Fig. 1.  The numeric rating scale (NRS) pain score in the postanesthesia care unit (PACU) (by repeated-measures analysis of variance). Plots show mean NRS pain scores (mean ± SD) at different time points in the PACU. A between-subject factor group was significant at level P = 0.026 (partial η squared 0.071), and a within subject factor time was significant at level P  less than 0.0005 (partial η squared 0.236). However, an interaction (group × time) was not significant. The post hoc  comparisons with Bonferroni correction on factor group was not found to be significant. The post hoc  comparisons with Bonferroni correction on factor time was significant between adjacent time points (30 and 45 min: P  less than 0.0005, partial η squared = 0.160; 45 min and D/C: P = 0.001, partial η squared = 0.134). Group 1: LA control = local anesthetic block + intramuscular placebo; group 2: intramuscular control = local anesthetic block + intramuscular buprenorphine; group 3: additive = local anesthetic/buprenorphine block + intramuscular placebo. D/C = discharge time.