Determination of the Minimum Alveolar Concentration (MAC) of Isoflurane and Sevoflurane in Callithrix penicillata

Background: The minimum alveolar concentration (MAC) is a measure of quantitative anesthetic potency and has become the standard index for the evaluation and comparison of volatile anesthetics, in addition to guiding dose administration. Black-tufted marmosets (Callithrix penicillata) are primates present in the clinical and surgical routine of veterinary hospitals, as well as experimental models, especially in neuroscience. Few studies have evaluated the potency of the main volatile anesthetics in this species. This study aimed to determine the MAC of isoflurane and sevoflurane in C. penicillata using the up-and-down method and to evaluate the effects of these drugs on the quality of anesthetic induction, maintenance, and recovery. Materials, Methods & Results: Twenty-four animals of undetermined age were used. All marmosets were healthy according to hematological and physical evaluation. The animals were randomly divided into 2 groups: ISOMAC and SEVOMAC. Each animal was induced to general anesthesia in an anesthetic box with oxygen (5 L/min) and sevoflurane at 7% in the SEVOMAC group or isoflurane at 5% in the ISOMAC. Upon reaching lateral decubitus, orotracheal intubation was performed. General anesthesia was maintained with isoflurane or sevoflurane diluted in oxygen (0.8 L/min) using a non-rebreathing delivery system under spontaneous ventilation. As defined in the pilot study, the first animal from ISOMAC started the maintenance of anesthesia with 2.6% isoflurane, while the first animal in SEVOMAC received 4% sevoflurane. After finishing the instrumentation to assess heart rate, respiratory rate, systolic blood pressure, pulse oximeter oxygen saturation, end-tidal carbon dioxide concentration, and rectal temperature, a 15-min wait to reach anesthetic equilibrium was allowed, and then an electrical noxious stimulation (50 mA and 50 Hz) was performed on the lateral aspect of the thigh (a faradic current of 3 consecutive single stimuli, followed by 2 continuous stimuli). The animals' responses to the electrical stimulus were observed. The presence of a positive response (gross movement of the limbs, head, or vocalization) or a negative response (absence of gross movements) determined the increase or reduction, respectively, of the inhalation anesthetic concentration by 10% in the subsequent marmoset. The quality of anesthetic induction and recovery from anesthesia was evaluated using a scale that measured the intensity of agitation, coughing, nausea, and vomiting. Physiological variables were recorded before (M0) and after (M1) applying the nociceptive stimulus. Isoflurane and sevoflurane MAC values in C. penicillata were 2.29 ± 0.10% and 3.93 ± 0.61 % respectively. Physiological parameters, quality of anesthetic induction and recovery did not differ significantly between groups. However, isoflurane caused irritation of the airway and ocular mucous membranes, more coughing episodes, and tearing at induction. There was no difference between groups for time to extubation and recovery time to regain sternal position. Discussion: Previous studies in primates found lower MAC values for both anesthetics, except for Lemur catta. Those findings may be explained by the use of different nociceptive stimuli and the MAC determination method employed, although no differences in MAC values have been described between bracketing or up-and-down methods in human primates and dogs. It is unlikely that the stimulus and technique alone are the determining factors for the high concentration of isoflurane and sevoflurane observed in the present study since MAC was high with both halogenates, indicating that dose extrapolation from other species can lead to the wrong anesthetic