Effects of a stepwise alveolar recruitment maneuver on lung volume distribution in dogs assessed by computed tomography.

Background: Pulmonary atelectasis is a commonly occurs during anesthesia. In these cases, mechanical ventilation (MV) associated with alveolar recruitment maneuvers (ARMs) and positive end-expiratory pressure (PEEP) is indicated to reverse the condition, ensure adequate gas exchange and improve oxygenation. ARMs can trigger volutrauma, barotrauma, and atelectrauma. Therefore, computed tomography (CT) is the gold-standard method for monitoring lung aeration after ARM. Objective: To evaluate lung volume distribution after stepwise ARMs using computed tomography (CT). Methods: Twelve dogs weighing 24.0 ± 6.0 kg, aged 3 ± 1 years, of both sexes and different breeds, underwent orchiectomy or ovariohysterectomy. The animals were anesthetized and ventilated in volume-controlled mode. ARMs were then initiated by positive end-expiratory pressure (PEEP) titration (5, 10, 15, and 20 cmH2O). CT scans, cardiovascular parameters, and ventilatory mechanics were evaluated at all time points. Data were assessed for normality using the Shapiro-Wilk test and a two-way analysis of variance, followed by a post-hoc Bonferroni test to identify differences between time points. Statistical significance was attributed to a value of p of <0.05. Results: CT demonstrated that the ARMs increased ventilation throughout the lung, including the dependent regions, with volumes that increased and decreased proportionally with PEEP titration. When they reached PEEP 10 and 5 cmH2O descending (d), they remained significantly higher than those in PEEP 0 cmH2O (baseline). Static compliance improved about 40% at PEEP 10d and PEEP 5d compared to baseline. There was an increase in heart rate (HR) from PEEP 15 increasing (i) (74.5%) to PEEP 10d (54.8%) compared to baseline. Mean arterial blood pressure (MABP) decreased approximately 9% from PEEP 15i to PEEP 15d compared to baseline. Conclusion: Lung attenuation and regional and global volumes assessed by CT showed that maximum pulmonary aeration distribution followed by PEEP titration occurred at PEEP 20 cmH2O, maintaining the lungs normoaerated and without hyperaeration.

Imatinib Mesylate for the Treatment of Canine Mast Cell Tumors: Assessment of the Response and Adverse Events in Comparison with the Conventional Therapy with Vinblastine and Prednisone.

Mast cell tumors (MCTs) are common neoplasms in dogs, and treatments for these diseases include surgery, polychemotherapy and targeted therapy with tyrosine kinase inhibitors. This study aimed to evaluate the response and the adverse events of treatment with imatinib mesylate (IM) compared to conventional therapy using vinblastine and prednisolone (VP) in canine cutaneous MCTs. Twenty-four dogs were included in the study; 13 animals were treated with IM and 11 with VP. Tumor tissue samples were submitted for histological diagnosis, grading and KIT immunostaining. The response to treatment was assessed by tomographic measurements according to VCOG criteria. Adverse events were classified according to VCOG-CTCAE criteria. The IM and VP groups had dogs with similar breeds, gender, ages, MCT localization, WHO stages and lymph node metastasis profiles. Most MCTs were grade 2/low and had KIT- patterns 2 and 3. The objective response rate (ORR) was significantly higher (30.79%) in the IM group then in VP group (9.09%). Adverse events (AE) in IM group were all grade 1, significantly different from VP. In conclusion, IM presented better ORR and less severe adverse events when compared to VP, representing a suitable option for the treatment of low-grade canine MCTs.

Comparison of standard radiography and computed tomography in 21 dogs with maxillary masses.

Imaging of patients with oral cancer is required to determine tumor extension in order to assist in prognosis and surgical planning. Conventional screen-film radiography (SFR) used to be the most common method for oral assessment, but computed tomography (CT) has become more available and is being used for obtaining complementary information. CT examinations eliminate superimposition by acquiring cross-sectional images of the region of interest. The objective of this study was to determine the diagnostic value of SFR compared with CT examinations for evaluation of oral masses in dogs. Twenty-one dogs received head and thorax SFR, and pre- and post-contrast head CT. Bony changes were observed in 80.9% and 95.2% of the cases in SFR and CT studies, respectively. Invasion of adjacent structures (i.e. nasal cavity, frontal and sphenoidal sinuses, orbit, maxillary recess, nasopharynx) was observed in only 30% of cases with SFR while CT showed 90.4% involvement. CT is an important preoperative examination modality and is more effective in identifying bone changes and tumor invasion of adjacent structures compared with SFR.

