Evaluation and comparison of postoperative analgesic effects of dexketoprofen and methadone in dogs

The standards of reporting trials in pets (PetSORT): Explanation and elaboration

Well-designed randomized controlled trials (RCTs) provide the best evidence of the primary research designs for evaluating the effectiveness of interventions. However, if RCTs are incompletely reported, the methodological rigor with which they were conducted cannot be reliably evaluated and it may not be possible to replicate the intervention. Missing information also may limit the reader's ability to evaluate the external validity of a trial. Reporting guidelines are available for clinical trials in human healthcare (CONSORT), livestock populations (REFLECT), and preclinical experimental research involving animals (ARRIVE 2.0). The PetSORT guidelines complement these existing guidelines, providing recommendations for reporting controlled trials in pet dogs and cats. The rationale and scientific background are explained for each of the 25 items in the PetSORT reporting recommendations checklist, with examples from well-reported trials.

Intraperitoneal administration of lidocaine or tramadol alone or in combination on postoperative pain after ovariohysterectomy in dogs

The present prospective randomized experimental study aimed to assess the intraperitoneal (ip) administration of lidocaine or tramadol, alone or in combination, on postoperative pain management following ovariohysterectomy in dogs. Eighteen healthy female mixed‐breed dogs, aged 1–2 years, weighed 16.7 ± 3.8 kg, were used. Animals were sedated with acepromazine (0.1 mg/kg, intramuscular). Forty minutes later, anaesthesia was induced through intravenous titration with diazepam (0.5 mg/kg) and ketamine (10 mg/kg) and maintained with isoflurane 1.5%. Afterwards, ovariohysterectomy was performed, and prior to the closure of the linea alba, animals received lidocaine containing epinephrine (8.8 mg/kg, ip) in group L, tramadol (4 mg/kg, ip) in group T and lidocaine containing epinephrine (8.8 mg/kg, ip) plus tramadol (4 mg/kg, ip) in the LT group. Cortisol, vital signs and pain scoring systems were evaluated at different time points. Vital signs did not change among the groups. Cortisol level in the LT group significantly decreased compared to the L and T groups one, three and six hours after surgery. Pain scores also did not change among the groups based on Sammarco and Simple descriptive (SDS) scoring method. However, pain scores in the LT group were higher than the two other groups according to the University of Melbourne pain scale (UMPS) and the short form of Glasgow pain scale (CMPS‐SF). According to the obtained results, the combination of lidocaine and tramadol seemed to be able to provide better analgesia compared with their separate administration. Therefore, combined intraperitoneal administration of lidocaine (8.8 mg/kg) and tramadol (4 mg/kg) with a final volume of (0.2 ml/kg) following ovariohysterectomy is recommended.

Determination of acute tolerance and hyperalgesia to remifentanil constant rate infusion in dogs undergoing sevoflurane anaesthesia

OBJECTIVE

To determine if acute opioid tolerance (AOT) or opioid-induced hyperalgesia (OIH) could develop and limit the remifentanil-induced reduction in the sevoflurane minimum alveolar concentration (MAC). The response to mechanical nociceptive threshold (MNT) was evaluated and related to OIH.

STUDY DESIGN

A crossover, randomized, experimental animal study.

ANIMALS

A total of nine Beagle dogs.

METHODS

The dogs were anaesthetized with sevoflurane in 50% oxygen. Baseline sevoflurane MAC was measured (MACb1). Remifentanil (0.3 μg kg^-1 minute^-1) or 0.9% saline constant rate infusion (CRI) was administered intravenously (IV). Sevoflurane MAC was determined 20 minutes after CRI was initiated (MACpostdrug1), 30 minutes after MACpostdrug1 determination (MACpostdrug2) and after 1 week (MACb2). The MNT was determined at baseline (before anaesthesia), 3 and 7 days after anaesthesia. An increase of MACpostdrug2 ≥0.25% compared to MACpostdrug1 was considered evidence of AOT. A decrease in MNT at 3 and 7 days or an increase in MACb2 or both with respect to MACb1 were considered evidence of OIH.

RESULTS

Remifentanil CRI reduced sevoflurane MACpostdrug1 by 43.7% with respect to MACb1. MACpostdrug2 was no different from MACpostdrug1 with the saline (p = 0.62) or remifentanil (p = 0.78) treatments. No significant differences were observed in the saline (p = 0.99) or remifentanil (p = 0.99) treatments between MACb1 and MACb2, or for MNT values between baseline, 3 and 7 days.

CONCLUSION AND CLINICAL RELEVANCE

In dogs, under the study conditions, remifentanil efficacy in reducing sevoflurane MAC did not diminish in the short term, suggesting remifentanil did not induce AOT. Hyperalgesia was not detected 3 or 7 days after the administration of remifentanil. Contrary to data from humans and rodents, development of AOT or OIH in dogs is not supported by the findings of this study.