Patrones espirométricos en la disfunción de cuerdas vocales / Spirometry patterns in vocal cord dysfunction

Introducción: La disfunción de cuerdas vocales (DCV) es una enfermedad poco frecuente caracterizada por un cierre paradójico de las cuerdas vocales, habitualmente en la inspiración. Produce una obstrucción de la vía respiratoria que provoca disnea y estridor. La alteración espirométrica más frecuentemente descrita es el aplanamiento de la curva inspiratoria, aunque es posible encontrar también aplanamiento del asa espiratoria. El objetivo de este estudio fue evaluar las características espirométricas más frecuentes de la DCV y, de forma secundaria, describir las características clínicas, demográficas y el tratamiento seguido en los pacientes con un diagnóstico definitivo de DCV. Material y métodos: Estudio retrospectivo de los casos de DCV entre 2000 y 2010. Se consideró definitivo el diagnóstico cuando se evidenció el cierre paradójico de las cuerdas vocales en la laringoscopia. Se realizó una prueba de esfuerzo sobre tapiz rodante para provocar los síntomas. Se recogieron los datos clínicos y demográficos y se estudiaron las curvas de espirometría forzada. Resultados: De 36 casos sospechosos, se confirmó la DCV en 11 (30,5%), con una edad media 13,5 años; 10 eran mujeres. Se encontraron posibles desencadenantes en 5 de los pacientes. Seis pacientes presentaban antecedentes de asma. Todos los pacientes presentaron aplanamiento de la curva inspiratoria y 9 de ellos (81%) también de la espiratoria. Solo 4 pacientes presentaron una ratio entre los flujos espiratorio e inspiratorio máximos al 50% de la capacidad vital forzada (MEF50%/MIF50%) > 2,2. Conclusiones: Aunque la alteración espirométrica más frecuente en la DCV es el aplanamiento de la curva inspiratoria, un porcentaje importante de pacientes presentan aplanamiento también de la curva espiratoria. Este hecho podría invalidar la ratio MEF50%/MIF50% para el diagnóstico de DCV(AU)

Introduction: Vocal cord dysfunction (VCD) is a rare disease characterized by a paradoxical closure of the vocal cords, usually in inspiration, that causes dyspnea and stridor. The spirometry pattern that is more often described is a plateau in the inspiratory curve, but it can be also found in the expiratory loop The aim of this study was to evaluate the most common spirometry characteristics of patients with VCD and, secondarily, to describe the clinical and demographic characteristics and the treatment of patients with a definitive diagnosis of this disease. Material and methods: A retrospective study was made of cases of VCD between 2000 and 2010. Diagnosis was considered definitive when a paradoxical closure of the vocal cords became clear on laryngoscopy. Exercise challenge on a treadmill was performed to produce symptoms. Demographic and clinical data were collected, and flow-volume curves were studied. Results: Of 36 suspected cases, VCD was confirmed in 11 (30.5%). The mean age was 13.5 years, 10 were female. Possible triggers were found in 5 patients. Six patients had a previous history of asthma. All patients had a plateau in the inspiratory curve, and 9 (81%) of them also in the expiratory loop. Only 4 patients had a ratio between maximum inspiratory and expiratory flows at 50% of forced vital capacity (MEF50%/MIF50%) > 2.2. Conclusions: Although the most frequent spirometry pattern in VCD is a plateau in the inspiratory curve, a significant percentage of patients also have a plateau in the expiratory curve. This could invalidate the MEF50%/MIF50% ratio for the diagnosis of VCD(AU)

[Spirometry patterns in vocal cord dysfunction]. / Patrones espirométricos en la disfunción de cuerdas vocales.

INTRODUCTION: Vocal cord dysfunction (VCD) is a rare disease characterized by a paradoxical closure of the vocal cords, usually in inspiration, that causes dyspnea and stridor. The spirometry pattern that is more often described is a plateau in the inspiratory curve, but it can be also found in the expiratory loop The aim of this study was to evaluate the most common spirometry characteristics of patients with VCD and, secondarily, to describe the clinical and demographic characteristics and the treatment of patients with a definitive diagnosis of this disease. MATERIAL AND METHODS: A retrospective study was made of cases of VCD between 2000 and 2010. Diagnosis was considered definitive when a paradoxical closure of the vocal cords became clear on laryngoscopy. Exercise challenge on a treadmill was performed to produce symptoms. Demographic and clinical data were collected, and flow-volume curves were studied. RESULTS: Of 36 suspected cases, VCD was confirmed in 11 (30.5%). The mean age was 13.5 years, 10 were female. Possible triggers were found in 5 patients. Six patients had a previous history of asthma. All patients had a plateau in the inspiratory curve, and 9 (81%) of them also in the expiratory loop. Only 4 patients had a ratio between maximum inspiratory and expiratory flows at 50% of forced vital capacity (MEF50%/MIF50%) > 2.2. CONCLUSIONS: Although the most frequent spirometry pattern in VCD is a plateau in the inspiratory curve, a significant percentage of patients also have a plateau in the expiratory curve. This could invalidate the MEF50%/MIF50% ratio for the diagnosis of VCD.

