Outcome respiratorio a lungo termine nei soggetti affetti da cardiopatia congenita sottoposti ad intervento cardiochirurgico

Introduction: In the last years cardiac surgery for congenital heart disease (CHD) reduced dramatically mortality modifying prognosis, but, at the same time, increased morbidity in this patient population. Respiratory and cardiovascular systems are strictly anatomically and functionally connected, so that alterations of pulmonary hemodynamic conditions modify respiratory function. While very short-term alterations of respiratory mechanics after surgery were investigated by many authors, not as much works focused on long-term changes. In these subjects rest respiratory function may be limited by several factor: CHD itself (fetal pulmonary perfusion influences vascular and alveolar development), extracorporeal circulation (CEC), thoracotomy and/or sternotomy, rib and sternal contusions, pleural adhesions and pleural fibrosis, secondary to surgical injury. Moreover inflammatory cascade, triggered by CEC, can cause endothelial damage and compromise gas exchange. Aims: The project was conceived to 1) determine severity of respiratory functional impairement in different CHD undergone to surgical correction/palliation; 2) identify the most and the least CHD involved by pulmonary impairement; 3) find a correlation between a specific hemodynamic condition and functional anomaly, and 4) between rest respiratory function and cardiopulmonary exercise test. Materials and methods: We studied 113 subjects with CHD undergone to surgery, and distinguished by group in accord to pulmonary blood flow (group 0: 28 pts with normal pulmonary flow; group 1: 22 pts with increased flow; group 2: 43 pts with decreased flow; group 3: 20 pts with total cavo-pulmonary anastomosis-TCPC) followed by the Pediatric Cardiology and Cardiac Surgery Unit, and we compare them to 37 age- and sex-matched healthy subjects. In Pediatric Pulmonology Unit all pts performed respiratory function tests (static and dynamic volumes, flow/volume curve, airway resistances-raw- and conductance-gaw-, lung diffusion of CO-DLCO- and DLCO/alveolar volume), and CHD pts the same day had cardiopulmonary test. They all were examined and had allergological tests, and respiratory medical history. Results: restrictive pattern (measured on total lung capacity-TLC- and vital capacity-VC) was in all CHD groups, and up to 45% in group 2 and 3. Comparing all groups, we found a significant difference in TLC between healthy and group 2 (p=0.001) and 3 (p=0.004), and in VC between group 2 and healthy (p=0.001) and group 1(p=0.034). Inspiratory capacity (IC) was decreased in group 2 related to healthy (p<0.001) and group 1 (p=0.037). We showed a direct correlation between TLC and VC with age at surgery (p=0.01) and inverse with number of surgical interventions (p=0.03). Reduced FEV1/FVC ratio, Gaw and increased Raw were mostly present in group 3. DLCO was impaired in all groups, but up to 80% in group 3 and 50% in group 2; when corrected for alveolar volume (DLCO/VA) reduction persisted in group 3 (20%), 2 (6.2%) and 0 (7.1%). Exercise test was impaired in all groups: VO2max and VE markedly reduced in all but especially in group 3, and VE/VCO2 slope, marker of ventilatory response to exercise, is increased (<36) in 62.5% of group 3, where other pts had anyway value>32. Comparing group 3 and 2, the most involved categories, we found difference in VO2max and VE/VCO2 slope (respectively p=0.02 and p<0.0001). We evidenced correlation between rest and exercise tests, especially in group 0 (between VO2max and FVC, FEV1, VC, IC; inverse relation between VE/VCO2slope and FVC, FEV1 and VC), but also in group 1 (VO2max and IC), group 2 (VO2max and FVC and FEV1); never in group 3. Discussion: According with literature, we found a frequent impairment of rest pulmonary function in all groups, but especially in group 2 and 3. Restrictive pattern was the most frequent alteration probably due to compromised pulmonary (vascular and alveolar) development secondary to hypoperfusion in fetal and pre-surgery (and pre-TCPC)life. Parenchymal fibrosis, pleural adhesions and thoracic deformities can add further limitation, as showed by the correlation between group 3 and number of surgical intervention. Exercise tests were limited, particularly in group 3 (complex anatomy and lost of chronotropic response), and we found correlations between rest and exercise tests in all but group 3. We speculate that in this patients hemodynamic exceeds respiratory contribution, though markedly decreased.

