[Spirometric caracterization of cystic fibrosis patients]. / Caracterización espirométrica de pacientes con fibrosis quística.

INTRODUCTION: The prognosis of patients with cystic fibrosis (CF) has remarkably improved. The as sessment of the disease progression is based on the measurement of the FEV1 (Forced Expiratory Volume in one second). OBJECTIVES: 1. To describe forced expiratory flows and volumes and com pare their interpretation according to different reference standards (Knudson, Gutiérrez, and multi ethnic GLI); 2. To describe bronchodilator response. PATIENTS AND METHOD: The medical records and spirometries of all patients with CF controlled at the Dr. Sotero del Rio Hospital were reviewed. Demographic background, sweat test results, genetic study , and bacteriological study were obtained. In addition, Forced Vital Capacity (FVC) was recorded as well as FEV1 and FEV1/FVC ratio. Re sults: Data from 14 patients, were analyzed, seven males, aged 6-24 years, median 15 years, median BMI 18.15 (range 14.6-23.3), median sweat chloride test 76 mEq/l (range 50,2-119 mEq/l), seven patients with at least one F508del mutation. Using multi-ethnic and Gutierrez predictive formulas, lung function involvement occurred previously in relation to the use of Knudson equations. None of the patients had a significant bronchodilator response. CONCLUSION: The group of patients descri bed mostly presents functional respiratory involvement and had no bronchodilator response. The interpretation of functional respiratory involvement varies according to the theoretical values used.

[Quality scale for preschool spirometry interpretation]. / Elaboración de una escala de calidad para la interpretación de espirometrías en preescolares.

Since 2007, there are international guidelines for implementation and interpretation of spirometry in preschool children. A percentage of these patients cannot obtain maneuvers that meet all eligibility criteria. The objective of this study was to develop a quality scale for interpreting these partially acceptable spirometry. MATERIAL AND METHOD: Delphi methodology was used, which allows to reach consensus among experts analyzing a defined problem. We invited to participate pediatric pneumologists dedicated to lung function and who participated actively in scientific specialty societies in Chile. Successive rounds were conducted with questionnaires about criteria used to assess spirometry in preschool children. These criteria define the acceptability of spirometric maneuvers according to international guidelines. Proposed quality grades were “very good”, “good”, “fair” and “bad”. RESULTS: Thirteen of the 15 invited experts accepted our invitation. In the first round 9 disagreed with the degree of “regular” quality. In the second round this was removed and 11 experts answered, 9 of them agreed with the use of this new version. The most contentious criterion was the end of expiration. CONCLUSION: Most experts agreed with the final scale, using “very good”, “good” and “bad” judgments. This would help to improve the performance of spirometry in children between 2 and 5 years.

[Spirometric values in healthy Chilean children and adolescents]. / Valores espirométricos en niños y adolescentes chilenos sanos.

BACKGROUND: Spirometric flow and volume measurement are essential to evaluate patients with pulmonary disease. In Chile, several reference equations are used. AIM: To measure flow and expiratory volumes in healthy children and adolescents and compare their results with theoretical values according to Knudson, Quanjer, Gutierrez and NANHES III. SUBJECTS AND METHODS: Spirometries were performed according to international standards in 1589 healthy children and adolescents aged 6 to 18 years (861 females) who lived in Santiago, Chile. RESULTS: The obtained values for forced vital capacity, expiratory volume in one second, peak expiratory flow, were significantly higher than those calculated according to the above mentioned standards (p < 0.0001) with differences up to 18.7%. We constructed reference formulas for ages ranging from 6 to 18 years, separated by gender, using age, weight and height as independent variables. The latter had the greater influence on formula construction. CONCLUSIONS: The use of these new local formulas with allow the correct interpretation of spirometric results obtained in Chilean children and adolescents.

Spirometry interpretation feasibility among pre-school children according to the European Respiratory Society and American Thoracic Society Guidelines / Factibilidad de la interpretación de espirometrías en preescolares según criterios ATS/ERS.

