Variáveis antatômicas, cardiovasculares e hemogasométricas em cães com a síndrome braquicefálica

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, 2014.A síndrome braquicefálica caracteriza-se pelo aumento da resistência à passagem do ar nas vias aéreas superiores, devido a combinações de deformidades anatômicas como estenose de narinas, alongamento de palato mole, eversão de sáculos laríngeos e hipoplasia traqueal. Vinte cães braquicefálicos (GB) e 20 cães dolicocefálicos (GC), com até cinco anos de idade, foram incluídos no estudo. Avaliaram-se pressão arterial sistólica, média e diastólica, hemogasometria, ecodopplercardiografia, eletrocardiografia, eletrocardiografia ambulatorial, hematimetria e radiografias torácica e cervical. A média ± desvio padrão da abertura da narina no GB foi estatisticamente menor comparado ao GC (0,23 ± 0,08 cm versus 0,56 ± 0,05 cm, p < 0,001). A SaO2 foi menor no GB (p < 0,001) e a pressão arterial média foi maior no GB (p = 0,05). Todos os cães braquicefálicos apresentaram arritmia sinusal (AS) e 15 (75%) destes tinham AS maior que 20% de variação entre intervalo RR adjacente, enquanto no GC, 17 (85%) animais apresentaram AS e 13 (65%) destes demonstraram AS maior que 20% de variação entre intervalo RR adjacente. A [HCO3-]v e PvCO2 foram maiores no GB (p < 0,001). Resultados deste estudo sugerem que cães braquicefálicos jovens já apresentam menor SaO2 e maior pressão arterial média quando comparados com cães dolicocefálicos. ______________________________________________________________________________ ABSTRACTThe brachycephalic syndrome is characterized by increased upper airway resistance to airflow due to combinations of anatomical deformities such as stenotic nares, elongation of the soft palate, eversion of the laryngeal saccules and tracheal hypoplasia. Twenty brachycephalic (BG) and 20 dolicocephalic dogs (CG), aged up to five years, were included in the study. Systolic (SAP), mean (MAP), and diastolic (DAP) arterial blood pressure recordings were recorded. Blood gases and complete blood count (CBC) were measured. Doppler echocardiography, electrocardiography, ambulatory electrocardiography as well as thoracic and cervical radiographs were evaluated. The mean ± standard deviation diameter of the nares was significantly lower in BG compared to CG (0.23 ± 0.08 versus 0.56 ± 0.05 cm, p < 0.001). The SaO2 was lower (p < 0.001) and mean arterial pressure higher in BG (p = 0.05). All brachycephalic dogs had sinus arrhythmia (SA), and 15 (75 %) of these showed more than 20 % variation between adjacent R-R intervals, whereas in CG, 17 (85 %) of the animals presented SA and 13 (65 %) of these showed more than 20 % variation between adjacent R-R intervals. Both [HCO3-]v and PvCO2 were higher in BG (p < 0.001). Results of this study suggest that young brachycephalic dogs already have lower SaO2 and higher MAP when compared with dolichocephalic dogs

Anatomical, Cardiovascular, and Blood Gas Parameters in Dogs with Brachycephalic Syndrome