A função respiratória dos doentes adultos com fibrose quística, em repouso e no esforço

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Children's health and indoor air quality in primary schools and homes in Portugal-Study design

The main aim of the research project "On the Contribution of Schools to Children's Overall Indoor Air Exposure" is to study associations between adverse health effects, namely, allergy, asthma, and respiratory symptoms, and indoor air pollutants to which children are exposed to in primary schools and homes. Specifically, this investigation reports on the design of the study and methods used for data collection within the research project and discusses factors that need to be considered when designing such a study. Further, preliminary findings concerning descriptors of selected characteristics in schools and homes, the study population, and clinical examination are presented. The research project was designed in two phases. In the first phase, 20 public primary schools were selected and a detailed inspection and indoor air quality (IAQ) measurements including volatile organic compounds (VOC), aldehydes, particulate matter (PM2.5, PM10), carbon dioxide (CO2), carbon monoxide (CO), bacteria, fungi, temperature, and relative humidity were conducted. A questionnaire survey of 1600 children of ages 8-9 years was undertaken and a lung function test, exhaled nitric oxide (eNO), and tear film stability testing were performed. The questionnaire focused on children's health and on the environment in their school and homes. One thousand and ninety-nine questionnaires were returned. In the second phase, a subsample of 68 children was enrolled for further studies, including a walk-through inspection and checklist and an extensive set of IAQ measurements in their homes. The acquired data are relevant to assess children's environmental exposures and health status.

Caracterización paraclínica de trabajadores con patologías respiratorias de un centro de referencia neumológico, Bucaramanga, 2014-2016

Introducción: La enfermedad respiratoria ocupacional es causada por la exposición a diferentes agentes en el trabajo. Las pruebas objetivas realizadas en sospecha de enfermedad respiratoria de origen laboral, son importantes herramientas que permiten realizar un adecuado diagnóstico, una detección precoz de la enfermedad respiratoria ocupacional, disminuye el progreso rápido de la patología, la morbilidad de los trabajadores y el impacto negativo sobre su futuro laboral. Objetivo: Caracterizar las pruebas paraclínicas de las patologías respiratorias de trabajadores, en un centro de referencia neumológico de Bucaramanga año 2014-2016. Materiales y métodos: Se realizó un estudio descriptivo retrospectivo con datos secundarios de 96 trabajadores que laboran en diferentes actividades económicas. Se incluyeron variables sociodemográficas, laborales, ayudas imagenológicas y pruebas de función pulmonar, realizando 3 grupos de acuerdo a su patología que fueron: Asma, síndrome de disfunción reactiva de la vía aérea y neumoconiosis. En el análisis estadístico se emplearon medidas de tendencia central y dispersión. Resultados: De los 96 trabajadores 84.4% son hombres, las actividades económicas más frecuentes fueron la industria del petróleo y gas en un 27.1% y trabajadores en materiales de construcción en un 19.8%. En la caracterización paraclínica por grupo de patología, para asma predominó la obstrucción en la espirometría (46.9%) y los volúmenes pulmonares con atrapamiento aéreo (95.5%), en RADS (síndrome de disfunción de vías aéreas reactivas) los volúmenes pulmonares con atrapamiento aéreo (77%) y en las neumoconiosis para Rx de tórax (90.3%) y Tac de tórax (100%) reportaron alteraciones parenquimatosas, espirometría con obstrucción (54.8%) y volúmenes pulmonares con atrapamiento aéreo (62.5 %).Discusión y Conclusiones: Las ocupaciones de mayor riesgo para desarrollo de neumopatías de origen ocupacional fuero, , son la minería y construcción y para asma la agricultura y manufacturas. Para asma se evidenció que no hay significancia diagnóstica para estudios imagenológicos pero sí para las pruebas de función pulmonar. Para neumoconiosis el estudio imagenológico es el de mayor importancia ya que en las radiografías se presentan cambios incluso mucho antes de la afectación de la función pulmonar. Para RADS se concluyó que la realización de un test de provocación con metacolina sería el Gold estándar para el diagnóstico. Las pruebas de función respiratoria son de vital importancia para determinar la enfermedad ocupacional en trabajadores expuestos para vigilancia y detección precoz, es conveniente la realización de protocolos para la evaluación y diagnóstico de la enfermedad respiratoria de origen ocupacional. Palabras claves: Neumoconiosis, asma ocupacional, función pulmonar, radiografía de tórax, ocupación, Colombia.

