Mecânica respiratória de pacientes com obesidade mórbida / Respiratory mechanics of patients with morbid obesity

RESUMO Objetivo avaliar os diferentes componentes da resistência do sistema respiratório e a força muscular respiratória, bem como investigar a ocorrência de limitação de fluxo expiratório (LFE) de pacientes obesos mórbidos (OM) na posição sentada. Métodos a amostra foi composta de OM (IMC ≥ 40 kg/m2) e de indivíduos não obesos (NO) com IMC entre 18 e 30 kg/m2. O protocolo foi composto de: avaliação antropométrica e da função respiratória (espirometria, pressões inspiratória (PIM) e expiratória máximas (PEM) e oscilometria de impulso). Na comparação entre os grupos, foi utilizado o teste T para amostras não pareadas. As correlações foram avaliadas pelo teste de Pearson, e o nível de significância foi de 5%. Resultados Foram avaliados 50 OM (idade 40,0 ± 10,4 anos, 1,64 ± 0,09 m, 138,8 ± 33,6 kg e 50,7 ± 8,9 kg/m2), além de 30 NO (idade 37,6 ± 11,5 anos, 1,67 ± 0,09 m, 65,2 ± 10,3 kg e 23,2 ± 22 kg/m2). Os OM apresentaram maiores valores de resistência total, central, de vias aéreas, tecidual e periférica quando comparados aos NO. Nenhum paciente apresentou LFE. A circunferência abdominal se associou com variáveis espirométricas PIM e PEM. A relação cintura-quadril se correlacionou com variáveis de mecânica respiratória, além das espirométricas PIM e PEM. Conclusões pacientes com obesidade mórbida e sem padrão espirométrico obstrutivo apresentam aumento nas resistências total, de vias aéreas, periférica e tecidual do sistema respiratório quando comparados a não obesos. Esses indivíduos, entretanto, não apresentam limitação de fluxo expiratório e redução da força muscular respiratória.

ABSTRACT Objective To evaluate the different components of the resistance of the respiratory system, respiratory muscle strength and to investigate the occurrence of expiratory flow limitation (EFL) in patients with morbid obesity (MO) when seated. Methods The sample was composed of MO (BMI≥40 kg/m2) and non-obese individuals (NO) with a BMI between 18 and 30 kg/m2. The protocol consisted of the anthropometric assessment and the following measures of respiratory function: spirometry, maximal inspiratory and expiratory pressures (MIP and MEP, respectively) and impulse oscillometry. The group comparison was performed using T-test for unpaired samples. The correlations were evaluated by the Pearson test with a significance level of 5%. Results Fifty MO (age 40±10.4 years, 1.64±0.09 m, 138.8±33.6 kg and 50.7±8.9 kg/m2), and 30 NO (age 37.6±11.5 years, 1.67±0.09 m, 65.2±10.3 kg and 23.2±22 kg/m2) were evaluated. The MO showed higher values of total, peripheral, airways, tissue and central resistance when compared to the NO. No patient showed EFL. The waist circumference was associated with spirometric variables, MIP, and MEP. The waist-to-hip ratio was correlated to respiratory mechanics and spirometric variables, MIP, and MEP. Conclusion Morbidly obese patients with no obstructive spirometric pattern show increased total, airway, peripheral, and tissue respiratory system resistance when compared to nonobese. These individuals, however, do not present with expiratory flow limitation and reduced respiratory muscles strength.

Pneumo-phono-articulatory coordination assessment in dysarthria cases: a cross-sectional study

ABSTRACT BACKGROUND: Pneumo-phono-articulatory coordination is often impaired in dysarthric patients. Because all speech is produced upon exhalation, adequate respiratory support and coordination are essential for communication. Nevertheless, studies investigating respiratory parameters for speech are scarce. The objectives of the present study were to analyze and compare the numbers of words and syllables (universal measurement) per exhalation among healthy and dysarthric speakers, in different speech tasks. DESIGN AND SETTING: A cross-sectional analytical study with a control group was conducted at the Department of Speech, Language and Hearing Sciences at UNIFESP. METHODS: The study sample consisted of 62 individuals: 31 dysarthric patients and 31 healthy individuals matched for sex, age and education level. All participants performed number counting and text reading tests in which the numbers of words and syllables per exhalation were recorded. All measurements obtained from the two groups were compared. RESULTS: Statistically significant differences between the dysarthric and healthy groups were found in the two tasks (counting of syllables and words per exhalation) (P < 0.001). In contrast, the performance of the dysarthric patients did not vary according to the task: reading and number counting in syllables/exhalation (P = 0.821) or words/exhalation (P = 0.785). CONCLUSIONS: The mean numbers of words and syllables per exhalation among dysarthric subjects did not vary according to the speech task used but they clearly showed differences between dysarthric patients and normal healthy subjects. The study also made it possible to obtain preliminary data on the average numbers of words and syllables per expiration produced by healthy individuals during their speech production.

