Spirometric Lung Function Research Articles

Noninvasive Ventilation Immediately After Extubation Improves Lung Function in Morbidly Obese Patients with Obstructive Sleep Apnea Undergoing Laparoscopic Bariatric Surgery

Noninvasive positive pressure ventilation (NIPPV) may improve postoperative lung function and reduce postoperative complications in patients undergoing abdominal surgery. The purpose of our study was to determine whether the timing of postoperative NIPPV affects lung function 1 day postoperatively. Forty morbidly obese patients with known obstructive sleep apnea undergoing laparoscopic bariatric surgery with standardized anesthesia care were randomly assigned to receive NIPPV immediately after tracheal extubation (immediate group) or supplemental oxygen (standard group). All patients had continuous positive airway pressure initiated 30 minutes after extubation in the postanesthesia care unit (PACU) via identical noninvasive ventilators. Spirometry was performed by a blinded observer in the perioperative holding area 1 hour after admission to the PACU and 1 day postoperatively. The primary outcome was the change in forced vital capacity (FVC) from baseline to 24 hours (FVC baseline-FVC 24 hours). Forty patients, 20 in each group, were enrolled in the study. Forced expiratory volume in 1 second, FVC, and peak expiratory flow rate were significantly reduced in both groups from perioperative values throughout the study. At 24 hours, the intervention group had lost only 0.7 L FVC, versus 1.3 L for the intervention group (P = 0.0005). An analysis of covariance confirmed this and indicated that the immediate postoperative NIPPV better preserved spirometric function at 1 and 24 hours postoperatively. Specifically, the differences in the primary outcome were statistically significant. NIPPV given immediately after extubation significantly improves spirometric lung function at 1 hour and 1 day postoperatively, compared with continuous positive airway pressure started in the PACU, in morbidly obese patients with obstructive sleep apnea undergoing laparoscopic bariatric surgery.

Spirometric Lung Function in School-Age Children

Few studies have investigated childhood respiratory outcomes of intrauterine growth retardation (IUGR), and it is unclear if catch-up growth in these children influences lung function. We determined if lung function differed in 8- to 9-year-old children born at term with or without growth retardation, and, in the growth-retarded group, if lung function differed between those who did and those who did not show weight catch up. Caucasian singleton births of 37 weeks or longer gestation from the Avon Longitudinal Study of Parents and Children (n = 14,062) who had lung spirometry at 8-9 years of age were included (n = 5,770). Infants with gestation-appropriate birthweight (n = 3,462) had significantly better lung function at 8-9 years of age than those with IUGR (i.e., birthweight <10th centile [n = 576] [SD differences and confidence intervals adjusted for sex, gestation, maternal smoking during pregnancy, and social class: FEV(1), -0.198 (-0.294 to -0.102), FVC, -0.131 (-0.227 to -0.036), forced midexpiratory flow between 25 and 75% of vital capacity -0.149 (-0.246 to -0.053)]). Both groups had similar respiratory symptoms. All spirometry measurements were higher in children with IUGR who had weight catch-up growth (n = 430) than in those without (n = 146), although the differences were not statistically significant. Both groups remained significantly lower than control subjects. Growth-retarded asymmetric and symmetric children had similar lung function. IUGR is associated with poorer lung function at 8-9 years of age compared with control children. Although the differences were not statistically significant, spirometry was higher in children who showed weight catch-up growth, but remained significantly lower than the control children.

