Clinical evaluation of the sedative, antinociceptive and cardiorespiratory effects of intranasal dexmedetomidine combined with methadone in healthy dogs.

In this prospective, randomised, blinded clinical study, we compared the sedative, antinociceptive and cardiorespiratory effects of intranasal (IN) dexmedetomidine at 5 µg/kg (diluted with 0.03 mL/kg NaCl 0.9%, DEX) with or without methadone (0.3 mg/kg; DEXMET), through a mucosal atomization device to one nostril in twenty healthy client-owned dogs. At 5-min intervals over 45 min, sedation score, onset, cardiopulmonary variables, mechanical nociceptive thresholds (MNTs) were assessed, also ease of administration, adverse effects, and response to IV catheterization. Statistical analysis employed t-test, the Mann-Whitney U, repeated measures ANOVA and Chi-square tests as appropriate (P < 0.05). Higher sedation ocurred in DEXMET (7 [5-10]) compared to DEX (5 [2-7]) from 15 to 30 min (P < 0.01, median [interquartile range]). Heart rate was lower in DEXMET (P < 0.01; 65% reduction vs. 41% in DEX, P = 0.001). The MNTs were higher in DEXMET than DEX from 15 to 45 min (P < 0.01), peaking at T30 (17.1 ± 3.8, DEXMET and 8.5 ± 5.4 N, DEX). No differences were observed in mean arterial blood pressure and respiratory rate. Intranasal administration was considered easy for 8 dogs per group. Reverse sneezing (8 dogs; P < 0.001), sialorrhea and retching (4 and 2 dogs, respectively) occurred in DEXMET. Response to catheterisation was lower in DEXMET than DEX (P = 0.039; 2 and 7 dogs, respectively). In conclusion, intranasal methadone (0.3 mg/kg) increased the sedative and antinociceptive effects produced by dexmedetomidine (5 µg/kg) in healthy dogs and resulted in lower heart rate.

Factors affecting respiratory system compliance in anaesthetised mechanically ventilated healthy dogs: a retrospective study.

OBJECTIVES: To determine the influence of several factors on respiratory system compliance in volume-controlled mechanically ventilated healthy anaesthetised dogs. MATERIALS AND METHODS: Review of 100 dogs anaesthetised for elective surgeries between 2015 and 2016. Dogs were mechanically ventilated with a respiratory rate adjusted to maintain normocapnia and a fraction of inspired oxygen of 50%. Body weight, body condition score, age, thoracic shape, time in spontaneous ventilation before volume-controlled ventilation, time with a fraction of inspired oxygen of 100% until starting mechanical ventilation, type of surgery and patient position were recorded. Respiratory system compliance, expressed per kg of bodyweight, was recorded every 15 minutes following initiation of volume-controlled ventilation. RESULTS: Baseline respiratory system compliance was 1.3 ± 0.3 mL/cmH2 O/kg and was reduced by high body condition score and barrel-shaped thorax but not by age, type of surgery or patient position, time in spontaneous ventilation nor time with a fraction of inspired oxygen of 100%. CLINICAL SIGNIFICANCE: Respiratory system compliance is lower in overweight and barrel-chested dogs and should be taken into account during monitoring of lung function and ventilation management under general anaesthesia.

Clinical comparison of the effects of isoflurane or propofol anaesthesia on mean arterial blood pressure and ventilation in dogs undergoing orthopaedic surgery receiving epidural anaesthesia.

The aim of this study was to compare the effects on mean arterial pressure (MAP) and ventilation of propofol total IV anaesthesia (TIVA) and isoflurane as anaesthetic maintenance in healthy dogs undergoing orthopaedic surgery, with epidural anaesthesia. Dogs were premedicated IM with dexmedetomidine (4µg/kg) and methadone (0.3mg/kg), induced with IV propofol (0.65-5mg/kg) and randomly assigned to be maintained with isoflurane (group I) or propofol (group P). Isoflurane end-tidal concentration (EtISO) and propofol infusion rate were adjusted during the surgery to maintain a suitable anaesthetic depth. All dogs received bupivacaine (1mg/kg) and morphine (0.1mg/kg) in the lumbosacral epidural space (total volume 0.2mL/kg). MAP was recorded every 5min during the procedure. Statistical analysis was performed using parametric (Student's t test) and nonparametric (Mann-Whitney U-test, chi-square) tests, as appropriate. Anaesthetic maintenance in groups I and P was accomplished by providing a mean EtISO of 1.12±0.15% and a mean propofol infusion rate of 15.0±4.7mg/kg/h, respectively. MAP was significantly higher in group P than in group I (92±17mmHg versus 78±10mmHg; P=0.021). Eleven dogs in group P and two dogs in group I reached an EtCO2>7.3kPa, requiring mechanical ventilation (P=0.001). In combination with epidural anaesthesia, propofol TIVA improved MAP and is a suitable alternative to isoflurane in orthopaedic surgery of the hind limb in healthy dogs. Nevertheless, since it was associated with increased respiratory depression, mechanical ventilation should be available.

