Effects of fentanyl–lidocaine–ketamine versus sufentanil–lidocaine–ketamine on the isoflurane requirements in dogs undergoing total ear canal ablation and lateral bulla osteotomy

ObjectiveTo compare the isoflurane-sparing effects of sufentanil–lidocaine–ketamine (SLK) and fentanyl–lidocaine–ketamine (FLK) infusions in dogs undergoing total ear canal ablation and lateral bulla osteotomy (TECA–LBO).Study designRandomized blinded clinical study.AnimalsA group of 20 client-owned dogs undergoing TECA–LBO.MethodsIntravenous (IV) administration of lidocaine (3 mg kg^–1) and ketamine (0.6 mg kg^–1) with fentanyl (5.4 μg kg^–1; n = 10; FLK group) or sufentanil (0.72 μg kg^–1; n = 10; SLK group) was immediately followed by the corresponding constant rate infusion (CRI) (lidocaine 3 mg kg^–1 hour^–1; ketamine 0.6 mg kg^–1 hour^–1; either fentanyl 5.4 μg kg^–1 hour^–1 or sufentanil 0.72 μg kg^–1 hour^–1). Anaesthesia was induced with propofol 3–5 mg kg^–1 IV and was maintained with isoflurane. End-tidal isoflurane concentration (Fe′Iso) was decreased in 0.2% steps every 15 minutes until spontaneous movements were observed (treated with propofol 1 mg kg^–1 IV) or an increase of > 30% in heart rate or mean arterial pressure from baseline occurred (treated with rescue fentanyl or sufentanil). Quality of recovery and pain were assessed at extubation using the short-form Glasgow Composite Pain Scale (SF-GCPS), Colorado State University Canine Acute Pain scale (CSU-CAP), and visual analogue scale (VAS). Data were analysed with analysis of variance, t tests, Fisher test and Spearman coefficient (p < 0.05).ResultsFe′Iso decreased significantly in SLK group (45%; p = 0.0006) but not in FLK (15%; p = 0.1135) (p = 0.0136). SLK group had lower scores for recovery quality (p = 0.0204), SF-GCPS (p = 0.0071) and CSU-CAP (p = 0.0273) than FLK at extubation. Intraoperative rescue analgesia and VAS were not significantly different between groups.Conclusions and clinical relevanceCompared with FLK infusion, CRI of SLK at these doses decreased isoflurane requirements, decreased pain scores and improved recovery quality at extubation in dogs undergoing TECA–LBO.     

Preperitoneal ropivacaine infusion versus epidural ropivacaine–morphine for postoperative analgesia in dogs undergoing ovariohysterectomy: a randomized clinical trial

ObjectiveTo assess the effect of continuous wound infusion (CWI) with preperitoneal ropivacaine on postoperative analgesia and compare it with the epidural administration of ropivacaine and morphine in bitches undergoing ovariohysterectomy.Study designA parallel, randomized, clinical, prospective and nonblinded study.AnimalsA group of 38 Greyhound bitches.MethodsIn the catheter group (CathG), CWI with ropivacaine 1% (1 mg kg^–1 + 0.8 mg kg^–1 hour^–1) was applied to the preperitoneal space over the surgical incision. In the epidural group (EpiG), ropivacaine 0.5% (1.3 mg kg^–1) and morphine (0.1 mg kg^–1) were epidurally administered. Occipital-coccygeal length was used to calculate the volume for the epidural. Pain was scored using a dynamic interactive visual analogue scale (DIVAS) and Glasgow composite measure pain scale–short form (CMPS-SF) before anaesthesia and at 2, 4, 6, 18, 21 and 24 hours after extubation. Incisional sensitivity using a dynamometer (MWTs-incision) was evaluated simultaneously. Plasma ropivacaine and cortisol concentrations, degree of sedation, motor blockade and response to interdigital clamping were measured or assessed. A two-way mixed analysis of variance and a Mann–Whitney U test were used to analyse data; p < 0.05.ResultsNo differences were detected in the DIVAS (p = 0.301), CMPS-SF (p = 0.600) scores, MWTs-incision measurements (p = 0.257) and cortisol values (p = 0.878) between the groups. Rescue analgesia was required in two dogs, one in each group, at 2 hours. Sedation, motor blockade and negative response to interdigital clamping were detected in EpiG at 2, 4 and 6 hours. Mean plasma ropivacaine values were higher in CathG (0.475 ± 0.164 ng mL^–1) than in EpiG (0.184 ± 0.213 ng mL^–1; p = 0.001).Conclusion and clinical relevanceCompared with epidural ropivacaine and morphine, CWI with preperitoneal ropivacaine is an effective analgesic technique for postoperative pain management in bitches undergoing ovariohysterectomy without motor blockade.