Fig. 1.
Pain during cold pressor test at each target-controlled infusion (TCI) level. Data are presented as mean visual analog scale ± SD. Linear mixed random intercept model with Bonferroni correction for multiple comparisons was used to estimate the differences between treatment groups. Level of significance: P < 0.05. All treatments increased analgesia compared with placebo (P < 0.001). By pairwise comparisons at each TCI level 0.6 to 2.4 ng/ml (levels 1 to 3), pregabalin + remifentanil increased analgesia compared with placebo + remifentanil; −12 mm (−18 to −5, *P < 0.001) at level 1, −20 mm (−28 to −13, *P < 0.001) at level 2, and −10 mm (−17 to −3, **P = 0.002) at level 3.