Lung function is related to salivary cytokines and hormones in healthy children. An exploratory cross-sectional study.

Pulmonary mechanics has been traditionally viewed as determined by lung size and physical factors such as frictional forces and tissue viscoelastic properties, but few information exists regarding potential influences of cytokines and hormones on lung function. Concentrations of 28 cytokines and hormones were measured in saliva from clinically healthy scholar children, purposely selected to include a wide range of body mass index (BMI). Lung function was assessed by impulse oscillometry, spirometry, and diffusing capacity for carbon monoxide, and expressed as z-score or percent predicted. Ninety-six scholar children (55.2% female) were enrolled. Bivariate analysis showed that almost all lung function variables correlated with one or more cytokine or hormone, mainly in boys, but only some of them remained statistically significant in the multiple regression analyses. Thus, after adjusting by height, age, and BMI, salivary concentrations of granulocyte-macrophage colony-stimulating factor (GM-CSF) in boys were associated with zR5-R20 and reactance parameters (zX20, zFres, and zAX), while glucagon inversely correlated with resistances (zR5 and zR20). Thus, in physiological conditions, part of the mechanics of breathing might be influenced by some cytokines and hormones, including glucagon and GM-CSF. This endogenous influence is a novel concept that warrants in-depth characterization.

Arterial Blood Gases in Normal Subjects at 2240 Meters Above Sea Level: Impact of Age, Gender, and Body Mass Index

ABSTRACT Background The values of arterial blood gases (ABG) change with altitude above sea level; empirical verification is essential because ventilatory acclimatization varies with ethnicity and a population's adaptation. Objective The aim of the study was to describe ABG in a healthy population residing at 2,240 meters above sea level, to identify the mean level of alveolar ventilation (PaCO2), and to know whether a progressive increase in PaCO2 occurs with age and the impact of increasing body mass index (BMI). Methods We conducted a cross-sectional study in a referral center for respiratory diseases in Mexico City. Associations among variables with correlation coefficient and regression models of PaO2, SaO2, and P(A-a)O2 as dependent variables as a function of age, BMI, minute ventilation, or breathing frequency were explored. Results Two hundred and seventeen healthy subjects were evaluated with a mean age of 40 ± 15 years, mean of the PaO2 was 71 ± 6 mmHg, SaO2 94% ± 1.6%, PaCO2 30.2 ± 3.4 mmHg, HCO3 20 ± 2 mmol/L, BE-2.9 ± 1.9 mmol/L, and the value of pH was 7.43 ± 0.02. In a linear regression, the main results were PaO2 = 77.5-0.16*age (p < 0.0001) and with aging P(A-a)O2 tended to increase 0.12 mmHg/year. PaCO2 in women increased with age by 0.075 mmHg/year (p = 0.0012, PaCO2 =26.3 + 0.075*age). SaO2 and PaO2 decreased significantly in women with higher BMI 0.14% and 0.52 mmHg per kg/m2, (p = 0.004 and 0.002 respectively). Conclusion Mean PaCO2 was 30.7 mmHg, implying a mean alveolar ventilation of around 30% above that at sea level.

Lung volumes measurement using novel pressure derived method in participants with obstructive, restrictive and healthy lungs.

Background.Lung volumes can be measured by body plethysmography (BP), by inert gas dilution during a single-breath or multiple breaths and by radiographic methods based on chest roentgenogram or CT scanning. Our objective was to analyze the concordance between several methods including a new pressure-derived method (PDM) in a variety of pulmonary conditions.Methods. We recruited four groups of adult volunteers at the chronic obstructive pulmonary disease and tobacco clinic of a respiratory referral hospital: patients with lung bullae, with obstructive lung diseases, with restrictive lung diseases and healthy controls; all subjects underwent lung volume measurements according to ATS/ERS standards in random order with each method and then CT scanning. Differences among groups were estimated by Kruskal-Wallis tests. Concordance correlation coefficients (CCC) and Bland-Altman plots were performed.Results. Sixty-two patients were studied including 15 with lung bullae, 14 with obstructive lung diseases, 12 with restrictive lung disease and 21 healthy subjects. Highest concordance was obtained between BP and CT scanning (CCC 0.95, mean difference -0.35 l) and the lowest, with TLC-DLCOsb(CCC 0.65, difference -1.05 l). TLC measured by BP had a moderate concordance with the PDM (CCC = 0.91, mean difference -0.19 l). The PDM on the other hand had the lowest intra-test repeatability (2.7%) of all tested methods.Conclusions. Lung volumes measured by BP and CT had high concordance in the scenario of varied pulmonary conditions including lung bullae, restrictive and obstructive diseases. The new PDM device, had low intra-test variability, and was easy to perform, with a reasonable concordance with BP.

