Horse choanae are directionally asymmetric / Las coanas de los caballos son direccionalmente asimétricas

SUMMARY: Studies related to the upper respiratory pathway asymmetries are still scarce in the veterinary literature. We present here a study of choanae asymmetries of a pure horses belonging to "Cavall Pirinenc Català" (Pyrenean Horse Breed). For this goal, the palates of 23 dry skulls with no apparent pathologies were photographed and evaluated using geometric morphometrics. On each photo, we identified and digitized a total of 26 points (subset of 2 mid-sagittal, 4 paired landmarks (discrete homologous points) and 10 semilandmarks (points on an outline determined by extrinsic criteria) per side on the choana. Both fluctuating and directional asymmetries appeared statistically significant, the latter accounting more than half of the total variation. The lateral bend observed in horse choanae may be due to the asymmetrically positioned nasal passages. So detected equine choana asymmetry must rather be considered functional, with no clinical implication and presents an important consideration when equine choanae shape.

RESUMEN: Los estudios relacionados con las asimetrías de las vías respiratorias superiores aún son escasos en la literatura veterinaria. Presentamos un estudio de coanas asimetrías de un caballo puro perteneciente al "Cavall Pirinenc Català" (Raza del Caballo de los Pirineos). Para ello, se fotografiaron y evaluaron los paladares de 23 cráneos secos sin patologías aparentes mediante morfometría geométrica. En cada foto, identificamos y digitalizamos un total de 26 puntos (subconjunto de 2 puntos medio sagitales, 4 puntos de referencia emparejados (puntos homólogos discretos) y 10 puntos semillanos (puntos en un contorno determinado por criterios extrínsecos) por lado de la coana. Ambos fluctúan Las asimetrías direccionales aparecieron estadísticamente significativas, representando estas últimas más de la mitad de la variación total. La curvatura lateral observada en las coanas de caballo puede deberse a los conductos nasales asimétricamente posicionados. Por lo tanto, la asimetría de coanas equinas detectada debería considerarse funcional, sin implicación clínica y presenta una importante consideración cuando se forman coanas equinas.

The effect of the volumetric flow rate and endotracheal tube diameter on the pressure distribution in human airways.

The comprehension of the fluid flow in the upper airways is of paramount importance when treating patients under clinical conditions that demand mechanical ventilation. Barotrauma and overdistension are related to undesirable pressures and might be responsible for morbidity and mortality. In the current work we use computational fluid dynamics to investigate the pressure field in the upper respiratory airways. We performed a set of simulations varying the volumetric flow rate of mechanical ventilators and we have shown that the pressure profile can be calculated by means of the volumetric flow rate in accordance with a mathematical expression given by Pav=aV˙2, where Pav is the average pressure at selected sections of the upper airways and V˙ is the volumetric flow rate. Numerical findings provide evidence that the constant a varies with the location of the plane in the upper airways. We also show that some particular diameters of endotracheal tubes (ETT) must be used with care for a given range of volumetric flow rates. Overall, we document an important relationship among pressure, volumetric flow rate and selected internal diameters from ETT.

Antibody response against Pseudomonas aeruginosa and its relationship with immune mediators in the upper and lower airways of cystic fibrosis patients.

BACKGROUND: The upper airways (UAW) are a niche and a reservoir of Pseudomonas aeruginosa strains that cause chronic infection of the lower airways (LAW) in cystic fibrosis (CF). Here, we assessed the role of anti-P. aeruginosa immunoglobulin A (IgA) and IgG antibodies in upper and lower airway infections in cystic fibrosis patients. METHODS: Nasal lavage fluid and induced sputum samples of 40 CF patients were microbiologically cultured. We searched for correlations between anti-P. aeruginosa IgA and IgG levels, measured by enzyme-linked immunosorbent assay (optical density), and unspecific immune mediators in both specimens. RESULTS: Anti-P. aeruginosa IgA (median optical density: 0.953 vs 0.298) and IgG (0.120 vs 0.059) were significantly higher in nasal lavage than in sputum, but not significantly different between patients with and without chronic P. aeruginosa infection in UAW. Matrix metallopeptidase-9 (MMP-9) in nasal lavage and neutrophil elastase (NE) in sputum were predictors of IgA in nasal lavage and IgA in sputum, respectively. IgA was a predictor of myeloperoxidase (MPO) in nasal lavage. Tissue inhibitor of metalloproteinases-1 (TIMP-1) was a predictor of IgG in sputum. IgG, TIMP-1, and NE in sputum were predictors of IgG in nasal lavage. CONCLUSION: The anti-P. aeruginosa IgA response was more prominent in CF patients' UAW, indicating a lower degree of inflammatory responses. Proteases may play a role in the anti-P. aeruginosa humoral response in the upper and LAW, and anti-P. aeruginosa IgG may be involved in the crosstalk between upper and lower airways in cystic fibrosis patients.