La terapia asistida con perros en el tratamiento de las personas con dolor crónico: una revisión sistemática / Dog-assisted therapy in the treatment of people with chronic pain: a systematic review

Objetivo: La terapia asistida con animales se está utilizando de diversas formas para mejorar la calidad de vida de las personas con dolor crónico. El objetivo de este trabajo fue realizar una revisión sistemática de las publicaciones disponibles y resumir lo que se sabe sobre esta forma de terapia complementaria. Material y métodos: Se realizó una búsqueda en las bases de datos MEDLINE (vía PubMed), CINAHL, PsycINFO, Web of Science Core Collection, Psychology and Behavioral Sciences Collection desde sus inicios hasta enero de 2016. Resultados: Se identificaron un total de 179 artículos, de los que se revisaron 135 para su potencial inclusión en este trabajo. Finalmente, se han incluido 7 trabajos. Los resultados de estos estudios muestran que, en general, las personas que han participado de estas terapias informan de una menor intensidad de dolor, mejor estado de ánimo y, en general, de mejor calidad de vida. Los trabajos publicados no describen detalladamente el tipo de intervención planteada ni sus componentes específicos; así son difíciles de replicar. Conclusiones: Aunque los estudios revisados muestran resultados positivos, las investigaciones han utilizado diseños poco elaborados y de escasa exigencia metodológica. En futuras investigaciones es de esperar un mayor rigor y control. También una mejor descripción de las intervenciones, detalle fundamental para identificar qué variables son las responsables últimas de los efectos beneficiosos de los que se informan (AU)

Objective: Animal-assisted therapy is used in various ways to improve the quality of life of people with chronic pain. The aim of this work was to conduct a systematic review of the literature, and summarize what is known about this form of complementary therapy. Methods: A search was conducted in the following databases MEDLINE (via PubMed), CINAHL, PsycINFO, Web of Science Core Collection, Psychology and Behavioral Sciences Collection, since its inception until January 2016. Results: A total of 179 items were found, and 135 were reviewed for potential inclusion in this study. Finally, we have included 7 articles. The results of the studies reported in these articles show that, in general, people who have participated in animal-assisted therapy report lower pain intensity, improved mood and overall better quality of life. Published reports do not provide detailed information about the type of intervention being used, nor its specific components, thus offering little possibility of replication. Conclusions: Reviewed studies show positive results, however these are based on poor designs. Future research with greater rigor and control is warranted. Future publications need to provide better descriptions of the interventions that are used, this is critical to identify which variables are ultimately responsible for the beneficial effects that are being reported (AU)

Effects of dexmedetomidine administered at acupuncture point GV20 compared to intramuscular route in dogs.

OBJECTIVE: To compare the sedative effects produced by dexmedetomidine in dogs, administered either intramuscularly or into the Governing Vessel 20 acupuncture point. MATERIALS AND METHODS: Six dogs were sedated with 125 µg/m2 dexmedetomidine injected either intramuscularly in the gluteal muscles or subcutaneously into the acupuncture point and in random order. Sedation and analgesia were assessed blindly before and after treatments at regular intervals for 90 minutes or until the dogs fully recovered. Duration and quality of sedation were assessed with a numerical sedation rating scale and a dynamic and interactive visual analogue scale. Analgesia was also assessed with a numerical rating scale. Heart and respiratory rates and rectal temperatures were recorded. RESULTS: Sedative and analgesic scores were significantly increased when dexmedetomidine was administered at the Governing Vessel 20 acupuncture point compared with the routine intramuscular route. Duration of sedation was longer in the acupuncture site injection group compared to the intramuscular group (93 ±38 and 41 ±16 minutes). Bradycardia was significantly more pronounced in the acupuncture site group than the intramuscular group, whereas respiratory rates and rectal temperatures did not differ between administration routes. CLINICAL SIGNIFICANCE: Administration at the Governing Vessel 20 acupuncture point increased the duration and degree of sedation and analgesic effects of dexmedetomidine compared with the intramuscular route.

