Comparative analysis of pulmonary ventilation distribution between low-cost and branded incentive spirometers using electrical impedance tomography in healthy adults: Study protocol.

BACKGROUND: The Incentive Spirometer (IS) increases lung volume and improves gas exchange by visually stimulating patients to take slow, deep breaths. It prevents respiratory complications and treats postoperative atelectasis in patients undergoing abdominal, thoracic, and neurosurgical procedures. Its effectiveness has been validated in studies that support improved lung capacities and volumes in individuals with respiratory complications, postoperative thoracic surgery, upper abdominal surgery, and bariatric surgery. The modified Pachón incentive spirometer (MPIS) is a cost-effective alternative to branded IS. It is crucial to validate whether the MPIS distributes ventilation as effectively as commercial devices do. Ventilation distribution will be measured using electrical impedance tomography. OBJECTIVE: The aim is to compare the distribution of pulmonary ventilation between the MPIS and another commercial IS in healthy adults using electrical impedance tomography. METHODS: A crossover clinical trial is proposed to evaluate the measurement of pulmonary ventilation distribution using EIT in a sample of healthy adults. All participants will use a commercial flow IS and the MPIS, with the order of assignment randomized. This research will use electrical impedance tomography to validate the operation of the MPIS. CONCLUSIONS: This study protocol will compare two incentive spirometers' impact on pulmonary ventilation, potentially endorsing the adoption of a cost-effective device to enhance accessibility for targeted populations. TRIAL REGISTRATION: The study was registered in ClinicalTrials.gov (NTC05532748).

A Sensor for Spirometric Feedback in Ventilation Maneuvers during Cardiopulmonary Resuscitation Training.

This work proposes adapting an existing sensor and embedding it on mannequins used in cardiopulmonary resuscitation (CPR) training to accurately measure the amount of air supplied to the lungs during ventilation. Mathematical modeling, calibration, and validation of the sensor along with metrology, statistical inference, and spirometry techniques were used as a base for aquiring scientific knowledge of the system. The system directly measures the variable of interest (air volume) and refers to spirometric techniques in the elaboration of its model. This improves the realism of the dummies during the CPR training, because it estimates, in real-time, not only the volume of air entering in the lungs but also the Forced Vital Capacity (FVC), Forced Expiratory Volume (FEVt) and Medium Forced Expiratory Flow (FEF20-75%). The validation of the sensor achieved results that address the requirements for this application, that is, the error below 3.4% of full scale. During the spirometric tests, the system presented the measurement results of (305 ± 22, 450 ± 23, 603 ± 24, 751 ± 26, 922 ± 27, 1021 ± 30, 1182 ± 33, 1326 ± 36, 1476 ± 37, 1618 ± 45 and 1786 ± 56) × 10-6 m3 for reference values of (300, 450, 600, 750, 900, 1050, 1200, 1350, 1500, 1650 and 1800) × 10-6 m3, respectively. Therefore, considering the spirometry and pressure boundary conditions of the manikin lungs, the system achieves the objective of simulating valid spirometric data for debriefings, that is, there is an agreement between the measurement results when compared to the signal generated by a commercial spirometer (Koko brand). The main advantages that this work presents in relation to the sensors commonly used for this purpose are: (i) the reduced cost, which makes it possible, for the first time, to use a respiratory volume sensor in medical simulators or training dummies; (ii) the direct measurement of air entering the lung using a noninvasive method, which makes it possible to use spirometry parameters to characterize simulated human respiration during the CPR training; and (iii) the measurement of spirometric parameters (FVC, FEVt, and FEF20-75%), in real-time, during the CPR training, to achieve optimal ventilation performance. Therefore, the system developed in this work addresses the minimum requirements for the practice of ventilation in the CPR maneuvers and has great potential in several future applications.

Spirometry: basic concepts. / Espirometría: conceptos básicos.

Spirometry is a pulmonary function test that allows screening, diagnosis and monitoring of respiratory diseases. This is a simple, non-invasive test that is easy to perform. By quantifying the respiratory volumes and flows, such as forced vital capacity (FVC) or forced expiratory volume in six seconds (FEV6), forced expiratory volume in the first second (FEV1), and the relationship between these parameters (FEV1/FVC or FEV1/FEV6 ratio), obstruction can be detected with high sensitivity and specificity; likewise, it is possible to classify the severity and response to the bronchodilator. This article presents indications, contraindications, and basic concepts for the interpretation of spirometry.

