Longitudinal Changes In Pulmonary Function Research Articles

Air pollution exposure and longitudinal changes in pulmonary function in adults: A community-based cohort study in Korea

Air pollution exposure and longitudinal changes in pulmonary function in adults: A community-based cohort study in Korea

Longitudinal changes in pulmonary function and patient-reported outcomes after lung cancer surgery

BackgroundSurgery is the mainstay of treatment for non-small cell lung cancer, but the decline in pulmonary function after surgery is noticeable and requires attention. This study aimed to evaluate longitudinal changes in pulmonary function and integrated patient-reported outcomes (PROs) after lung cancer surgery.MethodsData were obtained from a prospective cohort study, the Coordinate Approach to Cancer Patients’ Health for Lung Cancer. Changes in forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) at 2 weeks, 6 months, and 1 year after surgery, and the corresponding modified Medical Research Council (mMRC) dyspnea scale and chronic obstructive lung disease assessment test (CAT) scores were evaluated. Mixed effects model was used to investigate changes in pulmonary function and PROs.ResultsAmong 620 patients, 477 (76.9%) underwent lobectomy, whereas 120 (19.4%) and 23 (3.7%) were treated with wedge resection/segmentectomy and bilobectomy/pneumonectomy, respectively. Both FVC and FEV1 markedly decreased 2 weeks after surgery and improved thereafter; however, they did not recover to baseline values. The corresponding mMRC dyspnea scale and CAT scores worsened immediately after surgery. The dyspnea scale of the mMRC was still higher, while CAT scores returned to baseline one year after surgery, although breathlessness and lack of energy persisted. Compared to the changes from baseline of FVC and FEV1 in patients who underwent lobectomy, patients who underwent bilobectomy/pneumonectomy showed a greater decrease in FVC and FEV1, while wedge resection/segmentectomy patients had smaller decreases in FVC and FEV1 at 2 weeks, 6 months, and 1 year after surgery. Bilobectomy/pneumonectomy patients had the highest mMRC dyspnea grade among the three groups, but the difference was not statistically significant one year after surgery.ConclusionsAfter lung cancer surgery, pulmonary function and PROs noticeably decreased in the immediate post-operative period and improved thereafter, except for dyspnea and lack of energy. Proper information on the timeline of changes in lung function and symptoms following lung cancer surgery could guide patient care approaches after surgery.Trial registration: ClinicalTrials.gov; No.: NCT03705546; URL: www.clinicaltrials.gov

Estimation of an Exposure Threshold Value for Compensation of Silica-Induced COPD Based on Longitudinal Changes in Pulmonary Function.

(1) Background: To estimate the cumulative exposure to respirable crystalline silica (RCS) that reduces lung function to an extent corresponding with airway obstruction equivalent to chronic obstructive pulmonary disease (COPD). (2) Methods: The study is based on a miners’ cohort with longitudinal data on lung function and RCS exposure. Random-effects linear regression models, allowing for a possible threshold concerning the exposure concentration were used to analyze the impact of RCS on the ratio of forced expiratory volume in 1 s and forced vital capacity (FEV1/FVC). The proposed threshold is the amount of RCS resulting in a decrease in FEV1/FVC from the expected value to the lower limit of normal. (3) Results: The analysis shows that a threshold model fits the data significantly better than the usual linear model. The estimated threshold value for the exposure concentration is 0.089 mg/m3. Using this threshold, the estimate for the corresponding reference dose for RCS is 2.33 mg/m3·y. (4) Conclusions: The analysis confirmed that RCS has a negative impact on lung function. The effect is primarily due to exposure above a concentration threshold of 0.1 mg/m3. It is recommended that COPD should be compensated as an occupational disease if cumulative exposure was at least 2 mg/m3·y above this threshold.

A prospective cohort study of pulmonary function during pregnancy in women with and without asthma