Offline exhaled nitric oxide in children: chemiluminescence vs. electrochemical devices / Óxido nítrico exhalado «fuera de línea¼ en niños: comparación entre equipos de quimioluminiscencia y electroquímicos

Abstract Background: Exhaled nitric oxide (eNO) is a noninvasive marker of airway inflammation that has been used in children, using the "offline" technique. To the extent of our knowledge, no article reported in literature compares the concordance and correlation between the two different technologies used to measure eNO at tidal volume offline. This study aimed to report the concordance and correlation of the eNO measured "offline" at tidal volume, using chemioluminiscence (cl) vs electrochemical devices (eq). Methods: A cross-sectional, observational, and prospective study was conducted in the National Institute of Respiratory Diseases (Instituto Nacional de Enfermedades Respiratorias), Mexico City. Healthy children and those with a lung disease between 1 and 11 years of age were included. The exhaled air sample at tidal volume was obtained by attaching a mask connected to a Mylar® bag. Results: We studied 36 children. The mean ± standard deviation (SD) age of the study population was 6 ± 2.6 years; 25% of the subjects included were healthy, and the rest had a lung disease. The concordance correlation coefficient between the two measuring devices was 0.98 (p < 0.001), with a mean difference of 1.46 ± 3.5 ppb and 95% limits of agreement from -5.3 ppb to 8.3 ppb. The linear regression model equation for the estimation of eNO was eNOcl = (eNOeq·1.0718) - 0.1343 (r2 = 0.97). Conclusions: The measurement of eNO at tidal volume by the offline method can be analyzed by electrochemical devices, and the results are interchangeable with those analyzed by chemiluminescence technology.

Resumen Introducción: El óxido nítrico exhalado (eNO) es un marcador no invasivo de inflamación de la vía aérea que se ha utilizado en niños mediante técnica «fuera de línea¼. Por lo que sabemos, en la literatura no existen reportes que comparen la concordancia y la correlación entre dos técnicas diferentes a volumen corriente. El objetivo de este trabajo es informar la concordancia y la correlación del eNO obtenido por la técnica fuera de línea a volumen corriente en los equipos de quimioluminiscencia (cl) y electroquímico (eq). Métodos: Se realizó un estudio transversal, observacional y prospectivo en el Instituto Nacional de Enfermedades Respiratorias, en Ciudad de México. Se incluyeron niños sanos y con enfermedad pulmonar de 1-11 años de edad. La muestra de aire exhalado se obtuvo a volumen corriente mediante una máscara con conexión a una bolsa de Mylar®. Resultados: Se estudiaron 36 niños. La edad promedio con su desviación estándar de la población de estudio fue de 6 ± 2.6 años. El 25% de los sujetos incluidos estaban sanos y el resto tenían alguna enfermedad pulmonar. El coeficiente de correlación de concordancia entre los dos equipos fue de 0.98 (p < 0.001), con una diferencia media de 1.46 ± 3.5 ppb y unos límites de concordancia del 95% de −5.3 a 8.3 ppb. La ecuación del modelo de regresión lineal del eNO fue eNOcl = (eNOeq·1,0718) − 0.1343 (r2 = 0.97). Conclusiones: La medición del eNO por el método fuera de línea a volumen corriente puede analizarse en dispositivos electroquímicos. Los resultados son intercambiables con los de quimioluminiscencia.

Gas Exchange Impairment During COVID-19 Recovery.