Association between Airflow Obstruction and the Metabolic Syndrome or Its Components in Japanese Men

The aim of this cross-sectional study was to investigate the association between airflow obstruction and the metabolic syndrome (MS) or its components in Japanese men. The study included 7,189 male subjects, aged 45-88 years, who underwent spirometric lung function tests at a medical check-up. The spirometric criteria for diagnosis of airflow obstruction were forced expiratory volume in 1 second (FEV(1))/forced vital capacity (FVC) <70%. The severity of airflow obstruction was defined according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guideline. The prevalence of airflow obstruction was 9.0% and the frequency of MS was 25.6%. In logistic regression models adjusting for age, body mass index, smoking, and alcohol, the risk of MS was higher in subjects with airflow obstruction of GOLD stage II-IV compared to those with normal lung function [odds radio (OR), 1.33; 95% confidence interval (95% CI), 1.01-1.76)]. Of the MS components, waist circumference (OR, 1.76; 95% CI, 1.24-2.50) and blood pressure (OR, 1.37; 95% CI, 1.08-1.74) were associated with airflow obstruction of GOLD stage II-IV, after controlling for potential confounders. Airflow obstruction of GOLD stage II-IV might be associated with MS, waist circumference and blood pressure components in Japanese men.

Spirometric Pulmonary Function Test in Preschool Children

Children aged 3~5 years old represent the challenge in pulmonary function assessment, since evaluating lung function in preschool age group is important for the appropriate treatment for patient with chronic and recurrent cough and wheeze during this period. The joint American Thoracic Society/European Respiratory Society task force has produced recommendations for the spirometric lung function test currently used in the preschool age group. The reliable scientific evidence, documented references and reviews by the experts were used as a support. Reference data of spirometry lung function in preschool children were available in several countries including USA, Norway, Czech, Israel, Canada, and Taiwan. Spirometric pulmonary function tests are feasible in 3~ to 5~year~old children. However, the existing data are not sufficient to make definitive recommendations. Recommendations will need to be revised periodically until sufficient evidence has been collected to make definitive guidelines in various situations.

No relationship between lung function and high‐sensitive C‐reactive protein in adolescence

Several studies on adults have indicated that lower spirometric lung function may be associated with increased systemic inflammation, but no studies have investigated if this association is already present in adolescence. We explored the temporal relationship between changes in lung function and concentrations of plasma C-reactive protein (CRP) in a population-based cohort study at ages 14 and 20 years using a high-sensitivity CRP assay. CRP measurements were performed in a total of 420 subjects at mean age of 13.9 years. Of these, 262 subjects (62%) participated in the follow-up investigation at mean age of 20.1 years. Levels of log-CRP at age 14 were not significantly associated with forced expiratory volume (FEV(1) ) or FEV(1) / forced vital capacity (FVC) ratio at age 20, nor with the change in FEV(1) , FVC or FEV(1) /FVC ratio between 14 and 20 years after controlling for body mass index (BMI), airway hyperresponsiveness (AHR), eosinophil cationic protein (ECP), asthma, smoking, sex, and height at 14 years, and change in height between 14 and 20 years. Sex, BMI, AHR, ECP and change in height between 14 and 20 years were identified as independent factors associated with the change in FEV(1) , FVC and FEV(1) /FVC ratio in adolescence. We did not find an association between CRP levels at age 14 and change in lung function by age 20; whereas, sex, change in height, BMI, AHR and ECP were associated with lung function change in adolescence. Our findings indicate that systemic inflammation is of less importance for change in lung function in adolescence. Please cite this paper as: Nybo M, Hansen HS, Siersted HC and Rasmussen F. No relationship between lung function and high-sensitive C-reactive protein in adolescence.

Common cold decreases lung function in infants with recurrent wheezing

BackgroundCommon acute viral respiratory infections (colds) are the most frequent cause of exacerbations in infants with recurrent wheezing (RW). However, there is no quantitative information about the effect of colds on the lung function of infants with RW. This study was undertaken to determine the effect of common cold on forced expiratory parameters measured from raised lung volume in infants with RW.MethodsSpirometric lung function (expiratory flows from raised lung volume) was randomly assessed in 28 infants with RW while they had a common cold and when asymptomatic.ResultsIt was found that during colds there was a significant decrease in all forced expiratory parameters and this was much more evident for flows (FEF50%, FEF75% and FEF25–75%) which were definitively abnormal (less than −1.65 z-score) in the majority of infants. There was not association between family asthma, tobacco exposure, and other factors, with the extent of lung function decrease during colds. Tobacco during pregnancy but not a history of family asthma was significantly associated to lower expiratory flows; however, the association was significant only when infants were asymptomatic.ConclusionThis study shows that common colds cause a marked reduction of lung function in infants with RW.