INTRODUCTION: Spirometry is the most used test to evaluate pulmonary function. Guidelines that defined acceptability and repeatability criteria for its implementation and interpretation among preschoolers were published in 2007. Our objective was to quantify the actual compliance with these criteria among pre-school patients. METHODS: A review was performed on the baseline spirometry measured in patients aged 2 to 5 years in the Pediatric Respiratory Laboratory of the Pontificia Universidad Católica de Chile, who were admitted due to recurrent or persistent coughing or wheezing. Only those results obtained in patients who took the test for the first time were considered. They were analyzed by international standards. RESULTS: A total of 93 spirometry results (mean age 57.4 ± 8.6 months, 48 males) were obtained, of which 44 (47%) met all acceptable criteria, 87 (93%) obtained expiratory time of ≥ 0.5seconds, and 67 (72%) of the patients had an end-expiratory flow of ≤10% from peak flow. The variation in the measurement of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) was very low (intraclass correlation coefficient > 0.9). CONCLUSION: It was possible to meet the acceptability and repeatability criteria for spirometry among pre-school children in our Center, which was similar to previous reports. As in older children, this test is fully recommended for pre-school children who require lung function studies.

[Pulse Oximetry Values in Preterm infants at 34-36 weeks postmenstrual age]. / Valores de Oximetría de Pulso en Prematuros a las 34-36 semanas post-concepcional.

Pulse oximetry (SpO2) is essential for guiding oxygen therapy in preterm infants. Data on SpO2 values before discharge are limited. OBJECTIVE: To establish SpO2 values in asymptomatic premature infants at 34, 35, and 36 weeks of postmenstrual age (PMA). SUBJECTS AND METHOD: Longitudinal, multicen ter study carried out from May 2018 to May 2019 in three neonatal intensive care units in Santiago, Chile (altitude 579 m) which included premature infants born ≤ 32 weeks of gestational age, healthy, with clinical stability, and without respiratory morbidity at the moment of the study or until dis charge. The following parameters were analyzed: mean accumulated SpO2 and SD, minimum SpO2 value, SpO2 time percentage < 90%, SpO2 time percentage < 80%, DI4, and DI80. Continuous over night SpO2 was obtained with Masimo Radical-7 or Rad-8 (USA), mean artifact-free-recording-time (AFRT) ≥ 6 hours. RESULTS: 101 SpO2 recordings were registered in 44, 33, and 24 studies at 34, 35, and 36 weeks of PMA, respectively, from 62 preterm infants, twenty-eight (45%) were male, median gestational age at birth 30 weeks (range 26-32), and median birth weight 1480 g (range 785-2700g). Oximetry variables were mean AFRT (± SD) 8.6 (± 1.5) hours; median mean SpO2 96.9% (range 93.3-99.3%); median minimum SpO2 74% (range 51-89%); median time of SpO2 < 90% 2% (range 0-10.6%); median time of SpO2 < 80% 0.1% (range 0-1.3%); median desaturation event ≥ 4% (DI4) within ≥ 10 seconds per hour sampled 15 (range 3.5-62.5); and median desaturation event <80% (DI80) 0.58 (range 0-10.8). We found no differences in SpO2 values between the different PMA wee ks. CONCLUSIONS: We described SpO2 values in very preterm infants, asymptomatic at 34-36 PMA weeks. These values could be used as a reference for guiding oxygen therapy.

Exercise challenge test: is a 15% fall in FEV(1) sufficient for diagnosis?