Concordance between the Piko - 1(R) portable device and pneumotachography in measuring PEF and FEV1 in asthmatic children

Objective: To assess concordance in the measurement of peak expiratory flow (PEF) and forced expiratory volume in one second (FEV1) between the portable device Piko-1 (Ferraris) and a pneumotachograph. Patients and methods: Forced spirometry (Master Screen Jaeger) was performed according to ATS/ERS norms, selecting the best value of three curves, and three measurements with the Piko-1 were recorded, following the recommendations of the manufacturer. Results. Eighty patients between 5–18 years of age were studied. Based on the Bland-Altman method, the mean differences obtained were 9.82 (95%CI: 2.43–17.21) for PEF and 0.17 (95%CI: 0.12–0.21) for FEV1. The intraclass correlation coefficient was 0.96 (p<0,001; 95%CI: 0.93–0.97) for FEV1 and 0.93 (p<0,001; 95%CI: 0.89–0.95) for PEF. Conclusions: Piko-1 offers FEV1 measurements close to those obtained with forced spirometry, thus allowing more exact patient assessment in home-based follow-up, emergency services, or hospital wards (AU)

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Concordance between the Piko - 1 portable device and pneumotachography in measuring PEF and FEV(1) in asthmatic children.

OBJECTIVE: To assess concordance in the measurement of peak expiratory flow (PEF) and forced expiratory volume ino ne second (FEV(1)) between the portable device Piko-1 (Ferraris) and a pneumotachograph. PATIENTS AND METHODS: Forced spirometry (Master Screen Jaeger) was performed according to ATS/ERS norms, selecting the best value of three curves, and three measurements with the Piko-1 were recorded the recommendations of the manufacturer. RESULTS: Eighty patients between 5-18 years of age were studied. Based on the Bland-Altman method, the mean differences obtained were 9.82 (95%Cl: 2.43-17.21) for PEF and 0.17 (95%CL: 0.12-0.21 for FEV(1). The intraclass correlation coefficient was 0.96 (p <0,001; 95%Cl: 0.93-0.97) for PEV(1) and 0.93 (p<0,0001; 95%Cl: 0.89-0.95) for PEF. CONCLUSIONS: Piko-1 offers FEV(1) measurements close to those obtained with forced spirometry, thus allowing more exact patient assessment in home-based follow-up emergency services, or hospital wards.

Prueba de broncodilatación: ¿9% sobre el valor teórico o 12% sobre el valor basal es lo mismo? / Bronchodilator test: is 9% of the predicted value the same as 12% of the initial value?

Objetivos: La prueba de broncodilatación (PBD) es una herramienta fundamental para el estudio de la función pulmonar. El incremento del volumen espiratorio máximo en el primer segundo (FEV1) puede expresarse como valor absoluto en mililitros o como porcentaje de mejoría con respecto al valor teórico o al valor previo (basal). Al utilizar este último se puede cometer un sesgo ya que, cuanto menor sea éste mayor parecerá la respuesta. El objetivo de este estudio es determinar si existen diferencias al considerar una PBD como positiva si el incremento del FEV1 se refiere al valor teórico o al valor basal, y si estas diferencias estarían influidas por el grado de obstrucción inicial del paciente. Material y métodos: Análisis retrospectivo de los resultados de PBD realizadas entre octubre de 1997 y febrero de 2008. Se compararon los resultados utilizando como referencia un incremento del 9% sobre el FEV1 teórico y un incremento del 12% sobre el FEV1 basal. Se dividió la muestra en 3 grupos en función del grado inicial de obstrucción: no obstruido (FEV1 mayor del 80% del valor teórico), leve (FEV1 de entre el 60 y el 80% del valor teórico) y moderada a grave (FEV1 menor del 60% del valor teórico). Se calculó el índice k de concordancia entre ambos métodos. Resultados: Se analizaron 4.352 PBD. La concordancia entre ambos métodos fue muy buena (k=0,832). En el grupo sin obstrucción inicial (n=3007) el índice k fue de 0.781, en el grupo con obstrucción leve (n=1.067) el índice k fue de 0,966 y en el grupo con obstrucción moderada a grave (n=278) el índice k fue de 0,788. Conclusiones: El estudio demuestra que aunque hay una buena concordancia entre ambos índices, en los pacientes con obstrucción inicial moderada a grave y en los pacientes inicialmente no obstruidos esta concordancia tiende a ser menor (AU)