New concepts for expressing forced expiratory volume in 1 s arising from survival analysis

Spirometric lung function is partly determined by sex, age and height (Ht). Commonly, lung function is expressed as a percentage of the predicted value (PP) in order to account for these effects. Since the PP method retains sex, age and Ht bias, forced expiratory volume in 1 s (FEV(1)) standardised by powers of Ht and by a new sex-specific lower limit (FEV(1) quotient (FEV(1)Q)) were investigated to determine which method best predicted all-cause mortality in >26,967 patients and normal subjects. On multivariate analysis, FEV(1)Q was the best predictor, with a hazard ratio for the worst decile of 6.9 compared to 4.1 for FEV(1)PP. On univariate analysis, the hazard ratios were 18.8 compared to 6.1, respectively; FEV(1) x Ht(-3) was the next-best predictor of survival. Median survival was calculated for simple cut-off values of FEV(1)Q and FEV(1) x Ht(-3). These survival curves were accurately fitted (r(2) = 1.0) by both FEV(1)Q and FEV(1) x Ht(-3) values expressed polynomially, and so an individual's test result could be used to estimate survival (with sd for median survival of 0.22 and 0.61 yrs, respectively). It is concluded that lung function impairment should be expressed in a new way, here termed the FEV(1)Q, or, alternatively, as FEV(1) x Ht(-3), since these indices best relate spirometric lung function to all-cause mortality and survival.

Continuous Positive Airway Pressure via the Boussignac System Immediately after Extubation Improves Lung Function in Morbidly Obese Patients with Obstructive Sleep Apnea Undergoing Laparoscopic Bariatric Surgery

Morbidly obese patients are at elevated risk of perioperative pulmonary complications, including airway obstruction and atelectasis. Continuous positive airway pressure may improve postoperative lung mechanics and reduce postoperative complications in patients undergoing abdominal surgery. Forty morbidly obese patients with known obstructive sleep apnea undergoing laproscopic bariatric surgery with standardized anesthesia care were randomly assigned to receive continuous positive airway pressure via the Boussignac system immediately after extubation (Boussignac group) or supplemental oxygen (standard care group). All subjects had continuous positive airway pressure initiated 30 min after extubation in the postanesthesia care unit via identical noninvasive ventilators. The primary outcome was the relative reduction in forced vital capacity from baseline to 24 h after extubation. Forty patients were enrolled into the study, 20 into each group. There were no significant differences in baseline characteristics between the groups. The intervention predicted less reduction in all measured lung functions: forced expiratory volume in 1 s (coefficient 0.37, SE 0.13, P = 0.003, CI 0.13-0.62), forced vital capacity (coefficient 0.39, SE 0.14, P = 0.006, CI 0.11-0.66), and peak expiratory flow rate (coefficient 0.82, SE 0.31, P = 0.008, CI 0.21-0.1.4). Administration of continuous positive airway pressure immediately after extubation maintains spirometric lung function at 24 h after laparoscopic bariatric surgery better than continuous positive airway pressure started in the postanesthesia care unit.

Respiratory and skin effects of exposure to wood dust from the rubber tree Hevea brasiliensis

Objectives: Potential health effects related to wood dust from the rubber tree, which produces natural rubber latex, have not been previously investigated. The main aim of this study was to...