Can infant lung function predict respiratory morbidity during the first year of life in preterm infants?

Compared with term-born infants, preterm infants have increased respiratory morbidity in the first year of life. We investigated whether lung function tests performed near term predict subsequent respiratory morbidity during the first year of life and compared this to standard clinical parameters in preterms.The prospective birth cohort included randomly selected preterm infants with and without bronchopulmonary dysplasia. Lung function (tidal breathing and multiple-breath washout) was measured at 44 weeks post-menstrual age during natural sleep. We assessed respiratory morbidity (wheeze, hospitalisation, inhalation and home oxygen therapy) after 1 year using a standardised questionnaire. We first assessed the association between lung function and subsequent respiratory morbidity. Secondly, we compared the predictive power of standard clinical predictors with and without lung function data.In 166 preterm infants, tidal volume, time to peak tidal expiratory flow/expiratory time ratio and respiratory rate were significantly associated with subsequent wheeze. In comparison with standard clinical predictors, lung function did not improve the prediction of later respiratory morbidity in an individual child.Although associated with later wheeze, noninvasive infant lung function shows large physiological variability and does not add to clinically relevant risk prediction for subsequent respiratory morbidity in an individual preterm.

Health effects of daily airborne particle dose in children : direct association between personal dose and respiratory health effects

Air pollution is a widespread health problem associated with respiratory symptoms. Continuous exposure monitoring was performed to estimate alveolar and tracheobronchial dose, measured as deposited surface area, for 103 children and to evaluate the long-term effects of exposure to airborne particles through spirometry, skin prick tests and measurement of exhaled nitric oxide (eNO). The mean daily alveolar deposited surface area dose received by children was 1.35×103 mm2. The lowest and highest particle number concentrations were found during sleeping and eating time. A significant negative association was found between changes in pulmonary function tests and individual dose estimates. Significant differences were found for asthmatics, children with allergic rhinitis and sensitive to allergens compared to healthy subjects for eNO. Variation is a child’s activity over time appeared to have a strong impact on respiratory outcomes, which indicates that personal monitoring is vital for assessing the expected health effects of exposure to particles.

Ventricular repolarization during cardiovascular autonomic function testing

The autonomic nervous system is an important modulator of ventricular repolarization and arrhythmia vulnerability. This study explored the effects of cardiovascular autonomic function tests on repolarization and its heterogeneity, with a special reference to congenital arrhythmogenic disorders typically associated with stress-induced fatal ventricular arrhythmias. The first part explored the effects of standardized autonomic tests on QT intervals in a 12-lead electrocardiogram and in multichannel magnetocardiography in 10 healthy adults. The second part studied the effects of deep breathing, Valsalva manouvre, mental stress, sustained handgrip and mild exercise on QT intervals in asymptomatic patients with LQT1 subtype of the hereditary long QT syndrome (n=9) and in patients with arrhythmogenic right ventricular dysplasia (ARVD, n=9). Even strong sympathetic activation had no effects on spatial QT interval dispersion in healthy subjects, but deep respiratory efforts and Valsalva influenced it in ways that were opposite in electrocardiographic and magnetocardiographic recordings. LQT1 patients showed blunted QT interval and sinus nodal responses to sympathetic challenge, as well as an exaggerated QT prolongation during the recovery phases. LQT1 patients showed a QT interval recovery overshoot in 2.4 ± 1.7 tests compared with 0.8 ± 0.7 in healthy controls (P = 0.02). Valsalva strain prolonged the T wave peak to T wave end interval only in the LQT1 patients, considered to reflect the arrhythmogenic substrate in this syndrome. ARVD patients showed signs of abnormal repolarization in the right ventricle, modulated by abrupt sympathetic activation. An electrocardiographic marker reflecting interventricular dispersion of repolarization was introduced. It showed that LQT1 patients exhibit a repolarization gradient from the left ventricle towards the right ventricle, significantly larger than in controls. In contrast, ARVD patients showed a repolarization gradient from the right ventricle towards the left. Valsalva strain amplified the repolarization gradient in LQT1 patients whereas it transiently reversed it in patients with ARVD. In conclusion, intrathoracic volume and pressure changes influence regional electrocardiographic and magnetocardiographic QT interval measurements differently. Especially recovery phases of standard cardiovascular autonomic functions tests and Valsalva manoeuvre reveal the abnormal repolarization in asymptomatic LQT1 patients. Both LQT1 and ARVD patients have abnormal interventricular repolarization gradients, modulated by abrupt sympathetic activation. Autonomic testing and in particular the Valsalva manoeuvre are potentially useful in unmasking abnormal repolarization in these syndromes.