La espirometría es una prueba de función pulmonar que permite el cribado, diagnóstico y monitorización de las enfermedades respiratorias. Esta prueba es sencilla, fácil de realizar y no invasiva. Mediante la cuantificación de los volúmenes y los flujos respiratorios como la capacidad vital forzada (CVF) o volumen espiratorio forzado en seis segundos (VEF6), el volumen espiratorio forzado en el primer segundo (VEF1) y la relación entre estos parámetros (índice VEF1/CVF o VEF1/VEF6) se detecta obstrucción, con alta sensibilidad y especificidad; asimismo, es posible clasificar la gravedad y la respuesta al broncodilatador. En este artículo se exponen indicaciones, contraindicaciones y conceptos básicos para la interpretación de la espirometría.

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.

Sustained maximal inspiration has similar effects compared to incentive spirometers.

PURPOSE: To compare the effects of flow incentive spirometer (FIS), volume incentive spirometer (VIS), and sustained maximal inspiration exercise (SMI) on breathing pattern, chest wall motion, and thoracoabdominal asynchrony. METHODS: Sixteen healthy adults aged 27.63 ± 5.26 years were evaluated by optoelectronic plethysmography in the supine position with trunk inclination of 45° during quiet breathing and during exercise performance. RESULTS: In the comparisons among exercises, VIS promoted a significantly higher inspiratory time and lower mean inspiratory flow compared with FIS. The rating of perceived exertion according to the Borg Scale was significantly higher after the performance of FIS compared with VIS. Regarding asynchrony, none of the exercises caused changes in thoracoabdominal synchrony between the rib cage and abdomen. However, both devices significantly reduced the asynchrony between the pulmonary and abdominal rib cage compared with quiet breathing. CONCLUSION: SMI exercise was equivalent to incentive spirometers and may be an interesting alternative for clinical use in cases in which it is not possible to acquire the devices.

Atypical reaction to anesthesia in Duchenne/Becker muscular dystrophy / Reação atípica à anestesia em distrofia muscular de Duchenne/Becker

Abstract Background and objectives Duchenne/Becker muscular dystrophy affects skeletal muscles and leads to progressive muscle weakness and risk of atypical anesthetic reactions following exposure to succinylcholine or halogenated agents. The aim of this report is to describe the investigation and diagnosis of a patient with Becker muscular dystrophy and review the care required in anesthesia. Case report Male patient, 14 years old, referred for hyperCKemia (chronic increase of serum creatine kinase levels - CK), with CK values of 7,779-29,040 IU.L-1 (normal 174 IU.L-1). He presented with a discrete delay in motor milestones acquisition (sitting at 9 months, walking at 18 months). He had a history of liver transplantation. In the neurological examination, the patient showed difficulty in walking on one's heels, myopathic sign (hands supported on the thighs to stand), high arched palate, calf hypertrophy, winged scapulae, global muscle hypotonia and arreflexia. Spirometry showed mild restrictive respiratory insufficiency (forced vital capacity: 77% of predicted). The in vitro muscle contracture test in response to halothane and caffeine was normal. Muscular dystrophy analysis by Western blot showed reduced dystrophin (20% of normal) for both antibodies (C and N-terminal), allowing the diagnosis of Becker muscular dystrophy. Conclusion On preanesthetic assessment, the history of delayed motor development, as well as clinical and/or laboratory signs of myopathy, should encourage neurological evaluation, aiming at diagnosing subclinical myopathies and planning the necessary care to prevent anesthetic complications. Duchenne/Becker muscular dystrophy, although it does not increase susceptibility to MH, may lead to atypical fatal reactions in anesthesia.

Resumo Justificativa/objetivos Distrofia muscular de Duchenne/Becker afeta a musculatura esquelética e leva a fraqueza muscular progressiva e risco de reações atípicas anestésicas após exposição à succinilcolina ou halogenados. O objetivo do presente relato é descrever investigação e diagnóstico de paciente com distrofia muscular de Becker e revisar os cuidados necessários na anestesia. Relato de caso Paciente masculino, 14 anos, encaminhado por hiperCKemia (aumento crônico dos níveis séricos de creatinoquinase - CK), com valores de CK de 7.779-29.040 UI.L-1 (normal 174 UI.L-1). Apresentou discreto atraso da aquisição de marcos motores (sentou aos nove meses, andou aos 18). Antecedente de transplante hepático. No exame neurológico apresentava dificuldade para andar nos calcanhares, levantar miopático (apoiava mãos nas coxas para ficar de pé), palato arqueado alto, hipertrofia de panturrilhas, escápulas aladas, hipotonia muscular global e arreflexia. Havia insuficiência respiratória restritiva leve na espirometria (capacidade vital forçada: 77% do previsto). O teste de contratura muscular in vitro em resposta ao halotano e à cafeína foi normal. Estudo da distrofina muscular por técnica de Western blot mostrou redução da distrofina (20% do normal) para ambos os anticorpos (C e N-terminal), e permitiu o diagnóstico de distrofia muscular de Becker. Conclusão Na avaliação pré-anestésica, história de atraso do desenvolvimento motor, bem como sinais clínicos e/ou laboratoriais de miopatia, deve motivar avaliação neurológica, com o objetivo de diagnosticar miopatias subclínicas e planejar cuidados necessários para prevenir complicações anestésicas. Distrofia muscular de Duchenne/Becker, apesar de não conferir suscetibilidade aumentada à HM, pode levar a reações atípicas fatais na anestesia.

