Objective: To compare the effects of thiopental, propofol and alfaxalone on arytenoid cartilage motion and establish dose rates to achieve a consistent oral laryngoscopy examination. Study design: Prospective, randomised, blinded crossover study. Animals: Six healthy adult beagle dogs. Methods: Each dog was administered three induction agents in a random order with a one week washout period between treatments. No premedication was used prior to induction of anaesthesia. Thiopental, propofol or alfaxalone were administered at 7.5 mg/kg, 3 mg/kg and 1.5 mg/kg, over 1 minute to effect, for induction of anaesthesia, respectively. If the dog was deemed inadequately anaesthetised then top-up boluses of 1.8 mg/kg, 0.75 mg/kg and 0.4 mg/kg, respectively, were administered over 10 seconds, repeated every 20 seconds, until an adequate anaesthetic plane had been reached. Continual examination of the larynx, using a laryngoscope, commenced once an adequate anaesthetic depth had been reached until recovery from anaesthesia. The number of arytenoid motions and deep inspiratory efforts (vital breaths) were counted within three time periods and compared over time among treatments. Data were analysed using Friedman test, Mann-Whitney U test, Spearman's rho, linear mixed model with post-hoc pairwise comparison with Tukey correction. Results interpreted at a 5% level of significance. Results: The median (range) induction time was 2.8 (2.0, 3.0), 2.7 (2.0, 3.3) and 2.5 (1.7, 3.3) minutes for thiopental, propofol and alfaxalone, respectively (p = 0.727). The median (range) dose rate required to achieve an adequate depth of anaesthesia was 6.3 (6.0, 6.6), 2.4 (2.4, 2.4) and 1.2 (1.2, 1.2) mg/kg/minute for thiopental, propofol and alfaxalone, respectively. Therefore, the median (range) total dose administered over the induction time was 17.8 (13.2, 18.8), 6.8 (5.3, 8.3) and 3.2 (2.3, 4.1) mg/kg for thiopental, propofol and alfaxalone, respectively. There was no significant difference for the total number of arytenoid motions (p =0.662) or vital breaths (p = 0.789) among induction agents. The median (range) examination times were 14.1 (8.0, 41.8), 5.4 (3.3, 14.8) and 8.5 (3.8, 31.6) minutes for thiopental, propofol and alfaxalone, respectively (p=0.016). Conclusion and clinical relevance: There was no significant difference in the total number of arytenoid motions among the induction agents. However, at the dose rates used in this study, propofol provided adequate conditions for evaluation of the larynx within a shorter examination time which may be advantageous during laryngoscopy in dogs. / Mini Dissertation (MMedVet)--University of Pretoria, 2016. / Companion Animal Clinical Studies / MMedVet / Unrestricted

Submitted by ADAMAS TASSINARI BONFADA null (adamasb@gmail.com) on 2018-03-27T18:57:18Z No. of bitstreams: 1 Tese_Adamas_Tassinari_Bonfada.pdf: 2239986 bytes, checksum: 3c02247506a6cf8c070fea8a0f8a3862 (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-03-28T12:49:28Z (GMT) No. of bitstreams: 1 bonfada_at_dr_jabo.pdf: 2239986 bytes, checksum: 3c02247506a6cf8c070fea8a0f8a3862 (MD5) / Made available in DSpace on 2018-03-28T12:49:28Z (GMT). No. of bitstreams: 1 bonfada_at_dr_jabo.pdf: 2239986 bytes, checksum: 3c02247506a6cf8c070fea8a0f8a3862 (MD5) Previous issue date: 2018-02-05 / As afecções respiratórias com sede em faringe, laringe e traqueia podem ter sinais clínicos que dificultam o diagnóstico. As técnicas atuais de videodiagnóstico permitem a diferenciação destas alterações com mais acurácia. O objetivo deste trabalho foi caracterizar a videolaringoscopia como ferramenta importante para o auxílio no diagnóstico acurado de alterações da laringe em cães, através de três artigos, sendo um em forma de breve revisão de literatura, o segundo, um estudo retrospectivo com ênfase na região metropolitana de Salvador e, por fim, para o terceiro artigo, escolheu-se um dos casos para detalhamento em forma de outro artigo devido a sua excentricidade. Como material e métodos do estudo foram avaliados o histórico dos pacientes e o diagnóstico das alterações encontradas na videolaringoscopia durante o período