dosage. Keywords: Callithrix penicillata, marmoset, isoflurane, sevoflurane, minimum alveolar concentration (MAC).Background: The minimum alveolar concentration (MAC) is a measure of quantitative anesthetic potency and has become the standard index for the evaluation and comparison of volatile anesthetics, in addition to guiding dose administration. Black-tufted marmosets (Callithrix penicillata) are primates present in the clinical and surgical routine of veterinary hospitals, as well as experimental models, especially in neuroscience. Few studies have evaluated the potency of the main volatile anesthetics in this species. This study aimed to determine the MAC of isoflurane and sevoflurane in C. penicillata using the up-and-down method and to evaluate the effects of these drugs on the quality of anesthetic induction, maintenance, and recovery. Materials, Methods & Results: Twenty-four animals of undetermined age were used. All marmosets were healthy according to hematological and physical evaluation. The animals were randomly divided into two groups: ISOMAC and SEVOMAC. Each animal was induced to general anesthesia in an anesthetic box with oxygen (5 L/min) and sevoflurane at 7% in the SEVOMAC group or isoflurane at 5% in the ISOMAC. Upon reaching lateral decubitus, orotracheal intubation was performed. General anesthesia was maintained with isoflurane or sevoflurane diluted in oxygen (0.8 L/min) using a non-rebreathing delivery system under spontaneous ventilation. As defined in the pilot study, the first animal from ISOMAC started the maintenance of anesthesia with 2.6% isoflurane, while the first animal in SEVOMAC received 4% sevoflurane. After finishing the instrumentation to assess heart rate, respiratory rate, systolic blood pressure, pulse oximeter oxygen saturation, end-tidal carbon dioxide concentration, and rectal temperature, a 15-minute wait to reach anesthetic equilibrium was allowed, and then an electrical noxious stimulation (50 mA and 50 Hz) was performed on the lateral aspect of the thigh (a faradic current of 3 consecutive single stimuli, followed by 2 continuous stimuli). The animals' responses to the electrical stimulus were observed. The presence of a positive response (gross movement of the limbs, head, or vocalization) or a negative response (absence of gross movements) determined the increase or reduction, respectively, of the inhalation anesthetic concentration by 10% in the subsequent marmoset. The quality of anesthetic induction and recovery from anesthesia was evaluated using a scale that measured the intensity of agitation, coughing, nausea, and vomiting. Physiological variables were recorded before (M0) and after (M1) applying the nociceptive stimulus. Isoflurane and sevoflurane MAC values in C. penicillata were 2.29 ± 0.10% and 3.93 ± 0.61% respectively. Physiological parameters, quality of anesthetic induction and recovery did not differ significantly between groups. However, isoflurane caused irritation of the airway and ocular mucous membranes, more coughing episodes, and tearing at induction. There was no difference between groups for time to extubation and recovery time to regain sternal position. Discussion: Previous studies in primates found lower MAC values for both anesthetics, except for Lemur catta. Those findings may be explained by the use of different nociceptive stimuli and the MAC determination method employed, although no differences in MAC values have been described between bracketing or up-and-down methods in human primates and dogs. It is unlikely that the stimulus and technique alone are the determining factors for the high concentration of isoflurane and sevoflurane observed in the present study since MAC was high with both halogenates, indicating that dose extrapolation from other species can lead to the wrong anesthetic dosage