Avaliação das alterações nas vias aéreas superiores através de tomografia computadorizada Cone-Beam em pacientes submetidos à cirurgia ortognática de avanço bimaxilar / Evaluation of upper airway alterations by Cone-Beam computed tomography in patients submitted to bimaxillary advancement orthognathic surgery

Os softwares de avaliação em três dimensões revolucionaram os planejamentos da cirurgia ortognática. Com eles é possível realizar desde simulações dos movimentos cirúrgicos, até avaliação das vias aéreas superiores (VAS) em volume e área, o que não era possível nas radiografias bidimensionais. Muitos pacientes recorrem à cirurgia ortognática com finalidade de melhorar a oclusão e a estética. Dependendo da movimentação cirúrgica, o espaço aéreo pode aumentar ou diminuir. O presente trabalho tem como objetivo avaliar as alterações de área e de volume do espaço aéreo faríngeo em pacientes submetidos à cirurgia ortognática de avanço bimaxilar. Foi realizada a análise da área axial mínima e do volume aéreo superior pré-operatório (T0) e pós-operatório (T1) de 50 pacientes, sendo 17 do sexo masculino e 33 do sexo feminino, com média de idade de 36,6 (±12,1) anos. As avaliações foram feitas através de tomografia computadorizada de feixe cônico, utilizando o Programa Nemoceph 3DOS. Foi utilizado o teste ´´t`` pareado para comparar os dados pré e pós-operatórios de volume e o teste de Wilcoxon para comparar os dados pré e pós-operatório de área axial mínima. Todos os testes foram realizados com o programa Statistica, adotando um nível de significância de 5%. No estudo do erro do método, não houve erro casual nem sistemático entre a primeira e a segunda aferição das variáveis (p > 0,05 em todas as medidas). A cirurgia de avanço bimaxilar apresentou uma média de 70,46% (59,38) de aumento volumétrico e uma mediana de 61,27% de aumento na área axial mínima, onde a mesma variou de -22,50% à 659,06%. Com este trabalho, conclui-se que o avanço bimaxilar proporciona um aumento significativo de volume e área axial mínima das vias aéreas superiores, porém este ganho não é homogêneo em todos os pacientes.(AU)

Software in three dimensions has come to revolutionize the orthognathic surgery planning. With them it is possible to perform from simulations of the surgical movements, until evaluation of the upper airways in volume and area, which wasnt possible in two dimensions software. Many patients resort to orthognathic surgery in order to improve occlusion and facial profile. Depending of the surgical movements, the airway space may increase or decrease. The aim of the study is to evaluate the changes in the area and volume of the pharyngeal airway space in patients submitted to bimaxillary advancement in orthognathic surgery. It was analyzed the minimum axial area and the volume of the pharyngeal airway space preoperative (T0) and postoperative (T1) air volumes of 50 patients, which 17 were male and 33 were female, with a mean age of 36.6 (± 12.1) years. The evaluations were done using Cone-beam computed tomography in Nemoceph 3D-OS Program. It was used the paired t test to compare the pre and postoperative volume data and the Wilcoxon test to compare the pre and postoperative data of the minimal axial area. All the tests were performed with the Statistica program, adopting a level of significance of 5%. In the study of the method error, there was no casual or systematic error between the first and second measurements of the variables (p> 0.05 in all measurements). The bimaxillary advancement surgery presented a mean of 70.46% (59.38) of volumetric increase and a median increase of 61.27% in the minimum axial area, that varied from -22.50% to 659.06%. In this study, it was concluded that bimaxillary advancement provides a significant increase in volume and minimum axial area of the upper airways, but the increase it isnt homogeneous in all patients.(AU)

Blood gases of horses subjected to jugular vein occlusion during treadmill exercise / Gases sanguíneos em equinos submetidos à oclusão da veia jugular durante o exercício em esteira