Nonlinear Flow Sensor Calibration with an Accurate Syringe.

Flow sensors are required for monitoring patients on mechanical ventilation and in respiratory research. Proper calibration is important for ensuring accuracy and can be done with a precision syringe. This procedure, however, becomes complex for nonlinear flow sensors, which are commonly used. The objective of the present work was to develop an algorithm to allow the calibration of nonlinear flow sensors using an accurate syringe. We first noticed that a power law equation could properly fit the pressure-flow relationship of nonlinear flow sensors. We then developed a software code to estimate the parameters for this equation using a 3 L syringe (calibration syringe). Finally, we tested the performance of a calibrated flow sensor using a different 3 L syringe (testing syringe) and a commercially available spirometer. After calibration, the sensor had a bias ranging from −1.7% to 3.0% and precision from 0.012 L to 0.039 L for volumes measured with the 3 L testing syringe. Calibrated sensor performance was at least as good as the commercial sensor. This calibration procedure can be done at the bedside for both clinical and research purposes, therefore improving the accuracy of nonlinear flow sensors.

Respiratory function in patients with lumbar stenosis: A comparative analysis / Função respiratória em pacientes com estenose lombar: uma análise comparativa

The degenerative diseases of the spine are conditions involving the loss of structure and normal function of the spine and may lead to the worsening of functional capacity, decreased exercise tolerance, and reduced quality of life because of neurogenic claudication and chronic low-back pain. The choice for arthrodesis occurs due to the presence of evolutionary neurological injury, or intractable pain. Objective: To analyze and compare spirometric values and respiratory muscle strength in patients with lumbar stenosis. Method: Cross-sectional study with 38 patients of both genders, divided into a group of 19 operated patients and another group of 19 patients awaiting surgery, aged between 50 and 80 years, who were evaluated by spirometry and manovacuometry. Results: In our study, lung function was observed to be consistent with the expected standards, considering that the group of operated patients performed better in both spirometry and manovacuometry. Conclusion: Operated patients showed improvement in lung function as compared to non-operated patients.

As doenças degenerativas da coluna vertebral são condições que envolvem a perda de estrutura e a função normal da coluna e podem levar à piora da capacidade funcional, a diminuição da tolerância ao exercício e a redução da qualidade de vida por claudicação neurogênica e dor lombar crônica. A escolha da artrodese ocorre devido a presença de lesão neurológica evolutiva ou dor intratável. Objetivo: Analisar e comparar valores espirométricos e força muscular respiratória em pacientes com estenose lombar. Método: estudo transversal com 38 pacientes de ambos os sexos, dividido em um grupo de 19 pacientes operados e outro grupo de 19 pacientes que aguardavam cirurgia, com idade entre 50 e 80 anos, que foram avaliados por espirometria e manovacuometria. Resultados: Em nosso estudo, observou-se que a função pulmonar estavam dentro dos valores de referências, considerando que o grupo de pacientes operados apresentou melhor desempenho em espirometria e manovacuometria. Conclusão: pacientes operados apresentaram melhora na função pulmonar em comparação com pacientes não operados.

