Efficacy comparison of intraperitoneal anaesthesia and post-operative analgesia regimens in laboratory rats

Introduction: Effective and safe anesthesia for rodents has long been a leading concern among biomedical researchers. Intraperitoneal injection constitutes an alternative to inhalant anesthesia. Purpose: The aim of this study was to identify a safe, reliable, and effective anesthesia and postoperative analgesia protocol for laboratory rats exposed to painful procedures. Material and methods: Twenty-seven female Wistar rats in an ongoing study that required surgery were randomized into groups for three different intraperitoneal anesthesia protocols and three different analgesia regimens. The anesthesia groups were (1) medetomidine + ketamine (MK), (2) ketamine + xylacine (KX), and (3) fentanyl + medetomidine (FM). Three analgesia groups were equally distributed among the anesthesia groups: (1) local mepivacaine + oral ibuprofen (MI), (2) oral tramadol + oral ibuprofen (TI), and (3) local tramadol + oral tramadol + + oral ibuprofen (TTI). A core was assigned to measure anesthesia (0-3) and analgesia (0-2) effectiveness; the lower the score, the more effective the treatment. Results: The mean MK score was 0.44 versus 2.00 for FM and 2.33 for KX. Mean score for analgesia on the first postoperative day was TTI (4.66) TI (9.13), and MI (10.14). Mean score 48 hours after surgery was TTI (3.4), TI (6.71), and MI (9.5). These differences were statistically significant. Conclusion: MK was shown to be a reliable, safe, and effective method of anesthesia. The TTI analgesia regimen is strongly recommended in light of these results.