The purpose of the present investigation was to examine the effects of unilateral and bilateral jugular vein occlusion via temporary surgical ligature on arterial blood gases in horses during treadmill exercise. Six horses performed three exercise tests (ETs). ET1, considered to be the control, was performed in horses without jugular occlusion. ET2 and ET3 were performed in horses with unilateral and bilateral occlusion via temporary surgical ligature of the jugular veins, respectively. The partial pressure of oxygen (PO2) and partial pressure of carbon dioxide (PCO2) were determined. The PO2 showed decreased values during ET2 and ET3, suggesting that horses presenting acute jugular thrombophlebitis may have airflow limitations when exercising.(AU)

O objetivo do presente trabalho foi avaliar os efeitos da oclusão da veia jugular por ligadura cirúrgica unilateral e bilateral sobre os gases do sangue arterial em equinos durante o exercício em esteira. Seis equinos realizaram três exercícios teste (ETs). ET1, considerado como controle, foi realizado por eqüinos sem oclusão jugular. ET2 e ET3 foram cumpridos por equinos apresentando oclusão da veia jugular por ligadura temporária unilateral e bilateral, respectivamente. A pressão parcial de oxigênio (PO2) e a pressão parcial de dióxido de carbono (PCO2) foram determinadas. A (PO2) demonstrou diminuição em ET2 e ET3, sugerindo que equinos com tromboflebite jugular aguda podem apresentar limitação no fluxo de ar inspirado durante o exercício.(AU)

Upper airway dimensions in patients undergoing orthognathic surgery: a systematic review and meta-analysis.

The objective of this systematic review was to evaluate the effect of different types of orthognathic surgery on the dimensions of the upper airways assessed using three-dimensional images. An electronic search was performed in Cochrane Library, Medline, Scopus, VHL, Web of Science, and the System for Information on Grey Literature in Europe, ending January 2015. Inclusion criteria encompassed clinical studies in humans, patient age >15 years, patients submitted to maxillary or mandibular advancement or setback surgery, isolated or in combination, and presentation of airway measures, specifically volume and/or minimum cross-sectional area (CSA), obtained from computed tomography or magnetic resonance imaging. Additional searches were conducted on the references of included articles and in the NLM catalogue. An assessment of the risk of bias was performed. A total of 1180 studies were retrieved, of which 28 met the eligibility criteria; one was later excluded as it presented a high risk of bias. A meta-analysis was performed. There is moderate evidence to conclude that the upper airway minimum CSA increases significantly (124.13 mm(2)) after maxillomandibular advancement (MMA); the total volume increases significantly after MMA (7416.10mm(3)) and decreases significantly after maxillary advancement+mandibular setback (-1552.90 mm(3)) and isolated mandibular setback (-1894.65 mm(3)).

Blood gases of horses subjected to jugular vein occlusion during treadmill exercise / Gases sanguíneos em equinos submetidos à oclusão da veia jugular durante o exercício em esteira

The purpose of the present investigation was to examine the effects of unilateral and bilateral jugular vein occlusion via temporary surgical ligature on arterial blood gases in horses during treadmill exercise. Six horses performed three exercise tests (ETs). ET1, considered to be the control, was performed in horses without jugular occlusion. ET2 and ET3 were performed in horses with unilateral and bilateral occlusion via temporary surgical ligature of the jugular veins, respectively. The partial pressure of oxygen (PO2) and partial pressure of carbon dioxide (PCO2) were determined. The PO2 showed decreased values during ET2 and ET3, suggesting that horses presenting acute jugular thrombophlebitis may have airflow limitations when exercising.

O objetivo do presente trabalho foi avaliar os efeitos da oclusão da veia jugular por ligadura cirúrgica unilateral e bilateral sobre os gases do sangue arterial em equinos durante o exercício em esteira. Seis equinos realizaram três exercícios teste (ETs). ET1, considerado como controle, foi realizado por eqüinos sem oclusão jugular. ET2 e ET3 foram cumpridos por equinos apresentando oclusão da veia jugular por ligadura temporária unilateral e bilateral, respectivamente. A pressão parcial de oxigênio (PO2) e a pressão parcial de dióxido de carbono (PCO2) foram determinadas. A (PO2) demonstrou diminuição em ET2 e ET3, sugerindo que equinos com tromboflebite jugular aguda podem apresentar limitação no fluxo de ar inspirado durante o exercício.

Immunology.

