Reference values for spirometric parameters in healthy children living in a Colombian city located at 2640 m altitude.

OBJECTIVES: To identify the spirometric equations that are most appropriate for use in children and adolescents living in Bogota, Colombia after evaluating a set of relevant previously-developed equations, including the Global Lung Function Initiative (GLI) 2012 spirometry reference equations. METHODS: Healthy children aged between 6 and 17 years that were attending two randomly-selected schools in Bogota were invited to participate in the study, from January 2017 to January 2018. All participants underwent spirometry, following the procedures recommended by the American Thoracic Society/European Respiratory Society (ATS/ERS) Task Force. To identify the model or group of models that best predict each spirometric parameter in our population, we performed extensive residuals analyses and constructed Bland-Altman plots. RESULTS: Three hundred twenty-six spirometric tests (149 boys, 177 girls) formed the reference data set. Knudson and GLI-2012 spirometry reference equations proved to be the most accurate in predicting the majority of spirometry parameters in both sexes and both age groups, each providing the lowest median prediction error in the residual analyses or the narrowest limits of agreement in the Bland-Altman plots in approximately one-third of the spirometry parameters analyzed. CONCLUSION: For the majority of spirometry parameters, we recommend the use of Knudson and GLI-2012 spirometry reference equations for evaluating the respiratory function of children living in Bogota, Colombia, a city located at an altitude of 2640 m. Future investigations should target additional spirometric equations from Latin American populations living at moderate to high altitude to improve the GLI-2012 equations.

Pulmonary function of a paediatric cohort of patients with postinfectious bronchiolitis obliterans. A long term follow-up.

BACKGROUND: Postinfectious bronchiolitis obliterans (BO) is a chronic respiratory disease that usually follows a severe adenovirus infection. OBJECTIVE: To determine the evolution of pulmonary function and clinical outcome of children with postinfectious BO during childhood. METHODS: The study included patients diagnosed with postinfectious BO in whom at least two spirometries were performed within a minimum interval of 3 months. RESULTS: 46 met the inclusion criteria. The mean (±SD) follow-up period was 12.5 (±3.5) years. 197 spirometries and 41 plethysmographies were performed. Initial (9±3 years old) lung function was as follows (z score, mean±SD): forced vital capacity (FVC) -3.8±1; forced expiratory volume in 1 s (FEV1) -4.4±1; FEV1/FVC -2.2±1; forced expiratory flow (FEF)(25-75) -3.7±1; total lung capacity (TLC) 120±26%; residual volume (RV) 309±108%; and RV/TLC 55±13. During childhood, FVC and FEV1 increased by a mean of 11%/year (95% CI 9.3% to 12.6%; p<0.0001) and 9%/year (95% CI 7.7% to 10.2%; p<0.0001), and the FEV1/FVC ratio decreased by 1.9%/year (95% CI 1% to 2.8; p<0.001). The z score for FVC, FEV1 and FEV1/FVC decreased by 0.07 z score/year (95% CI 0.1 to 0.01; p<0.05), 0.09 z score/year (95% CI 0.1 to 0.05; p<0.01) and 0.04 z score/year (95% CI 0.09 to 0.001; p<0.02), respectively. During the follow-up period, 69% of patients required at least one hospital readmission and five required mechanical ventilation. Nine patients developed a thoracic deformity, and seven whose bronchiectasis did not respond to clinical treatment underwent a lobectomy. CONCLUSIONS: After a 12 year follow-up period, pulmonary function remained severely impaired, showing an obstructive pattern with air trapping that slowly improved during childhood. An unequal growth of lung parenchyma over the airways suggests dysinaptic growth. Patients required frequent readmission due to recurrent respiratory infections, and hypoxaemia improved slowly over time.

Ozone exposure, vitamin C intake, and genetic susceptibility of asthmatic children in Mexico City: a cohort study.