Long-Term Burden and Respiratory Effects of Respiratory Syncytial Virus Hospitalization in Preterm Infants — The SPRING Study

The health status of premature infants born 32(1)-35(0) weeks' gestational age (wGA) hospitalized for RSV infection in the first year of life (cases; n = 125) was compared to that of premature infants not hospitalized for RSV (controls; n = 362) through 6 years. The primary endpoints were the percentage of children with wheezing between 2-6 years and lung function at 6 years of age. Secondary endpoints included quality of life, healthcare resource use, and allergic sensitization. A significantly higher proportion of cases than controls experienced recurrent wheezing through 6 years of age (46.7% vs. 27.4%; p = 0.001). The vast majority of lung function tests appeared normal at 6 years of age in both cohorts. In children with pulmonary function in the lower limit of normality (FEV1 Z-score [-2; -1]), wheezing was increased, particularly for cases vs. controls (72.7% vs. 18.9%, p = 0.002). Multivariate analysis revealed the most important factor for wheezing was RSV hospitalization. Quality of life on the respiratory subscale of the TAPQOL was significantly lower (p = 0.001) and healthcare resource utilization was significantly higher (p<0.001) in cases than controls. This study confirms RSV disease is associated with wheezing in 32-35 wGA infants through 6 years of age.

Analysis of the respiratory dynamics during normal breathing by means of pseudo phase plots and pressure-volume loops

This paper reports on the analysis of tidal breathing patterns measured during noninvasive forced oscillation lung function tests in six individual groups. The three adult groups were healthy, with prediagnosed chronic obstructive pulmonary disease, and with prediagnosed kyphoscoliosis, respectively. The three children groups were healthy, with prediagnosed asthma, and with prediagnosed cystic fibrosis, respectively. The analysis is applied to the pressure–volume curves and the pseudophaseplane loop by means of the box-counting method, which gives a measure of the area within each loop. The objective was to verify if there exists a link between the area of the loops, power-law patterns, and alterations in the respiratory structure with disease. We obtained statistically significant variations between the data sets corresponding to the six groups of patients, showing also the existence of power-law patterns. Our findings support the idea that the respiratory system changes with disease in terms of airway geometry and tissue parameters, leading, in turn, to variations in the fractal dimension of the respiratory tree and its dynamics.

Is multidimensional scaling suitable for mapping the input respiratory impedance in subjects and patients?

This paper presents the application of multidimensional scaling (MDS) analysis to data emerging from noninvasive lung function tests, namely the input respiratory impedance. The aim is to obtain a geometrical mapping of the diseases in a 3D space representation, allowing analysis of (dis)similarities between subjects within the same pathology groups, as well as between the various groups. The adult patient groups investigated were healthy, diagnosed chronic obstructive pulmonary disease (COPD) and diagnosed kyphoscoliosis, respectively. The children patient groups were healthy, asthma and cystic fibrosis. The results suggest that MDS can be successfully employed for mapping purposes of restrictive (kyphoscoliosis) and obstructive (COPD) pathologies. Hence, MDS tools can be further examined to define clear limits between pools of patients for clinical classification, and used as a training aid for medical traineeship.