Between-occasion repeatability of fractional exhaled nitric oxide measurements in children / Repetibilidade de medidas da fração de óxido nítrico exalado em crianças em duas ocasiões

ABSTRACT The aim of the study was to assess short-term repeatability of measurements of fractional exhaled nitric oxide (FENO) and its correlates in children in the 6- to 9-year age bracket participating in a respiratory epidemiological survey. FENO was measured in two sessions one week apart in 101 children. Participants were divided into three groups: asymptomatic (n = 76); symptomatic (n = 14); and asthma (n = 11). Absolute and relative differences between the measurements, as well as concordance correlation coefficients, were used in order to assess repeatability. The two FENO measurements were strongly correlated (0.98). Although intragroup comparisons of the two measurements were not significantly different (p = 0.2), intergroup comparisons were. FENO measurements are reproducible in children in epidemiological settings.

RESUMO O objetivo do estudo foi avaliar a repetibilidade em curto prazo de medidas da fração de óxido nítrico exalado (FENO) e seus correlatos em crianças de 6-9 anos participantes de uma pesquisa epidemiológica respiratória. A FENO foi medida em duas sessões, com uma semana de intervalo, em 101 crianças. Os participantes foram divididos em três grupos: assintomático (n = 76), sintomático (n = 14) e asma (n = 11). A repetibilidade foi avaliada por meio de diferenças absolutas e relativas entre as medidas, bem como por coeficientes de correlação de concordância. As duas medidas da FENO correlacionaram-se fortemente (0,98). Embora as comparações entre as duas medidas em um mesmo grupo não tenham sido significativamente diferentes (p = 0,2), as comparações entre os grupos o foram. Medidas da FENO são reprodutíveis em crianças em cenários epidemiológicos.

Influencia del polimorfismo inserción / deleción (rs4646994) del gen de la enzima convertidora de angiotensina en la presión inspiratoria y espiratoria máxima de jóvenes chilenos sedentarios / Influence of the polymorphism insertion / deletion (rs4646994) of the angiotensin converting enzyme (ACE) gene on maximum inspiratory and expiratory pressure of Chilean sedentary youth

RESUMEN: La expresión de los genes puede impactar sobre el rendimiento muscular. En este aspecto el polimorfismo del gen de la Enzima Convertidora de Angiotensina (ECA), dependiendo de su inserción (Ins) o deleción (Del) puede potenciar diferentes cualidades musculares. Del mismo modo, si consideramos la ventilación como un proceso vital, sería relevante investigar si existe una influencia de este polimorfismo sobre los músculos que llevan a cabo tan importante función. El objetivo de este trabajo consistió en determinar el rendimiento muscular inspiratorio y espiratorio según alelos y polimorfismos del gen de la ECA. Se sometió a 83 sujetos (18 a 35 años), 46 hombres y 37 mujeres, a evaluaciones de capacidad vital forzada (CVF), presión inspiratoria máxima y presión espiratoria máxima (PIM-PEM). Posterior a esto, la genotipificación fue realizada por polimerase chain reaction (PCR) y electroforesis en gel de agarosa. Las variables fueron sometidas al análisis estadístico correspondiente según su distribución paramétrica, el nivel de significancia establecido fue un p<0,05. La distribución genotípica fue: Ins/Ins: 28 %, Ins/Del: 62 % y Del/Del: 19 %. Las mujeres homocigoto Ins, presentaron mayor PIM y PEM en modelos por genotipos (p=0,043; p=0,0001 respectivamente) y por dominancia (p=0,019; p=0,0008 respectivamente). La distribución genotípica y frecuencia alélica fue similar a la descrita anteriormente en población chilena. Además, las mujeres portadoras del alelo Ins, presentaron mayor PIM y PEM.

SUMMARY: Gene expression can impact muscle performance. In this aspect genetic polymorphism of the Angiotensin Converting Enzyme (ACE), depending on its insertion or deletion can strengthen different muscle qualities. Similarly, if we consider ventilation as a vital process, it would be important to research whether or not, there is an influence of this polymorphism on the muscles that perform such an important function. The aim of this study was to determine the inspiratory and expiratory muscle performance according alleles and polymorphisms of the ACE gene. We subjected 83 individuals (18-35 years), 46 men and 37 women, to forced vital capacity evaluations, maximum inspiratory pressure and expiratory pressure. Genotyping was subsequently performed by polymerase chain reaction (PCR) and agarose gel electrophoresis. The variables were subjected to appropriate statistical analysis by parametric distribution, the significance level was set at p <0.05. The genotype distribution was: Ins/Ins: 28 %, Ins/Del: 62 % and Del/Del: 19 %. Women homozygous Ins, exhibited a higher maximum inspiratory pressure and expiratory pressure in models for genotypes (p = 0.043; p = 0.0001 respectively) and for dominance (p = 0.019; p = 0.0008 respectively). The genotype distribution and allele frequency was similar to that described above, in Chilean population. Furthermore, women carrying the Ins allele had a higher maximum inspiratory pressure and expiratory pressure.

