Figure 8. Presence of the observer had a minimal effect on Rat Grimace Scale (RGS) scores.

No observer effect was observed in the saline (A) p = 0.30) and multimodal treatment groups (C) p = 0.28). A significant difference between observation periods was present in the buprenorphine group (B) at 24 hours, between V1 and V2 (p < 0.0001) and between IMG-O+V and V2 (p = 0.01). V1 and V2 = video only, no observer present. O+V = video, with observer present. Data are mean ± SEM. Broken horizontal line represents a previously derived analgesic intervention threshold¹⁶.