TeleCondutas: doença pulmonar obstrutiva crônica / TeleGuides: chronic obstructive pulmonary disease

A Doença Pulmonar Obstrutiva Crônica (DPOC) é caracterizada por sintomas respiratórios (dispneia, tosse e expectoração) e pela limitação persistente ao fluxo aéreo, que não é completamente reversível. É uma doença progressiva decorrente a resposta inflamatória anormal das vias aéreas e dos pulmões a partículas nocivas e gases inalados. A doença afeta 5% da população e está associada a alta morbidade e mortalidade. O tabagismo é o principal fator de risco, porém outros poluentes (produtos químicos, poeira, pó de carvão, combustíveis e fumaças) devem ser considerados na avaliação do paciente. Estabelecer o diagnóstico corretamente é importante, pois o manejo adequado reduz sintomas, frequência e gravidade das exacerbações, melhor qualidade de vida e aumenta a sobrevida do paciente. Esta guia apresenta informação que orienta a conduta para casos de doença pulmonar obstrutiva crônica no contexto da Atenção Primária à Saúde, incluindo: Sinais e sintomas, Diagnóstico, Avaliação, Abordagem Integral, Tratamento Oxigenoterapia Domiciliar Prolongada, Exacerbação, Técnica Inalatória, Encaminhamento para serviço especializado.

A eficácia do cicloergômetro no condicionamento cardiovascular em pacientes com lesão medular / Effectiveness of the cycle ergometer in cardiovascular conditioning of spinal cord injured patients

OBJETIVO: Avaliar a eficácia do cicloergômetro de membros superiores no condicionamento ardiorrespiratório em pacientes com lesão medular. MÉTODOS: Três pacientes participantes do programa de reabilitação do Hospital Estadual Mário Covas realizaram o programa de condicionamento físico durante 6 semanas (duas vezes/semana). Para avaliação inicial, foram utilizados: anamnese inicial, escala da American Spinal Injury Association, Functional Independence Measure, Medical Outcomes Study 36 - Item Short - Form Health Survey, exame espirométrico e mensuração da pressão inspiratória. As sessões de fisioterapia constaram de treino com cicloergômetro, sendo repetida a avaliação inicial ao término do estudo. RESULTADOS: Houve aumento de 40%, 53,4%, 20% na pressão inspiratória, respectivamente, para o paciente de nível cervical, torácico e lombar, com aumento na capacidade vital forçada e volume expiratório forçado no primeiro segundo (VEF1) nos pacientes tetraplégico e paraplégico nível torácico e redução na capacidade vital forçada e volume expiratório no primeiro segundo no paraplégico baixo. CONCLUSÃO: O cicloergômetro de membro superiores mostrou-se eficaz no programa de reabilitação em pacientes com diferentes níveis de lesão medular, apresentando melhora na pressão inspiratória e capacidades pulmonares não apresentando alteração quanto à escala de independência funcional e qualidade de vida.

OBJECTIVE: To evaluate the effectiveness of the upper limb cycle ergometer on cardiorespiratory fitness in spinal cord injured patients METHODS: Three patients participating in the rehabilitation program of Hospital Estadual Mário Covas participated in the fitness program for 6 weeks (2 times/week). For the initial evaluation, the following were used: initial anamnesis, American Spinal Injury Association scale, Functional Independence Measure, Medical Outcomes Study 36 - Item Short - Form Health Survey, spirometry and measurement of inspiratory pressure. The physiotherapy sessions consisted of training with a cycle ergometer, with the same initial assessment being repeated at the end of the study. RESULTS: There was an increase of 40%, 53.4%, 20% in the inspiratory pressure, for the patient with an injury at the cervical, thoracic, and lumbar levels, respectively, with an increase in forced vital capacity and forced expiratory volume in the first second (FEV1) in quadriplegic and paraplegic patients with thoracic level of injury, and reduction in forced vital capacity and forced expiratory volume in the first second in a paraplegic patients with a low injury. CONCLUSION: The upper limb cycle ergometer was effective in the rehabilitation program in patients with different levels of spinal cord injury, with an improvement in inspiratory pressure and lung capacity, showing no change as for functional independence scale and quality of life.

Respirar aire contaminado es tan nocivo como fumar cigarrillo / Breathing contaminated air is as harmful as cigarette smoking

Objetivo Averiguar ¿Cuál de los dos factores es más nocivo? ¿Cuál es la magnitud de su efecto? y ¿Qué pasa cuando alguien se expone a ambos factores a la vez? Métodos Estudio ecológico que evalúa la asociación epidemiológica (riesgo relativo) entre la contaminación atmosférica y el tabaquismo con la función pulmonar, evaluada mediante espirometría funcional en 489 adultos. Se comparan dos ambientes con diferentes niveles de contaminación, 30 y 60 µg/m³ de material particulado respirable (PM10) y grupos de fumadores contra no fumadores. Resultados La función pulmonar está disminuida (VEF1<80 %) en los fumadores en mayor proporción que en los no fumadores, con un exceso de riesgo de 52 % (RR. 1,52 IC95 % 1,11-2,07). Las personas expuestas a un mayor nivel de contaminación ambiental presentan una mayor proporción de disfunción pulmonar con un exceso de riesgo de 64 % (RR. 1,64 IC95 % 1,19-2,25). Cuando los sujetos se exponen a ambos factores, es decir fuman y además se encuentran en ambientes contaminados, el exceso de riesgo es del 129 % (RR 2,29 IC95 % 1,45-3,61). Conclusiones Las personas que respiran ambientes contaminados presentan disfunción pulmonar en una magnitud similar o superior a la que presentan los fumadores, es decir, podríamos afirmar que en relación con los efectos, respirar aire contaminado equivale a estar fumando, solo que en contra de la voluntad.(AU)