Microalgas biorremediadoras: tratamentos biológicos e viabilidade de fermentação na produção de bioetanol

Considered as one of the most promising biofuels, bioethanol is an alternative and attractive energy source for the future. The high prices of oil and its derivatives, high energy demand and intense environmental debates have a decisive influence in stimulating research on alternative sources of energy. In addition, there is an intense demand for studies that evaluate the influence of the residues of the composition of the various effluents on the biomass productivity. Biofuels produced from microalgae can be an attractive option due to their rapid growth rate, high biomass content, low utilization of arable land and high rate of carbon dioxide absorption, and a good acceptance in the current scenario. Therefore, the objective was to produce bioethanol from microalgal biomass grown in domestic effluents and to analyze the efficiency in bioremediation during cultivation. It was possible to observe that the D467WC strain showed a more pronounced growth curve in the 25% and 50% dilutions of domestic effluent (ED) in relation to the other species studied, however, the growth shown to be more promising in the 25% dilution of ED. The reduction of effluent parameters is observed when comparing the analyzes done before the cultivation, at a 25% dilution, and after the cultivation, attesting that the microalga reduces the levels of ED nutrients, which would contribute to the treatment before water bodies. Cell counting resulted in a cell density equivalent to 43 x 105 cells mL-1, a larger number of cells in the shortest time in the culture in domestic effluent at 25% dilution when compared to the number obtained in the culture in the medium of synthetic WC culture. The dry weight of the obtained biomass was 0.200 g.L-1 and the total sugar content was 35.04%, which when extracted by the acid hydrolysis method yielded 55.6% glucose. From the results obtained in the cultivation and analysis of sugars of the microalgal biomass it is possible to produce bioethanol from the fermentation of the hydrolyzate with the yeast Saccharomyces cerevisiae.NenhumaConsiderado como um dos biocombustíveis mais promissores, o bioetanol se mostra como uma fonte de energia alternativa e atrativa atualmente. Os altos preços do petróleo e seus derivados, a elevada demanda energética e intensos debates ambientais exercem influência decisiva no estímulo às pesquisas sobre fontes alternativas de energia. Além disto, há uma intensa demanda por estudos que avaliem a influência dos resíduos da composição dos diversos efluentes na produtividade de biomassa. Os biocombustíveis produzidos a partir de microalgas podem ser uma atraente opção devido a sua taxa de crescimento rápido, alto teor de biomassa, baixa utilização de terrenos cultiváveis e alta taxa de absorção de dióxido de carbono, além de uma boa aceitação no cenário atual. Diante disso, objetivou-se produzir bioetanol a partir de biomassa microalgal cultivada em efluentes domésticos e analisar a eficiência na biorremediação durante o cultivo. No desenvolvimento da pesquisa, foi possível perceber que a cepa D467WC obteve uma curva de crescimento mais acentuada nas diluições a 25% e a 50% de efluente doméstico (ED) em relação às outras espécies estudadas, porém, o crescimento mostrou-se mais promissor na diluição a 25% de ED. Observa-se a redução dos parâmetros do efluente quando se compara as análises feitas antes do cultivo, a uma diluição de 25%, e depois do cultivo, atestando que a microalga reduz os níveis de nutrintes do ED, o que contribuiria no tratamento antes do lançamento em corpos hídricos. No acompanhamento por contagem celular foi possível obter uma densidade celular equivalente a 43 x 105 células mL-1, um número maior de células em tempo mais curto no cultivo em efluente doméstico na diluição a 25% se comparado ao número obtido no cultivo realizado no meio de cultura sintético WC. O peso seco da biomassa obtida foi correspondente 0,200 g.L-1 e o teor de açúcares totais foi de 35,04 %, que ao ser extraído pelo método de hidrólise ácida obteve-se 55,6 % de glucose. A partir dos resultados obtidos no cultivo e das análises de açúcares da biomassa microalgal é possível ocorrer a produção de bioetanol a partir da fermentação do hidrolisado com a levedura Saccharomyces cerevisiae

Determination of the Minimum Alveolar Concentration (MAC) of Isoflurane and Sevoflurane in Callithrix penicillata

Background: The minimum alveolar concentration (MAC) is a measure of quantitative anesthetic potency and has become the standard index for the evaluation and comparison of volatile anesthetics, in addition to guiding dose administration. Black-tufted marmosets (Callithrix penicillata) are primates present in the clinical and surgical routine of veterinary hospitals, as well as experimental models, especially in neuroscience. Few studies have evaluated the potency of the main volatile anesthetics in this species. This study aimed to determine the MAC of isoflurane and sevoflurane in C. penicillata using the up-and-down method and to evaluate the effects of these drugs on the quality of anesthetic induction, maintenance, and recovery. Materials, Methods & Results: Twenty-four animals of undetermined age were used. All marmosets were healthy according to hematological and physical evaluation. The animals were randomly divided into 2 groups: ISOMAC and SEVOMAC. Each animal was induced to general anesthesia in an anesthetic box with oxygen (5 L/min) and sevoflurane at 7% in the SEVOMAC group or isoflurane at 5% in the ISOMAC. Upon reaching lateral decubitus, orotracheal intubation was performed. General anesthesia was maintained with isoflurane or sevoflurane diluted in oxygen (0.8 L/min) using a non-rebreathing delivery system under spontaneous ventilation. As defined in the pilot study, the first animal from ISOMAC started the maintenance of anesthesia with 2.6% isoflurane, while the first animal in SEVOMAC received 4% sevoflurane. After finishing the instrumentation to assess heart rate, respiratory rate, systolic blood pressure, pulse oximeter oxygen saturation, end-tidal carbon dioxide concentration, and rectal temperature, a 15-min wait to reach anesthetic equilibrium was allowed, and then an electrical noxious stimulation (50 mA and 50 Hz) was performed on the lateral aspect of the thigh (a faradic current of 3 consecutive single stimuli, followed by 2 continuous stimuli). The animals' responses to the electrical stimulus were observed. The presence of a positive response (gross movement of the limbs, head, or vocalization) or a negative response (absence of gross movements) determined the increase or reduction, respectively, of the inhalation anesthetic concentration by 10% in the subsequent marmoset. The quality of anesthetic induction and recovery from anesthesia was evaluated using a scale that measured the intensity of agitation, coughing, nausea, and vomiting. Physiological variables were recorded before (M0) and after (M1) applying the nociceptive stimulus. Isoflurane and sevoflurane MAC values in C. penicillata were 2.29 ± 0.10% and 3.93 ± 0.61 % respectively. Physiological parameters, quality of anesthetic induction and recovery did not differ significantly between groups. However, isoflurane caused irritation of the airway and ocular mucous membranes, more coughing episodes, and tearing at induction. There was no difference between groups for time to extubation and recovery time to regain sternal position. Discussion: Previous studies in primates found lower MAC values for both anesthetics, except for Lemur catta. Those findings may be explained by the use of different nociceptive stimuli and the MAC determination method employed, although no differences in MAC values have been described between bracketing or up-and-down methods in human primates and dogs. It is unlikely that the stimulus and technique alone are the determining factors for the high concentration of isoflurane and sevoflurane observed in the present study since MAC was high with both halogenates, indicating that dose extrapolation from other species can lead to the wrong anesthetic dosage. Keywords: Callithrix penicillata, marmoset, isoflurane, sevoflurane, minimum alveolar concentration (MAC).Background: The minimum alveolar concentration (MAC) is a measure of quantitative anesthetic potency and has become the standard index for the evaluation and comparison of volatile anesthetics, in addition to guiding dose administration. Black-tufted marmosets (Callithrix penicillata) are primates present in the clinical and surgical routine of veterinary hospitals, as well as experimental models, especially in neuroscience. Few studies have evaluated the potency of the main volatile anesthetics in this species. This study aimed to determine the MAC of isoflurane and sevoflurane in C. penicillata using the up-and-down method and to evaluate the effects of these drugs on the quality of anesthetic induction, maintenance, and recovery. Materials, Methods & Results: Twenty-four animals of undetermined age were used. All marmosets were healthy according to hematological and physical evaluation. The animals were randomly divided into two groups: ISOMAC and SEVOMAC. Each animal was induced to general anesthesia in an anesthetic box with oxygen (5 L/min) and sevoflurane at 7% in the SEVOMAC group or isoflurane at 5% in the ISOMAC. Upon reaching lateral decubitus, orotracheal intubation was performed. General anesthesia was maintained with isoflurane or sevoflurane diluted in oxygen (0.8 L/min) using a non-rebreathing delivery system under spontaneous ventilation. As defined in the pilot study, the first animal from ISOMAC started the maintenance of anesthesia with 2.6% isoflurane, while the first animal in SEVOMAC received 4% sevoflurane. After finishing the instrumentation to assess heart rate, respiratory rate, systolic blood pressure, pulse oximeter oxygen saturation, end-tidal carbon dioxide concentration, and rectal temperature, a 15-minute wait to reach anesthetic equilibrium was allowed, and then an electrical noxious stimulation (50 mA and 50 Hz) was performed on the lateral aspect of the thigh (a faradic current of 3 consecutive single stimuli, followed by 2 continuous stimuli). The animals' responses to the electrical stimulus were observed. The presence of a positive response (gross movement of the limbs, head, or vocalization) or a negative response (absence of gross movements) determined the increase or reduction, respectively, of the inhalation anesthetic concentration by 10% in the subsequent marmoset. The quality of anesthetic induction and recovery from anesthesia was evaluated using a scale that measured the intensity of agitation, coughing, nausea, and vomiting. Physiological variables were recorded before (M0) and after (M1) applying the nociceptive stimulus. Isoflurane and sevoflurane MAC values in C. penicillata were 2.29 ± 0.10% and 3.93 ± 0.61% respectively. Physiological parameters, quality of anesthetic induction and recovery did not differ significantly between groups. However, isoflurane caused irritation of the airway and ocular mucous membranes, more coughing episodes, and tearing at induction. There was no difference between groups for time to extubation and recovery time to regain sternal position. Discussion: Previous studies in primates found lower MAC values for both anesthetics, except for Lemur catta. Those findings may be explained by the use of different nociceptive stimuli and the MAC determination method employed, although no differences in MAC values have been described between bracketing or up-and-down methods in human primates and dogs. It is unlikely that the stimulus and technique alone are the determining factors for the high concentration of isoflurane and sevoflurane observed in the present study since MAC was high with both halogenates, indicating that dose extrapolation from other species can lead to the wrong anesthetic dosage