Within-breath respiratory impedance and airway obstruction in patients with chronic obstructive pulmonary disease

OBJECTIVE: Recent work has suggested that within-breath respiratory impedance measurements performed using the forced oscillation technique may help to noninvasively evaluate respiratory mechanics. We investigated the influence of airway obstruction on the within-breath forced oscillation technique in smokers and chronic obstructive pulmonary disease patients and evaluated the contribution of this analysis to the diagnosis of chronic obstructive pulmonary disease. METHODS: Twenty healthy individuals and 20 smokers were assessed. The study also included 74 patients with stable chronic obstructive pulmonary disease. We evaluated the mean respiratory impedance (Zm) as well as values for the inspiration (Zi) and expiration cycles (Ze) at the beginning of inspiration (Zbi) and expiration (Zbe), respectively. The peak-to-peak impedance (Zpp=Zbe-Zbi) and the respiratory cycle dependence (ΔZrs=Ze-Zi) were also analyzed. The diagnostic utility was evaluated by investigating the sensitivity, the specificity and the area under the receiver operating characteristic curve. ClinicalTrials.gov: NCT01888705. RESULTS: Airway obstruction increased the within-breath respiratory impedance parameters that were significantly correlated with the spirometric indices of airway obstruction (R=−0.65, p<0.0001). In contrast to the control subjects and the smokers, the chronic obstructive pulmonary disease patients presented significant expiratory-inspiratory differences (p<0.002). The adverse effects of moderate airway obstruction were detected based on the Zpp with an accuracy of 83%. Additionally, abnormal effects in severe and very severe patients were detected based on the Zm, Zi, Ze, Zbe, Zpp and ΔZrs with a high degree of accuracy (>90%). CONCLUSIONS: We conclude the following: (1) chronic obstructive pulmonary disease introduces higher respiratory cycle dependence, (2) this increase is proportional to airway obstruction, and (3) ...

Diagnostic methods to assess inspiratory and expiratory muscle strength / Métodos diagnósticos para avaliação da força muscular inspiratória e expiratória

Impairment of (inspiratory and expiratory) respiratory muscles is a common clinical finding, not only in patients with neuromuscular disease but also in patients with primary disease of the lung parenchyma or airways. Although such impairment is common, its recognition is usually delayed because its signs and symptoms are nonspecific and late. This delayed recognition, or even the lack thereof, occurs because the diagnostic tests used in the assessment of respiratory muscle strength are not widely known and available. There are various methods of assessing respiratory muscle strength during the inspiratory and expiratory phases. These methods are divided into two categories: volitional tests (which require patient understanding and cooperation); and non-volitional tests. Volitional tests, such as those that measure maximal inspiratory and expiratory pressures, are the most commonly used because they are readily available. Non-volitional tests depend on magnetic stimulation of the phrenic nerve accompanied by the measurement of inspiratory mouth pressure, inspiratory esophageal pressure, or inspiratory transdiaphragmatic pressure. Another method that has come to be widely used is ultrasound imaging of the diaphragm. We believe that pulmonologists involved in the care of patients with respiratory diseases should be familiar with the tests used in order to assess respiratory muscle function.Therefore, the aim of the present article is to describe the advantages, disadvantages, procedures, and clinical applicability of the main tests used in the assessment of respiratory muscle strength.

O acometimento da musculatura ventilatória (inspiratória e expiratória) é um achado clínico frequente, não somente nos pacientes com doenças neuromusculares, mas também nos pacientes com doenças primárias do parênquima pulmonar ou das vias aéreas. Embora esse acometimento seja frequente, seu reconhecimento costuma ser demorado porque seus sinais e sintomas são inespecíficos e tardios. Esse reconhecimento tardio, ou mesmo a falta de reconhecimento, é acentuado porque os exames diagnósticos usados para a avaliação da musculatura respiratória não são plenamente conhecidos e disponíveis. Usando diferentes métodos, a avaliação da força muscular ventilatória é feita para a fase inspiratória e expiratória. Os métodos usados dividem-se em volitivos (que exigem compreensão e colaboração do paciente) e não volitivos. Os volitivos, como a medida da pressão inspiratória e expiratória máximas, são os mais empregados por serem facilmente disponíveis. Os não volitivos dependem da estimulação magnética do nervo frênico associada a medida da pressão inspiratória na boca, no esôfago ou transdiafragmática. Finalmente, outro método que vem se tornando frequente é a ultrassonografia diafragmática. Acreditamos que o pneumologista envolvido nos cuidados a pacientes com doenças respiratórias deve conhecer os exames usados na avaliação da musculatura ventilatória. Por isso, o objetivo do presente artigo é descrever as vantagens, desvantagens, procedimentos de mensuração e aplicabilidade clínica dos principais exames utilizados para avaliação da força muscular ventilatória.