BACKGROUND: Knowledge of our immune system functions is critical for understanding allergic airway disease development as well as for selection of appropriate diagnostic and therapeutic options for patients with respiratory allergies. METHODS: This review explains the current understanding of the basic immunology of the upper airways and the pathophysiology of allergic responses, including the mechanisms behind allergic rhinitis. RESULTS: The immune system can be divided to 2 main defense systems that function differently-innate immunity and adaptive immunity. Innate immunity includes several defensive mechanisms such as anatomic or physical barriers, physiological barriers, phagocytosis, and inflammation. The adaptive immune response is activated in an antigen-specific way to provide for the elimination of antigen and induce lasting protection. Hypersensitivity reactions occur when an exaggerated adaptive immune response is activated. Allergic rhinitis is an example of a type I, immunoglobulin E, mediated hypersensitivity reaction. CONCLUSION: Today we have several immunomodulatory treatment options for patients with allergic airway diseases, such as subcutaneous and sublingual immunotherapy. An understanding of the basics of our immune system and its method of functions is key for using these therapies appropriately.

A negative expiratory pressure test during wakefulness for evaluating the risk of obstructive sleep apnea in patients referred for sleep studies

OBJECTIVE: Obstructive sleep apnea is characterized by increased upper airway collapsibility during sleep. The present study investigated the use of the negative expiratory pressure test as a method to rule out obstructive sleep apnea. METHODS: Flow limitation was evaluated in 155 subjects. All subjects underwent a diurnal negative expiratory pressure test and a nocturnal sleep study. The severity of sleep apnea was determined based on the apneahypopnea index. Flow limitation was assessed by computing the exhaled volume at 0.2, 0.5, and 1.0 s (V0.2, V0.5, and V1.0, respectively) during the application of a negative expiratory pressure and expressed as a percentage of the previous exhaled volume. Receiver-operating characteristic curves were constructed to identify the optimal threshold volume at 0.2, 0.5, and 1.0 s for obstructive sleep apnea detection. RESULTS: Mean expiratory volumes at 0.2 and 0.5 s were statistically higher (p <0.01) in healthy subjects than in all obstructive sleep apneic groups. Increasing disease severity was associated with lower expiratory volumes. The V0.2 ( percent) predictive parameters for the detection of sleep apnea were sensitivity (81.1 percent), specificity (93.1 percent), PPV (98.1 percent), and NPV (52.9 percent). Sensitivity and NPV were 96.9 percent and 93.2 percent, respectively, for moderate-to-severe obstructive sleep apnea, and both were 100 percent for severe obstructive sleep apnea. CONCLUSION: Flow limitation measurement by V 0.2 ( percent) during wakefulness may be a very reliable method to identify obstructive sleep apnea when the test is positive and could reliably exclude moderate and severe obstructive sleep apnea when the test is negative. The negative expiratory pressure test appears to be a useful screening test for suspected obstructive sleep apnea.

Upper airway collapsibility evaluated by a negative expiratory pressure test in severe obstructive sleep apnea

OBJECTIVES: To investigate the usefulness of measuring upper airway collapsibility with a negative expiratory pressure application as a screening test for severe obstructive sleep apnea (OSA). INTRODUCTION: OSA is a risk factor for cardiovascular disease, and it may have serious consequences. Its recognition may have important implications during the perioperative period. Increased upper airway collapsibility is one of the main determinants of OSA, and its evaluation could be useful for identifying this condition. METHODS: Severe OSA and normal subjects (24 in each group) were matched by body mass index and referred to our sleep laboratory. The subjects were enrolled in an overnight sleep study, and a diurnal negative expiratory pressure test was performed. Flow drop (DV) and expiratory volume were measured in the first 0.2 s (V02) of the negative expiratory pressure test. RESULTS: DV ( percent) and V02 ( percent) values were statistically different between normal and OSA subjects. OSA patients showed a greater decrease in flow than normal subjects. In addition, severely OSA patients exhaled during the first 0.2 s of the negative expiratory pressure application was an average of only 11.2 percent of the inspired volume compared to 34.2 percent for the normal subjects. Analysis of the receiver operating characteristics showed that V02 ( percent) and DV ( percent) could accurately identify severe OSA in subjects with sensitivities of 95.8 percent and 91.7 percent, respectively, and specificities of 95.8 percent and 91.7 percent, respectively. CONCLUSIONS: V02 ( percent) and DV ( percent) are highly accurate parameters for detecting severe OSA. The pharyngeal collapsibility measurement, which uses negative expiratory pressure during wakefulness, is predictive of collapsibility during sleep.