BACKGROUND: We previously reported that asthmatic children with GSTM1 null genotype may be more susceptible to the acute effect of ozone on the small airways and might benefit from antioxidant supplementation. This study aims to assess the acute effect of ozone on lung function (FEF(25-75)) in asthmatic children according to dietary intake of vitamin C and the number of putative risk alleles in three antioxidant genes: GSTM1, GSTP1 (rs1695), and NQO1 (rs1800566). METHODS: 257 asthmatic children from two cohort studies conducted in Mexico City were included. Stratified linear mixed models with random intercepts and random slopes on ozone were used. Potential confounding by ethnicity was assessed. Analyses were conducted under single gene and genotype score approaches. RESULTS: The change in FEF(25-75) per interquartile range (60 ppb) of ozone in persistent asthmatic children with low vitamin C intake and GSTM1 null was -91.2 ml/s (p = 0.06). Persistent asthmatic children with 4 to 6 risk alleles and low vitamin C intake showed an average decrement in FEF(25-75) of 97.2 ml/s per 60 ppb of ozone (p = 0.03). In contrast in children with 1 to 3 risk alleles, acute effects of ozone on FEF25-75 did not differ by vitamin C intake. CONCLUSIONS: Our results provide further evidence that asthmatic children predicted to have compromised antioxidant defense by virtue of genetic susceptibility combined with deficient antioxidant intake may be at increased risk of adverse effects of ozone on pulmonary function.

Off-pump versus on-pump coronary artery revascularization: effects on pulmonary function.

Many studies have shown important changes in lung function tests after coronary artery surgeries. It is controversial if off-pump surgery can give a better and shorter recovery than the on-pump. A prospective study was conducted on 42 patients submitted to coronary artery surgery and divided into two groups: 21 off-pump using intraluminal shunt (G (I)) and 21 on-pump (G (II)), matched by the anatomical location of the coronary arteries lesions. All patients had spirometric evaluation, blood gas measurements and alveolo-arterial oxygen gradient (A-aDO(2)), at the fourth and 10th postoperative days (PO(4) and PO(10)). Preoperatively, G(I) and G(II) had similar results (P>0.372). Spirometry showed decreases at PO(4) and remained decreased until PO(10) for both groups, with significant differences between the groups. The blood gas measurements showed reduction in arterial oxygen pressure (PaO(2)) and carbon dioxide pressure (PaCO(2)), while there was an increase in A-aDO(2) at PO(4) and PO(10) in both groups. The results suggest that different changes occur in pulmonary function when the surgery is performed with or without cardiopulmonary bypass. The off-pump patients showed significantly greater improvement than the on-pump group.

Effect of preterm birth on airway function and lung growth.

Obstructive lung diseases remain as important complications of preterm birth, usually attributed to a combination of lung immaturity, oxygen therapy and ventilator support. This is particularly true for low birth weight infants with severe respiratory neonatal disease; however, preterm infants that did not initially demonstrate significant respiratory neonatal disease also have reduced lung function when examined later in life, suggesting that prematurity alone could generate a persistent obstructive disease. Recent data have shown a significant reduction in maximal expiratory flows in healthy premature infants compared with control infants and reference values, when tested in the first months of life. Reduced expiratory flows were associated with male sex, low gestational age, smoking exposure and increased weight gain. The mechanism for this has not been determined and could result from smaller airways, a decrease in pulmonary elastic recoil secondary to abnormal alveolarisation of the lung parenchyma, as well as more compliant airways.

Nutritional status, especially body mass index, from birth to adulthood and lung function in young adulthood.

OBJECTIVE: The study assessed the impact of body mass index (BMI) at birth, infancy, and adulthood, and waist circumference on lung function. METHODS: Using a longitudinal design 1221 Chilean young adults were studied. A standardized respiratory questionnaire was used. Forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), height, weight and waist circumference were measured. Data at birth and at 1 year were obtained from clinical notes. RESULTS: Males with a BMI > or = 30 and women with a BMI < 20 had a lower FEV(1) (-230 mL, 95% CI -363 to -98; -106 mL, 95% CI -211 to -0.18, respectively). In both sexes those with a BMI 20-25 had the highest FEV(1) and FVC. In males there was a negative association between waist circumference and FEV(1) and FVC while in women the middle tertile had the highest FEV(1) and FVC. There was an association between birthweight and BMI at birth, and FEV(1) in men, when unadjusted for other measurements. CONCLUSIONS: BMI and waist circumference in adulthood make a greater impact on lung function in adulthood than anthropometric measurements at birth and infancy. Proxy measures of fatness in adulthood reduce lung function, but the pattern between fatness and lung function by sex may be different.