Analysis of the Respiratory Dynamics During Normal Breathing by Means of Pseudophase Plots and Pressure–Volume Loops

This paper reports on the analysis of tidal breathing patterns measured during noninvasive forced oscillation lung function tests in six individual groups. The three adult groups were healthy, with prediagnosed chronic obstructive pulmonary disease, and with prediagnosed kyphoscoliosis, respectively. The three children groups were healthy, with prediagnosed asthma, and with prediagnosed cystic fibrosis, respectively. The analysis is applied to the pressure-volume curves and the pseudophase-plane loop by means of the box-counting method, which gives a measure of the area within each loop. The objective was to verify if there exists a link between the area of the loops, power-law patterns, and alterations in the respiratory structure with disease. We obtained statistically significant variations between the data sets corresponding to the six groups of patients, showing also the existence of power-law patterns. Our findings support the idea that the respiratory system changes with disease in terms of airway geometry and tissue parameters, leading, in turn, to variations in the fractal dimension of the respiratory tree and its dynamics.

Respiratory chemoreceptor function in vertebrates - Comparative and evolutionary aspects

The sensing of blood gas tensions and/or pH is an evolutionarily conserved, homeostatic mechanism, observable in almost all species studied from invertebrates to man. In vertebrates, a shift from the peripheral O2-oriented sensing in fish, to the central CO2/pH sensing in most tetrapods reflects the specific behavioral requirements of these two groups whereby, in teleost fish, a highly O2-oriented control of breathing matches the ever-changing and low oxygen levels in water, whilst the transition to air-breathing increased the importance of acid-base regulation and O2-related drive, although retained, became relatively less important. The South American lungfish and tetrapods are probably sister groups, a conclusion backed up by many similar features of respiratory control. For example, the relative roles of peripheral and central chemoreceptors are present both in the lungfish and in land vertebrates. In both groups, the central CO2/pH receptors dominate the ventilatory response to hypercarbia (60-80), while the peripheral CO2/pH receptors account for 20-30. Some basic components of respiratory control have changed little during evolution. This review presents studies that reflect the current trends in the field of chemoreceptor function, and several laboratories are involved. An exhaustive review on the previous literature, however, is beyond the intended scope of the article. Rather, we present examples of current trends in respiratory function in vertebrates, ranging from fish to humans, and focus on both O2 sensing and CO2 sensing. As well, we consider the impact of chronic levels of hypoxia - a physiological condition in fish and in land vertebrates resident at high elevations or suffering from one of the many cardiorespiratory disease states that predispose an animal to impaired ventilation or cardiac output. This provides a basis for a comparative physiology that is informative about the evolution of respiratory functions in vertebrates and about human disease. Currently, most detail is known for mammals, for which molecular biology and respiratory physiology have combined in the discovery of the mechanisms underlying the responses of respiratory chemoreceptors. Our review includes new data on nonmammalian vertebrates, which stresses that some chemoreceptor sites are of ancient origin.

Impaired lung function in individuals chronically exposed to biomass combustion

Background: The use of biomass for cooking and heating is considered an important factor associated with respiratory diseases. However, few studies evaluate the amount of particulate matter less than 2.5 mu in diameter (PM2.5), symptoms and lung function in the same population. Objectives: To evaluate the respiratory effects of biomass combustion and compare the results with those of individuals from the same community in Brazil using liquefied petroleum gas (Gas). Methods: 1402 individuals in 260 residences were divided into three groups according to exposure (Gas, Indoor-Biomass, Outside-Biomass). Respiratory symptoms were assessed using questionnaires. Reflectance of paper filters was used to assess particulate matter exposure. In 48 residences the amount of PM2.5 was also quantified. Pulmonary function tests were performed in 120 individuals. Results: Reflectance index correlated directly with PM2.5 (r=0.92) and was used to estimate exposure (ePM2.5). There was a significant increase in ePM2.5 in Indoor-Biomass and Outside-Biomass, compared to Gas. There was a significantly increased odds ratio (OR) for cough, wheezing and dyspnea in adults exposed to Indoor-Biomass (OR=2.93, 2.33, 2.59, respectively) and Outside-Biomass (OR=1.78, 1.78, 1.80, respectively) compared to Gas. Pulmonary function tests revealed both Non-Smoker-Biomass and Smoker-Gas individuals to have decreased %predicted-forced expiratory volume in the first second (FEV1) and FEV1/forced vital capacity (FVC) as compared to Non-Smoker-Gas. Pulmonary function tests data was inversely correlated with duration and ePM2.5. The prevalence of airway obstruction was 20% in both Non-Smoker-Biomass and Smoker-Gas subjects. Conclusion: Chronic exposure to biomass combustion is associated with increased prevalence of respiratory symptoms, reduced lung function and development of chronic obstructive pulmonary disease. These effects are associated with the duration and magnitude of exposure and are exacerbated by tobacco smoke. (C) 2011 Elsevier Inc. All rights reserved.