Quantitative Assessment of Global and Regional Air Trappings Using Non-Rigid Registration and Regional Specific Volume Change of Inspiratory/Expiratory CT Scans: Studies on Healthy Volunteers and Asthmatics

OBJECTIVE: The purpose of this study was to compare air trapping in healthy volunteers with asthmatics using pulmonary function test and quantitative data, such as specific volume change from paired inspiratory CT and registered expiratory CT. MATERIALS AND METHODS: Sixteen healthy volunteers and 9 asthmatics underwent paired inspiratory/expiratory CT. DeltaSV, which represents the ratio of air fraction released after exhalation, was measured with paired inspiratory and anatomically registered expiratory CT scans. Air trapping indexes, DeltaSV0.4 and DeltaSV0.5, were defined as volume fraction of lung below 0.4 and 0.5 DeltaSV, respectively. To assess the gravity effect of air-trapping, DeltaSV values of anterior and posterior lung at three different levels were measured and DeltaSV ratio of anterior lung to posterior lung was calculated. Color-coded DeltaSV map of the whole lung was generated and visually assessed. Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 were compared between healthy volunteers and asthmatics. In asthmatics, correlation between air trapping indexes and clinical parameters were assessed. RESULTS: Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 in asthmatics were significantly higher than those in healthy volunteer group (all p < 0.05). DeltaSV values in posterior lung in asthmatics were significantly higher than those in healthy volunteer group (p = 0.049). In asthmatics, air trapping indexes, such as DeltaSV0.5 and DeltaSV0.4, showed negative strong correlation with FEF25-75, FEV1, and FEV1/FVC. DeltaSV map of asthmatics showed abnormal geographic pattern in 5 patients (55.6%) and disappearance of anterior-posterior gradient in 3 patients (33.3%). CONCLUSION: Quantitative assessment of DeltaSV (the ratio of air fraction released after exhalation) shows the difference in extent of air trapping between health volunteers and asthmatics.

Proposal Intensity Adequacy of Expiratory Effort and Heart Rate Behavior During the Valsalva Maneuver in Preadolescents / Proposta de Adequação da Intensidade do Esforço Expiratório e Comportamento da Frequência Cardíaca Durante a Manobra de Valsalva em Pré-Adolescentes

Background: When performing the Valsalva maneuver (VM), adults and preadolescents produce the same expiratory resistance values. Objective: To analyze heart rate (HR) in preadolescents performing VM, and propose a new method for selecting expiratory resistance. Method: The maximal expiratory pressure (MEP) was measured in 45 sedentary children aged 9-12 years who subsequently performed VM for 20 s using an expiratory pressure of 60%, 70%, or 80% of MEP. HR was measured before, during, and after VM. These procedures were repeated 30 days later, and the data collected in the sessions (E1, E2) were analyzed and compared in periods before, during (0-10 and 10-20 s), and after VM using nonparametric tests. Results: All 45 participants adequately performed VM in E1 and E2 at 60% of MEP. However, only 38 (84.4%) and 25 (55.5%) of the participants performed the maneuver at 70% and 80% of MEP, respectively. The HR delta measured during 0-10 s and 10-20 s significantly increased as the expiratory effort increased, indicating an effective cardiac autonomic response during VM. However, our findings suggest the VM should not be performed at these intensities. Conclusion: HR increased with all effort intensities tested during VM. However, 60% of MEP was the only level of expiratory resistance that all participants could use to perform VM. Therefore, 60% of MEP may be the optimal expiratory resistance that should be used in clinical practice. .

Fundamento: Durante a manobra de Valsalva (MV), os valores de resistência expiratória utilizados por adultos são os mesmos aplicados em pré-adolescentes. Objetivo: Analisar as respostas da frequência cardíaca (FC) de pré-adolescentes durante a MV e propor nova metodologia para eleição da resistência expiratória. Métodos: Submeteram-se 45 pré-adolescentes com idades entre 9 e 12 anos à avaliação das pressões expiratórias máximas (PEmáx). Valores de 60%, 70% e 80% dessas PEmáx foram selecionados para ser aplicados nas MV, mantidas por 20 s. Batimentos cardíacos foram registrados antes, durante e após a manobra. Trinta dias após, todos os procedimentos foram repetidos, e os dados da primeira (A1) e da segunda (A2) avaliações foram comparados. As análises foram feitas com testes não paramétricos, destacando-se os momentos antes, durante (0-10 s e 10-20 s) e após as manobras. Resultados: Os 45 pré-adolescentes conseguiram realizar adequadamente a manobra à resistência de 60% da PEmáx, enquanto apenas 38 (84,4%) e 25 (55,5%) a realizaram com resistências de 70% e 80% da PEmáx, respectivamente. Os deltas de FC 0-10 s e 10-20 s, calculados durante o esforço, foram significativamente maiores quanto maior foi o esforço expiratório, revelando efetiva resposta autonômica cardíaca durante a manobra. Entretanto, o estudo sugere que essas intensidades não devam ser empregadas. Conclusão: A FC se elevou em todas as intensidades de esforço testadas durante a MV, porém somente quando foi realizada com resistência expiratória de 60% da PEmáx é que todos os participantes conseguiram realizá-la, sugerindo ser a intensidade ideal para ser empregada na prática clínica. .