BACKGROUND: Persistent impairment of pulmonary function and exercise capacity has been known to last for months or even years in the survivors who recovered from other coronavirus pneumonia. Some reports showed that subjects with coronavirus disease 2019 pneumonia after being discharged could have several sequelae, but there are few studies on gas exchange and exercise capacity complications in these subjects. AIMS: To describe residual gas exchange abnormalities during recovery from coronavirus disease 2019 pneumonia. METHODS: In an observational study, ∼90 d after onset of disease, we scheduled almost 200 subjects for an out-patient visit with pulmonary function testing and computed tomography of the lungs. Lung mechanics by using body plethysmography, gas exchange with diffusing lung capacity for carbon monoxide determined by the single-breath technique (DLCOsb) and diffusing lung capacity for nitric oxide determined by the single-breath technique (DLNOsb), and exercise ability by using the 6-min walk test (6MWT) were measured in the subjects. The results were compared between those who required invasive mechanical ventilation and those who did not. RESULTS: A total of 171 subjects were included, the majority (96%) had signs of residual pneumonia (such as an excess of high attenuation areas) on computed tomography of the lungs. The DLCOSB results were below the lower limit of the normal range in 29.2% of the subjects; during the 6MWT, 67% experienced oxygen desaturation ([Formula: see text]) > 4%; and, in 81 (47%), the dropped below 88%. Subjects who required invasive mechanical ventilation (49.7%) were more likely to have lower lung volumes, more gas exchange abnormality, less exercise capacity and more radiologic abnormality. CONCLUSIONS: Subjects who recovered from severe COVID-19 pneumonia continued to have abnormal lung function and abnormal radiologic findings.

Manifestaciones pulmonares y radiológicas del Sars-Cov2 en pediatría / Pulmonary manifestations and radiological findings of SarsCov2 in children

Las infecciones respiratorias agudas son causa de alta morbi-mortalidad a nivel mundial. El Coronavirus descubierto en Wuhan, China en el 2019 es de interés mundial por las diferentes manifestaciones clínicas que pueden aparecer en niños. Nuestro objetivo principal es revisar las manifestaciones del COVID-19 en el aparato respiratorio y los hallazgos a nivel radiológicos en pediatría. Se estiman que solo el 5,7% de los niños han sido hospitalizados, siendo los niños con comorbilidades y menores de 1 año los que suponen un riesgo mayor para enfermedad grave. A nivel global la mediana de edad de presentación de los casos es alrededor de 7 años, detectándose más casos a mayor edad, pero siendo la gravedad inversamente proporcional a la edad. La forma asintomática o leve son las presentaciones más comunes reportadas en niños, siendo de hasta en el 90% de los niños infectados. Los estudios de laboratorio pueden ser normales o presentar leucocitos alterados en un 69,2% y a nivel radiológico se ha observado en niños que en un 69% presentan opacidades bilaterales en vidrio despulido. En este momento, cualquier infección respiratoria aguda hay que descartar COVID-19, para poder evitar complicaciones en el paciente...(AU)

[Follow-up of patients after COVID-19 pneumonia. Pulmonary sequelae]. / Seguimiento de los pacientes después de neumonía por COVID-19. Secuelas pulmonares.

Coronavirus disease 2019 (COVID-19) is an infection caused by SARS-CoV-2 that has caused an unprecedented pandemic with a high rate of morbidity and mortality worldwide. Although most cases are mild, there are a considerable number of patients who develop pneumonia or even acute respiratory distress syndrome (ARDS). After having recovered from the initial disease, many patients continue with various symptoms (fatigue, dry cough, fever, dyspnea, anosmia, and chest pain, among others.), which has led to consider the possible existence of "post-COVID-19 syndrome". Although the definition and validity of this syndrome are not clear yet, several studies report that individuals who have recovered from COVID-19 may have persistent symptoms, radiological abnormalities, and compromised respiratory function. Current evidence suggests that there is a large number of pulmonary sequelae after COVID-19 pneumonia (interstitial thickening, ground glass opacities, crazy paving pattern, and bronchiectasis, among others.). Likewise, it seems that pulmonary function tests (spirometry, DLCO, 6MWT, and measurement of maximum respiratory pressures), in addition to high-resolution computed axial tomographies (CAT scan), are useful for the assessment of these post-COVID-19 pulmonary sequelae. This review aims to describe the possible pulmonary sequelae after COVID-19 pneumonia, as well as to suggest diagnostic procedures for their correct assessment and follow-up; thus, allowing proper management by a multidisciplinary medical team.