Background: Brachycephalic syndrome is characterized by increased airflow resistance in upper airways due to the combinations of anatomical deformities such as stenotic nares, elongated soft palate, everted laryngeal saccules, and tracheal hypoplasia. There is little information in recent literature about assessment of anatomical, cardiovascular, and blood gases’ parameters of these animals at early stages of the syndrome. The purpose of this study was to characterize and to compare anatomical, cardiovascular, and blood gases’ parameters in young brachycephalic or dolichocephalic and mesocephalic dogs.Materials, Methods &amp; Results: Twenty brachycephalic dogs (BG) and 20 dolichocephalic and mesocephalic dogs (CG), aged up to 5 years, were included in the study. Anatomical abnormalities, systolic (SAP), mean (MAP), and diastolic (DAP) arterial blood pressure were recorded. Blood gas analysis and complete blood counts (CBC) were analyzed. Doppler echocardiography, electrocardiography, ambulatory electrocardiography, and thoracic and cervical radiographs were evaluated. The diameter of the nares in BG was lower when compared to CG (0.23 ± 0.08 versus 0.56 ± 0.05 cm, P &lt; 0.001). The SaO2 was lower (P &lt; 0.001) and MAP was higher in BG (P = 0.05). All brachycephalic dogs had sinus arrhythmia (SA), and 15 (75 %) of these showed SA higher than 20% variation  between adjacent RR intervals, whereas in CG, 17 (85%) of animals presented SA and 13 (65%) of these showed SA higher than 20 % variation between adjacent RR intervals. The smallest opening of the nostril, in brachycephalic dogs, was accompanied by a lower SaO2 and higher MAP. Results of this study suggest that young brachycephalic dogs have lower SaO2 and higher MAP when compared with dolichocephalic and mesocephalic dogs.Discussion: The most relevant aspect of this survey was the confirmation that brachycephalic dogs have lower SaO2 and higher MAP when compared to non brachycephalic animals. Few studies correlate upper airway obstruction to cardiovascular and blood gas alterations. Although there were no significant differences between groups for PaO2 and AaDO2, the means for BG were lower and higher, respectively, than CG, showing that obstruction of airways may lead to lower PaO2 and higher AaDO2. In the present study, brachycephalic animals tended to have higher tHb, PCV, DAP, and MAP, and lower SaO2. Even with no significant differences between groups for tHb, PCV, and DAP, one can assume that young animals may not already have presented such alterations, but as the syndrome progresses, these types of abnormalities tend to develop. Hypoventilation results in significantly lower SaO2 in these animals, as observed in this study. All brachycephalic dogs in our study had SA and 2 (10%) showed sinus pauses of 4 s and 6 s duration, which demonstrates a stimulated vagal tone. The percentage of cervical soft tissue (CST) in brachycephalic dogs was proposed in an attempt to objectively measure the soft tissue concentrated in the neck region of these animals, which may be considered a risk factor for development of the syndrome. The CST percentage was higher in BG, probably due to the increased amount of adipose tissue in the neck of these animals, fact that can contribute to an increase in tracheal pressure and vascular resistance in the region. Therefore, alterations of brachycephalic syndrome result in significant cardiovascular and blood gas abnormalities in young brachycephalic dogs, as higher MAP and lower SaO2

Anatomical, Cardiovascular, and Blood Gas Parameters in Dogs with Brachycephalic Syndrome

Background: Brachycephalic syndrome is characterized by increased airflow resistance in upper airways due to the combinations of anatomical deformities such as stenotic nares, elongated soft palate, everted laryngeal saccules, and tracheal hypoplasia. There is little information in recent literature about assessment of anatomical, cardiovascular, and blood gases’ parameters of these animals at early stages of the syndrome. The purpose of this study was to characterize and to compare anatomical, cardiovascular, and blood gases’ parameters in young brachycephalic or dolichocephalic and mesocephalic dogs.Materials, Methods &amp; Results: Twenty brachycephalic dogs (BG) and 20 dolichocephalic and mesocephalic dogs (CG), aged up to 5 years, were included in the study. Anatomical abnormalities, systolic (SAP), mean (MAP), and diastolic (DAP) arterial blood pressure were recorded. Blood gas analysis and complete blood counts (CBC) were analyzed. Doppler echocardiography, electrocardiography, ambulatory electrocardiography, and thoracic and cervical radiographs were evaluated. The diameter of the nares in BG was lower when compared to CG (0.23 ± 0.08 versus 0.56 ± 0.05 cm, P &lt; 0.001). The SaO2 was lower (P &lt; 0.001) and MAP was higher in BG (P = 0.05). All brachycephalic dogs had sinus arrhythmia (SA), and 15 (75 %) of these showed SA higher than 20% variation  between adjacent RR intervals, whereas in CG, 17 (85%) of animals presented SA and 13 (65%) of these showed SA higher than 20 % variation between adjacent RR intervals. The smallest opening of the nostril, in brachycephalic dogs, was accompanied by a lower SaO2 and higher MAP. Results of this study suggest that young brachycephalic dogs have lower SaO2 and higher MAP when compared with dolichocephalic and mesocephalic dogs.Discussion: The most relevant aspect of this survey was the confirmation that brachycephalic dogs have lower SaO2 and higher MAP when compared to non brachycephalic animals. Few studies correlate upper airway obstruction to cardiovascular and blood gas alterations. Although there were no significant differences between groups for PaO2 and AaDO2, the means for BG were lower and higher, respectively, than CG, showing that obstruction of airways may lead to lower PaO2 and higher AaDO2. In the present study, brachycephalic animals tended to have higher tHb, PCV, DAP, and MAP, and lower SaO2. Even with no significant differences between groups for tHb, PCV, and DAP, one can assume that young animals may not already have presented such alterations, but as the syndrome progresses, these types of abnormalities tend to develop. Hypoventilation results in significantly lower SaO2 in these animals, as observed in this study. All brachycephalic dogs in our study had SA and 2 (10%) showed sinus pauses of 4 s and 6 s duration, which demonstrates a stimulated vagal tone. The percentage of cervical soft tissue (CST) in brachycephalic dogs was proposed in an attempt to objectively measure the soft tissue concentrated in the neck region of these animals, which may be considered a risk factor for development of the syndrome. The CST percentage was higher in BG, probably due to the increased amount of adipose tissue in the neck of these animals, fact that can contribute to an increase in tracheal pressure and vascular resistance in the region. Therefore, alterations of brachycephalic syndrome result in significant cardiovascular and blood gas abnormalities in young brachycephalic dogs, as higher MAP and lower SaO2