Efectos del entrenamiento muscular inspiratorio/espiratorio sobre función respiratoria de pacientes tetrapléjicos / Effects of inspiratory/expiratory muscular training on respiratory function in quadriplegic patients

Introduction: Functional impairment in patients with high spinal cord injuries is associated to ventilatory dysfunction due to paretic respiratory muscles, which causes alterations in the ventilatory and in the cough mechanisms. Respiratory muscle training has been studied as a therapeutic alternative for this group of patients with no conclusive results, whereas a mixed protocol, which stimulates both inspiratory and expiratory muscles, had not been previously investigated. Objective: To evaluate the effects of systematic respiratory muscle training during four months, on pulmonary function, respiratory muscles strength and effort tolerance, cough efficacy and dyspnea perception, in a group of quadriplegic patients with at least one year of evolution post injury. Method: A quasi-experimental design was used. Six adults with cervical spinal cord injuries were enlisted and incorporated in a mixed respiratory muscles training for four months. Pulmonary function, respiratory muscles strength and resistance, cough efficacy and dyspnea perception were assessed pre and post training. Results: The application of the mixed training protocol significantly improved inspiratory muscle strength (p = 0,028),respiratory muscles effort tolerance (p = 0,028) and cough efficacy (p = 0,034).The other measures did not reach statistical significance. Conclusion: Mixed(inspiratory/expiratory) muscular training, shows partially favorable results in the improvement of pulmonary function. Studies using greater numbers of patients are necessary to achieve more categorical results.

Introducción: El compromiso funcional en pacientes con lesiones medulares altas se asocia a disfunción ventilatoria por paresia de musculatura respiratoria y provoca alteraciones ventilatorias y en el mecanismo de la tos. El entrenamiento de la musculatura respiratoria ha sido analizado como alternativa terapéutica para neumo este grupo de pacientes sin resultados concluyentes, mientras que un protocolo mixto, que estimule músculos inspiratorios y espiratorios no ha sido estudiado con anterioridad. Objetivo: Evaluar la respuesta del sistema respiratorio al entrenamiento sistemático de la musculatura respiratoria durante cuatro meses, sobre la función pulmonar, fuerza y tolerancia al esfuerzo de la musculatura respiratoria, eficacia de la tos y percepción de disnea de un grupo de pacientes tetrapléjicos. Materiales y Métodos: Se aplicó un diseño cuasi-experimental. Seis pacientes con lesiones medulares cervicales de al menos un año de evolución fueron reclutados e incluidos en un programa de entrenamiento mixto de la musculatura respiratoria durante 4 meses. Se evaluó la función pulmonar, fuerza y resistencia de la musculatura respiratoria, eficacia de la tos y percepción de disnea antes y después del período de entrenamiento. Resultados: El protocolo de entrenamiento mixto aplicado incrementó significativamente la fuerza muscular inspiratoria (p= 0,028), la tolerancia al esfuerzo de los músculos respiratorios (p = 0,028) y la eficacia de la tos (p = 0,034). El incremento en todas las otras variables medidas no alcanzó significancia estadística. Conclusión: El entrenamiento muscular mixto(inspiratorio/espiratorio) muestra resultados parcialmente favorables en la mejoría de indicadores de función pulmonar. Estudios de mayor número de pacientes son necesarios para acceder a resultados más categóricos.

Valores de presión espiratoria mantenida en la vía aérea como indicador de tolerancia al uso de válvula de fonación en pacientes traqueostomizados / Maintained expiratory airway pressure values as an indicator of tolerance of speaking valve in tracheostomized patients

Introduction: Speaking valve (SV) is an unidirectional flow device installed over the tracheostomy tube allowing phonation. Tolerance to this device depends on the permeability of the upper airway (UA), which may be indirectly assessed by measuring UA maintained expiratory pressure (PEMant). Objective: To evaluate the usefulness of the maintained expiratory pressure as a clinical indicator of tolerance to the SV. Method: Twenty three tracheostomized patients (median age 22 months-old) were evaluated with an aneroid manometer during 15 minutes, recording PEMant, arterial oxygen saturation (SaO2), heart rate, respiratory rate, accessory muscle use and wheezing as signs of respiratory distress Results: PEMant values less than 10 cmH2O are associated with tolerance of the SV and values over 20 cmH2O are associated with intolerance. Conclusion: Values under 10 cmH2O of PEMant can be used as an indicator of tolerance to VF.

Introducción: La válvula de fonación (VF), es un dispositivo de flujo unidireccional instalado sobre la cánula de traqueostomía posibilitando la fonación. La tolerancia a este dispositivo depende de la permeabilidad de la vía aérea superior (VAS), pudiendo ser valorada indirectamente a través de la medición de la presión espiratoria mantenida (PEMant) en vía aérea. Objetivo: Estudiar esta técnica como indicador clínico de tolerancia a la VF. Método: Se evaluaron 23 pacientes traqueostomizados (mediana de edad 22 meses) con un manómetro aneroide durante 15 minutos, registrando PEMant, saturación arterial de oxígeno (SaO2), frecuencia cardiaca, frecuencia respiratoria, uso de musculatura accesoria y sibilancias para valorar la dificultad respiratoria. Resultados: Valores de PEMant menores a 10 cmH2O se asocian con tolerancia a la VFy valores sobre 20 cmH2O a intolerancia a ésta. Conclusión: Valores bajo 10cmH2O de PEMant pueden ser indicadores de tolerancia al uso de VF.