Hematology of Nile tilapia (Oreochromis niloticus) subjected to anesthesia and anticoagulation protocols

 A hematologia clínica é uma ferramenta que auxilia na realização do diagnóstico de doenças e pode atuar como um indicador prognóstico das condições patológicas de peixes. O objetivo deste estudo foi avaliar os valores hematológicos de tilápias do Nilo (Oreochromis niloticus) submetidas a diferentes anestésicos e amostras obtidas com diferentes anticoagulantes. Foram utilizados trinta peixes, com peso médio de 473±35,50g e comprimento total médio de 29,33±0,37cm, adquiridos de piscicultura comercial localizada no município de Lages (SC). Os animais foram divididos aleatoriamente em três grupos (n=10) conforme a forma de indução: grupo eugenol (GE) na concentração de 70mg L-1, grupo cloridrato de benzocaína (GB) na concentração de 100mg L-1 e grupo controle (GC) sem o uso de anestésicos. As amostras de sangue foram obtidas por venopunção dos vasos caudais e acondicionadas em microtubos contendo heparina sódica ou Na2EDTA e posteriormente processadas. Os resultados foram avaliados pelo Sigma Stat, sendo utilizado o teste-t pareado para dados entre diferentes anticoagulantes pertencentes ao mesmo grupo e análise de variância, seguida de teste de Tukey para comparação das médias entre grupos (p?0,05). A maioria das alterações observadas no eritrograma foram superiores com o anticoagulante heparina e no grupo benzocaína comparados com o grupo controle. Porém no leucograma, os valores obtidos foram maiores com o anticoagulante Na2EDTA em todos os grupos, sugerindo que a heparina pode causar aglomeração celular. Baseado nos resultados encontrados conclui-se que os anestésicos testados minimizaram o efeito do estresse causado por manipulações e procedimentos invasivos quando comparado ao grupo controle e a heparina foi o anticoagulante que causou menor hemólise quando comparado com o Na2EDTA para esta espécie no teste de fragilidade osmótica eritrocitária. Assim, as variações hematológicas a partir de amostras obtidas com diferentes protocolos anestésicos e/ou diferentes anticoagulantes devem ser consideradas para a espécie Oreochromis niloticus.Clinical hematology facilitates the diagnosis of disease and can act as a prognostic indicator of pathological conditions in fish. The aim of the present study was to evaluate hematological parameters of Nile tilapia (Oreochromis niloticus) subjected to different anesthetics and anticoagulants. Thirty apparently healthy fishes (average weight of 473 ± 35. 50 g and mean total length of 29. 33 ± 0. 37 cm), were selected from the local commercial fish farm in the Lages municipality (Santa Catarina, Brazil). The animals were randomly divided into three groups of 10. In two groups, anesthesia was induced with eugenol (70 mg·L- 1) (EG) and Benzocaine hydrochloride (100 mg·L-1) (BG), respectively. Anesthesia was not administered to fish of the third group (CG/control group). Blood samples were obtained by venipuncture of the caudal vessels and placed into microtubes containing sodium heparin or Na2EDTA for further analysis. The results were analyzed by Sigma Stat for Windows, the paired t-test for significant differences between anticoagulants of the same group, and analysis of variance followed by the Tukey test for comparison of means between groups (p ? 0. 05). Most of the observed changes in the erythrogram were significantly higher for the anticoagulant heparin and benzocaine group in comparison to the control group. However, the values obtained for the leukogram were significantly higher for all groups subjected to the Na2EDTA anticoagulant, suggesting that heparin may cause cell clumping. The results suggest that the anesthetics under investigation effectively minimizes the effects of stress caused by handling and invasive procedures, and that the anticoagulant heparin causes less hemolysis in comparison to Na2EDTA for Nile tilapia. Thus, the hematological variations attributed to different anesthetic protocols and/or different anticoagulants should be considered for the species Oreochromis niloticus