Anatomical, Cardiovascular, and Blood Gas Parameters in Dogs with Brachycephalic Syndrome

Background: Brachycephalic syndrome is characterized by increased airflow resistance in upper airways due to the combinations of anatomical deformities such as stenotic nares, elongated soft palate, everted laryngeal saccules, and tracheal hypoplasia. There is little information in recent literature about assessment of anatomical, cardiovascular, and blood gases’ parameters of these animals at early stages of the syndrome. The purpose of this study was to characterize and to compare anatomical, cardiovascular, and blood gases’ parameters in young brachycephalic or dolichocephalic and mesocephalic dogs.Materials, Methods &amp; Results: Twenty brachycephalic dogs (BG) and 20 dolichocephalic and mesocephalic dogs (CG), aged up to 5 years, were included in the study. Anatomical abnormalities, systolic (SAP), mean (MAP), and diastolic (DAP) arterial blood pressure were recorded. Blood gas analysis and complete blood counts (CBC) were analyzed. Doppler echocardiography, electrocardiography, ambulatory electrocardiography, and thoracic and cervical radiographs were evaluated. The diameter of the nares in BG was lower when compared to CG (0.23 ± 0.08 versus 0.56 ± 0.05 cm, P &lt; 0.001). The SaO2 was lower (P &lt; 0.001) and MAP was higher in BG (P = 0.05). All brachycephalic dogs had sinus arrhythmia (SA), and 15 (75 %) of these showed SA higher than 20% variation  between adjacent RR intervals, whereas in CG, 17 (85%) of animals presented SA and 13 (65%) of these showed SA higher than 20 % variation between adjacent RR intervals. The smallest opening of the nostril, in brachycephalic dogs, was accompanied by a lower SaO2 and higher MAP. Results of this study suggest that young brachycephalic dogs have lower SaO2 and higher MAP when compared with dolichocephalic and mesocephalic dogs.Discussion: The most relevant aspect of this survey was the confirmation that brachycephalic dogs have lower SaO2 and higher MAP when compared to non brachycephalic animals. Few studies correlate upper airway obstruction to cardiovascular and blood gas alterations. Although there were no significant differences between groups for PaO2 and AaDO2, the means for BG were lower and higher, respectively, than CG, showing that obstruction of airways may lead to lower PaO2 and higher AaDO2. In the present study, brachycephalic animals tended to have higher tHb, PCV, DAP, and MAP, and lower SaO2. Even with no significant differences between groups for tHb, PCV, and DAP, one can assume that young animals may not already have presented such alterations, but as the syndrome progresses, these types of abnormalities tend to develop. Hypoventilation results in significantly lower SaO2 in these animals, as observed in this study. All brachycephalic dogs in our study had SA and 2 (10%) showed sinus pauses of 4 s and 6 s duration, which demonstrates a stimulated vagal tone. The percentage of cervical soft tissue (CST) in brachycephalic dogs was proposed in an attempt to objectively measure the soft tissue concentrated in the neck region of these animals, which may be considered a risk factor for development of the syndrome. The CST percentage was higher in BG, probably due to the increased amount of adipose tissue in the neck of these animals, fact that can contribute to an increase in tracheal pressure and vascular resistance in the region. Therefore, alterations of brachycephalic syndrome result in significant cardiovascular and blood gas abnormalities in young brachycephalic dogs, as higher MAP and lower SaO2

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora