Clinical efficacy of intra-articular lidocaine with or without adrenaline during shoulder arthroscopy in dogs

Introduction: Intra-articular (IA) administration of local anaesthetic drugs has been widely reported in shoulder, elbow, ankle and knee arthroscopy in human medicine. The use of IA adrenaline to control bleeding in arthroscopy is relatively common, but its combined effect with local anaesthetics on perioperative pain has not been studied in dogs. This study aims at evaluating the efficacy of IA shoulder administration of lidocaine or lidocaine plus adrenaline in dogs (Canis lupus familiaris) as pre-emptive analgesia during arthroscopic surgery under general anaesthesia. Methods: Twenty-four dogs were randomly assigned to receive a bolus of lidocaine 2% (group L), a mixture of lidocaine and adrenaline (group LA) or saline solution (NaCl 0.9%) (Control group-group C), injected into a shoulder joint before arthroscopic surgery. Haemodynamic and respiratory parameters were recorded at scheduled times: Baseline (B) at stable anaesthesia and before the painful stimuli; joint injection (J) and 5, 10, 15 minutes post J; trocar insertion (T) and 5, 10, 20, 30, 45, 60 minutes post T. If at least one of the baseline parameters among heart rate, respiratory rate and indirect systolic blood pressure increased by more than 20%, a bolus of 0.2 μg/kg of sufentanil was administered intravenously as rescue analgesia. Results: Results of this study show that the total dose of sufentanil and the number of boluses required during surgery were significantly lower in group L [odds ratio 6.28 (95% CI: 2-07-18.98)] and LA [odds ratio 8.45 (95% CI: 2.44-29.27)] compared to group C. In group LA, the time of first sufentanil bolus administration was significantly delayed compared to the other two groups. Significant differences in the variability of haemodynamic parameters were observed for HR (p = < 0.001), DAP (p = 0.041), RR (p = 0.013) at T0 (Baseline, before treatment). These findings indicate greater parameter variability in dogs of Group C (control group) compared with the other groups. Discussion/conclusion: Compared with placebo, intra articular administration of lidocaine or lidocaine combined with adrenaline just before shoulder arthroscopic surgery in dogs reduces the intraoperative requirement for sufentanil, indicating that this local analgesic approach contributes effectively to a multimodal analgesic protocol.