Pain cat dental extractions Dexmedetomidine and anaesthesic block



1/ A multidisciplinary study of pain in cats undergoing dental extractions: A prospective, blinded, clinical trial

Watanabe R, Doodnaught G, Proulx C, Auger J-P, Monteiro B, Dumais Y, et al. (2019) 

Résumé : This study aimed to evaluate pain scores, analgesic requirements, food intake and serum inflammatory cytokines in cats before and after clinically recommended dental treatment. Twenty-four cats were included in a prospective, blinded clinical trial. Cats were equally divided into minimal (minimal dental treatment) or severe (multiple dental extractions) oral disease groups. They were admitted (day 0) and underwent oral examination/radiographs/treatment under general anesthesia (day 1; acepromazine-hydromorphone-propofol-isoflurane-meloxicam-local anesthetic blocks). Serum inflammatory cytokines were measured on days 0 and 6. Pain was scored using the Glasgow composite measure pain scale-feline (CMPS-F). Rescue analgesia was administered with hydromorphone if CMPS-F ≥ 5/20. Dry and soft food intake (%) during 3 minutes and 2 hours, and daily soft food were calculated. The Cochran-Mantel-Haenszel and Chi-square tests, Spearman’s rank correlation and linear mixed models were used for statistical analysis (alpha = 0.05). Pain scores were significantly increased in cats with severe disease when compared with baseline (up to day 4) and minimal disease (all postoperative time points). Prevalence of rescue analgesia was significantly higher in severe (91.7%) than minimal disease (0%); analgesics were required up to day 3. Pain scores and frequency of rescue analgesia were significantly correlated with the number of tooth extractions, gingival and calculus index. Prevalence of rescue analgesia was significantly correlated with the number of missing teeth, teeth extractions and gingival index. Dry and soft food intake during 3 minutes, and dry food intake during 2 hours were significantly lower in the severe than minimal disease group throughout the study. Some cytokines differed between groups between day 0 and day 6 and were associated with the presence of tooth resorption and number of missing tooth and tooth fractures. Long-term analgesia is required after dental extractions in cats with severe oral disease. This condition reduces food intake and influences serum inflammatory cytokines.

2/ Effects of intravenous dexmedetomidine infusion on local anaesthetic block: A spinal anaesthesia clinical model in dogs undergoing hind limb surgery

D. Sarotti, R. Rabozzi, P. Franci

Res. Vet. Sci., In Press, Accepted Manuscript, Available online 2 March 2019

Résumé : The aim of this randomised, prospective clinical trial was to determine how the administration of a low dose of dexmedetomidine (DEX) by IV constant rate infusion, modified the duration of the nerve block in dogs undergoing spinal anaesthesia (SA) in a clinical setting. Forty-four dogs undergoing hind limb orthopaedic surgery in a day-surgery regime, maintained under anaesthesia with isoflurane plus SA, were randomly assigned to receive 1 μg/kg/h (IV) of DEX (group D) or not (group C). Spinal anaesthesia was performed with a hyperbaric solution of bupivacaine and morphine at the L5–6 interspace. Every mean arterial pressure (MAP) increase by 30% above the pre-skin incision value was considered an intraoperative analgesic failure and treated with a bolus of fentanyl as intraoperative rescue analgesia (iRA). Time free from iRA was analysed with a Kaplan-Maier survival curve. The ability to walk at 5 h from SA and the event of bradycardia (HR lower 60 beat per min) and hypotension (MAP value lower 60 mmHg) were recorded. The mean times at which iRA was required were 77.4 (3.2) in group C and 112.2 (8.6) in group D (Logrank test P = 0.038). In groups C and D hypotension incidence was 11/17 (65%) and 2/22 (9%), (P = 0.0004) and bradycardia 3/17 (18%) and 6/22 (27%) (P = 0.704), respectively. The ability to walk 5 h after SA was 14/14 (100%) and 13/14 (93%) in groups C and D, respectively. DEX infusion significantly prolonged the duration of the nociceptive nervous block without prolonging the motor block or increasing the bradycardia events.