INTRODUCTION: In the exercise challenge test (ECT), a drop in forced expiratory volume in the first second (FEV(1)) of between 10 and 15% is the determinant variable for a diagnosis of exercise-induced bronchospasm. HYPOTHESIS: The use of FEV(1) plus mean forced expiratory flow between 25% and 75% of the forced vital capacity (FEF(25-75%)) may increase the sensitivity of the ECT in asthmatic children. SPECIFIC OBJECTIVE: To compare FEV(1) and FEF(25-75%) changes in a group of asthmatic and healthy children. METHODOLOGY: This was a cross-sectional study. Asthmatics were categorized by their severity (GINA) and after 1 month without controller therapy, an ECT was done under standard protocol. As well, a questionnaire about rhinitis and asthma was conducted with the entire population. ROC curves were used for analysis. RESULTS: A total of 147 children (34 healthy and 113 asthmatics, 18 and 58 males, respectively) were evaluated. Divided into healthy children and intermittent, mild and moderate persistent asthmatics, they had similar average ages (9.4, 9.48, 8.97, and 11.2 years, respectively). Using a 15% fall in FEV(1), we obtained 29% sensitivity and 100% specificity. However, when we used a 10% fall in FEV(1), sensitivity was 47% and specificity was 97%. Adding a 28% fall in FEF(25-75%), sensitivity was 52% and specificity was 94%. CONCLUSION: This study suggests that test sensitivity can increase by using a lower FEV(1) cut-off (10%) and adding a 28% fall in FEF(25-75%).

Bronchial hyperreactivity to methacholine in atopic versus nonatopic asthmatic schoolchildren and preschoolers.

BACKGROUND: Atopy and bronchial hyperreactivity are factors related to severe and unremitting asthma of childhood; however, the prevalence of these factors could be different according to age of the child. OBJECTIVE: To determine if methacholine bronchial hyperreactivity (BHR) differs between atopic and nonatopic preschoolers and schoolchildren with mild-moderate asthma. METHODS: Data obtained from 340 children with diagnosis of asthma or recurrent wheezing, matched by atopic conditions (positive or negative skin prick test) and age, and who underwent a methacholine bronchial challenge test (by spirometry in schoolchildren and by transcutaneous oxygen pressure [TcP(O2)] in preschoolers) were reviewed. RESULTS: Among 136 schoolchildren (9.07 ± 2.5 years), the prevalence of positive BHR was significantly higher among atopics than nonatopics (75% versus 48.5%, p = .001, respectively), even after controlling for gender and nutritional status (adjusted odds ratio [aOR] = 3.2129, 95% confidence interval [CI]: 1.5-6.8; p = .002). In addition, atopic schoolchildren had lower PC(20) and required a lower threshold dose of methacholine to induce a reaction (0.53 versus 0.82 mg/ml, p = .055 and .5 versus 1 mg/ml, p = .02, respectively) than nonatopics. Nevertheless, basal and predicted forced expiratory volume in one second (FEV1) were similar between groups. In contrast, among 204 preschoolers (4.74 ± 1.1 years), there were no differences in the prevalence of positive BHR between atopics and nonatopics (74.5% versus 72.5%, p = .75, respectively). Furthermore, basal TcP(O2), a higher fall of TcP(O2) and lower threshold doses of methacholine required for induction as measured by TcP(O2) were similar between the atopic and nonatopic preschoolers. CONCLUSIONS: Atopic asthmatic schoolchildren have greater hyperresponsiveness to methacholine than nonatopics (only among those with normal nutritional status). However, atopic and nonatopic asthmatic preschoolers have similar hyperresponsiveness to methacholine. Therefore, factors different from atopy may be responsible for wheeze in younger children.

Función pulmonar: función pulmonar en pacientes con displasia broncopulmonar / Pulmonary function: pulmonary function in patients with bronchopulmonary dysplasia

La displasia broncopulmonar (DBP) es una complicación frecuente en los prematuros extremos. La detención de la alveolarización determina menor volumen pulmonar total, el cual se recupera al menos parcialmente en el trayecto de la vida. La vía aérea se ve afectada en su crecimiento en mayor proporción que los alvéolos, y en los pacientes con displasia severa va a existir hasta la etapa adulta una limitación al flujo aéreo debido a su menor calibre. En este artículo, se describirá el origen, hallazgos característicos y evolución de las alteraciones en la función pulmonar, especialmente, en los pacientes con la nueva DBP.

Bronchopulmonary dysplasia (BPD) is a frequent complication in extremely premature infants. The arrest of alveolarization determines a lower total lung volume, which recovers at least partially during life. The airway is affected in its growth to a greater extent than the alveoli, and in patients with severe dysplasia there will be airflow limitation until adulthood due to its smaller caliber. In this article, the origin, characteristic findings, and evolution of changes in lung function will be described, especially in patients with the new BPD.