Association of A/T Polymorphism of the CHRM2 Gene with Bronchodilator Response to Ipratropium Bromide in Asthmatic Children

Introduction: The aim of this study was to analyze the possible association of A/T polymorphism of the CHRM2 gene with asthma, and pharmacogenetic analysis of the polymorphism with bronchodilator response to ipratropium bromide, an anticholinergic drug used in asthma. Material and methods: Analysis was performed in a group of 113 children diagnosed with bronchial asthma, and in a group of 123 healthy children from a control group. Moreover, in the group of 32 asthmatic children without concurrent treatment with long-acting β2-agonists, bronchodilator response to ipratropium bromide was evaluated by the spirometric lung function test. Genetic analysis was performed for A/T polymorphism (rs6962027) of the CHRM2 gene. Genotyping was done with the PCR-RFLP method. Statistical analysis was performed using Statistica v.7.1 software. Results: No association of A/T polymorphism was found with asthma (p = 0.865 for genotypes and p = 0.782 for alleles). In the pharmacogenetic analysis, it was observed that patients carrying TT genotype of CHRM2 gene polymorphism demonstrated significantly poorer response to anticholinergic drug as compared to the patients with other genotypes for this polymorphism (p = 0.035). Conclusions: We found that TT genotype in the CHRM2 gene was associated with poor bronchodilator response in asthmatic patients. The results should be analyzed carefully considering the small sample size and should be confirmed by other research groups.

Associations between birth weight, early childhood weight gain and adult lung function

Background:Low birth weight is associated with lower values for spirometry in adults but it is not known if birth weight influences other measures of pulmonary function. It is also unclear...

Changes in pCO2, Symptoms, and Lung Function of Asthma Patients During Capnometry-assisted Breathing Training

In a recent pilot study with asthma patients we demonstrated beneficial outcomes of a breathing training using capnometry biofeedback and paced breathing assistance to increase pCO(2) levels and reduce hyperventilation. Here we explored the time course changes in pCO(2), respiration rate, symptoms and lung function across treatment weeks, in order to determine how long training needs to continue. We analyzed in eight asthma patients whether gains in pCO(2) and reductions in respiration rate achieved in home exercises with paced breathing tapes followed a linear trend across the 4-week treatment period. We also explored the extent to which gains at home were manifest in weekly training sessions in the clinic, in terms of improvement in symptoms and spirometric lung function. The increases in pCO(2) and respiration rate were linear across treatment weeks for home exercises. Similar increases were seen for in-session measurements, together with gradual decreases in symptoms from week to week. Basal lung function remained stable throughout treatment. With our current protocol of paced breathing and capnometry-assisted biofeedback at least 4 weeks are needed to achieve a normalization of pCO(2) levels and reduction in symptoms in asthma patients.

High-sensitive C-reactive protein is associated with reduced lung function in young adults

Systemic inflammation has been associated with reduced lung function. However, data on the interrelationships between lung function and inflammation are sparse, and it is not clear if low-grade inflammation leads to reduced lung function. Associations between high-sensitive C-reactive protein (CRP) and spirometric lung function were assessed in a population-based cohort of approximately 1,000 Danes aged 20 yrs. In males, the average decline in forced expiratory volume in one second (FEV(1)) in the highest CRP quintile was 23 mL.yr(-1) versus 1.6 mL.yr(-1) in the lowest quintile. In females, the average decline was 6.2 mL.yr(-1) in the highest CRP quintile versus an increase of 1.8 mL.yr(-1) in the lowest CRP quintile. In a multiple regression analysis adjusted for sex, body mass index, cardiorespiratory fitness, smoking, asthma, airway hyperresponsiveness and serum eosinophil cationic protein, higher levels of CRP at age 20 yrs were associated with a greater reduction in both FEV(1) and forced vital capacity between ages 20 and 29 yrs. The findings show that higher levels of C-reactive protein in young adults are associated with subsequent decline in lung function, suggesting that low-grade systemic inflammation in young adulthood may lead to impaired lung function independently of the effects of smoking, obesity, cardiorespiratory fitness, asthma and eosinophilic inflammation.

