intensity than placebo, with SMDs ranging between -3.06 (95% CI: -4.67, -1.45) for amantadine and -0.62 (95% CI: -1.23, -0.01) for magnesium sulphate. In terms of the incidence of PONV, intervene with dexmedetomidine (OR=0.25, 95% CI: 0.11, 0.54) or flurbiprofen plus dexmedetomidine (OR=0.27, 95% CI: 0.08, 0.87) means lower incidence of PONV than placebo.
The league table (Figure 4 ) illustrates head-to-head comparisons for postoperative pain intensity (lower left portion) and the incidence of PONV (upper right portion) of all pharmacological intervention strategies and placebo. The pairwise comparison outcome are expressed as SMD (95%CI) and OR (95%CI) respectively. The two-dimensional graph (Figure 5 ) shows that only dexmedetomidine and flurbiprofen plus dexmedetomidine are superior to placebo in terms of both postoperative pain intensity and the incidence of PONV.
In the ranking probability plot (Appendix4 Figure 4 ), for postoperative pain intensity, amantadine seemed to be the best agent among all 20 treatments whose SUCRA values was 96.2. In terms of the incidence of PONV, it was proved that dexmedetomidine appeared to be the best option among all 17 treatments for PONV with an SUCRA value of 90.3.