Función pulmonar: medición continua de la saturación del pulso arterial de oxígeno: propuesta para interpretación / Continuous measurement of oxygen arterial pulse saturation: an interpretation proposal

La medición continua de la saturación de pulso arterial de oxígeno (SpO2) es un método no invasivo, confiable y seguro. El consolidado permite obtener valores promedio de SpO2 y frecuencia cardiaca, gráficos y valores acumulados, rangos de valores de SpO2, que permiten definir si existe o no alguna alteración. Los avances tecnológicos han dado paso a la fabricación de equipos con alta exactitud de las mediciones, mediante algoritmos matemáticos que filtran los artefactos debido a movimientos y/o hipoperfusión. La ventaja, es una mayor precisión para determinar estados de hipoxemia en distintas situaciones clínicas. Las principales indicaciones en pediatría son la determinación de hipoxemia y titulación de oxígeno en niños con enfermedades que comprometen el sistema respiratorio, especialmente displasia broncopulmonar. También se usa como screening para apneas obstructivas del sueño en rango moderado a severo en situaciones en que no es posible realizar poligrafía o polisomnografía, dado la facilidad con la que se puede realizar la medición continua de SpO2 en domicilio u hospitalizado. En este artículo se describen características importantes del procedimiento, y se propone un esquema para ordenar su interpretación.

Continuous measurement of arterial oxygen saturation by pulse oximetry (SpO2) is a non-invasive, reliable, and safe method. The consolidated allows obtaining average values of SpO2 and heart rate, graphs and accumulated values, ranges of SpO2 values, which allow defining whether or not there is any alteration. Technological advances have given way to the manufacture of equipment with high measurement accuracy, using mathematical algorithms that filter artifacts due to movements and/or hypoperfusion. The main indications are the diagnosis of hypoxemia and titration of oxygen requirements in patients with chronic lung damage and other diseases that compromise the respiratory system. Also, it is used as screening of moderate to severe obstructive apneas when other sleep studies, such as polysomnography or polygraphy, are not available. It can be done at home or hospitalized. This article describes important characteristics of the procedure, and a scheme is proposed to order its interpretation.

Airway anomalies in children with Down syndrome: endoscopic findings.

Down syndrome (DS) is the most common chromosomal anomaly in humans. Numerous congenital malformations associated with DS have been described. However, there are insufficient data available about airway anomalies. Our objective was to characterize the clinical presentation, frequency, and type of airway anomalies in a population of patients with DS. A retrospective evaluation of flexible bronchoscopies performed in 24 DS patients due to significant respiratory morbidity was compared to the findings in 324 non-DS patients during the same time period. The procedure was carried out under sedation, using an Olympus BF3C20 bronchoscope. The main indications for the procedure were atelectasis of the right upper lobe (12/24) and stridor (7/24). The most common associated conditions were congenital heart disease (12/24) and reactive airways disease (12/24). The most important endoscopic findings were: laryngomalacia (12/24), tracheomalacia (8/24), tracheal bronchus (5/24), and bronchomalacia (5/24). Only six patients had a normal examination. Multiple airway anomalies (>/=2) were a common finding in this series. We conclude that patients with DS and respiratory symptoms have a high incidence of airway anomalies compared to non-DS patients. The clinician should have a high index of suspicion for airway anomalies in DS patients with respiratory symptoms.

Clinical characteristics of children with tracheobronchial anomalies.