Background and objective: Pregnancy alters the severity of asthma unpredictably. Uncertainty still exists about longitudinal changes in pulmonary function during pregnancy in both healthy and asthmatic women. This study aimed to compare pulmonary function changes during pregnancy in healthy and asthmatic women and to determine the relationship between pulmonary function and asthma-related quality of life during pregnancy. A secondary aim was to investigate the application of forced expiratory volume in 6 s (FEV6) for monitoring asthma during pregnancy. Methods: Pregnant women with (n = 20) and without asthma (n = 20) had pulmonary function tests at 8–20, 21–28 and 29–40 weeks gestation. Those with asthma also completed the Asthma Control Questionnaire (ACQ) and mini Asthma Quality of Life Questionnaire (mAQLQ) at each visit. Results: Pulmonary function declined in both groups at follow-up #1 (more markedly in those with asthma) but then improved at follow-up #2 (more markedly in those with asthma). In those with asthma, ACQ scores increased, while mAQLQ scores declined at follow-up #1; whilst at follow-up #2 these changes were in the opposite direction. FEV6 and forced vital capacity (FVC) were highly correlated (r = 0.88, p < 0.01) in asthmatics. Conclusions: Pulmonary function changes during second and third trimesters were more pronounced in asthmatics than in healthy women. FEV6 monitoring may assist pregnant women and their health professionals in optimizing asthma management. The changes in pulmonary function in women with asthma were not significantly associated with changes in asthma control or asthma-related quality of life.

TU‐A‐12A‐01: Consistency of Lung Expansion and Contraction During Respiration: Implications for Quantitative Imaging

Purpose:Four‐dimensional computed tomography (4DCT) can be used to evaluate longitudinal changes in pulmonary function. The sensitivity of such measurements to identify function change may be improved with reproducible breathing patterns. The purpose of this study was to determine if inhale was more consistent than exhale, i.e., lung expansion during inhalation compared to lung contraction during exhalation.Methods:Repeat 4DCT image data acquired within a short time interval from 8 patients. Using a tissue volume preserving deformable image registration algorithm, Jacobian ventilation maps in two scanning sessions were computed and compared on the same coordinate for reproducibility analysis. Equivalent lung volumes (ELV) were used for 5 subjects and equivalent title volumes (ETV) for the 3 subjects who experienced a baseline shift between scans. In addition, gamma pass rate was calculated from a modified gamma index evaluation between two ventilation maps, using acceptance criterions of 2mm distance‐to‐agreement and 5% ventilation difference. The gamma pass rates were then compared using paired t‐test to determine if there was a significant difference.Results:Inhalation was more reproducible than exhalation. In the 5 ELV subjects 78.5% of the lung voxels met the gamma criteria for expansion during inhalation when comparing the two scans, while significantly fewer (70.9% of the lung voxels) met the gamma criteria for contraction during exhalation (p = .027). In the 8 total subjects analyzed the average gamma pass rate for expansion during inhalation was 75.2% while for contraction during exhalation it was 70.3%; which trended towards significant (p = .064).Conclusion:This work implies inhalation is more reproducible than exhalation, when equivalent respiratory volumes are considered. The reason for this difference is unknown. Longitudinal investigation of pulmonary function change based on inhalation images appears appropriate for Jacobian‐based measure of lung tissue expansion.NIH Grant: R01 CA166703

Lung Function after Allogeneic Hematopoietic Stem Cell Transplantation in Children: A Longitudinal Study in a Population-Based Cohort

Reduction in pulmonary function (PF) has been reported in up to 85% of pediatric patients during the first year after hematopoietic stem cell transplantation (HSCT). Our understanding of the etiology for this decrease in lung function is, however, sparse. The aim of this study was to describe PF during follow-up in a population-based pediatric HSCT cohort and to investigate factors in the transplantation process associated with PF decline. A retrospective, population-based, single-center study of HSCT patients spanning 2 decades was performed. Longitudinal changes in PF over time and associations to transplantation-related factors were investigated using a mixed linear model. One hundred thirty patients were included in the longitudinal analysis and observed for a median (range) of 3.3 (.2 to 16.8) years, during which 1084 PF tests were performed. Sixty-two percent of the patients experienced a decline in lung function of more than 10% during the first 3 to 9 months after HSCT. The decline in forced expiratory volume in 1 second, forced expiratory volume in 1 second/forced vital capacity and diffusion capacity of the lung for carbon monoxide were strongly associated with acute graft-versus-host disease (GvHD). Other factors associated with PF decline were malignant diagnosis, busulfan-based conditioning, patient and donor age, female donor to male recipient, as well as chronic GvHD. Mild to moderate decline in PF is frequent and appears associated with acute GvHD and other parameters that are risk factors for chronic GvHD in children. This indicates that alloreactivity is central in pathogenesis of the decrease in PF that follows HSCT in children.

Chronic obstructive pulmonary disease and longitudinal changes in pulmonary function due to occupational exposure to respirable quartz

ObjectivesThe present study sought to examine the long-term effects of exposure to respirable quartz on pulmonary function with particular focus on chronic obstructive pulmonary disease (COPD).MethodsThe study is based on...