Avaliação ultrassonográfica de linfonodos na pesquisa de metástases de neoplasia mamária em cadelas / Ultrasonographic evaluation of lymph nodes for metastasis research of canine mammary tumor

A avaliação de linfonodo, parte importante do estadiamento das neoplasias mamárias em cadelas, pode auxiliar no estabelecimento do prognóstico e na escolha da conduta terapêutica. A ultrassonografia em modo B possibilita avaliação de tamanho, contorno, borda, forma, arquitetura, ecotextura e ecogenicidade do parênquima dos linfonodos e, em modo Doppler, da quantidade e distribuição dos seus vasos internos. Este trabalho visou identificar as características ultrassonográficas mais importantes utilizadas para classificar os linfonodos em metastáticos e não-metastáticos, estabelecer elementos de confiabilidade do ultrassom como ferramenta para diferenciar linfonodos metastáticos de não-metastáticos e estabelecer procedimentos de reprodução deste exame. Foram examinados 67 linfonodos inguinais superficiais de 30 cadelas com tumor mamário e cada linfonodo foi classificado como metastático ou não-metastático. A impressão diagnóstica ultrassonográfica foi associada aos resultados do exame histopato lógico dos linfonodos obtendo-se taxa de concordância de 92,5 por cento, índice de sensibilidade de 94,1 por cento, índice de especificidade de 92 por cento, valor preditivo positivo de 0,8 e valor preditivo negativo de 0,9787. Características ultrassonográficas que classificaram um linfonodo como metastático ou como não-metastático foram listadas. O exame ultrassonográfico dos linfonodos regionais constitui importante ferramenta na detecção de metástase e sugere-se incluí-lo como rotina do estadiamento de neoplasias mamárias em cadelas.

Evaluation of lymph nodes is part of the staging of the mammary tumors and helps to establish a prognosis and therapy. B-mode ultrasonography was used to evaluate size, edge, nodal borders, shape, architecture, echotexture and echogenicity of lymph nodes and Doppler ultrasonography to evaluate the quantity and distribution of the vessels. The aims of this work were to identify which ultrasound features can be used to classify a lymph node as metastatic or non-metastatic; to establish its accuracy as a useful tool to this differentiation, and to establish procedures that permit the reproducibility of the results. Sixty seven lymph nodes of 30 female dogs with mammary tumors were examined by ultrasound and classified as metastatic or non-metastatic. The ultrasonographic diagnostic impression was confronted with the histopathologic results. The ultrasonographic classification of the lymph nodes was correct in 92.5 percent of the cases, with sensibility of 94.1 percent, specificity of 92 percent, positive predictive value of 0.8, and negative predictive value of 0.9787.The characteristics of the nodes to classify them as metastatic or non metastatic were registered. Ultrasound imaging of regional lymph nodes is important to detect metastases and it is suggested that it becomes a regular procedure in the staging of canine mammary tumors.

Avaliação radiográfica da silhueta cardíaca pelo método de mensuração VHS (vertebral heart size) em cães da raça Poodle clinicamente normais / Radiographic evaluation of the cardiac silhouette in clinically normal Poodles through the vertebral heat size (VHS) method

Para avaliação radiográfica da silhueta cardíaca têm sido propostos inúmeros métodos de mensuração com a finalidade de tentar diminuir a subjetividade da avaliação empírica. O objetivo deste estudo foi determinar o valor de VHS (vertebral heart size) em cães da raça Poodle, amplamente difundida em nosso meio, através do método de mensuração proposto por Buchanan e Bücheler . Foram selecionados trinta cães clinicamente normais, machos e fêmeas, com idades variando de um a seis anos. Os animais foram submetidos ao exame radiográfico do tórax nas projeções látero-lateral direita e ventro-dorsal. As radiografias foram avaliadas de forma empírica e posteriormente foram realizadas as medidas propostas por Buchanan e Bücheler para a silhueta cardíaca e para a profundidade e largura do tórax. A avaliação empírica não demonstrou alterações radiográficas relevantes em vinte e um dos trinta cães (70 por cento). 80 por cento dos animais tiveram suas medidas de VHS menores ou iguais a 10,5 vértebras. Os valores de VHS obtidos apresentaram distribuição normal, com média de 10,12 vértebras e desvio padrão de 0,51, sendo o valor mínimo encontrado igual a 9,2 vértebras e o máximo igual a 11,1 vértebras. Os valores da razão profundidade pela largura do tórax também apresentaram distribuição normal, com média de 0,84 e desvio padrão de 0,09, sendo o valor mínimo encontrado igual a 0,64 e o máximo igual a 1,04. 40 por cento dos cães tiveram valores de VHS superiores ao valor médio de 10,12 vértebras obtido neste trabalho o que sugere que esse valor seja rigoroso para ser utilizado como limite superior para essa raça. Para que 96,67 por cento dos animais desse estudo tivessem valores de VHS considerados inferiores ao limite superior, esse deveria ser igual a 11 vértebras. Desta forma sugerimos com base nos dados observados nesta amostra, que o intervalo de 10,5 a 11,0v seja considerado como limite superior para cães da raça Poodle com razão de profundidade e largura do tórax de 0,84 (+ 0,09), já que observamos valor superior a 11,0v em apenas um animal.