COVID-19 es la enfermedad causada por el virus SARS-CoV-2, la cual ha ocasionado una pandemia sin precedentes, con gran cantidad de infectados y muertos en el mundo. Aunque la mayoría de los casos son leves, existe una cantidad considerable de pacientes que desarrollan neumonía o, incluso, síndrome de distrés respiratorio agudo (SDRA). Luego de recuperarse del cuadro inicial, muchos pacientes continúan con diversos síntomas (fatiga, tos seca, fiebre, disnea, anosmia, dolor torácico, entre otras), lo que ha llevado a considerar la posible existencia del "síndrome pos-COVID-19". Aunque la definición y validez de este síndrome aún no son claras, varios estudios reportan que los individuos recuperados de la COVID-19 pueden tener persistencia de síntomas, anormalidades radiológicas y compromiso en la función respiratoria. La evidencia actual sugiere que existe gran cantidad de secuelas pulmonares despues de una neumonía por COVID-19 (engrosamiento intersticial, infiltrado en vidrio esmerilado, patrón en empedrado, bronquiectasias, entre otras.). De igual forma, parece ser que las pruebas de función pulmonar (espirometría, prueba de difusión pulmonar de monóxido de carbono, prueba de caminata de seis minutos y la medición de las presiones respiratorias máximas), además de la tomografía axial computarizada de alta resolución, son útiles para evaluar las secuelas pulmonares pos-COVID-19. En esta revisión se pretende describir las posibles secuelas a nivel pulmonar posteriores a neumonía por COVID-19, así como sugerir procedimientos diagnósticos para su correcta evaluación y seguimiento, que permitan el manejo adecuado por parte de un equipo médico multidisciplinario.

Asma: uso adecuado de dispositivos para inhalación / Asthma: correct use of inhalation drug-delivery devices

Resumen La terapia inhalada se considera la piedra angular del manejo del asma. Sin embargo, a pesar de ser la forma ideal de administración de estos medicamentos, solamente el 70% de los pacientes cumple el tratamiento adecuadamente y sólo del 39 al 67% de los médicos conocen y pueden explicar de forma adecuada las distintas técnicas de inhalación. La terapia inhalada tiene características muy particulares. El depósito pulmonar de un medicamento inhalado a través del tracto respiratorio es más complejo que cuando se administra por vía oral, y varía dependiendo de varios factores, tanto inherentes al medicamento como a la forma de administrarlo. Para que la terapia inhalada sea exitosa, se requiere que se generen partículas del medicamento de un tamaño apropiado que penetren más allá de la orofaringe y la laringe, y que puedan depositarse en los pulmones. Existen múltiples dispositivos para la administración de medicamentos en la vía respiratoria baja. Cada uno ha probado tener una eficacia similar, siempre y cuando se utilicen con la técnica correcta. La decisión para su uso se realiza con base en la edad del paciente, la capacidad de coordinar entre la inhalación y la activación del dispositivo y la presencia de síntomas agudos. La elección del dispositivo a utilizar siempre deberá hacerse de forma conjunta, evaluando pros y contras de cada uno de los dispositivos y siempre de forma individualizada.

Abstract Inhaled therapy is considered the cornerstone of asthma treatment. However, despite being the ideal form of drug delivery, it is recognized that only 70% of patients have an adequate attachment to their treatment and only 39-67% of physicians can explain the optimal inhaler technique. Inhaled therapy has very specific characteristics. Pulmonary deposit of an inhaled medication through the respiratory tract is more complex than when administered orally and depends on several factors inherent to both the medication and the administration. For successful inhaled therapy, the drug needs to be converted into particles of an appropriate size, which can enter beyond the oropharynx and larynx, and be deposited in the lungs. There are multiple devices for the administration of drugs in the lower respiratory tract, each one with a similar efficacy as long as it is used with the correct technique. The decision of which device should be used is made based on the age of the patient, the ability to coordinate between the inhalation and activation of the device, and the presence of acute symptoms. The choice of the device must be evaluated individually.

Longitudinal Evaluation of Lung Function in Patients With Advanced Non-Small Cell Lung Cancer Treated With Concurrent Chemoradiation Therapy.