Reduced lung function in healthy preterm infants in the first months of life.

RATIONALE: Preterm delivery has been associated with a higher incidence of respiratory morbidity even in infants that do not have significant respiratory disease during the neonatal period. Reduced flows have been reported in children and adolescents born prematurely. OBJECTIVE: The aim of this study was to assess lung function in healthy preterm infants in the first months of life. METHODS: Preterm infants with less than 48 h of supplemental oxygen were recruited. Lung function was assessed by the raised-volume rapid thoracic compression in the first months of life. The control group consisted of full-term infants without a history of respiratory diseases. MEASUREMENTS AND MAIN RESULTS: Sixty-two preterm (29 male) and 27 full-term (10 male) infants were tested. Adjusting for length, age, and sex, we found a mean significant reduction of 92 ml/s (22%) in FEF(50), 73 ml/s (21%) in FEF(25-75), and 19 ml (28%) in FEV(0.5) in the preterm group. These differences in expiratory flows remained significant using another model that adjusts for lung volume (p < 0.01 for FEF(50), FEF(25-75), and FEV(0.5), and p < 0.05 for FEF(75)). In the preterm group, after adjusting for length, male sex, lower gestational age, and increased weight were significantly and independently associated with reduced flows. CONCLUSIONS: Our findings confirm that prematurity is independently associated with reduced lung function and that this is detectable in the first months of life. Male sex, lower gestational age, and weight are important predictors for reduced expiratory flows in this group.

Assessment of pulmonary function in patients before and after laparoscopic and open esophagogastric surgery.

BACKGROUND: Laparoscopy is a technique used in various surgical procedures. Few studies in the literature compare stress between laparoscopic and open surgery used for esophagogastric surgical procedures. Pulmonary function is known to be significantly affected in open surgeries, increasing postoperative morbidity and mortality. The current study aimed to assess pulmonary function in patients before and after open and laparoscopic esophagogastric surgery. METHODS: For this study, 75 patients were divided into two groups: 50 patients undergoing laparoscopy and 25 patients undergoing open surgery. The following parameters were determined by spirometry before and after surgery: forced expiratory volume in the first second (FEV(1)), forced vital capacity (FVC), and forced expiratory flow in the midexpiratory phase (FEF(25-75%)). RESULTS: A decrease in FEV(1,) FVC, and FEF((25-75%)) was observed in the two groups on postoperative days 2, 3, and 4, as compared with the preoperative period. Likewise, FEV(1) and FVC showed a significant reduction on postoperative days 2, 3, and 4 in the patients who underwent to open surgery, but only on the day 2 in those who underwent to laparoscopic surgery. A significant decrease in FEF((25-75%)) was observed only on postoperative day 2 in the group that underwent open surgery. Significant differences in FEV(1) between the groups were observed on postoperative days 2, 3, and 4. No significant difference in FVC was noted between the groups, and a difference in FEF((25-75%)) was observed only on postoperative day 4. CONCLUSIONS: Postoperative pulmonary dysfunction was more important for the patients undergoing open surgery than for those undergoing laparoscopic surgery.

Training of aerobic and anaerobic fitness in children with asthma.

OBJECTIVE: To assess the effect of a training protocol on aerobic and anaerobic fitness in children with asthma. STUDY DESIGN: Sixteen boys (mean age: 13 years; range: 10-16 years) with mild-to-moderate asthma participated in a rehabilitation program that included 6 weeks of individualized training on a cycle ergometer. Two groups were randomly formed: the control group (CG, n = 7) and the training group (TG, n = 9), which exercised at an intensity set at the heart rate corresponding to the ventilatory threshold, with 1-minute sprints against the maximal aerobic power (MAP) every 4 minutes. Session duration was 45 minutes, 3 sessions per week. Changes in maximal oxygen uptake (VO(2)max), MAP, short-term peak power (PP), and pulmonary function were assessed. RESULTS: Two patients of the training group did not complete the study. Pulmonary function remained unchanged in both groups. Improvement in both aerobic and anaerobic fitness was significant only in the training group (TG vs CG): VO(2)max +18% +/- 2.1% versus +9% +/- 4.5% (P <.05), MAP +32% +/- 5% versus 12% +/- 7% (P <.05), PP +21% +/- 5.7% versus +8.8% +/- 10% (P <.01). CONCLUSION: Exercise training with high-intensity bouts is well tolerated in children with mild-to-moderate asthma. When included in a global rehabilitation program, this type of training improves both aerobic and anaerobic fitness. Anaerobic activities should be considered in sports rehabilitation programs for children with asthma.