Dreno de sucção fechado em mastectomias unilaterais totais em cadelas

RESUMO: O objetivo deste estudo foi avaliar a utilização de dreno de sucção fechado em feridas cirúrgicas de mastectomias unilaterais totais em cadelas. Foram utilizadas 18 cadelas com peso médio de 14,87±9,29kg, idade média 9,34±2,68 anos, provenientes da rotina hospitalar, as quais foram selecionadas por meio de avaliação clínica e oncológica. Os animais foram alocados em dois grupos: Convencional (GC, n=9) que foram submetidas à cirurgia de mastectomia unilateral total, sem colocação de dreno e grupo Dreno (GD, n=9) que foram submetidas à mastectomia unilateral total com colocação do dreno de sucção fechado (Biovácuo?), sendo o diâmetro do dreno determinado conforme peso do animal. Foram realizadas cinco avaliações durante o período pós-operatório: avaliação clínica diária dos animais através da frequência cardíaca (FC), frequência respiratória (f), temperatura retal (TR), coloração de mucosas, tempo de preenchimento capilar (TPC), grau de desidratação, hemograma, perfil bioquímico (ureia, creatinina, colesterol, triglicérides e glicose); avaliação qualitativa do dreno; avaliação qualitativa da ferida cirúrgica, sendo esta também realizada em 14 e 30 dias quanto à presença ou não de exsudato, edema, integridade da pele, deiscência, necrose e fibrose cicatricial; avaliação quantitativa do fluido drenado e avaliação qualitativa do fluido drenado, quanto à celularidade, tipo e morfologia celular. Houve aumento dos valores médios de densidade, neutrófilos, linfócitos, e aumento do valor de mediana de fibrinogênio do fluido drenado em 72 horas em relação às 24 horas no grupo GD. Ocorreu aumento do exsudato em 24, 48 e 72 horas no GD quando comparado ao GC. Houve aumento do volume de fluido drenado em 60 e 72 horas em relação às 12 horas no grupo GD. Houve redução do valor médio de eritrócitos em 72 horas em relação ao basal no grupo GD. Observou-se aumento nos valores médios de hemoglobina e hematócrito em 24 horas no grupo GC quando comparado ao GD. Houve aumento no valor médio de neutrófilos segmentados no basal no GD quando comparado ao GC. Conclui-se que a técnica de colocação de dreno de sucção fechado apresenta maior teor de exsudato. Recomenda-se que o vácuo do dreno seja refeito de 12 em 12 horas, sendo inicialmentrealizado 6 horas após o término da cirurgia. O dreno de sucção fechado não gera desconforto adicional ao paciente; recomenda-se que o mesmo seja removido 72 horas após o término da cirurgia, quando a produção de fluido diminui, porém mesmo assim alguns indivíduos podem apresentar formação de seroma no pós-operatório tardio

Determinação da influência da fluidoterapia nos parâmetros hematológicos e urinários em cães

O objetivo deste estudo foi avaliar os efeitos de diferentes taxas de infusão de fluidoterapia sobre parâmetros hematológicos e urinários em cães. Foram utilizados 30 cães, sem raça definida, machos, distribuídos em três grupos que receberam fluidoterapia (NaCl 0,9%) pelo período de uma hora nas taxas: G5 (5mL/kg); G10 (10mL/ kg); G50 (50mL/kg). Amostras de sangue para realização de hemograma, e de urina para realização de densidade urinária foram colhidas ao longo de diferentes momentos, assim como a avaliação do volume urinário produzido. Os valores do eritrograma foram menores estatisticamente de T10 a T240 em G10 e G50, em relação a T0. Na comparação entre grupos, os menores valores para o eritrograma foram encontrados em G50. A densidade urinária apresentou diminuição estatística entre momentos somente em G50, sendo que este grupo apresentou valores menores em relação a G5 e G10. O débito urinário apresentou diferenças estatísticas entre grupos, com maiores valores em G50 em praticamente todos os momentos estudados. Assim, pode-se concluir que a fluidoterapia altera os valores hematológicos em taxas de 10 e 50mL/ kg/h, se devendo esperar um período superior a quatro horas após o término da infusão para coleta de amostras de sangue. Ainda, a fluidoterapia altera a densidade urinária apenas em altas taxas de infusão (50mL/kg por 1 hora), sendo que, nesses casos, amostras de urina devem ser colhidas num período superior a 4 horas após o término da infusão, porém taxas mais baixas (5 e 10mL/Kg por 1 hora) não interferem com a densidade urinária