Introduction: The bronchodilator test (BDT) is an important tool used in pulmonary function. Changes in forced expiratory volume in one second (FEV1) can be expressed as absolute change, or per cent of initial or predicted value. When the initial value is used, there may be a bias, as the smaller this value is, the greater the response will be. The main objective of this study is to establish whether there is any difference in using per cent of the initial spirometry value or per cent of the predicted value in order to consider a bronchodilator test positive, and if the initial obstruction of the patient influences such differences. Material and methods: A retrospective analysis of the BDT made between October 1997 and February 2008. The results using an increase of 9% from the predicted FEV1 were compared with using 12% from the initial FEV1. The patients were divided into three groups depending on initial obstruction: no obstruction (FEV1>80% of predicted), mild (FEV1=60¨C80% of predicted) and moderate-severe (FEV1<60% of predicted). The kappa index of agreement between both methods was calculated. Results: A total of 4352 BDT were analysed. The agreement between both methods was high (k=0.832). In the group without initial obstruction (N=3007) the kappa index was 0.781, in the mild obstruction group (N=1067) the kappa index was 0.966 and in the moderate-severe group (N=278) it was 0.788. Conclusion: This study demonstrates that, although there is a good agreement between both methods, in patients with initial moderate-severe obstruction and in patients without initial obstruction this agreement tends to be lower (AU)

[Bronchodilator test: is 9% of the predicted value the same as 12% of the initial value]. / Prueba de broncodilatación: ¿9% sobre el valor teórico o 12% sobre el valor basal es lo mismo?

INTRODUCTION: The bronchodilator test (BDT) is an important tool used in pulmonary function. Changes in forced expiratory volume in one second (FEV1) can be expressed as absolute change, or per cent of initial or predicted value. When the initial value is used, there may be a bias, as the smaller this value is, the greater the response will be. The main objective of this study is to establish whether there is any difference in using per cent of the initial spirometry value or per cent of the predicted value in order to consider a bronchodilator test positive, and if the initial obstruction of the patient influences such differences. MATERIAL AND METHODS: A retrospective analysis of the BDT made between October 1997 and February 2008. The results using an increase of 9% from the predicted FEV1 were compared with using 12% from the initial FEV1. The patients were divided into three groups depending on initial obstruction: no obstruction (FEV1>80% of predicted), mild (FEV1=60-80% of predicted) and moderate-severe (FEV1<60% of predicted). The kappa index of agreement between both methods was calculated. RESULTS: A total of 4352 BDT were analysed. The agreement between both methods was high (k=0.832). In the group without initial obstruction (N=3007) the kappa index was 0.781, in the mild obstruction group (N=1067) the kappa index was 0.966 and in the moderate-severe group (N=278) it was 0.788. CONCLUSION: This study demonstrates that, although there is a good agreement between both methods, in patients with initial moderate-severe obstruction and in patients without initial obstruction this agreement tends to be lower.

¿Es necesario utilizar pinza nasal para la realización de la espirometría en niños? / Is it necessary to use a noseclip for the performance of spirometry in children?

A pesar de que la mayoría de las guías recomiendan el uso de pinza nasal para la realización de la espirometría, no existe acuerdo entre los autores sobre su necesidad. Los niños pequeños rechazan con frecuencia el uso de la pinza, lo que dificulta hacer estudios de función pulmonar. Este trabajo pretende estudiar si hay realmente diferencias entre la espirometría realizada con o sin pinza nasal en niños. Se estudiaron 119 niños entre 4 y 17 años de edad, a los que se les realizaron 2 espirometrías con y sin pinza nasal en un orden aleatorio. Los resultados obtenidos en el volumen máximo espirado en el primer segundo (FEV1), la capacidad vital forzada (FVC) y el flujo espiratorio forzado (FEF25-75%) fueron muy similares con y sin pinza nasal, sin diferencias significativas. Sólo el pico de flujo espiratorio (PEF) fue estadísticamente superior cuando se realizó sin pinza. Nuestro estudio ha comprobado que no utilizar la pinza nasal en niños durante la espirometría forzada no modifica significativamente los resultados de ésta(AU)

Although the majority of the guidelines recommend the use of noseclips for the performance of spirometry, there is no consensus among specialists as to whether it is really necessary. Small children frequently refuse the noseclip, thus making the performance of pulmonary function studies difficult. The purpose of this study was to determine whether there are differences between spirometry performed with and without noseclips in children. We studied 119 children between 4 and 17 years of age. They underwent two sets of measurements (with and without noseclips) in random order. The results obtained in forced vital capacity (FVC), forced expiratory volume in one second(FEV1) and forced expiratory flow (FEF25-75%) were very similar, with no significant differences. Only the peak expiratory flow (PEF) measurement was statistically superior when it was performed without a noseclip. This study has demonstrated that the non-use of noseclips in children during spirometry does not significantly modify the results of the test(AU)