Tracheobronchial anomalies (TBA) originate between the third and sixteenth week of gestation, and they primarily affect the main bronchi. The reported incidence varies between 1-3% of pediatric endoscopic studies. The objective of our review was to describe the clinical characteristics of patients with TBA diagnosed by flexible bronchoscopy (FB). During the period from March 1993-May 2001, we performed 580 FB at the Pediatric Services of the Catholic University Hospital. During this study period, 52 patients (9.65%) had a TBA (32 males, or 61.5%), with a mean age of 21.2 months (range, 7 days to 6 years). In 39 cases (75%), the diagnosis was made under age 2 years. Thirty-six patients with symptoms related to TBA were symptomatic (70%), and in 16 cases (30%) the TBA was an accidental finding during FB. The main clinical manifestations were recurrent atelectasis of the right upper lobe (RUL), recurrent pneumonia, or congenital stridor. Most of the TBA were localized at the RUL bronchus (47%) and were characterized by an anomaly at its origin, either agenesis or a supernumerary bronchus. Also, we found patients with tracheal bronchus and congenital tracheal stenosis. In 6 patients (12%), we had more than one TBA, the most frequent being the association between RUL and RML anomalies. In 12 cases we found another congenital airway anomaly, mainly laryngomalacia. Patients had associated diseases, such as genetic disorders in 16 cases (particularly Down syndrome), and congenital cardiopathies. In summary, in our clinical experience, TBA are more frequent than previously reported. The majority of young patients have symptoms or signs, and most are localized to the RUL. We found patients with more than one TBA, laryngomalacia associated with TBA, and at a high frequency related to Down syndrome.

Risk factors for recurrent wheezing following acute bronchiolitis: a 12-month follow-up.

The objective of this study was to identify wheezing recurrences and related risk factors in two groups of infants with bronchiolitis: respiratory syncytial virus (RSV)+ and RSV- as determined by RSV enzyme immunoassay. A 1-year prospective cohort study was conducted with infants younger than 2 years old. Follow-up was made monthly, by a clinical visit and/or by telephone, checking the number of wheezing episodes per month and possible related risk factors. There were 96 subjects enrolled, of whom 77 reached complete follow-up: 36 were RSV+ (46.8%), and 41 were RSV- (53.2%). In the RSV+ group, there were 17 males (47%), vs. RSV- with 30 males (73%) (P < 0.05); 22 RSV+ (61%) were admitted to hospital, vs.14 RSV- (34%) (P < 0.05). Mean age was not significantly different in both groups. The mean number of recurrences was 3.36 episodes/infant/year in the RSV+ and 2.34 in the RSV- group (P = 0.06). Crude relative risk (RR) for a new recurrence of an obstructive episode was 1.33 (95% CI, 0.99-1.79). After adjustment for several potential confounders, the RR was 1.41 (95% CI, 1.03-1.93). Hospitalization stay was longer in the RSV+ than the RSV- group (P < 0.05). In the RSV+ group, patients who had been hospitalized showed more recurrences (4.18) than those with outpatient treatment (2.07) (P < 0.05); this difference did not exist in the RSV- group. The related risk factors for recurrent wheeze in the RSV- group were male gender, number of siblings, and daycare attendance (P < 0.05). In the RSV+ group, the risk of recurrent wheeze was only increased by admission to hospital during the acute bronchiolitis episode (P < 0.05). We speculate that there may be a higher rate of increased airway reactivity and/or preexisting diminished lung function in RSV+ infants requiring hospitalization for their initial illness. In conclusion, RSV-proven bronchiolitis, particularly in those infants who are hospitalized, is associated with a higher recurrence of wheezing episodes in the subsequent 12 months. Other factors appear to account for recurrent wheeze in the RSV- group.

Actualización en espirometría en el preescolar / Preeschools spirometry update

Spirometry is better pulmonary function test for evaluating preschoolers with chronic lung disease and recurrent wheeze. It is useful, accessible and very good performance. For a correct interpretation it must be under the conditions specially controlled for this age group. In this review, product of the work done during the year 2018, by the Committee on pulmonary function in pediatric pulmonology Chilean society, will be showcased aspects for the realization and interpretation of spirometry in preschool children, with emphasis on the differences in the criteria typically described for older children and adults.

La espirometría es la prueba de función pulmonar más adecuada para evaluar a preescolares con enfermedades pulmonares crónicas y sibilancias recurrentes. Es útil, accesible y de buen rendimiento. Para una correcta interpretación debe realizarse bajo las condiciones especialmente normadas para este grupo etario. En esta revisión, producto del trabajo realizado durante el año 2018, por la comisión de función pulmonar de la sociedad Chilena de Neumología Pediátrica, se expondrán los aspectos actualizados para la realización e interpretación de la espirometría en preescolares, con énfasis en las diferencias de los criterios clásicamente descritos para niños mayores y adultos.