Efeito da terminação precoce da expiração nos parâmetros espirométricos em crianças pré-escolares saudáveis / Early termination of exhalation: effect on spirometric parameters in healthy preschool children

OBJETIVO: Avaliar a aceitabilidade e a reprodutibilidade da espirometria em pré-escolares; estimar o tamanho do efeito da terminação precoce da expiração (TPE) nos valores de CVF, VEF1 e VEF0,5; e avaliar a validade do VEF0,5 em curvas com TPE. MÉTODOS: Espirometrias foram obtidas em 240 pré-escolares saudáveis, selecionados por amostragem simples. Três grupos foram formados com base na melhor curva de cada criança de acordo com o término da expiração: sem TPE (sTPE); com TPE e fluxo < 10 por cento do maior PFE (TPE<10); e com TPE e fluxo > 10 por cento do maior PFE (TPE>10). Foram comparadas a reprodutibilidade da CVF, VEF1 e VEF0,5 nos três grupos. Foi avaliado o efeito da TPE em CVF, VEF1 e VEF0,5. RESULTADOS: Das 240 crianças testadas, 112 (46.5 por cento) realizaram curvas aceitáveis para todos os parâmetros - 82 (34,0 por cento) no grupo sTPE e 30 (12,5 por cento) no grupo TPE<10. Em 64 (27,0 por cento) no grupo TPE>10, as curvas foram aceitáveis apenas para VEF0,5, aumentando para 73,0 por cento a proporção de crianças com VEF0,5 válido. Não houve diferenças significantes nas médias dos parâmetros avaliados entre os grupos sTPE e TPE<10. CONCLUSÕES: Manobras com TPE e fluxo < 10 por cento do maior PFE são válidas. Em indivíduos com fluxo > 10 por cento do maior PFE, essas manobras são válidas somente para VEF0,5.

OBJECTIVE: To evaluate the acceptability and reproducibility of spirometry in preschool children; to estimate the effect size of early termination of exhalation (ETE) on FVC, FEV1 and FEV0.5; and to evaluate the validity of FEV0.5 in curves with ETE. METHODS: Spirometric data were obtained from 240 healthy preschool children, who were selected by simple sampling. On the basis of the best curve from each child according to the end of exhalation, three groups were formed: no ETE (nETE); ETE and flow < 10 percent of the highest PEF (ETE<10); and ETE and flow > 10 percent of the highest PEF value (ETE>10). The reproducibility of FVC, FEV1 and FEV0.5 was compared among the three groups. The effect of ETE on FVC, FEV1, and FEV0.5 was assessed. RESULTS: Of the 240 children tested, 112 (46.5 percent)-82 (34.0 percent) of those in the nETE group and 30 (12.5 percent) of those in the ETE<10 group-had acceptable curves for all the parameters. In 64 (27.0 percent) of those in the ETE>10 group, the curves were acceptable only for FEV0.5, increasing the proportion of children with valid FEV0.5 to 73.0 percent. There were no significant differences between the nETE and ETE<10 groups in terms of the mean values of the parameters assessed. CONCLUSIONS: Maneuvers with ETE and flow < 10 percent of the highest PEF are valid. In individuals with a flow > 10 percent of the highest PEF value, these maneuvers are only valid for FEV0.5.

Variation of the anal resting pressure induced by postexpiratory apnea effort in patients with constipation / Variação da pressão anal de repouso induzida pela apneia pós-esforço expiratório em pacientes com constipação intestinal

CONTEXT: Intestinal constipation - a common symptom among the general population - is more frequent in women. It may be secondary to an improper diet or organic or functional disturbances, such as dyskinesia of the pelvic floor. This is basically characterized by the absence of relaxation or paradoxical contraction of the pelvic floor and anal sphincter during evacuation. OBJECTIVE: To analyze, by manometric data, the anal pressure variation at rest, during evacuation effort by using the Valsalva maneuver and forced post-expiratory apnea in subjects with secondary constipation. METHODS: Twenty-one patients (19 females - 90.4 percent) with a mean age of 47.5 years old (23-72) were studied. The diagnosis was performed using anorectal manometry, with a catheter containing eight channels disposed at the axial axis, measuring the proximal (1) and distal (2) portions of the anal orifice. The elevation of the pressure values in relation to the resting with the evacuation effort was present in all patients. The Agachan score was used for clinical evaluation of constipation. The variables studied were: mean anal pressure of the anal orifice for 20 seconds at rest, the effort of evacuation using Valsalva maneuver and the effort of evacuation during apnea after forced expiration, as well as the area under the curve of the manometric tracing at moments Valsalva and apnea. RESULTS: The analysis of the mean values of the anal pressure variation at rest evidenced difference between proximal and distal channels (P = 0.007), independent of the moment and tendency to differ during moments Valsalva and apnea (P = 0.06). The mean of values of the area under the manometric tracing curve showed differences between moments Valsalva and apnea (P = 0.0008), either at the proximal portion or at the distal portion of the anal orifice. CONCLUSION: The effort of evacuation associated with postexpiratory apnea, when compared with the effort associated with the Valsalva maneuver, provides lower elevation of anal pressure at rest by the parameter area under the curve.

CONTEXTO: A constipação intestinal é um sintoma comum na população, sendo mais frequente em mulheres, podendo ser secundária a erro alimentar, distúrbios orgânicos ou funcionais. Dentre estes, destaca-se a discinesia do assoalho pélvico, caracterizada basicamente por ausência de relaxamento ou contração paradoxal da musculatura pélvica e do canal anal no momento da evacuação. O melhor conhecimento dos mecanismos envolvidos na constipação de etiologia funcional pode contribuir em terapêuticas mais eficazes. OBJETIVO: Analisar através de dados manométricos, a variação da pressão anal de repouso durante o esforço de evacuação com a manobra de Valsalva e apneia pós-expiração forçada em pacientes com constipação. MÉTODOS: Foram estudados 21 pacientes, com idade média de 47,5 (23-72) anos, sendo 19 (90,4 por cento) do sexo feminino. Empregou-se manometria anorretal com cateter de oito canais dispostos no eixo axial, realizando-se as medidas na porção proximal (1) e distal (2) do canal anal. Todos os pacientes apresentavam elevação dos valores pressóricos em relação ao repouso com esforço de evacuação e para a avaliação do grau de constipação, empregou-se o escore de Agachan. As variáveis estudadas foram: pressão anal média do canal anal por 20 segundos em repouso, ao esforço de evacuação com manobra de Valsalva (V) e ao esforço de evacuação em apneia após expiração forçada (A), assim como a área sob a curva do traçado manométrico nos momentos V e A. RESULTADOS: A análise dos valores médios da variação da pressão anal de repouso evidenciou diferença entre os canais proximais e distais (P = 0,007), independente do momento, e tendência à diferença nos momentos V e A (P = 0,06). A média dos valores da área sob a curva do traçado manométrico demonstrou diferença entre os momentos V e A (P = 0,0008), tanto na porção proximal como na porção distal do canal anal. CONCLUSÃO: O esforço de evacuação associado à apneia pós-expiração quando comparada ao esforço de evacuação associado à manobra de Valsalva, proporciona menor contração do canal anal pela análise do parâmetro área sob a curva.

Total inspiratory and expiratory impedance in patients with severe chronic obstructive pulmonary disease

OBJECTIVES: Several studies have confirmed the high potential of the forced oscillation technique for the assessment of respiratory modifications related to chronic obstructive pulmonary disease. However, most of these studies did not employ within-breath analyses of the respiratory system. The aim of this study is to analyze respiratory impedance alterations in different phases of the respiratory cycle of chronic obstructive pulmonary disease patients and to evaluate their clinical use. METHODS: 39 individuals were evaluated, including 20 controls and 19 individuals with chronic obstructive pulmonary disease who experienced severe airway obstruction.Weevaluated the mean respiratory impedance (Zm) as well as values for inspiration (Zi) and expiration cycles (Ze), at the beginning of inspiration (Zbi) and expiration (Zbe). The peak-to-peak impedance (Zpp), and the impedance change (DZrs) were also analyzed. The clinical usefulness was evaluated by investigating the sensibility, specificity and the area under the receiver operating characteristic curve. RESULTS: The respiratory impedance increased in individuals with chronic obstructive pulmonary disease in all of the studied parameters (Zm, Zi, Ze, Zbi, Zbe, DZrs and Zpp). These changes were inversely associated with spirometric parameters. Higher impedanceswere observed in the expiratory phase of individualswith chronic obstructive pulmonary disease. All of the studied parameters, except for DZrs (area under the receiver operating characteristic ,0.8), exhibited high accuracy for clinical use (area under the receiver operating characteristic .0.90; Sensibility $ 0.85; Sp $ 0.85). CONCLUSIONS: The respiratory alterations in severe chronic obstructive pulmonary disease may be identified by the increase in respiratory system impedance, which is more evident in the expiratory phase. These results confirm the potential of within-breath analysis of respiratory impedance for the assessment of respiratory modifications related to chronic obstructive pulmonary disease.

Diseño y evaluación de un equipo para obtener aire espirado condensado / Design and evaluation of a device for collecting exhaled breath condensate

El análisis de muestras de aire espirado condensado ha cobrado gran relevancia en los últimos años como método no invasivo de estudio de la fisiología y las enfermedades de origen pulmonar. En el presente trabajo se describe un equipo para tomar muestras de aire espirado condensado de bajo costo, fácil de fabricar, de transportar al terreno y que permite tomar muestras en forma simultánea. La concentración de metabolitos relativos a procesos inflamatorios y al daño oxidativo (pH, peróxido de hidrógeno y nitrito) de muestras de aire espirado condensado obtenido con este equipo son comparables a los reportados con otros previamente.