Stress Effects on Lung Function in Asthma are Mediated by Changes in Airway Inflammation

To examine the association of changes in current negative mood and long-term daily hassles with changes in lung function and airway inflammation in patients suffering from asthma and in healthy controls. Associations between psychological factors and asthma symptoms have been documented, but the relationship between airway inflammation and psychological factors has been largely unexplored. Data were analyzed from 46 asthma patients and 25 controls who completed questionnaires on current mood and daily hassles at two assessments 3 months apart. Lung function was measured by spirometry (forced expiratory volume in the first second (FEV(1))) and airway inflammation by the fraction of nitric oxide in exhaled air (FeNO). Regression analyses controlling for allergen load and air pollution (ozone) were calculated to study the association between changes in psychological factors and changes in lung function and airway inflammation, and to examine the mediational role of airway inflammation in the stress-lung function association. In patients with asthma, increases in negative affect were associated with decreases in FEV(1) and increases in FeNO. For daily hassles, a reverse pattern of associations was found, with decreases in daily hassles linked to decreases in FEV(1) and increases in FeNO. Mediation analyses showed that FeNO was a significant mediator of the association of both negative affect and daily hassles with lung function changes. No significant associations were found for healthy controls. Psychological variables are consistently associated with spirometric lung function and airway inflammation in asthma patients. For asthma patients, effects of acute negative affect must be distinguished from more chronic distress due to daily hassles.

Respiratory effects of occupational exposures in a milk powder factory

Ingestion of milk powder is a known cause of allergies in children, but the risks to respiratory health from exposure to inhaled milk powder have not been studied previously. The aim of the present study was to assess the effects of occupational exposures in a milk powder factory on respiratory symptoms and lung function. A cross-sectional study was conducted on 167 milk powder factory workers (response rate 77%) and 76 office workers (73%) from four factories in Thailand. All participants answered a questionnaire and performed spirometry. Measurements of concentrations of dust were used to give additional information on exposures. Mean respirable dust concentrations in the factory were 0.02-2.18 mg x m(-3). The risk of breathlessness and nasal symptoms were significantly increased in production and packing staff. The risk of skin symptoms was significantly increased in those adding vitamin mixture to milk powder. Factory workers showed significantly lower forced expiratory volume in one second measured as percentage of predicted value. The present study provides new evidence that workers exposed to milk powder by inhalation are at an increased risk of nasal symptoms, wheezing and breathlessness, and exhibit reduced spirometric lung function, even at relatively low air concentrations of milk dust.

Reference Ranges for Spirometry Across All Ages

The Third National Health and Nutrition Examination Survey (NHANES III) reference is currently recommended for interpreting spirometry results, but it is limited by the lack of subjects younger than 8 years and does not continuously model spirometry across all ages. By collating pediatric data from other large-population surveys, we have investigated ways of developing reference ranges that more accurately describe the relationship between spirometric lung function and height and age within the pediatric age range, and allow a seamless transition to adulthood. Data were obtained from four surveys and included 3,598 subjects aged 4-80 years. The original analyses were sex specific and limited to non-Hispanic white subjects. An extension of the LMS (lambda, mu, sigma) method, widely used to construct growth reference charts, was applied. The extended models have four important advantages over the original NHANES III analysis as follows: (1) they extend the reference data down to 4 years of age, (2) they incorporate the relationship between height and age in a way that is biologically plausible, (3) they provide smoothly changing curves to describe the transition between childhood and adulthood, and (4) they highlight the fact that the range of normal values is highly dependent on age. The modeling technique provides an elegant solution to a complex and longstanding problem. Furthermore, it provides a biologically plausible and statistically robust means of developing continuous reference ranges from early childhood to old age. These dynamic models provide a platform from which future studies can be developed to continue to improve the accuracy of reference data for pulmonary function tests.