Actualización en espirometría y curva flujo / volumen en escolares y adolescentes / School and adolescent spirometry and flow / volume curve update

Spirometry is the most commonly used test to evaluate lung function in children and adults. To obtain good quality results, several requirements must be fulfilled: professional capacity of the technician, the quality of the equipment, the patient's collaboration, the use of appropriate reference standards. The purpose of spirometry is to define types of ventilatory alterations of the central and peripheral airways, to evaluate the response to bronchodilators and to guide the presence of restrictive diseases. The new consensus of national and international experts are described, which have been perfecting several aspects of this test.

La espirometría es el examen más comúnmente utilizado para evaluar la función pulmonar en niños y adultos. Para obtener resultados de buena calidad deben cumplirse varios requisitos, desde la capacidad profesional del técnico, calidad de los equipos, colaboración del paciente y utilización de patrones de referencia adecuados. La espirometría tiene como utilidad definir alteraciones ventilatorias obstructivas de vía aérea central y periférica, evaluar respuesta a broncodilatador y orientar al diagnóstico de enfermedades restrictivas. Se describen los nuevos consensos de expertos nacionales e internacionales, los cuales han ido perfeccionando varios aspectos de este examen.

Actualización en la prueba de provocación bronquial con metacolina en el niño / Update in the bronchial challenge test with methacholine in children

This document updates the recommendations of the bronchial challenge test with methacholine in children. It is based primarily on the recommendations contained in the guide on the technical standard of the bronchial challenge test for methacholine from the European Society of Respiratory Diseases. The main change is the recommendation to use PD20 (methacholine dose that causes a 20% drop in FEV1) instead of PC20 (methacholine concentration that causes a 20% drop in FEV1), which allows for comparable results when different devices and different protocols are used.

Este documento actualiza las recomendaciones de la prueba de provocación bronquial con metacolina en niños. Se basa fundamentalmente en las recomendaciones contenidas en la guía sobre el estándar técnico de la prueba de provocación bronquial de metacolina de la Sociedad Europea de Enfermedades Respiratorias. El principal cambio es la recomendación de utilizar la PD20 (dosis de metacolina que provoca una caída de 20% del VEF1) en vez de PC20 (concentración de metacolina que provoca una caída del 20% en el VEF1), lo cual permite tener resultados comparables cuando se usan diferentes dispositivos y diferentes protocolos.

Actualización de la prueba de provocación bronquial con ejercicio (PPBE) / Update of the bronchial provocation test with exercise

The bronchial challenge test with exercise aims to demonstrate the presence of exercise-induced bronchial hyperreactivity, characteristic of bronchial asthma. Its realization is well standardized, requiring special environmental conditions, preparation and submaximum effort of the patient. The response is measured by spirometry, and it is considered a positive exercise test a drop in the expired volume at the first second (FEV1) of 10%. This article describes the elements necessary to facilitate this exam, according to national and international standards and guidelines.

La prueba de provocación bronquial con ejercicio tiene como objetivo demostrar la presencia de hiperreactividad bronquial inducida por ejercicio, característica del asma bronquial. Su realización está bien estandarizada, requiriendo de condiciones ambientales especiales, preparación y esfuerzo submáximo del paciente. La respuesta se mide mediante espirometría, y se considera una prueba de provocación con ejercicio positivo, a una caída del volumen espirado al primer segundo (VEF1) del 10%. En este artículo se describen los elementos necesarios para facilitar la realización de este examen, acorde a normas y guías nacionales e internacionales.

