Sedation Quality and Cardiorespiratory, Echocardiographic, Radiographic and Electrocardiographic Effects of Intramuscular Alfaxalone and Butorphanol in Spanish Greyhound Dogs.

The quality of sedation and changes in cardiorespiratory variables after the intramuscular administration of alfaxalone and butorphanol in Spanish greyhound dogs were evaluated. Twenty-one adult dogs were included. The dogs received alfaxalone (2 mg/kg) and butorphanol (0.2 mg/kg) intramuscularly. Sedation scoring, cardiorespiratory parameters (including blood gas analysis), echocardiography, thoracic radiography and electrocardiography were performed before sedation and 30 min after drug administration. Moderate sedation was observed, and side effects, such as tremors, nystagmus and auditory hyperesthesia, were noticed. Statistically significant changes in heart rate, invasive blood pressure, pH, arterial saturation of O2 and partial pressure of O2 and CO2 were found. Echocardiographic variables, including end-diastolic volume, left ventricular diameter in diastole, aortic and pulmonic flow, diastolic transmitral flow and left atrial/aortic ratio, and electrocardiography parameters, including PQ interval and QT interval, showed statistically significant changes. In conclusion, the intramuscular administration of alfaxalone and butorphanol to healthy dogs produced moderate sedation with mild cardiorespiratory, echocardiographic and electrocardiographic changes, without alterations in cardiac size on radiographic images.

Cartilage regeneration using a novel autologous growth factors-based matrix for full-thickness defects in sheep.

PURPOSE: To investigate the chondrogenic-regenerative properties of a novel autologous-made matrix composed of hyaline cartilage chips combined with a growth factors-based clot for full-thickness defects in sheep. METHODS: A full-thickness, 8-mm diameter cartilage defect was created in the weight-bearing area of the medial femoral condyle in 6 sheep. Treatment consisted of surgical implantation of an autologous-based matrix of hyaline cartilage chips combined with a clot of plasma poor in platelets and intraarticular injection of plasma rich in growth factors. Outcome measures at 1, 3 and 6 months included macroscopic International Cartilage Repair Society (ICRS) score, histological and immunohistochemical analysis for collagen expression, and transmission electron microscopy study. RESULTS: The 6-month macroscopic evaluation showed nearly normal (11.1 ± 0.7) cartilage repair assessment. The ICRS score was significantly higher at 6 months compared to 3 months (5.5 ± 1.3; p < 0.0001) and 1 (1.1 ± 0.4; p < 0.0001) month. At 6 months, hyaline cartilage tissue filling the defect was observed with adequate integration of the regenerated cartilage at the surrounding healthy cartilage margin. At 6 months, mature chondrons and cartilage matrix contained collagen fibers with masked fibrillary structure, and the expression of collagen in the newly formed cartilage was similar in intensity and distribution pattern compared to the healthy adjacent cartilage. CONCLUSIONS: This novel treatment enhanced chondrogenesis and regenerated hyaline cartilage at 6 months with nearly normal macroscopic ICRS assessment. Histological analysis showed equivalent structure to mature cartilage tissue in the defect and a collagen expression pattern in the newly formed cartilage similar to that found in adjacent healthy articular cartilage. The present technique may have clinical application for chondral injuries in humans because this procedure is cheap (no need for allograft, or expensive instrumentation/biomaterials/techniques), easy and fast-performing through a small arthrotomy, and safe (no rejection possibility because the patients' own tissue, cells, and plasma are used).

Evaluation of gastric and bladder tonometry as indicators of tissue perfusion in induced hypotension in dogs.

OBJECTIVE: To evaluate the use of gastric (PgCO2 ) and bladder (PbCO2 ) tonometry for assessing tissue hypoperfusion in dogs during sevoflurane-induced hypotension, and to compare these measurements with delivery of oxygen, arterial oxygen content, and plasma lactate concentration. DESIGN: Prospective experimental trial. SETTING: University veterinary teaching hospital. ANIMALS: Fourteen adult Beagle dogs. INTERVENTIONS: Anesthetic induction was performed by mask with sevoflurane and oxygen. Heart rate, direct arterial pressures, respiratory rate, and end-tidal carbon dioxide were recorded; arterial blood samples were taken to measure blood gases, and venous samples were sampled to measure plasma lactate. A tonometric catheter was introduced into the stomach to measure PgCO2 . Samples of saline from the balloon of a Foley catheter placed in the bladder were collected every 10 minutes and used to measure PbCO2 by gas analysis. Tonometry measurements, plasma lactate, and oxygen delivery and consumption were compared at 3 time points: at baseline, during hypotension, and during treatment periods. A hypotensive period (mean arterial pressure (MAP) < 60 mm Hg) of 15 minutes was induced by an overdose of sevoflurane, whereas during the treatment period, a constant-rate infusion of dopamine (10 µg/kg/min) was administered intravenously for 40 minutes. MEASUREMENTS AND MAIN RESULTS: Values for PgCO2 and PbCO2 increased significantly during the hypotensive period, and correlations were found between these values and the delivery of oxygen. Gastric tonometry values had stronger correlations compared with bladder tonometry values. CONCLUSIONS: Gastric and bladder tonometry can be used to detect hypoperfusion. Further studies are warranted to determine the potential use of gastric and bladder tonometry in assessing dogs in clinical situations.