Repeated Aerosolized AAV-CFTR for Treatment of Cystic Fibrosis: A Randomized Placebo-Controlled Phase 2B Trial

Previous studies have demonstrated that delivery of a recombinant adeno-associated virus (AAV) vector encoding the complete human cystic fibrosis transmembrane regulator (CFTR) cDNA (tgAAVCF) to the nose, sinus, and lungs of subjects with cystic fibrosis (CF) was safe and well tolerated. In a small randomized, double-blind study of three doses of aerosolized tgAAVCF or placebo at 30-day intervals, encouraging but non-significant trends in pulmonary function and induced sputum interleukin 8 (IL-8) levels were seen at early time points. This larger study was conducted to verify these trends. One hundred and two subjects aged 12 years and older with mild-to-moderate cystic fibrosis (forced expiratory flow in 1 sec [FEV1]:60% predicted) were randomized to two aerosolized doses of 1x10(13)DNase-resistant particles of tgAAVCF (n=51) or matching placebo (n=51) administered 30 days apart. Although tgAAVCF was well tolerated, the study did not meet its primary efficacy end point of statistically significant improvement in FEV1 30 days after initial administration of tgAAVCF compared with placebo. There were no significant differences in spirometric lung function over time, induced sputum biologic markers, or days of antibiotic use in either treatment group. Thus repeated doses of aerosolized tgAAVCF were safe and well tolerated, but did not result in significant improvement in lung function over time. Because gene transfer is the simplest, most basic way to correct the underlying genetic defect that leads to disease in CF, further research is warranted to develop an effective gene transfer agent for the treatment of CF.

Systemic inflammation and lung function in young adults

Background:Impaired lung function is associated with systemic inflammation and is a risk factor for cardiovascular disease in older adults. It is unknown when these associations emerge and to what extent...

Acapella ® versus `usual airway clearance' during acute exacerbation in bronchiectasis: a randomized crossover trial

Devices such as the Acapella may facilitate independent airway clearance, however, few clinical trials have investigated the efficacy of Acapella. The aim of this study was to compare the effectiveness of Acapella to 'usual airway clearance' in adults during an acute exacerbation of bronchiectasis requiring oral antibiotic therapy. Twenty patients with bronchiectasis and an acute exacerbation requiring oral antibiotic therapy were recruited into a randomized crossover trial. Patients were allocated to one of two groups determined by concealed computer generated randomization. Group 1 (n=10): airway clearance session using Acapella at home twice daily during oral antibiotic therapy. Group 2 (n=10): 'usual' airway clearance sessions at home during oral antibiotic therapy. Patients recorded duration of each treatment session, volume of sputum produced and perception of breathlessness. An independent assessor performed outcome measures of spirometric lung function, pulse oximetry and breathlessness at the beginning and end of the study period. The mean volume of sputum expectorated during Acapella sessions was greater than for usual airway clearance sessions although this difference was not significant 2.61 ml (95% CI-1.62 to 6.84). Mean duration of Acapella sessions was greater than usual airway clearance sessions and approached significance. There were no significant between group differences in changes in lung function. This study demonstrates that the Acapella device may offer an acceptable, user-friendly method of airway clearance in patients with bronchiectasis.

Standard Reference for the Six-Minute-Walk Test in Healthy Children Aged 7 to 16 Years

We have previously reported that the six-minute-walk test (6MWT) is a reliable and valid functional test for assessing exercise tolerance and endurance. There is a lack of pediatric standard reference for the 6MWT. To construct height-specific standards for the 6MWT for children aged 7 to 16 years. The anthropometric data, spirometric lung function, and six-minute-walk distance (6MWD) of Chinese children aged 7 to 16 years were prospectively measured using standardized protocols. The findings were used to construct height-specific standards for the 6MWT. The least mean square (LMS) method using maximum penalized likelihood was used to facilitate model fitting. Factors significantly associated with 6MWD were also determined. From January 2005 to April 2006, a total of 1,445 subjects were studied. The measured variables showed a normal distribution. Height-specific reference standards for 6MWT were constructed for both male and female children. Forward stepwise multiple regression analysis revealed height and difference in heart rate before and after the walk test to be important clinical variables associated with 6MWD. These 6MWD standards will provide useful references for the care of pediatric patients.