PURPOSE: In lung cancer patients, radiation therapy modifies lung architecture, resulting in functional deterioration, which worsens symptoms and reduces quality of life. METHODS AND MATERIALS: A multicenter, prospective, longitudinal study was conducted in a cohort of patients with locally advanced and oligometastatic non-small cell lung cancer treated with concurrent chemoradiation therapy (CCRT). A wide array of pulmonary function tests (forced spirometry, body plethysmography, impulse oscillometry, carbon monoxide diffusing capacity, fraction of exhaled nitric oxide, arterial blood gases, and 6-minute walk test) were used to evaluate lung function at baseline; after radiation therapy; and at 6, 12, 24, and 48 weeks after CCRT. Relative changes in test results (percentages) were estimated at the aforementioned intervals and compared with baseline results. RESULTS: Thirty-seven patients completed the follow-up and were included in the analysis. After CCRT, patients showed a maximum decline in lung volumes as follows: (1) 31% in forced expiratory volume in the first second after 24 weeks (P = .008), (2) 9.6% in forced vital capacity after 48 weeks (P = .04), and (3) 15.1% in total lung capacity after 48 weeks (P = .0015). Similarly, at 12 weeks after CCRT, patients showed a 21.8% decrease in carbon monoxide diffusing capacity (P = .002). Increases were found in total airway resistance (respiratory system resistance at 5 Hz), frequency dependence of resistance (change in respiratory system resistance at 5 Hz-respiratory system resistance at 20 Hz, P = .012), and reactance (P = .0003 for respiratory system reactance at 5 Hz and P = .001 for reactance area), which together indicate small-airway dysfunction. CONCLUSIONS: The longitudinal evaluation of lung function through pulmonary function tests detects CCRT-induced damage before the appearance of clinical symptoms associated with CCRT lung toxicity.

Prevalence and Characteristics of Exercise-Induced Bronchoconstriction in High School and College Athletes at 2,240 m Altitude.

BACKGROUND: Athletes practicing strenuous physical activities may develop exercise-induced bronchoconstriction (EIB). We aimed to determine the prevalence and features of this condition in Mexico City (altitude, 2,240 m). METHODS: In the present study, 208 high school and college athletes performed a standardized EIB test on a treadmill. RESULTS: Responses to exercise had large between-subject variability in all physiological parameters (forced expiratory volume in one second [FEV1], heart rate, blood oxygen saturation level [SpO2], blood pressure), with nearly similar proportions of subjects in whom FEV1 increased or decreased. According to the recommended cut-off value of 10% FEV1 decrease, only 15 (7.2%) athletes had a positive EIB test. Weight lifters were more prone to develop EIB (three out of seven athletes; p = 0.01). Subjects with a positive EIB test already had a lower baseline forced expiratory volume in one second/forced vital capacity (FEV1/FVC) ratio (96.4 vs. 103.2% of predicted, respectively; p = 0.047), and developed more respiratory symptoms after exercise than subjects with a negative test. There were no differences with respect to age, gender, body mass index, history of asthma or atopic diseases, smoking habit, and exposure to potential indoor allergens. CONCLUSIONS: The relatively low prevalence of EIB in athletes from Mexico City raises the possibility that high altitude constitutes a protective factor for EIB. In contrast, weight lifters were especially prone to develop EIB, which suggests that repetitive Valsalva maneuvers could be a novel risk factor for EIB. There was a large between-subject variability of all physiological responses to exercise.

Respiratory impedance in patients with Duchenne muscular dystrophy.