Caracterización espirométrica de pacientes con fibrosis quística / Spirometric caracterization of cystic fibrosis patients

INTRODUCCIÓN: El pronóstico de los pacientes con fibrosis quística (FQ) ha mejorado en forma notable. La evaluación de la progresión de la enfermedad se basa en la medición del Volumen Espirado al primer segundo (VEF1). OBJETIVOS: 1. Describir volúmenes y flujos espiratorios forzados y comparar su interpretación según diferentes patrones de referencia (Knudson, multiétnicas Global Lung Initiative, Gutiérrez); 2. Comparar evolución de VEF1 según diferentes patrones de referencia; 3. Describir respuesta a broncodilatador. PACIENTES Y MÉTODO: Estudio retrospectivo de fichas clínicas y espirometrías de pacientes con FQ controlados en Hospital Dr. Sótero del Río. Se obtuvo antecedentes demográficos, resultados de prueba de sudor, estudio genético, estudio bacteriológico. Se evaluó respuesta a broncodilatador (salbutamol 400 ugr), considerando significativo un aumento en 12% en el VEF1. El valor de cloro en sudor se obtuvo mediante método de Gibson y Cooke. Se registraron: Capacidad Vital Forzada (CVF), Volumen Espirado al primer segundo (VEF1) y relación VEF1/CVF. Para graficar la progresión del VEF1 en el tiempo y las curvas teóricas de GLI, Knudson y Gutiérrez, se utilizó el software de libre distribución R versión 3.3.1. RESULTADOS: Se incluyeron 14 pacientes, 7 varones, edad entre 6 y 24 años, mediana 15 años, me diana índice de masa corporal (IMC) 18,15 (rango 14,6-23,3), mediana cloro en sudor 76 mEq/l (rango 50,2- 119), 7 pacientes con al menos 1 mutación F508del. Al utilizar fórmulas predictivas multiétnicas y de Gutiérrez, el compromiso de la función pulmonar ocurría con anterioridad en relación al uso de ecuaciones de Knudson. Ninguno de los pacientes presentó respuesta significativa a broncodilatador. CONCLUSIÓN: El grupo de pacientes descritos presenta en su mayoría compromiso funcional respiratorio y no tiene respuesta a broncodilatador. La interpretación del compromiso funcional respiratorio varía según los valores teóricos utilizados.

INTRODUCTION: The prognosis of patients with cystic fibrosis (CF) has remarkably improved. The as sessment of the disease progression is based on the measurement of the FEV1 (Forced Expiratory Volume in one second). OBJECTIVES: 1. To describe forced expiratory flows and volumes and com pare their interpretation according to different reference standards (Knudson, Gutiérrez, and multi ethnic GLI); 2. To describe bronchodilator response. Patients and Method: The medical records and spirometries of all patients with CF controlled at the Dr. Sotero del Rio Hospital were reviewed. Demographic background, sweat test results, genetic study , and bacteriological study were obtained. In addition, Forced Vital Capacity (FVC) was recorded as well as FEV1 and FEV1/FVC ratio. RESULTS: Data from 14 patients, were analyzed, seven males, aged 6-24 years, median 15 years, median BMI 18.15 (range 14.6-23.3), median sweat chloride test 76 mEq/l (range 50,2-119 mEq/l), seven patients with at least one F508del mutation. Using multi-ethnic and Gutierrez predictive formulas, lung function involvement occurred previously in relation to the use of Knudson equations. None of the patients had a significant bronchodilator response. CONCLUSION: The group of patients descri bed mostly presents functional respiratory involvement and had no bronchodilator response. The interpretation of functional respiratory involvement varies according to the theoretical values used.

Elaboración de una escala de calidad para la interpretación de espirometrías en preescolares / Quality scale for preschool spirometry interpretation