[Spirometric pulmonary age and its correlation with the chronological age of asthma patients]. / Edad pulmonar por espirometría y su correlación con la edad cronológica de pacientes con asma.

AIMS: Pulmonary age as a linear regression spirometric index, expresses pulmonary ventilatory function. OBJECTIVE: A pilot study was done to assess the differences of the values of the pulmonary age index and chronological age in patients with bronchial asthma and healthy volunteers. MATERIAL AND METHOD: We studies 111 subjects, 31 healthy and 80 with asthma. RESULTS: All of them underwent spirometry. Healthy individuals showed a mean chronological age of 35 years, and a pulmonary age of 26 years. Asthmatic patients showed a mean chronological age of 38 years, and a pulmonary age of 59 years. CONCLUSION: Both the time course and the severity of the disease increased pulmonary age.

Effect of body position changes on pulmonary gas exchange in Eisenmenger's syndrome.

Preliminary studies on sleep of patients with congenital heart disease and Eisenmenger's syndrome (ES) at our institution demonstrated nocturnal worsening arterial unsaturation, which appeared to be a body position-related phenomenon. To investigate the potential effect of body position on gas exchange in ES, we carried out a prospective study of 28 patients (mean age, 34.8 +/- 11.7 yr) with established ES due to congenital heart disease. In every patient, arterial blood gases were performed during both sitting and supine positions under three different conditions: room air, while breathing 100% oxygen, and after breathing oxygen at a flow rate of 3 L/min through nasal prongs. Alveolar oxygen pressure (PaO2) for the calculation of alveolar-arterial oxygen tension differences (AaPO2) was derived from the alveolar gas equation using PaCO2 and assuming R = 1. We used paired t test, repeated-measures two-way ANOVA with Bonferroni's test, and regression analysis. From sitting to supine position on room air, there was a significant decrease in PaO2 (from 52.5 +/- 7.5 to 47.5 +/- 5.5 mm Hg; p < 0. 001) and SaO2 (from 86.7 +/- 4.6 to 83.3 +/- 4.9%; p < 0.001), both of which were corrected by nasal O2 (to 68.2 +/- 21 mm Hg and to 92 +/- 4%, respectively, p < 0.005). PaCO2 and pH remained unchanged. The magnitude of the change in PaO2 correlated with the change in AaPO2 on room air (r = 0.77; p < 0.01) but not with the change in AaPO2 on 100% oxygen. It is concluded that in adult patients with ES there is a significant decrease in PaO2 and SaO2 when they change from the sitting to the supine position. A ventilation-perfusion (V/Q) distribution abnormality and/or a diffusion limitation phenomenon rather than an increase in true shunt may be the mechanisms responsible for this finding. The response to nasal O 2 we observed warrants a trial with long-term nocturnal oxygen therapy in these patients.

Repercusión del tabaquismo pasivo en la función ventilatoria de los trabajadores de una fábrica de cigarros / Effect of passive smoking on the respiratory function of workers in a cigarette factory

Se realiza un estudio descriptivo con el objetivo general de caracterizar funcionalmente el estado ventilatorio de 174 trabajadores, mediante la descripción del comportamiento de las pruebas funcionales respiratorias en los sujetos fumadores y no fumadores, previa identificación del hábito de fumar y del tabaquismo ambiental como factores de riesgo relevantes en la fábrica de cigarros "Orlando Nodarse". Se muestra en los resultados que todas las variables derivadas de las PFR presentaron valores anormales en una proporción elevada de los sujetos de manera global, y es predominante la presencia de trastornos ventilatorios restrictivos. No se encuentran diferencias en los sujetos fumadores y no fumadores, lo que demostró valores anormales en cada una de las variables de las pruebas funcionales respiratorias estudiadas. Se derivan recomendaciones orientadas a lograr cambios de actitudes y mejoramiento de las condiciones ambientales en que se desenvuelven los trabajadores del centro (AU)

Airway hyperreactivity in children with sickle cell disease.