Longitudinal measures of lung function in infants with bronchopulmonary dysplasia

We previously demonstrated that infants with a history of bronchopulmonary dysplasia (BPD) exhibit airflow obstruction and air trapping. The purpose of this study was to assess longitudinal changes in pulmonary function in infants with a history of BPD over the first 3 years of life, and the relationship to somatic growth. Spirometry was measured using the raised volume rapid thoracoabdominal compression technique, and lung volumes measured by plethysmography. Eighteen infants (mean gestational age ± SD 27.3 ± 2.2 weeks, birthweight 971 ± 259 g) underwent two lung function studies. Average age at first test was 58.8 weeks. Spirometry demonstrated significant reductions in forced expiratory volume in 0.5 sec (FEV(0.5), 76.0 ± 15.9% predicted, Z-score -2.13 ± 1.69), forced expiratory flow at 75% of expired forced vital capacity (FEF(75), 54.8 ± 31.1%, -3.58 ± 2.73), and FEF(25-75) (67.8 ± 33.3%, -1.79 ± 1.76). Group mean total lung capacity (TLC) was in the low normal range (82.9 ± 13.5% predicted) and residual volume (RV)/TLC was mildly elevated (122.4 ± 38.2% predicted). Repeat testing was performed an average of 32.7 weeks after initial testing. At re-evaluation, group mean lung volumes and flows tracked at or near their previous values; thus, in general, there was a lack of catch-up growth. However, compared to infants with below average or average somatic growth (as represented by g/day), infants with above average growth showed significantly greater improvements in percent predicted FVC, FEV(0.5), TLC, and RV/TLC (all P < 0.05, ANOVA). We conclude that longitudinal measures of pulmonary function in infants and young children with BPD demonstrate significant airflow obstruction and modest restriction, which tends to persist with time. On the other hand, infants with above average somatic growth showed greater lung growth than their peers. Additional studies examining the effects of various nutritional regimens on lung function are warranted.

Longitudinal Changes in Pulmonary Function of Asbestos Workers

To observe the longitudinal changes in pulmonary function associated with exposure to asbestos in a group of highly exposed workers. Pulmonary diffusing capacity (DLco) and spirometry of 243 Chinese asbestos workers were measured and remeasured after 5 and 10 yr. Their annual changes in relation to cumulative asbestos exposure and asbestosis were determined using multivariate analysis. The greatest annual decline was observed in DLco, particularly in workers with asbestosis, followed by FVC and FEV(1). A greater decline in DLco accorded with a higher level of cumulative asbestos exposure. A similar trend was also seen in FVC, in which the highest exposure level was associated with 223 ml loss over each 5 yr period or 45 ml/yr. There were substantial declines in DLco and FVC over time in the asbestos workers, and a dose-response trend between asbestos exposure and accelerating functional loss.

Inhaled Cyclosporine and Pulmonary Function in Lung Transplant Recipients

Chronic rejection, manifesting as bronchiolitis obliterans, is the leading cause of death in lung transplant recipients. In our previously reported double-blinded, placebo-controlled trial comparing inhaled cyclosporine (ACsA) to aerosol placebo, the rate of bronchiolitis-free survival improved. However, an independent analysis of pulmonary function, a secondary endpoint of the trial, was not performed. We sought to determine the effect of ACsA, in addition to systemic immunosuppression, on pulmonary function. From 1998-2001, 58 patients were randomly assigned to inhale either 300 mg of ACsA (28 patients) or placebo aerosol (30 patients) 3 days a week for the first 2 years after transplantation. Longitudinal changes in pulmonary function of ACsA patients were compared to aerosol placebo patients. In another analysis, the rate of decline from 6-month maximum FEV(1) in randomized patients was compared to the rate of decline in patients receiving conventional immunosuppression from the Novartis transplant database (644 patients, 12 centers worldwide, transplanted from 1990-1995). The average duration of ACsA and aerosol placebo was 400 days +/- 306 and 433 +/- 256, respectively. The change in FEV(1) of ACsA patients (adjusted for Cytomegalovirus (CMV) mismatch and transplant type, followed for a maximum duration of 4.6 years) was superior to the aerosol placebo controls (9.0 +/- 71.4 mL/year vs. -107.9 +/- 55.3, p = 0.007). The FEF(25-75) decreased by -220.3 +/- 117.7 L/(second x year) vs. -412.2 +/- 139.2, p = 0.07, respectively. Similarly, percent FEV(1) decline from maximal values was improved in ACsA patients compared to aerosol placebo and Novartis controls (ACsA -0.43 +/- 1.12%/year vs. aerosol placebo -4.08 +/- 1.4, p = 0.04; ACsA vs. Novartis -4.7 +/- 0.31, p = 0.007). Single-lung recipients receiving ACsA showed improvement in FEV(1) compared to Novartis controls (FEV(1) -0.8 +/- 1.8%/year vs. -4.94 +/- 0.4, p = 0.03) but double-lung recipients showed improvement compared to aerosol placebo controls only (FEV(1) -0.28 +/- 1.22%/year vs. -8.53 +/- 5.95, p = 0.048). In this single center trial, ACsA appears to ameliorate important pulmonary function parameters in lung transplant recipients compared to aerosol placebo and historical control patients. Single- and double-lung transplant recipients may not respond uniformly to treatment, and ongoing randomized trials in lung transplant recipients using ACsA may help elucidate our findings.