Desde el año 2007 existen guías internacionales para la realización e interpretación de espirometrías en preescolares. Un porcentaje de estos pacientes no logra obtener maniobras que cumplan con todos los criterios de aceptabilidad. El objetivo de este estudio fue desarrollar una escala de calidad mediante el juicio de expertos para interpretar estas espirometrías parcialmente aceptables. Material y Método: Se utilizó metodología Delphi, la cual permite llegar a un consenso entre expertos analizando un problema definido. Para esto se invitó a participar a pediatras especialistas en enfermedades respiratorias con dedicación en función pulmonar y que participan activamente en las sociedades científicas de la especialidad en Chile. Se realizaron rondas sucesivas solicitándoles su opinión por escrito acerca de los criterios utilizados para valorar espirometrías realizadas en preescolares. Estos criterios son los que definen la aceptabilidad de las maniobras espirométricas según las guías internacionales. Los grados de calidad propuestos fueron: “muy bueno”, “bueno”, “regular” y “malo”. Resultados: Participaron 13 de los 15 expertos invitados. En la primera ronda 9 de ellos estuvieron en desacuerdo con el grado de calidad “regular”. En la segunda ronda esta se eliminó y respondieron 11 expertos; 9 de ellos estuvieron de acuerdo con la utilización de esta nueva versión. El criterio más discutido fue el final de la espiración. Conclusión: La mayoría de los expertos estuvieron de acuerdo con la escala final, usando las apreciaciones “muy bueno”, “bueno” y “malo”. Esta contribuiría a mejorar el rendimiento de las espirometrías realizadas en niños entre 2 y 5 años.

Since 2007, there are international guidelines for implementation and interpretation of spirometry in preschool children. A percentage of these patients cannot obtain maneuvers that meet all eligibility criteria. The objective of this study was to develop a quality scale for interpreting these partially acceptable spirometry. Material and Method: Delphi methodology was used, which allows to reach consensus among experts analyzing a defined problem. We invited to participate pediatric pneumologists dedicated to lung function and who participated actively in scientific specialty societies in Chile. Successive rounds were conducted with questionnaires about criteria used to assess spirometry in preschool children. These criteria define the acceptability of spirometric maneuvers according to international guidelines. Proposed quality grades were “very good”, “good”, “fair” and “bad”. Results: Thirteen of the 15 invited experts accepted our invitation. In the first round 9 disagreed with the degree of “regular” quality. In the second round this was removed and 11 experts answered, 9 of them agreed with the use of this new version. The most contentious criterion was the end of expiration. Conclusion: Most experts agreed with the final scale, using “very good”, “good” and “bad” judgments. This would help to improve the performance of spirometry in children between 2 and 5 years.

Evaluación de flujos y volúmenes dinámicos en pacientes con compromiso muscular respiratorio / Dynamic flows and volumes evaluation in patients with respiratory muscle impairment

Spirometry measures the forced expiratory volumes and flows. In patients with neuromuscular disease, these are altered since there is some respiratory muscle involvement. The usefulness of this test is based on the interpretation of the shape of the flow / volume loop and values of spirometric variables. In patients with neuromuscular disease, Forced Vital Capacity is the most used especially for its prognosis value.

La espirometría mide volúmenes y flujos espiratorios forzados. En los pacientes con enfermedad neuromuscular (ENM) estos se ven alterados debido al compromiso muscular respiratorio. La utilidad de este examen se basa en la interpretación de la forma de la curva flujo/volumen y los valores de las variables espirométricas. En los pacientes con ENM la Capacidad Vital Forzada es la más utilizada ya que otorga valor pronóstico.

Valores espirométricos en niños y adolescentes chilenos sanos / Spirometric values in healthy Chilean children and adolescents

Background: Spirometric flow and volume measurement are essential to evaluate patients with pulmonary disease. In Chile, several reference equations are used. Aim: To measure flow and expiratory volumes in healthy children and adolescents and compare their results with theoretical values according to Knudson, Quanjer, Gutierrez and NANHES III. Subjects and Methods: Spirometries were performed according to international standards in 1589 healthy children and adolescents aged 6 to 18 years (861 females) who lived in Santiago, Chile. Results: The obtained values for forced vital capacity, expiratory volume in one second, peak expiratory flow, were significantly higher than those calculated according to the above mentioned standards (p < 0.0001) with differences up to 18.7%. We constructed reference formulas for ages ranging from 6 to 18 years, separated by gender, using age, weight and height as independent variables. The latter had the greater influence on formula construction. Conclusions: The use of these new local formulas with allow the correct interpretation of spirometric results obtained in Chilean children and adolescents.