Objective We want to determine: ¿Which of the two factors is more harmful? ¿What is the magnitude of its effect? and ¿What happens when someone is exposed to both factors at once?. Methods An ecological study that evaluates the epidemiological association (relative risk) between air pollution and smoking with lung functions as assessed by functional spirometry in 489 adults. We compare two environments with different pollution levels 30 and 60 g/m³ of particulate matter (PM10) and groups of smokers against nonsmokers. Results Lung function is impaired (FEV1 <80 %) in smokers at higher rates than the non-smokers, with an excess risk of 52 % (RR. 1.52 CI 95 % 1.11 -2.07). People exposed to higher levels of pollution have a higher proportion of pulmonary dysfunction than those exposed to less polluted environments with an excess risk of 64 % (RR. 1,64 CI 95% 1.19-2.25). When subjects are exposed to both factors, that is smokers who also live in contaminated environments, the excess of risk reaches 129 % (RR 2.29 CI 95 % 1.45-3.61). Conclusions People who breathe in polluted environments have impaired lung function in a similar magnitude or greater than smokers. Therefore, we could say that breathing contaminated air is equivalent to smoking, but sadly it occurs against the affected party's will.(AU)

Efficient screening for COPD using three steps: a cross-sectional study in Mexico City.

BACKGROUND: Underdiagnosis of chronic obstructive pulmonary disease (COPD) in primary care can be improved by a more efficient screening strategy. AIMS: To evaluate a three-step method of screening for COPD consisting of an initial short questionnaire followed by measurement of forced expiratory volume in 1s/forced expiratory volume in 6s (FEV1/FEV6) using an inexpensive pocket spirometer in those with high risk, and diagnostic quality spirometry in those with a low FEV1/FEV6. METHODS: We analysed two related Mexico City cross-sectional samples. The 2003 Mexico City PLATINO survey (n=542) was used to develop a short questionnaire to determine the risk of COPD and a 2010 survey (n=737) additionally used a pocket spirometer. The discriminatory power of the two instruments was assessed with receiver operator characteristic (ROC) curves using three COPD definitions. RESULTS: The developed COPD scale included two variables from a simple questionnaire and, in ROC analysis, an area under the curve (AUC) between 0.64 and 0.77 was found to detect COPD. The pocket spirometer had an AUC between 0.85 and 0.88 to detect COPD. Using the COPD scale as a first screening step excluded 35-48% of the total population from further testing at the cost of not detecting 8-18% of those with COPD. Using the pocket spirometer and sending those with a FEV1/FEV6<0.80 for diagnostic quality spirometry is very efficient, and substantially improved the positive predictive value at the cost of not detecting one-third of COPD cases. CONCLUSIONS: A three-step screening strategy for COPD substantially reduces the need for spirometry testing when only a COPD scale is used for screening.

PIKO-6® vs. forced spirometry in asthmatic children.

BACKGROUND: The PIKO-6® is an electronic device that measures forced expiratory volume at seconds 1 (FEV1) and 6 (FEV6) of a forced vital capacity (FVC) maneuver. This device could aid in diagnosing obstructive respiratory diseases. OBJECTIVES: To determine the concordance of FEV1, FEV6, and the FEV1/FEV6 quotient achieved with PIKO-6® versus spirometric values from asthmatic patients, and compare results with measures from healthy children. METHODS: A cross-sectional study with asthmatic and healthy 6-to-14-year-old children, all of whom performed a forced spirometry as well as a PIKO-6® test. RESULTS: The study included 82 subjects (58 asthmatics, 24 healthy children). Except for the functional parameters, the basal characteristics of the two groups were similar. The concordance correlation coefficient (CCC) for FEV1 was 0.938 (P < 0.001), with 95% limits of agreement of -0.591 to 0.512 L, and an average of differences of -0.040 L. For FEV6, CCC was 0.927 (P < 0.001), and the 95% limits of agreement were -0.751 to 0.598 L with an average of differences of -0.077 L. The concordance analysis and the FEV1 and FEV6 associations were better in children with controlled asthma and healthy subjects, as well as in the post-bronchodilator results. CONCLUSIONS: The concordance between PIKO-6® and spirometry was lower in patients with partially controlled or uncontrolled asthma compared to controlled or healthy children. The broad limits of agreement show that the FEV1, FEV6, and FEV1/FEV6 obtained with the PIKO-6® are not interchangeable with spirometry results. Longitudinal evaluations of asthma patients are necessary to assess the utility of PIKO-6®.