Comparison of sedation scores and propofol induction doses in dogs after intramuscular administration of dexmedetomidine alone or in combination with methadone, midazolam, or methadone plus midazolam.

The objectives of this study were to determine: (1) the sedative effects of dexmedetomidine in combination with methadone, midazolam, or both, and (2) the propofol dose required to achieve endotracheal intubation in healthy dogs. Seven healthy Beagle dogs were included in a prospective experimental, crossover, randomised and masked design. All dogs received four treatments IM, with at least 1 week between sessions, as follows: dexmedetomidine 5 µg/kg (D) alone, or combined with methadone 0.3 mg/kg (DMe), midazolam 0.3 mg/kg (DMi), or both (DMeMi). The degree of sedation was evaluated using a numerical scale (maximum 15 points). The dose of propofol required for intubation was also calculated for each group. Recovery time and quality were determined. Statistical analysis was performed using parametric (ANOVA) and nonparametric tests (Friedman, Cochran Q), as appropriate. The degree of sedation obtained with DMe and DMeMi (13, [7-14]; 13, [6-14], respectively) was significantly higher than in the control group (2, [1-4]; P = 0.023, P = 0.006, respectively). The required dose of propofol was lower in all groups (DMi, 1.5 ± 0.5 mg/kg, P = 0.002; DMe, 1.2 ± 0.5 mg/kg, P <0.001; DMeMi, 0.9 ± 0.3 mg/kg) than in the control group (2.9 ± 0.9 mg/kg; P <0.001). Recovery quality was not different between groups (P = 0.137). In healthy dogs, the addition of midazolam did not enhance the sedative effects of dexmedetomidine or a dexmedetomidine-methadone combination at the doses studied, and propofol requirements were reduced. The sedative effect of dexmedetomidine was enhanced with methadone, and the required dose of propofol was reduced.

Evaluation of an oesophageal Doppler device for monitoring cardiac output in anaesthetised healthy normotensive dogs.

OBJECTIVES: To compare cardiac output measured by oesophageal Doppler and by thermodilution monitoring and to correlate the Doppler cardiac output-generated minute distance with thermodilution cardiac output in healthy anaesthetised beagle dogs. MATERIALS AND METHODS: Prospective experimental study. Six healthy adult beagle dogs were pre-medicated with intramuscular acepromazine (0 · 05 mg/kg) and methadone (0 · 3 mg/kg). Anaesthesia was induced with intravenous propofol (dose-effect) and maintained with isoflurane in oxygen. Simultaneously, a constant rate infusion of dopamine (3 µg/kg/minute) was administered to the dogs to prevent hypotension. The minute distance, Doppler and thermodilution cardiac outputs were assessed at three different end-tidal concentrations of isoflurane (1 · 0, 1 · 3 and 2 · 0%). RESULTS: Correlation between Doppler and thermodilution cardiac output (r(2) = 0 · 582) and between minute distance and thermodilution cardiac output (r(2) = 0 · 658) were moderately good, but the limits of agreement between Doppler and thermodilution cardiac outputs were above the recommended values (±39%, for a recommended value up to 30%). CLINICAL SIGNIFICANCE: Doppler and minute distance cannot be considered as an alternative method to thermodilution to monitor cardiac output in the healthy anaesthetised dog.

Effects of fluid load on cardiovascular function during stepwise lung recruitment manoeuvre in healthy dogs.