determinado. Como critérios de inclusão estão o histórico clínico, a indicação para a videolaringoscopia, o resultado do exame, os detalhes sobre as alterações, as indicações clínicas ou cirúrgicas e a anestesia específica realizada para avaliar paralisia laríngea. Outros detalhes como o seguimento dos pacientes após o exame e após o tratamento aplicado também foram anotados e analisados, mas a ausência desses registros não excluiu os pacientes do estudo. Dos 19 pacientes 11 apresentavam palato mole alongado (todos braquicefálicos), nove manifestavam-se com colapso traqueal, nove com colapso laríngeo em grau I, cinco com paralisia laríngea, três com retroversão da epiglote, três com colapso laríngeo em grau III, um com edema da mucosa subepiglote, um paciente apresentou sialocele faríngea, um com colapso laríngeo de grau II e um teve um corpo estranho removido. Foram realizados procedimentos cirúrgicos de epiglotepexia, epiglotectomia, estafilectomia, ressecção de sacos laríngeos, lateralização das cartilagens aritenoides e correção nasal. As raças mais acometidas foram Pug, seguida de American Bully, Border Collie, Buldogue Francês, Staffordshire Bull Terrier, Pitbull Terrier, Buldogue Inglês, Maltês, Poodle e Yorkshire Terrier e SRD. Os resultados deste trabalho permitiram concluir que não há uma amostra homogênea de raças com dispneia, embora cães braquicefálicos tenham maior representatividade. A videolaringoscopia foi definitiva para o diagnóstico correto em todos os pacientes com dispneia, foi determinante para indicar o tratamento adequado aos pacientes e teve papel fundamental na condução dos casos analisados. / Upper respiratory diseases affecting pharynx, larynx and trachea may be presented with clinical signs with difficulty diagnostic. The current techniques of videodiagnosis allow the differentiation of these alterations with more accuracy. The objective of this study was to characterize videolaryngoscopy as an important tool to help accurate diagnosis of laryngeal changes in dogs. For this, it is presented three articles, one in the form of a brief review of the literature, the second a retrospective study with emphasis on the metropolitan region of Salvador-BA and, finally, for the third article, one of the cases was chosen for detailing in the form of another article due to its eccentricity. As material and methods of the study were evaluated the history of the patients and the diagnosis of the alterations found in videolaryngoscopy during the determined period. Inclusion criteria include clinical history, videolaryngoscopy indication, outcome of the examination, details of changes, clinical or surgical indications, and specific anesthesia performed to assess laryngeal paralysis. Other details such as follow-up of the patients after the examination and after the applied treatment were also noted and analyzed, but the absence of these records did not exclude patients from the study. Of the 19 patients, 11 had an elongated soft palate (all brachycephalic), nine had tracheal collapse, nine had laryngeal collapse in grade I, five had laryngeal paralysis, three had retroversion of the epiglottis, three had laryngeal collapse in grade III, one with edema of the subepiglote mucosa, one patient presented pharyngeal sialocele, one with grade II laryngeal collapse and one had a foreign body removed. Surgical procedures of epiglotepexy, epiglotectomy, staphylectomy, resection of laryngeal sacs, lateralization of arytenoid cartilages and nasal correction were performed. The most affected breeds were Pug, followed by American Bully, Border Collie, French Bulldog, Staffordshire Bull Terrier, Pitbull Terrier, English Bulldog, Maltese, Poodle and Yorkshire Terrier and mixbreed. The results of this study allowed to conclude that there is no homogeneous sample of races with dyspnea, although brachycephalic breeds are more representative. The videophayngolaryngtracheoscopy was definitive for the correct diagnosis in all the patients with dyspnea, it was determinant to indicate the appropriate treatment to the patients and had a fundamental role in the conduction of the analyzed cases.