Reference ranges for Mexican preschool-aged children using the forced oscillation technique.

INTRODUCTION: Recently, multi-ethnic reference ranges for spirometry have been created for use worldwide. In comparison, forced oscillation technique (FOT) reference values are limited to specific equipment and study populations, with current FOT reference ranges created in a Caucasian population. We aimed to develop FOT reference ranges for preschool-aged Mexican children and to compare these with current FOT reference ranges. PATIENTS AND METHODS: Respiratory resistance (Rrs) and reactance (Xrs) was measured in healthy Mexican children three to five years of age using commercial FOT equipment. The relationship between height and Rrs and Xrs was determined using regression analyses, taking into account age, weight, sex, and exposure to tobacco smoke. Reference equations were calculated for the Mexican children and Z-scores determined for Rrs and Xrs at 6 and 8Hz. A paired t-test assessed the difference in Z-scores between the Australian reference values and those created for the Mexican cohort. RESULTS: FOT was successfully measured in 584 children. Height was a significant predictor of Rrs and Xrs at 6 and 8Hz (P<.05). Z-scores calculated using the Australian reference equations overestimated lung function in Mexican children for both Rrs and Xrs at 6 and 8Hz (P<.001). CONCLUSION: The development of FOT reference ranges specific to Mexican preschool-aged children will allow for the correct interpretation of FOT measurements. This study also showed that current FOT reference ranges overestimate lung function in Mexican children. Highlighting, the importance of using ethnic appropriate reference ranges for interpreting lung function.

Características de los laboratorios de función pulmonar en Argentina / Characteristics of pulmonary function laboratories in Argentina

Introducción: se desconocen las características de los laboratorios de función pulmonar (LFP) del país. Estos datos pueden aportar elementos para el desarrollo de normativas que regulen su funcionamiento. Métodos: se estudiaron 35 LFP, agrupados en A) Área Metropolitana, y B) Interior del país, mediante entrevistas y formularios electrónicos, respectivamente. Se recabaron datos referidos a estructura y procesos. Resultados: se observó falta de uniformidad de diversa índole y magnitud en diversos aspectos. Estas diferencias fueron más evidentes bajo el análisis individual de los LFP que cuando se analizaron en conjunto según área geográfica y tipo de gestión. El 94% refiere basar su práctica en guías ATS/ERS, y la amplia mayoría de los responsables de los LFP están de acuerdo en implementar un programa de control de calidad. Discusión: la falta de uniformidad entre los LFP puede responder a múltiples causas: a) ausencia de normativas, b) LFP en espacios no diseñados para ese propósito, c) falta de programas de capacitación, d) costo de insumos y accesorios, e) ausencia de políticasnacionales de acceso al recurso.Conclusión: es necesaria la unificación de criterios en forma consensuada entre los participantes y las autoridades sanitarias, respecto de estructura y procesos. Se espera con esto garantizar un acceso uniforme y de alta calidad para pacientes, médicos y financiadores.

Introduction: The characteristics of pulmonary function laboratories (PFL) in our country are unknown. This information is essential to develop policies intended to harmonize theirfunctioning. Methods: Thirty-five PFL where surveyed in A) Buenos Aires Metropolitan Area, and B) Countryside, through interviews and electronic forms, respectively. Data on structure andprocesses were requested. Results: Lack of uniformity of different nature and magnitude in several aspects was observed. These differences were more apparent in the individual analysis than in the cluster analysis by geographic area and type of management of the PFL. Ninety-four percent of the PFL follow in their practice the ATS/ERS guidelines. The vast majority of their directors agree on implementing a quality control program. Discussion: The lack of uniformity among the PFL can be due to multiple causes: a) absenceof regulations, b) PFL located at inadequate premises, c) lack of training programs, d) cost of supplies and accessories, e) absence of national policies for access to their services.Conclusion: It is necessary to achieve agreement upon criteria among the participants and health authorities in respect of structure and processes. It is expected to ensure fast and high quality access to patients, physicians and health supporters.