Postnatal Changes in Pulmonary Mechanics and Energetics of Infants with Respiratory Distress Syndrome following Surfactant Treatment

Background: Postnatal alterations in pulmonary mechanics, energetics and functional residual capacity (FRC) describe the structural maturation of the preterm respiratory system. Objective: To evaluate longitudinal changes in pulmonary function in infants with respiratory distress syndrome (RDS) treated with oxygen, positive pressure ventilation and synthetic surfactant (Exosurf^®). Methods: Serial pulmonary function tests were performed in surfactant-treated infants [mean ± SD birth weight (BW) = 1,112 ± 276 g, gestational age (GA) = 29 ± 3 weeks] at postnatal ages: <3 days, 1, 2, 3, 4 and 6–8 weeks until term postmenstrual age (PMA). Tidal volume, pulmonary compliance (C_L), pulmonary resistance (R_T) and flow-resistive work were analyzed following simultaneous measurements of airflow and transpulmonary pressure signals. Serial FRC measurements were made in a randomly selected group. Results: Prior to 28 weeks’ PMA, C_L was unchanged irrespective of GA. At age 1 week the likelihood ratio (LR) for bronchopulmonary dysplasia (BPD) based on C_L, R_T and GA was predicted to be >90% for those with BW <750 g (LR >100) as compared to <10% probability (LR = 0.3) for infants >1,500 g. Significant linear increase in C_L to PMA was evident >28 weeks’ PMA (r = 0.86, p < 0.01) at 0.17 ml/cm H₂O/kg/week. By term PMA, mean C_L was 2.60 ± 0.07 ml/cm H₂O. Improvements in FRC of preterm infants with RDS who recovered occur at a more rapid rate (∼25 ml/kg) compared to those who developed BPD (∼20 ml/kg). Conclusions: Slow but incremental postnatal pulmonary improvement, minimal <28 weeks’ PMA, were comparable for all infants. Along with diminished FRC, these changes reflect persistent deleterious effects of positive pressure ventilation, alveolar hyperoxia and unrecognized pulmonary overdistension.

Measurement of Forced Expiratory Flows and Lung Volumes

After completing this article, readers should be able to: 1. Describe the information that measurements of forced expiratory flow can provide in spontaneously breathing and mechanically ventilated infants. 2. Delineate how lung volume can be measured. The measurements of forced expiratory flows and lung volumes are important to the evaluation of patients who have respiratory symptoms. Until recently, measurements have been restricted to adults and children old enough to cooperate with testing maneuvers. Newer techniques have enabled such measurements to be made in infants and led to improved understanding of normal lung and airway growth during infancy and early childhood, when dramatic changes occur. The measurements have had important clinical uses in the evaluation and treatment of infants who have respiratory disease, but their use has been limited because they require specialized equipment and expertise as well as sedation of the infant. In this article, we discuss the techniques required for measurement of forced expiratory flows and lung volumes, their limitations, and applications in clinical practice. Detection of airflow obstruction, by physical examination or by quantitative measurement techniques, is facilitated by increasing expiratory flow rates. Measurement of forced expiratory flows is useful because flow rates are inversely proportional to the fourth power of the radius of the airway and, therefore, are indicative of airway size when flow is limited. Disease states affecting the airways, including asthma, bronchopulmonary dysplasia (BPD), or congenital lesions such as pulmonary hypoplasia or vascular airway compression, are expected to decrease expiratory flow. Infants typically are sedated for testing to maintain relaxed breathing with a face mask placed over the mouth and nose. This sedation often is perceived by parents and physicians as one of the barriers to such testing. (1) However, sedation can be achieved safely using oral chloral hydrate at a dose of 80 to 100 mg/kg. …

Lung function over six years among professional divers

Aims: To analyse longitudinal changes in pulmonary function in professional divers and their relation with cumulative diving exposure. Methods: The study included 87 men at the start of their education...

