Perioperative analgesic effects of an ultrasound-guided transversus abdominis plane block with a mixture of bupivacaine and lidocaine in cats undergoing ovariectomy.

OBJECTIVE: To evaluate the perioperative analgesic effects of a transversus abdominis plane (TAP) block with a mixture of lidocaine and bupivacaine administered to cats undergoing ovariectomy. STUDY DESIGN: Controlled, randomized, prospective, blinded clinical study. ANIMALS: A group of 20 healthy cats. METHODS: Robenacoxib (2 mg kg-1) was administered subcutaneously 0.5 hour before intramuscular (IM) administration of ketamine (5 mg kg-1), methadone (0.1 mg kg-1) and dexmedetomidine (0.01 mg kg-1). General anesthesia was induced with intravenous (IV) propofol and maintained with isoflurane. An ultrasound-guided TAP block was performed by injecting 0.5% bupivacaine (0.2 mL kg-1) diluted in a total volume of 1.5 mL 2% lidocaine bilaterally (TAP group, n = 10) or the same volume of saline solution bilaterally in controls (CTR group, n = 10). During surgery, a 20% increase in heart rate and respiratory frequency was treated with IV fentanyl (0.001 mg kg-1). Before premedication and at 1, 2, 3, 4, 6, 8, 12, 16, 20 and 24 hours after extubation, pain was assessed with a simple descriptive pain scale, that ranged from 0 (no pain) to 4 (intense pain). For pain scores ≥3, IM methadone (0.1 mg kg-1) was administered. Data were analyzed with the Friedman or the analysis of variance (anova) test, and p < 0.05 was considered statistically significant. RESULTS: Only two cats in the CTR group were administered one dose of fentanyl during surgery. At 2, 6, 8, 12, 16, 20 and 24 hours after surgery, the pain score was higher in the CTR group. A mean dose of 0.5 ± 0.2 mg kg-1 methadone was administered to all cats in the CTR groups within 24 hours. Methadone was not administered to the TAP group (pain score < 3). CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasound-guided TAP block can be a reliable adjunctive technique, providing analgesia for up to 24 hours in cats undergoing ovariectomy.

Evaluation of in Vivo Response of Three Biphasic Scaffolds for Osteochondral Tissue Regeneration in a Sheep Model.

Osteochondral defects are a common problem in both human medicine and veterinary practice although with important limits concerning the cartilaginous tissue regeneration. Interest in the subchondral bone has grown, as it is now considered a key element in the osteochondral defect healing. The aim of this work was to generate and to evaluate the architecture of three cell-free scaffolds made of collagen, magnesium/hydroxyapatite and collagen hydroxyapatite/wollastonite to be implanted in a sheep animal model. Scaffolds were designed in a bilayer configuration and a novel "Honey" configuration, where columns of hydroxyapatite were inserted within the collagen matrix. The use of different types of scaffolds allowed us to identify the best scaffold in terms of integration and tissue regeneration. The animals included were divided into four groups: three were treated using different types of scaffold while one was left untreated and represented the control group. Evaluations were made at 3 months through CT analysis. The novel "Honey" configuration of the scaffold with hydroxyapatite seems to allow for a better reparative process, although we are still far from obtaining a complete restoration of the defect at this time point of follow-up.