Estenosis traqueal sintomática post intubación: análisis espirométrico pre y post dilatación terapéutica / Symptomatic post intubation tracheal stenosis: analysis pre and post spirometry therapeutic dilatation

Introducción: La estenosis traqueal (ET) es una complicación de la intubación traqueal o de la traqueostomía. La dilatación con endoscopía rígida (DER) es el tratamiento inicial en presencia de ET sintomática. Habitualmente estos pacientes presentan hallazgosespirométricos sugestivos de ET: aplanamiento en las ramas inspiratoria, espiratoria o ambas de la curva flujo-volumen (CFV). Asimismo, índices numéricos correlacionan valores espirométricos y sustentan el diagnóstico presuntivo de ET. Objetivos: Evaluar las características espirométricas de los pacientes con ET post intubación, previo y posterior a la DER. Materiales y métodos: Se analizaron todas las DER realizadasen pacientes con ET entre Noviembre de 2006 y Marzo de 2009. Todos los pacientes incluidos contaban con espirometría previa y posterior a la DER. Se analizó el volumen espiratorio forzado en 1° segundo (VEF1), pico flujo espiratorio (PFE), índice VEF1/PFEy la morfología de la CFV. Resultados: Veinticinco dilataciones traqueales fueron realizadas en 15 pacientes con ET. Posterior a la DER se observó un incremento en el VEF1 y PEF (total y %), así como una disminución en el índice VEF1/PEF. La CFV mostró un mayor área bajo la curva como consecuencia de menor aplanamiento de una o ambas ramas. Conclusiones: La espirometria pre-dilatación confirmó el diagnóstico de ET utilizando el VEF1, PEF y su índice (análisis numérico). La morfología de la CFV sustentó dicho diagnostico (análisis visual). La espirometría post-dilatación permitióobjetivar la mejoría de la ET a través de ambos tipos de parámetros, coincidiendo con el aumento del diámetro traqueal observado endoscópicamente.

Introduction: Tracheal stenosis (TS) is a complication of endotracheal intubation or tracheostomy. Rigid endoscopic dilatation (RED) is the initial treatment in symptomatic TS. Usually these patients have spirometric results that suggest such alteration: flatteningof the flow-volume curve (FVC), either in the espiratory, the inspiratory or bothcurves. Also, quantitative indexes among different spirometric values are correlated suggesting the presence of TS. Objectives: To assess spirometric characteristics in patients who suffer from symptomatic TS due to airway intubation, before and after therapeutic RED. Materials and methods: All RED procedures in patients with symptomatic TS performed between November 2006 and March 2009 were included in the analysis. All included patients should have a spirometry performed before andafter tracheal dilatation. Forced expiratory volume in 1st second (FEV1), peak expiratory flow rate (PEFR), FEV1/PEFR index and FVC morphology were taken into consideration. Results: Twenty five ED were performed in 15 patients with TS. An increase in FEV1(total and %) and PEFR (total and %) and a decrease in FEV1/PEFR index were observed in the post-dilatation values. The FVC showed an improvement in its morphology through a larger area under the curve because of less flattening in one or both curves.Conclusions: Pre-dilatation spirometry confirmed TS diagnosis using FEV1, PEFR and its index (quantitative analysis) and by the morphology of the FVC (visual analysis). Post-dilatation spirometry allowed the documentation of TS improvement through both kinds of parameters, in agreement with the improvement of the luminal diameter seen endoscopically.

Rastreio de patologia respiratória em crianças em idade escolar com o uso de espirometria portátil / Respiratory disease screening in school-aged children using portable spirometry