Progressive restrictive defect with increasing age, obstructive lung disease, and bronchodilator responsiveness have been reported in sickle cell disease (SCD). Because airway hyperreactivity (AHR) can be underestimated when assessed by bronchodilator responsiveness in patients with normal baseline lung function, the aim of this study was to investigate the prevalence of AHR in SCD by cold-air bronchial provocation testing, and to assess whether AHR can be present in symptom-free patients with SCD. Forty patients aged 6 to 19 years (mean, 10.7 years +/- 3.5 SD) performed pulmonary function tests. Eighteen were known to have a history of reactive airway disease (RAD group), and 22 had no known history of RAD (non-RAD group). A control group, aged 6 to 7 years (mean, 10.5 +/- 3.1 years), consisted of 10 siblings of the non-RAD SCD group. There were no significant differences in age and height among the groups. If the forced expiratory volume in 1 second (FEV1) was greater than 70%, cold air challenge (CACh) was performed; if the FEV1 was less than 70%, aerosolized bronchodilator therapy was given. A decrease in FEV1 of more than 10% after CACh or an increase in FEV1 of 12% or greater after bronchodilator inhalation was considered evidence of AHR. In the RAD group, the total lung capacity was 88.9% +/- 14.0% of race-corrected predicted values, the forced vital capacity was 91.2% +/- 12.6%, and FEV1 was 85.3% +/- 16.2%. The mean maximal percent fall in FEV1 after CACh (n = 13) was 18.5% +/- 9.6% and was greater than 10% in 11 of 13 patients. The mean increase in FEV1 after bronchodilator therapy (n = 5) was 11.5% +/- 8.3%, and it was greater than 12% in 4 of 5 patients. In the non-RAD group the baseline total lung capacity was 101.6% +/- 11.7%, forced vital capacity was 95.5% +/- 10.2%, and FEV1 was 93.3% +/- 13.2%. The mean maximal percent fall in FEV1 after CACh (n = 19) was 14.1% +/- 8.8% and was greater than 10% in 13 of 19 patients. The mean increase in FEV1 after bronchodilator therapy (n = 3) was 14.7% +/- 11.3%, and was 12% of greater in 1 of 3 patients. In the control group the baseline total lung capacity was 105.7% +/- 12.1%, forced vital capacity was 96.2% +/- 11.1%, and FEV1 was 92.9% +/- 10.3%. The mean maximal percent fall in FEV1 was 5.0% +/- 2.5%, and was greater than 10% in none of 10 patients. The prevalence of AHR in the control group, the RAD group, and the non-RAD group was zero, 83%, and 64%, respectively (p < 0.0001). The overall prevalence in the SCD group was 73%. We conclude that there is a high prevalence of AHR in children with SCD and that airway hyperreactivity may exist in patients with SCD even in the absence of the clinical symptoms of RAD. AHR may be a significant component of sickle cell lung disease.

[Pneumoconiosis and exposure to wood]. / Pneumoconiose et exposition au bois.

The authors report a case of an employee in the wood processing industry. The clinical presentation was respiratory with dyspnoea on effort. The chest x-ray showed bilateral interstitial changes. Following bronchioalveolar lavage electron microscopic studies showed evidence of silica particles. Respiratory function tests showed pulmonary performance of 51%-64% of theoretical values depending on the test used. His working position involved the up keep of the boilers and also the drainage of the silos for wood dust. The wood used was corupixa, a brazilian wood containing crystalline silica; 0.1% in fresh wood dust. Numerous analyses have specified the percentage of silica in the ashes in magma. The diagnosis of pneumoconiosis of the silicotic type was sustained. The occupational risk linked to using this type of wood should be understood and the need to take protective measures for the employees concerned.