In recent years, the analysis of exhaled breath condensate samples has been given great weight as a noninvasive methodology of studying physiology and lung diseases. The present study describes a device for measuring exhaled breath condensate that is affordable, easily constructed, portable and suitable for use in the field, as well as allowing the collection of simultaneous samples. The results obtained with this device in terms of the concentrations of pH, peroxide oxide and nitrite, metabolites related to inflammatory and oxidative damage, in exhaled breath condensate samples are comparable to those obtained with other devices previously described.

Treinamento muscular inspiratório e exercícios respiratórios em crianças asmáticas / Inspiratory muscle training and respiratory exercises in children with asthma

OBJETIVO: Avaliar efeitos do treinamento muscular inspiratório (TMI) e exercícios respiratórios na força muscular, pico de fluxo expiratório (PFE) e variáveis de gravidade em crianças asmáticas. MÉTODOS: Estudo analítico, experimental aleatório em 50 crianças asmáticas alocadas aleatoriamente em dois grupos: um grupo composto de 25 crianças que realizaram TMI em um programa de assistência e educação em asma (grupo TMI); e um grupo controle, composto de 25 crianças que foram submetidas apenas às consultas médicas mensais e educação em asma. O TMI foi realizado com o threshold com a carga de 40 por cento da pressão inspiratória máxima (PImáx). A análise dos resultados foi realizada através da análise da variância, teste de qui-quadrado e teste exato de Fisher, sendo considerado significante o valor de p > 0,05. RESULTADOS: Na análise comparativa, observou-se aumento significativo da PImáx, da pressão expiratória máxima (PEmáx) e do PFE pré- e pós-intervenção no grupo TMI, como se segue: PImáx de -;48,32 ± 5,7 para -;109,92 ± 18 (p < 0,0001); PEmáx de 50,64 ± 6,5 para 82,04 ± 17(p < 0,0001); e PFE de 173,6 ± 50 para 312 ± 54 (p < 0,0001). Entretanto, não houve aumento significativo da PImáx e PEmáx no grupo controle, somente no PFE, de 188 ± 43,97 para 208,80 ± 44,283 (p < 0,0001). Houve melhora significativa das variáveis de gravidade no grupo TMI (p < 0,0001). CONCLUSÕES: O TMI e exercícios respiratórios proporcionam uma melhora na eficiência mecânica nos músculos respiratórios, no PFE e variáveis de gravidade.

OBJECTIVE: The aim of the present study was to evaluate the effects that inspiratory muscle training (IMT) and respiratory exercises have on muscle strength, peak expiratory flow (PEF) and severity variables in children with asthma. METHODS: This was a randomized analytical study involving 50 children with asthma allocated to one of two groups: an IMT group, comprising 25 children submitted to IMT via an asthma education and treatment program; and a control group, comprising 25 children who were submitted only to monthly medical visits and education on asthma. The IMT was performed using a pressure threshold load of 40 percent of maximal inspiratory pressure (MIP). The results were evaluated using analysis of variance, the chi-square test and Fisher's exact test, values of p > 0.05 being considered significant. RESULTS: In the comparative analysis, pre- and post-intervention values of MIP, maximal expiratory pressure (MEP) and PEF increased significantly in the IMT group: MIP from -;48.32 ± 5.706 to -;109.92 ± 18.041 (p < 0.0001); MEP from 50.64 ± 6.55 to 82.04 ± 17.006 (p < 0.0001); and PEF from 173.6 ± 50.817 to 312 ± 54.848 (p < 0.0001). In the control group, however, there were no significant differences between the two time points in terms of MIP or MEP, although PEF increased from 188 ± 43.97 to 208.80 ± 44.283 (p < 0.0001). There was a significant improvement in the severity variables in the IMT group (p < 0.0001). CONCLUSIONS: Programs involving IMT and respiratory exercises can increase mechanical efficiency of the respiratory muscles, as well as improving PEF and severity variables.

Influencias de un protocolo kinésico para reeducar la respiración en intérpretes de flauta traversa / Kinesic protocol for respiratory reeducation in professional wind instrument players

Se estudiaron 16 intérpretes de flauta traversa y se evaluó la influencia de un protocolo de Reeducación Respiratoria (RR) a través de la función pulmonar y parámetros musicales. Las mediciones realizadas fueron: Espirometría Forzada con Curva Flujo-Volumen, Fuerza Muscular Inspiratoria (PIM) y parámetros Musicales (PM). Después de 8 sesiones de Reeducación Respiratoria, con una frecuencia de una vez por semana, no se observaron cambios significativos (p>0.05) en los parámetros espirométricos (CVF, VEF1, VEF1/CVF y FEMM 25-75), sin embargo hubo cambios significativos (p<0.05) en la relación FEF50/FIF50 de la Curva Flujo-Volumen, PIM y PM. Estos resultados muestran que si bien no mejoran los volúmenes y flujos respiratorios con la RR, la distribución de estos en ambos tiempos respiratorios (Inspiración-Espiración), la Fuerza Muscular Inspiratoria y los Parámetros Musicales son parámetros sensibles que evidencian la utilidad de la RR en este grupo estudiado.