A critical evaluation for validation of composite and unidimensional postoperative pain scales in horses.

Proper pain therapy requires adequate pain assessment. This study evaluated the reliability and validity of the Unesp-Botucatu horse acute pain scale (UHAPS), the Orthopedic Composite Pain Scale (CPS) and unidimensional scales in horses admitted for orthopedic and soft tissue surgery. Forty-two horses were assessed and videotaped before surgery, up to 4 hours postoperatively, up to 3 hours after analgesic treatment, and 24 hours postoperatively (168 video clips). After six evaluators viewing each edited video clip twice in random order at a 20-day interval, they chose whether analgesia would be indicated and applied the Simple Descriptive, Numeric and Visual Analog scales, CPS, and UHAPS. For all evaluators, intra-observer reliability of UHAPS and CPS ranged from 0.70 to 0.97. Reproducibility was variable among the evaluators and ranged from poor to very good for all scales. Principal component analysis showed a weak association among 50% and 62% of the UHAPS and CPS items, respectively. Criterion validity based on Spearman correlation among all scales was above 0.67. Internal consistency was minimally acceptable (0.51-0.64). Item-total correlation was acceptable (0.3-0.7) for 50% and 38% of UHAPS and CPS items, respectively. UHAPS and CPS were specific (90% and 79% respectively), but both were not sensitive (43 and 38%, respectively). Construct validity (responsiveness) was confirmed for all scales because pain scores increased after surgery. The cut-off point for rescue analgesia was ≥ 5 and ≥ 7 for the UHAPS and CPS, respectively. All scales presented adequate repeatability, criterion validity, and partial responsiveness. Both composite scales showed poor association among items, minimally acceptable internal consistency, and weak sensitivity, indicating that they are suboptimal instruments for assessing postoperative pain. Both composite scales require further refinement with the exclusion of redundant or needless items and reduction of their maximum score applied to each item or should be replaced by other tools.

Recovery Quality After Romifidine Versus Detomidine Infusion During Isoflurane Anesthesia in Horses.

To examine the influence of detomidine or romifidine on recovery quality from isoflurane anesthesia, 78 anesthetic records were reviewed, from horses that had received romifidine (group R) during premedication [80-120 µg kg-1 IV], anesthetic maintenance (40 µg kg-1 hour-1 IV), and recovery (20 µg kg-1 IV) or detomidine (group D), at doses of 10-20 µg kg-1 IV, 5 µg kg-1 hour-1 IV, and 2.5 µg kg-1 IV, respectively. Duration of the different recovery phases, the number of attempts to sternal and standing, scores for transition to standing (TrSta), balance and coordination once standing (BC), and final recovery score (FS) were compared between groups using a Mann-Whitney U-test, independent t-test, or chi-squared test, as appropriate (alpha 0.05). Parametric data are represented as the mean ± standard deviation, and nonparametric data as the median (interquartile range). Compared with group D (25 horses), horses in group R (53 horses) needed significantly fewer attempts to achieve sternal recumbency [R 1 (1-1) vs. D 1 (1-2)], remained significantly longer in sternal recumbency [R 10 (3-14,5) vs. D 5 (1-9,5) minutes], needed significantly less attempts to stand [R 1 (1-1) vs. D 2 (1-4)], and a significantly shorter time to stand after making their first attempt [R 0 (0-0) vs. D 3 (0-6) minutes], with significantly better scores for TrSta, BC, and FS in group R. The results suggest that, at the doses used, romifidine provides a better recovery quality.

Pharmacopuncture Analgesia Using Flunixin Meglumine Injection into the Acupoint GV1 (Ho Hai) After Elective Castration in Horses.

The study evaluated the effect of a 1/10 dose of flunixin meglumine administered into the governing vessel 1 (GV1) acupoint in horses that underwent castration. Twenty animals received 0.02 mg/kg detomidine intravenously, followed by 2.2 mg/kg ketamine and 0.1 mg/kg diazepam by the same route, and also a local anesthesia with 30 mL lidocaine. As postoperative analgesia, the animals received 1.1 mg/kg flunixin meglumine IV (FIV) or 0.11 mg/kg flunixin meglumine into the GV1 acupoint (FGV). Behavioral parameters were assessed 12 hours before the procedure (baseline) and at 4, 6, 12, and 24 hours after surgery; physiological parameters were measured at baseline and at 2, 4, 6, 8, 10, 12, 16, and 24 hours after surgery. The groups did not differ regarding pain scores. Heart rate was higher in the FIV group than in the FGV group 2 hours after surgery (46 ± 5.2 bpm vs. 37 ± 8.2 bpm); gut sounds decreased at 2, 4, and 6 hours in both groups. The temperature showed a decrease after 2 hours compared with baseline in the FGV group, and the systolic blood pressure was higher in the FGV group than in the FIV group at 8 hours (158 ± 18.1 mmHg vs. 134 ± 14.5 mmHg), 10 hours (157 ± 15.5 mm Hg vs. 130 ± 11.5 mmHg), and 12 hours (151 ± 18.7 mmHg vs. 134 ± 15.8 mmHg). Pharmacopuncture was as effective as conventional dose and route of flunixin meglumine in horses that underwent elective castration under those conditions.

Effect of Methadone Combined With Acepromazine or Detomidine on Sedation and Dissociative Anesthesia in Healthy Horses.

The aim of this study was to compare the effects of methadone combined with detomidine or acepromazine on the quality of sedation and its influence over dissociative anesthesia in healthy horses. In a crossover design, seven horses were administered with 0.1 mg/kg methadone and 0.02 mg/kg detomidine intravenously (group MD) or 0.1 mg/kg methadone and 0.05 mg/kg acepromazine intravenously (group MA). Subsequently, anesthesia was induced with a combination of 2.2 mg/kg ketamine and 0.1 mg/kg midazolam intravenously. Descriptive scales and footages were used to evaluate the quality of sedation, induction, anesthesia maintenance, and recovery. Physiological parameters, arterial blood gas, and electrolytes were assessed from baseline to the recovery of anesthesia. The MA group showed lower arterial blood pressure and higher heart rate compared with the group MD. A slight decrease in arterial blood oxygen levels was observed after recumbency, more prominently in the MA group. There was no difference in the quality or time of induction or maintenance or recovery of anesthesia between groups. The results suggest that both premedication protocols produce good sedation and quality of anesthesia. Methadone combined with detomidine produced a good cardiopulmonary stability compared with methadone combined with acepromazine and might be safer to be used as premedication for dissociative anesthesia compared with methadone combined with acepromazine in healthy horses.