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This prospective cohort study aimed to evaluate by echocardiogram the cardiovascular effects of α2 agents associated with butorphanol in cats. A group of 18 mixed-breed cats with a mean weight of 3.65 + 0.7 kg, with an approximate age of 6 months. The cats were assigned in three groups, XB (Xylazine/butorphanol group) sedation with 0.5 mg/kg of xylazine and 0.5 mg/kg of butorphanol IM; DB (Dexmedetomidine/butorphanol group): sedation with 20 µg/kg of dexmedetomidine and 0.5 mg/kg of butorphanol IM; C: control group which received saline solution in volume approximated to those used in the other groups, IM. Echocardiographic variables as ejection fraction (Simpson's method and M-mode) and left ventricular shortening fraction (M-mode), ejection volume, end-systolic volume and cardiac output (Teichholz), tissue Doppler E' and A' wave velocities and cardiac index were evaluated. There was a reduction in echocardiographic variables compared with the control group, being statistically significant for heart rate, ejection fraction (% by Simpson), shortening fraction (% in M-mode) and end-systolic volume in XB and DB groups, and tissue Doppler E' and A' wave velocity (m/s), E'/A' ratio, cardiac output and cardiac index only in XB group. When compared to each other, XB and DB differed significantly in the tissue Doppler E' and A' wave velocity (m/s), and E'/A' ratio. Xylazine was more deleterious than dexmedetomidine in most of the variables evaluated, leading to a significant reduction in cardiac output and cardiac index at the doses used in this study.

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Objectives. The aim of the study is to compare the sedative, cardiorespiratory, echocardiographic, and blood gas effects of dexmedetomidine and methadone associated or not with midazolam for restraint chemistry in cats. Methods. Eighteen healthy young cats (4.06 ± 0.48 kg) were randomly sedated with two protocols, through the intramuscular route: dexmedetomidine (5 µg.kg−1), methadone (0.3 mg. kg−1) and midazolam (0.3 mg. kg−1) (DMTM, n = 9), or dexmedetomidine (7.5 µg.kg−1) and methadone (0.3 mg. kg−1) (DMT, n = 9). The cardiorespiratory parameters were measured at baseline, 5 and 10 minutes after pharmacological latency. The sedation, analgesia, and muscle relaxation scores were assessed before and 5 minutes after pharmacological latency, while arterial blood gas analysis and echocardiography were assessed before and after 10 or 15 minutes, respectively. Results. There was no difference between the protocols regarding the cardiorespiratory, blood gas, and echocardiographic parameters used. The scores for sedation, analgesia, and muscle relaxation also did not differ between the protocols, with the degree of sedation, analgesia, and myorelaxation considered satisfactory in both groups. A significant decrease in heart rate (HR) was observed after administration of the sedative protocols, reaching a maximum reduction at T10 (46% and 53% reduction in the DMT and DMTM groups, respectively). The reduction in HR had an impact on echocardiographic parameters such as CO, which decreased 53% and 56% in the DMT and DMTM groups, respectively. There was a significant reduction in PaO2, SaO2, ejection fraction, and fractional shortening in both protocols. SpO2 decreased significantly after 5 minutes of sedation in the DMT group, but with a minimum mean SpO2 of 92% in T5. The respiratory rate decreased significantly at 5 and 10 minutes in the DMTM group, while PaCO2 increased in both groups, indicating respiratory depression caused by the drugs. Conclusions and Relevance. The study pointed out that both sedative protocols can be recommended for clinical sedation of young and healthy cats in the doses used. However, both protocols resulted in cardiorespiratory depression in cats and also the particularities of the animals should be evaluated regarding reducing cardiac output by more than 50%.

Resumo Este estudo teve como objetivo avaliar a eficácia das células-tronco mesenquimais (CTMs), isoladas ou associadas à dapsona (DAP), no tratamento de feridas dermonecróticas causadas pelo veneno de Loxosceles laeta. Vinte e cinco coelhos machos foram distribuídos em cinco grupos. O controle negativo recebeu água ultrapura (C-), enquanto todos os outros grupos foram injetados com 20 μg de veneno de L. laeta. Após 4 horas, cada grupo recebeu um dos seguintes tratamentos: PBS (C+), DAP, CTMs e DAP + CTMs. Os animais foram avaliados diariamente durante 12 dias, e feitos registros fotográficos para análise da ferida e no 12º dia, foram eutanasiados e, retiradas amostras de pele para análise histológica. Observou-se que a DAP apresentou o melhor percentual de contração da ferida no terceiro dia. Nos tratamentos com CTMs, observou-se uma contração negativa da ferida tanto para as CTMs isoladas, bem como a associação CTMs + DAP em relação ao PBS, possivelmente, pelo aumento da infamação inicial após a aplicação de células-tronco. Isso é devido ao fato de que as CTMs secretam um amplo espectro de moléculas bioativas como citocinas e fatores de crescimento que favorecem a regeneração. Histologicamente, observou-se que os animais de C+ apresentaram extensas áreas de necrose, úlceras, infiltrado neutrofílico, além de mineralização. Houve aumento de deposição de colágeno no tratamento CTMs + DAP, no entanto, a vascularização permaneceu inalterada. Este é o primeiro relato usando CTMs e CTMs + DAP como tratamento para loxoscelismo cutâneo e mais estudos são necessários para determinar seu uso como terapia alternativa para lesões demonecróticas causadas pela aranha Loxosceles.