Post-anesthetic CPS and EQUUS-FAP scores in surgical and non-surgical equine patients: an observational study

Abstract

BackgroundEquine pain scoring may be affected by the residual effect of anesthetic drugs.ObjectivesTo compare pain scores in the hours immediately following anesthetic recovery to baseline pre-anesthetic scores in equine patients undergoing surgical and non-surgical procedures.Study designClinical observational study.MethodsFifty adult horses undergoing anesthesia for surgical or non-surgical procedures were enrolled. Horses underwent pain scoring using the Composite Pain Score (CPS) and Equine Utrecht University Scale for Facial Assessment of Pain (EQUUS-FAP) prior to anesthesia (T0) and following anesthetic recovery to standing, every hour for 5 h (T1-T5). Data were analyzed using a generalized linear mixed effects model. A post-hoc Dunnett's test for multiple comparisons was performed for variables where an effect was detected.ResultsMean (95% confidence interval) CPS scores for T0-T5 were 1.6 (1.2–2.0), 6.8 (6.0–7.6), 5.1 (4.3–5.9), 4.3 (3.4–5.2), 3.7 (2.8–4.6), and 2.8 (2.0–3.6) and EQUUS-FAP scores were 0.6 (0.3–0.9), 3.0 (2.5–3.5), 1.9 (1.6–2.2), 1.1 (0.8–1.4), 0.6 (0.4–0.8), and 0.7 (0.4–1.0), respectively. For the CPS, scores greater than 5, and for the EQUUS-FAP scores greater than 3, are consistent with minor pain. There was no effect of type of procedure (surgical vs non-surgical) on CPS or EQUUS-FAP scores. There was an effect of time with CPS scores significantly greater than baseline at T1-T5 and EQUUS-FAP scores significantly greater than baseline at T1 and T2.Main limitationsDiscomfort caused by hoisting was not quantified and it was difficult to ascertain if this affected the results.ConclusionsPost-anesthetic pain scores may be influenced by the residual effect of anesthetic agents for as long as 5 h and 2 h for the CPS and EQUUS-FAP, respectively.

From facial expressions to algorithms: a narrative review of animal pain recognition technologies

“…However, since pain is a subjective experience, this approach may not eliminate bias. Additionally, the type and duration of pain need to be researched further, as there are postulations about differences in facial expressions of pain between acute nociceptive and chronic pain and on the effects of general anesthesia ( 14 , 47 , 95 ). These hypotheses, for example, could be tested to improve the understanding and detection of pain in animals.…”

“…In many cases, animals were assessed both before and after procedures requiring general anesthesia ( 8 , 22 , 27 , 29 , 31 ). However, studies have shown that the facial expression of pain can remain altered for several hours after inhalant anesthesia in both experimental mice and rats ( 45 , 46 ) and in horses ( 47 ). This effect likely holds for other animal species.…”