Efecto de tres esquemas terapéuticos sobre el flujo máximo espiratorio y la estancia hospitalaria en la crisis asmática / Effect of three therapeutic modalities upon peak expiratory flow and hospital staying in asthmatic crisis

El objetivo del presente estudio es evaluar el impacto de tres esquemas terapéuticos sobre el flujo máximo espiratorio (FME) y la estancia hospitalaria en pacientes adultos con crisis asmática. Se trata de un diseño causiexperimental, prospectivo, aleatorio, ciego simple y comparativo. Se estudiaron 38 pacientes adultos con diagnóstico de crisis asmática que se distribuyeron en tres grupos: 14 (36.84 por ciento) fueron tratados con aminofilina, 11 (28.94 por ciento con hidrocortisona y 13 (34.22 por ciento) con metilprednisolona. En cada grupo se asoció salbutamol nebulizado y se igualaron dosis de esteroides por la distinta potencia antiinflamatoria. Se medió el flujo máximo espiratorio (FME), grado de broncoespasmo, frecuencia cardiaca y respiratoria, repitiéndose dichas mediciones cada seis horas antes de la administración de los fármacos correspondientes. Se anotó la hora en que desaparecieron las sibilancias en cada grupo y se compararon entre sí. Los datos obtenidos sugieren que los tres esquemas terapéuticos empleados son adecuados y no impactan significativamente uno sobre el otro respecto al FME y la estancia hospitalaria

Comparison of manual and mechanical chest percussion in hospitalized patients with cystic fibrosis.

We compared the efficacy of manual and mechanical chest percussion during hospitalization for acute exacerbations of cystic fibrosis by evaluating changes in spirometry values. Fifty-one participants were randomly assigned to receive manual or mechanical chest percussion three times a day. Twenty-two participated during one subsequent admission and were assigned to the opposite form of chest percussion. The two groups were equal in severity of illness (mean National Institutes of Health score (+/- SEM): manual = 66.7 +/- 2.2; mechanical = 35.8 +/- 2.2; p = not significant). Mean improvement in forced expiratory volume at 1 second, forced vital capacity, and forced expiratory flow between 25% and 75% of forced vital capacity (+/- SEM) for manual percussion was 32.6% +/- 7%, 27.2% +/- 5%, and 38.1% +/- 10%, and for mechanical percussion was 28.5% +/- 4%, 28.7% +/- 4%, and 25.1% +/- 8%, respectively; p = not significant. Our participants did not prefer mechanical chest percussion. Although equal efficacy of outpatient therapy remains to be proved, this study suggests that patients can be encouraged to use the form of chest percussion that they prefer.

Prognostic implications of initial oropharyngeal bacterial flora in patients with cystic fibrosis diagnosed before the age of two years.

To evaluate the significance of early bacteriologic findings in infants and younger children with cystic fibrosis, we divided patients identified at < or = 2 years of age into groups by initial oropharyngeal culture: group NF, normal respiratory flora (n = 17); group SA, Staphylococcus aureus without Pseudomonas aeruginosa (n = 20); group PA, P. aeruginosa without S. aureus (n = 6); group PA/SA, P. aeruginosa and S. aureus (n = 7); and group O, other potentially pathogenic bacteria (n = 31). Follow-up of patients ranged in age from 5.4 to 13 years. At diagnosis, group PA/SA had lower Brasfield scores (p < 0.02) and higher gamma-globulin levels (p < 0.03) than the other groups. Five years after diagnosis, Brasfield scores were significantly lower in groups PA and PA/SA compared with the other groups; mean gamma-globulin levels did not differ significantly among the groups. Groups PA and PA/SA also had evidence of significantly greater obstructive pulmonary disease by spirometry than groups NF and O. Group PA/SA had a 10-year survival estimate of 57%, significantly lower than the 92% to 100% estimates of the other four groups (p < 0.0001). Thus P. aeruginosa in initial oropharyngeal cultures from patients < or = 2 years of age with cystic fibrosis was associated with significantly increased morbidity, and the finding of P. aeruginosa and S. aureus together in initial oropharyngeal cultures with a significantly increased mortality rate during the first 10 years after diagnosis.