OBJETIVOS: Avaliar a prevalência de doença respiratória em crianças em idade escolar e determinar o valor da espirometria de campo. MÉTODOS: Avaliaram-se 313 alunos do primeiro e quarto ano de quatro escolas de Lisboa. Aplicou-se questionário respiratório auto-preenchido, e efetuou-se espirometria. Realizou-se análise descritiva e bivariada seguida de análise de regressão logística múltipla. RESULTADOS: Trinta e cinco por cento das crianças tiveram pelo menos um episódio de sibilância (18 por cento > 2 episódios), e 4 por cento tiveram diagnóstico de asma. Sibilância foi mais frequente com história familiar de atopia (OR ajustado = 2,7, IC95 por cento 1,4-5,1), tabagismo na gravidez, infecção respiratória baixa (IRB) (OR ajustado = 2,8; IC95 por cento 1,2-6,2), bronquiolite (OR ajustado = 3,3; IC95 por cento 1,3-8,2) e alergia a aeroalérgenos (OR ajustado = 3,2; IC95 por cento 1,4-7,2). Asma foi mais frequente com história de IRB (OR ajustado = 14,6; IC95 por cento 1,7-122,9) e alergia a aeroalérgenos (OR ajustado = 8,2; IC95 por cento 2,0-34,2). Cento e sessenta e nove (54 por cento) valores espirométricos preencheram critérios de aceitabilidade. O grupo com sibilância tinha em média valores de escore z inferiores para volume expiratório forçado no primeiro segundo (VEF1), razão entre VEF1 e capacidade vital forçada (CVF) (VEF1/CVF) e fluxo expiratório forçado entre 25 e 75 por cento (FEF25-75) (p < 0,05), além de maior percentagem de crianças com valores anormais para VEF1, VEF1/CVF e FEF25-75 (FEF25-75, p < 0,05). CONCLUSÕES: Este estudo piloto revelou frequência elevada de sintomatologia respiratória obstrutiva em escolares em Lisboa. Verificou-se boa correlação entre o questionário e os valores espirométricos. A baixa prevalência de asma leva-nos a especular que este diagnóstico esteja subestimado nesta população.

OBJECTIVES: To assess the prevalence of respiratory disease in school-aged children and to determine the value of field spirometry. METHODS: Data on 313 1st and 4th graders from four public schools in Lisbon were analyzed. A respiratory self-answered questionnaire and standard spirometry were performed. Descriptive and bivariate analysis was followed by multiple logistic regression. RESULTS: Thirty-five percent of the children presented at least one episode of wheezing (18 percent > 2 episodes), and 4 percent had asthma. Wheezing was more frequent with family history of atopy (adjusted OR = 2.7; 95 percentCI 1.4-5.1), maternal smoking during pregnancy, lower respiratory tract infection (LRTI) (adjusted OR = 2.8; 95 percentCI 1.2-6.2), bronchiolitis (adjusted OR = 3.3; 95 percentCI 1.3-8.2), and allergy to aeroallergens (adjusted OR = 3.2; 95 percentCI 1.4-7.2). Asthma was more frequent with previous history of LRTI (adjusted OR = 14.6; 95 percentCI 1.7-122.9) and allergy to aeroallergens (adjusted OR = 8.2; 95 percentCI 2.0-34.2). Fifty-five percent of spirometry measurements met the acceptability criteria of the American Thoracic Society and of the European Respiratory Society. Wheezers presented mean lower z scores for forced expiratory volume in 1 second (FEV1), ratio between FEV1 and forced vital capacity (FVC) (FEV1/FVC), and forced expiratory flow between 25 and 75 percent (FEF25-75) (p < 0.05), as well as higher percentage of abnormal FEV1, FEV1/FVC and FEF25-75 (FEF25-75, p < 0.05). CONCLUSIONS: This pilot study showed a high prevalence of obstructive airway symptoms in school-aged children in Lisbon. Symptoms assessed by the questionnaire showed good correlation with spirometric values. The small prevalence of asthma leads us to speculate that asthma is under-diagnosed in this population.

Effects of temperature on responses to anoxia and oxygen reperfusion in Drosophila melanogaster.

Insects in general, and Drosophila in particular, are much more capable of surviving anoxia than vertebrates, and the mechanisms involved are of considerable biomedical and ecological interest. Temperature is likely to strongly affect both the rates of damage occurring in anoxia and the recovery processes in normoxia, but as yet there is no information on the effect of this crucial variable on recovery rates from anoxia in any animal. We studied the effects of temperature, and thus indirectly of metabolic flux rates, on survival and recovery times of individual male Drosophila melanogaster following anoxia and O(2) reperfusion. Individual flies were reared at 25°C and exposed to an anoxic period of 7.5, 25, 42.5 or 60 min at 20, 25 or 30°C. Before, during and after anoxic exposure the flies' metabolic rates (MRs), rates of water loss and activity indices were recorded. Temperature strongly affected the MR of the flies, with a Q(10) of 2.21. Temperature did not affect the slope of the relationship between time to recovery and duration of anoxic exposure, suggesting that thermal effects on damage and repair rates were similar. However, the intercept of that relationship was significantly lower (i.e. recovery was most rapid) at 25°C, which was the rearing temperature. When temperatures during exposure to anoxia and during recovery were switched, recovery times matched those predicted from a model in which the accumulation and clearance of metabolic end-products share a similar dependence on temperature.