The aim of this study was to evaluate the effects of a stepwise lung recruitment manoeuvre (RM) on cardiac output (CO) in mechanically ventilated dogs, with or without a previous fluid load. Eight healthy adult Beagle dogs were enrolled in a prospective crossover study. Following sedation with dexmedetomidine and methadone, anaesthesia was induced with propofol and maintained with isoflurane. CO (thermodilution method) and direct arterial blood pressure were monitored. The dogs were mechanically ventilated in a volume-controlled mode (tidal volume, VT = 10 mL/kg; positive end-expiratory pressure [PEEP] = 0 cm H2O) until normocapnia was achieved (end tidal CO2 35-45 mmHg). The RM was then performed in a pressure-controlled mode, with progressive increases of the PEEP and end-inspiratory pressure of 5 cm H2O, until 15 cm H2O and 30 cm H2O were reached, respectively. After the RM, the ventilatory mode was returned to volume-control, and the PEEP was sequentially decreased to 10, 5 and 0 cm H2O. Baseline ventilation was maintained for 30 min. Next, 10 mL/kg of lactated Ringer's solution was administered within 10 min, prior to a second RM. The CO was determined before each RM (baseline) and at each pressure step. A repeated measures ANOVA test was used to compare data. Compared to baseline, CO decreased during the RM in both groups. However, there was a significantly higher CO during the second RM at the highest pressure step (P<0.05) and during all decreasing pressure steps (P<0.05). In conclusion, a previous crystalloid fluid load could reduce the impact of a RM on CO in healthy dogs.

Effects of a stepwise lung recruitment manoeuvre and positive end-expiratory pressure on lung compliance and arterial blood oxygenation in healthy dogs.

This study was performed to evaluate the effects of a stepwise lung recruitment manoeuvre (RM) on dynamic lung compliance (Cdyn) and gas exchange in mechanically ventilated healthy dogs. Fourteen healthy adult dogs, scheduled for elective surgery in dorsal recumbency were employed. After anaesthetic induction, dogs were mechanically ventilated in a volume-controlled mode (tidal volume, VT=10 mL/kg); positive end-expiratory pressure (PEEP)=0 cm H(2)O; oxygen inspired fraction (FiO(2))=0.4 for 30 min (baseline). The dogs were then randomly allocated into two groups, control and RM. The ventilatory mode was maintained during the whole surgical procedure in the control group without any intervention, as in general practice. The RM was performed in a pressure-controlled mode, with progressive increases of PEEP and end-inspiratory pressure of 5 cm H(2)O until 15 cm H(2)O and 30 cm H(2)O, respectively. After RM, PEEP was decreased to 4 cm H(2)O, and the ventilatory mode was returned to volume-control. Arterial blood gases and Cdyn were determined at baseline, 20 and 60 min afterwards. Student's t test and the one-way ANOVA test were employed to compare data. Cdyn increased in the RM group (183 ± 30% and 165 ± 24% at 20 and 60 min, respectively; P=0.000). The baseline partial pressure of arterial oxygen to FiO(2) ratio (PaO(2)/FiO(2) ratio) did not change in the control group, but was higher in the RM group (527 ± 41 mm Hg and 511 ± 46 mm Hg at 20 and 60 min, respectively; baseline 371 ± 34 mm Hg, P<0.001). In conclusion, a stepwise RM followed by the use of PEEP improves Cdyn and oxygenation in mechanically ventilated healthy dogs.

Canine gastric carcinoma: immunohistochemical expression of cell cycle proteins (p53, p21, and p16) and heat shock proteins (Hsp27 and Hsp70).

Immunohistochemical staining for cell cycle proteins and heat shock proteins was performed on 17 canine gastric carcinomas. The immunoexpression of p53, p21, p16, Hsp27, and Hsp70 was investigated. A study was conducted to determine the histological type and parameters related to tumor malignancy. Possible associations and trends were assessed between the immunoexpression of each protein and tumor type as well as specific parameters of malignancy. High intratumor frequency of cellular p53 immunostaining was observed (61.96% average), but lower frequencies of p21 and p16 expression were present (34.65% and 10.41%, respectively). The p53 overexpression was associated with tumor infiltration (P = .0258). Expression of p21 was lower in undifferentiated carcinomas, and the loss of expression was associated with histopathological parameters characteristic of a poor prognosis such as lymphatic vessel invasion (P = .0258). The lack of p16 immunoreactivity was related to histopathological characteristics of malignancy such as the presence of evident and multiple nucleoli (P = .0475). In contrast, deep tumor infiltration was observed in those carcinomas with a high p16 index (P = .0475). Hsp70 appeared to be overexpressed in all gastric neoplasms included in this study. This is in contrast to Hsp27, because a group of tumors showed complete lack of Hsp27 immunoexpression, whereas the others displayed extensive Hsp27 immunostaining. The differences in Hsp27 did not correlate with any of the histopathological parameters, but Hsp27 immunoexpression was higher in the undifferentiated carcinoma. No significant differences in the expression of the proteins were found in canine gastric carcinomas according to their histological type. These findings may be useful for establishing a prognosis for canine gastric carcinoma.