Impulse oscillometry (IOS) evaluates non-effort-dependent respiratory mechanics, and thus it may be useful to evaluate patients with Duchenne muscular dystrophy (DMD). OBJECTIVES: We aimed (1) to describe the behavior of IOS parameters in patients with DMD, and compare it to those from a control group; (2) to determine whether resistances and reactances differ in relation to the severity of DMD; and (3) to compare IOS parameters with spirometry and maximal inspiratory (MIP) and expiratory (MEP) pressures. METHODS: Children and adolescents (<20 years old) with biopsy-confirmed DMD and age-paired subjects were cross-sectionally evaluated. All results were transformed to z scores with respect to the healthy subjects (reference population). RESULTS: Anthropometric characteristics did not differ between the 31 patients and 69 controls included in the study. Compared with controls, patients with DMD had higher IOS resistances and lower reactances. As expected, FEV1 and FVC were lower in patients and always declined as age increased. By contrast, MIP and MEP were lower-than-normal in youngest patients, tended to improve around puberty initiation, and declined thereafter. In general, there was a poor correlation between IOS parameters and spirometric variables or respiratory pressures, excepting for X20 Hz, which had an inverse correlation with FEV1 . Interestingly, IOS resistances were higher in patients with less disability (lower Vignos score; better FVC), but tended to be normalized in advanced stages of the disease. CONCLUSION: This study showed that IOS is feasible in children and adolescents with DMD and yields information about respiratory function not achievable with the usual forced techniques. Pediatr Pulmonol. 2016;51:1072-1079. © 2016 Wiley Periodicals, Inc.

Variability of FeNO in healthy subjects at 2240 meters above sea level.

Fraction of exhaled nitric oxide (FeNO) is a marker of eosinophilic airway inflammation. Altitude above sea level can affect measurements of this index, but there is only limited information regarding the diurnal variation (ante meridiem vs. post meridiem) and reproducibility of FeNO on consecutive days at moderate altitudes. To evaluate the diurnal variability of FeNO and assess its reproducibility over five consecutive days in healthy individuals living at 2240 m, and to compare the FeNO readings taken with two different analyzers. Healthy non-smoking adults were measured using NIOX MINO(®) or NOA 280i(®) devices. One group (n = 10) had readings taken morning and afternoon for five consecutive days with the NIOX MINO(®) equipment; while the second group (n = 17) was measured on only one morning but by both the electrochemical analyzer (NIOX MINO(®)) and the chemiluminescence method (NOA 280i(®)). The study group consisted of 27 subjects aged 28.7 ± 6 years. Morning and afternoon FeNO measurements were 15.2 ± 7.5 ppb and 15.2 ± 7.9 ppb (p = 0.9), respectively. The coefficient of variation (CV) of these measurements (a.m. vs. p.m.) was 10.7 %, and the coefficient of repeatability (CR), 4.2 ppb. The concordance correlation coefficient (CCC) between the two measures (morning vs. afternoon) was 0.91. The CV and CR of the five morning readings were 15.4 % and 4.3 ppb, respectively; while those of the five afternoon measures were 13.6 % and 3.5 ppb, respectively. The CCC between the NIOX MINO(®) equipment and the NOA-280i(®) device was 0.8, with 95 % limits of agreement of -8.35 to 0.29 ppb. In adults living at 2240 m above sea level, FeNO measurements show minimal diurnal variation, and readings are reproducible (<15 %) over a period of at least five consecutive days; however, the FeNO measurements obtained with the NIOX MINO(®) and NOA 280i(®) devices are not interchangeable due to the wide limits of agreement recorded.

Foreign body removal by flexible fiberoptic bronchoscopy in infants and children.

Rigid bronchoscopy is the preferred method for removal of foreign bodies lodged in the airways, but some studies found that flexible bronchoscopy can also achieve a high success rate. The aim of the present work was to report our experience in using flexible bronchoscopy for foreign body retrieval in infants and children. Reports of all bronchoscopies performed from 1994-2003 at a tertiary-level pediatric hospital in Mexico City were reviewed. Those with a final diagnosis of foreign body aspiration were analyzed. Of 2,376 bronchoscopies performed during the study period, 59 (2.5%) yielded a final diagnosis of foreign body aspiration: 28 lodged in the right bronchi, 15 in the left bronchi, and those remaining, in the larynx or trachea. Foreign bodies were organic in nature in 38 (64.4%), mainly peanuts, pumpkin seeds, and beans, while 21 (35.6%) were inorganic, mainly pen caps and pins. In 23 cases, flexible bronchoscopy was attempted as the initial therapeutic procedure. Among these latter patients, the procedure was successful in 21 (91.3%). Ages of these 21 patients ranged from 9 months to 16 years (median, 5 years). The only two patients in whom foreign bodies could not be removed through flexible bronchoscopy were males, 2 years of age, both with a peanut lodged in right main bronchus. In conclusion, flexible bronchoscopy must be taken into account as initial therapeutic method for foreign body removal in infants and children.