Use of the Colorado State University Feline Acute Pain Scale After Ovariohysterectomy

While validated pain scoring instruments are available for horses, dogs, and mice, many current tools for feline patients are restricted to certain situations (eg, ovariohysterectomy) or are not yet validated.

US researchers recently performed a study to assess inter-rater reliability (IRR) and preliminary validity of a recently developed pain assessment tool, the Colorado State University Feline Acute Pain Scale (CSU-FAPS), for use in a clinical setting.

Study Design

The investigators evaluated intact female cats undergoing ovariohysterectomy through the University of Minnesota College of Veterinary Medicine’s student surgery and anesthesia practice laboratory.

Cats were premedicated with dexmedetomidine, hydromorphone, and ketamine. Anesthesia was induced with propofol with or without ketamine and maintained with isoflurane. Cats were administered a constant-rate infusion of lactated Ringer solution under anesthesia, as well as hydromorphone during or immediately after surgery if signs of nociception or pain occurred.

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To assess IRR of the CSU-FAPS, 2 board-certified anesthesiologists and 2 anesthesiology residents independently evaluated 21 cats approximately 6 hours after returning to their cages following recovery from anesthesia. The raters were familiar with the CSU-FAPS and received verbal and written instructions on its use. Assessment began with observing the patient from a distance, then opening the cage door for examination. Raters circled areas of perceived pain on an anatomic diagram, checked off observed behaviors, and indicated an overall pain score of 0 to 4.

The remaining 47 cats were used to assess validity of the CSU-FAPS compared with the previously validated Glasgow Composite Measure Pain Scale (CMPS-Feline). A rotating small animal intern and a veterinary anesthesiologist independently evaluated cats twice daily on the day before and day of surgery, as well as the morning of the day after surgery. One rater used only the CSU-FAPS, while the other used only the CMPS-Feline.

Results

For the IRR portion of the study, CSU-FAPS pain scores ranged from 0 to 3.25 out of a possible score of 4. IRR, which was calculated using 2 tests (intra-class correlation coefficient and weighted Cohen’s kappa), was determined to be “good” between anesthesiologists and “moderate to good” between residents.

For the validity portion of the study, CSU-FAPS pain scores ranged from 0 to 2.5 out of 4, while CMPS-Feline scores ranged from 0 to 4 out of 20. Correlation between the 2 tests was significant (0.31) but fell short of the recommended validity range of 0.4 to 0.8. Five cats met the cut-off necessary to reassess analgesia with the CSU-FAPS, while no cats met the CMPS-Feline cut-off score for rescue analgesia.

Major Findings

The authors concluded that, while the CSU-FAPS was a relatively simple pain assessment tool, inter-rater reliability was lower than that of the more detailed, validated CMPS-Feline test. They recommended further refinement and testing of the CSU-FAPS before it becomes a standard test for feline pain in clinical settings.

Dr. Stilwell received her DVM from Auburn University, followed by a MS in Fisheries and Aquatic Sciences and a PhD in Veterinary Medical Sciences from the University of Florida. She provides freelance medical writing and aquatic veterinary consulting services through her business, Seastar Communications and Consulting.