Peer Review #2 of "Clinical applicability of the Feline Grimace Scale: real-time versus image scoring and the influence of sedation and surgery (v0.1)"

Abstract

Background. The Feline Grimace Scale (FGS) is a facial expression-based scoring system for acute pain assessment in cats with reported validity using image assessment. The aims of this study were to investigate the clinical applicability of the FGS in real-time when compared with image assessment, and to evaluate the influence of sedation and surgery on FGS scores in cats. Methods. Sixty-five female cats (age: 1.37 ± 0.9 years and body weight: 2.85 ± 0.76 kg) were included in a prospective, randomized, clinical trial. Cats were sedated with intramuscular acepromazine and buprenorphine. Following induction with propofol, anesthesia was maintained with isoflurane and cats underwent ovariohysterectomy (OVH). Pain was evaluated at baseline, 15 minutes after sedation, and at 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours after extubation using the FGS in real-time (FGS-RT). Cats were video-recorded simultaneously at baseline, 15 minutes after sedation, and at 2, 6, 12, and 24 hours after extubation for subsequent image assessment (FGS-IMG), which was performed six months later by the same observer. The agreement between FGS-RT and FGS-IMG scores was calculated using the Bland & Altman method for repeated measures. The effects of sedation (baseline versus 15 minutes) and OVH (baseline versus 24 hours) were assessed using linear mixed models. Responsiveness to the administration of rescue analgesia (FGS scores before versus one hour after) was assessed using paired ttests. Results. Minimal bias (-0.057) and narrow limits of agreement (-0.351 to 0.237) were observed between the FGS-IMG and FGS-RT. Scores at baseline (FGS-RT: 0.16 ± 0.13 and FGS-IMG: 0.14 ± 0.13) were not different after sedation (FGS-RT: 0.2 ± 0.15, p = 0.39 and FGS-IMG: 0.16 ± 0.15, p = 0.99) nor at 24 hours after extubation (FGS-RT: 0.16 ± 0.12, p = 0.99 and FGS-IMG: 0.12 ± 0.12, p = 0.96). Thirteen cats required rescue analgesia; their FGS scores were lower one hour after analgesic administration (FGS-RT: 0.21 ± 0.18 and FGS-IMG: 0.18 ± 0.17) than before (FGS-RT: 0.47 ± 0.24, p = 0.0005 and PeerJ reviewing PDF | Manuscript to be reviewed FGS-IMG: 0.45 ± 0.19, p = 0.015). Conclusions. Real-time assessment slightly overestimates image scoring; however, with minimal clinical impact. Sedation with acepromazine-buprenorphine and ovariohysterectomy using a balanced anesthetic protocol did not influence the FGS scores. Responsiveness to analgesic administration was observed with both the FGS-RT and FGS-IMG.Manuscript to be reviewed 1 Clinical applicability of the Feline Grimace Scale: real-2 time versus image scoring and the influence of 3 sedation and surgery 4 5 6 Marina Abstract 20 Background. The Feline Grimace Scale (FGS) is a facial expression-based scoring system for 21 acute pain assessment in cats with reported validity using image assessment. The aims of this 22 study were to investigate the clinical applicability of the FGS in real-time when compared with 23 image assessment, and to evaluate the influence of sedation and surgery on FGS scores in cats. ...