Predictors of longitudinal changes in pulmonary function among swine confinement workers.

To determine predictors of longitudinal changes in pulmonary function in swine confinement workers. Longitudinal study conducted from November 1989 to June 1991 and January 1994 to May 1995. Swine confinement workers in Saskatchewan. Forty-two swine confinement workers who were studied in 1989/90 and studied again in 1994/95. Of 98 male swine confinement workers (mean age SD 36.3 11.1 years) studied at baseline, 42 were studied again five years following. Complete information on baseline across-shift pulmonary function (preshift forced expiratory volume in 1 s [FEV1], forced vital capacity [FVC], and every 2 h FEV1 and FVC during the shift), and five-year follow-up pulmonary function (with FEV1 and FVC) were available on all 42 subjects. Mean across-shift changes (preshift measurement to last measurement of the day) at baseline were -159. 8 61.7 mL in FEV1 and -35.3 65.6 mL in FVC. Mean annual rate change between baseline and follow-up for FEV1 was -53.9 61.7 mL/year and for FVC -48.9 71.6 mL/year. After adjusting for age, height, smoking and hours spent in the barn, the baseline across-shift change in FEV1 and FVC was a significant predictor of annual rate change in FEV1 (P=0.01) and FVC (P=0.02), respectively. To determine the effects of indoor air quality on longitudinal lung function decline, indoor air environmental measurements were analysed. Complete information on respiratory health and indoor air quality was available on 34 of the 42 subjects. Assessment of indoor environment of swine barns included a summer and winter measurement for airborne dust, gases and endotoxin levels. After adjusting for age, height, smoking, ammonia and hours spent in the barn, the endotoxin level (Eu/mg)was a significant predictor of annual rate change for FEV1 but not FVC. These results suggest that shift change is an important predictor of longitudinal changes in lung function in swine confinement workers and that endotoxin exposures may mediate annual decline in FEV1 in these workers.

Longitudinal Changes in Pulmonary Function Following Bone Marrow Transplantation

We prospectively followed a well characterized cohort of patients post-bone marrow transplantation for changes in pulmonary function. Thirty-four recipients without respiratory symptoms were available for follow up with a mean of two years. Spirometry and other measures of lung volume were well preserved following bone marrow transplantation. A progressive 11.9 percent decline in percent predicted diffusing capacity per year occurred. Age, cigarette smoking, type of cytoreductive therapy, type of GVHD prophylaxis, and the occurrence of AGVHD did not affect longitudinal changes in pulmonary function. Patients receiving transplants for CML developed a highly significant fall in diffusing capacity. Asymptomatic patients with CGVHD developed evidence of progressive obstructive ventilatory impairment. This suggests a subclinical spectrum of patients who may progress to the development of bronchiolitis obliterans and respiratory failure post-bone marrow transplantation.

Cross‐sectional and longitudinal changes in pulmonary function associated with automobile pollution among bridge and tunnel officers

This study investigated the effects of emissions from the internal combustion engine on pulmonary function and respiratory symptoms in men collecting tolls and directing traffic in areas with high levels of air pollution. Bridge and tunnel officers (BTOs) were administered pulmonary function tests and respiratory questionnaires for up to 11 consecutive years (n = 944). Carboxyhemoglobin levels were also measured. Regression coefficients on year tested were calculated on 466 individuals (49% of all BTOs) tested at least 3 years. The tunnel workers had significantly lower FEV1S (forced expiratory volume at one second) and FVCs (forced vital capacity), respiratory symptoms, and higher carboxyhemoglobin levels than the bridge workers. BTOs working over 20 years had the lowest mean pulmonary function values, the steepest slopes, and the most respiratory symptoms. We believe that the data show an association between working as a bridge and tunnel officer and decreased pulmonary function and increased respiratory symptoms, but it was not readily evident whether the effects were of clinical importance.