Respiratory physiotherapy can increase lower esophageal sphincter pressure in GERD patients

Background: Inspiratory muscle training (IMT) has been shown to increase diaphragm thickness. We evaluated the effect of IMT on mid-respiratory pressure (MRP) in patients with gastroesophageal reflux disease (GERD) and hypotensive lower esophageal sphincter (LES), and compared the results with a sham group. Methods: Twenty consecutive patients (progressive loading group) and 9 controls (sham group) were included. All patients had end expiratory pressure (EEP) between 5 and 10 mmHg, underwent esophageal manometry and pulmonary function tests before and after 8 weeks of training, and used a threshold IMT twice daily. The threshold IMT was set at 30% of the maximal inspiratory pressure for the progressive loading group; while, the threshold for sham-treated patients was set at 7 cmH(2)O for the whole period. Results: There was an increase in MRP in 15 (75%) patients in the progressive loading group, with an average gain of 46.6% (p<0.01), and in six (66%) patients in the sham group with a mean increase of 26.2% (p<0.01). However, there was no significant difference between the groups (p = 0.507). The EEP also increased compared with measurements before training (p<0.01), but it did not differ between groups (p = 0.727). Conclusion: IMT increased LES pressure in patients with GERD, in both the treatment and sham groups, after an eight-week program. Although there was no statistically significant difference between groups, suggesting the pressure increase in LES occurs regardless of the resistance load of the threshold IMT. These findings need to be confirmed in further studies with a larger sample. Registration number: 0922/09. (C) 2012 Elsevier Ltd. All rights reserved.

Sleep desaturation and its relationship to lung function, exercise and quality of life in LAM

Background: Lymphangioleiomyomatosis (LAM) is characterised by progressive airway obstruction and hypoxaemia in young women. Although sleep may trigger hypoxaemia in patients with airway obstruction, it has not been previously investigated in patients with LAM. Methods: Consecutive women with lung biopsy proven LAM and absence of hypoxaemia while awake were evaluated with pulmonary function test, echocardiography, 6-min walk test, overnight full polysomnography, and Short Form 36 health-related quality-of-life questionnaire. Results: Twenty-five patients with (mean +/- SD) age 45 +/- 10 years, SpO(2) awake 95% +/- 2, forced expiratory volume in the first second (median-interquartile) FEV1 (% predicted) 77 (47-90) and carbonic monoxide diffusion capacity, DLCO (%) 55 (34-74) were evaluated. Six-minute walk test distance and minimum SpO(2) (median-interquartile) were, respectively, 447 m (411 -503) and 90% (82-94). Median interquartile apnoea-hypopnoea index was in the normal range 2 (1-5). Fourteen patients (56%) had nocturnal hypoxaemia (10% total sleep time with SpO(2) <90%), and the median sleep time spent with SpO(2) <90% was 136 (13-201) min. Sleep time spent with SpO(2) <90% correlated with the residual volume/total lung capacity ratio (r(s) = 0.5, p: 0.02), DLCO (r(s) = -0.7, p: 0.001), FEV1 (r(s) = -0.6, p: 0.002). Multivariate linear regression model showed that RV/TLC ratio was the most important functional variable related to sleep hypoxaemia. Conclusion: Significant hypoxaemia during sleep is common in LAM patients with normal SpO(2) while awake, especially among those with some degree of hyperinflation in lung function tests. (C) 2011 Published by Elsevier Ltd.