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PubMed1988

Pulmonary function in young and older athletes and untrained men.

This study compared the lung volumes and pulmonary functions of older endurance-trained athletes with those of healthy sedentary age-matched controls, young athletes, and young untrained men to determine whether training affects the age-associated changes in these variables. Despite large differences in maximal 02 consumption (VO2max), the older athletes and their sedentary peers had similar values for all pulmonary variables when expressed as absolute values. However, because the older athletes were shorter than the older sedentary men, their vital capacity, total lung capacity (TLC), and forced expiratory volume in 1 s were significantly larger than those of the older sedentary men when normalized for age and height; the average values for maximal voluntary ventilation and residual volume (RV) were also larger in the older athletes when normalized for age and height, but the differences were not significant. The young trained and untrained men did not differ in any of these measures. TLC was the only pulmonary variable that was the same in the young and older men; RV and the RV-to-TLC ratio were larger, whereas all other pulmonary function and volume measures were lower in the older men compared with the younger men. The older athletes were the only group whose lung volumes and pulmonary function measures were all, except for RV, substantially greater than expected based on their age and height. Thus prolonged strenuous endurance training in these older highly trained endurance athletes appears to have altered the decline in pulmonary function and volumes associated with aging.

Adult↗

PubMed1990

Effect of age on changes in flow rates and airway conductance after a deep breath.

The effects of aging on changes in maximal expiratory flow rates and specific airway conductance after a deep breath were evaluated in 64 normal subjects. Flow rates (Vp) on partial expiratory flow-volume curves (PEFV), initiated from 60-70% of the vital capacity (VC), were compared with those (Vc) on maximal flow-volume curves (MEFV), initiated from total lung capacity (TLC), at a lung volume corresponding to 25% of VC on the MEFV curves. Specific airway conductance was measured before (sGaw) and after a deep inspiration (sGawDI). Bronchodilation after inspiration to TLC was inferred by Vp/Vc less than 1 and sGaw/sGawDI less than 1. The mean Vp was less than Vc. However, the ratio Vp/Vc increased significantly with age (r = 0.75, P less than 0.001). Specific conductance also increased after a deep inspiration (sGaw less than sGawDI). The ratio sGaw/sGawDIj increased slightly but significantly with age (r = 0.28, P less than 0.02). Measurement of lung elastic recoil pressures before and after a deep breath in a subgroup of patients (n = 14) suggested that the age-related increase in Vp/Vc was secondary to a decrement in the ability of a deep breath to decrease the upstream airway resistance. These findings suggest that even though changes in airway size after a deep breath as measured by sGaw/sGawDI have minimal age dependence, aging diminishes expiratory flow rates of MEFV curves relative to PEFV curves because of a decrease in the ability of a deep breath to increase the size of the peripheral airways.

Adolescent↗

PubMed1994

Developmental pattern of hypercapnic and hypoxic ventilatory responses from childhood to adulthood.

The developmental pattern of ventilatory responses, through childhood and puberty into adulthood, is not known. Therefore we studied hypercapnic (HCVR) and hypoxic ventilatory responses (HOVR) in 59 subjects (29 males and 30 females) 4-49 yr of age, of whom 35 were children ( < 18 yr old). There was a significant correlation between HCVR and weight (r = 0.33, P < 0.02), vital capacity (r = 0.30, P < 0.05), and body surface area (r = 0.30, P < 0.05) but not height (r = 0.22, NS). There was no correlation between HOVR and any of the correcting factors. To account for disparities in body size, volume-related results were scaled for body weight. The HCVR corrected for weight (HCVR/WT) decreased with age (r = -0.57, P < 0.001). HCVR/WT was significantly higher in children than in adults (0.056 +/- 0.024 vs. 0.032 +/- 0.015 l.kg-1 x min-1. Torr end-tidal PCO2-1, P < 0.001). The (tidal volume/inspiratory duration)/weight, respiratory rate, and heart rate responses to hypercapnia were increased in the children, and the CO2 threshold was lower (36 +/- 5 vs. 40 +/- 6 Torr, P < 0.05). Similarly, the HOVR corrected for weight (HOVR/WT) decreased with age (r = 0.34, P < 0.05), and HOVR/WT was significantly higher in children than in adults (-0.035 +/- 0.017 vs. -0.024 +/- 0.016 l.kg-1 x min-1.% arterial O2 saturation-1, P < 0.02). The respiratory rate and heart rate responses to hypoxia were increased in the children. We conclude that rebreathing HCVR and HOVR are higher during childhood than during adulthood.

Adolescent↗

PubMed2000

Mechanisms for isolated volume response to a bronchodilator in patients with COPD.

We hypothesized that an altered effect of lung inflation on airway caliber may in part explain the isolated volume response to bronchodilators, i.e., an increase of forced vital capacity (FVC) without change in 1-s forced expiratory volume (FEV(1)). Small-airway caliber was measured by high-resolution computed tomography at functional residual capacity and total lung capacity in five chronic obstructive pulmonary disease patients with an isolated increase of FVC (FVC responders) and five with an increase of both FVC and FEV(1) (FVC-FEV(1) responders) after inhalation of salbutamol. In FVC-FEV(1) responders, the airway diameter increased with the cube root of increase in lung volume but was unchanged or even decreased in four of five FVC responders. FVC responders had more severe emphysema, as inferred from lung function and imaging studies, than FVC-FEV(1) responders. We speculate that longitudinal traction or space competition (Verbeken EK, Cauberghs M, and Van de Woestijne KP, J Appl Physiol 81: 2468-2480, 1996) are possible underlying mechanisms. We conclude that the isolated volume response to bronchodilators is associated with severe emphysema and likely results from an altered effect of lung inflation on airway caliber.

Administration, Inhalation↗

PubMed2002

Effect of gravity on chest wall mechanics.

Chest wall mechanics was studied in four subjects on changing gravity in the craniocaudal direction (G(z)) during parabolic flights. The thorax appears very compliant at 0 G(z): its recoil changes only from -2 to 2 cmH(2)O in the volume range of 30-70% vital capacity (VC). Increasing G(z) from 0 to 1 and 1.8 G(z) progressively shifted the volume-pressure curve of the chest wall to the left and also caused a fivefold exponential decrease in compliance. For lung volume <30% VC, gravity has an inspiratory effect, but this effect is much larger going from 0 to 1 G(z) than from 1 to 1.8 G(z). For a volume from 30 to 70% VC, the effect is inspiratory going from 0 to 1 G(z) but expiratory from 1 to 1.8 G(z). For a volume greater than approximately 70% VC, gravity always has an expiratory effect. The data suggest that the chest wall does not behave as a linear system when exposed to changing gravity, as the effect depends on both chest wall volume and magnitude of G(z).

Compliance↗

PubMed2006

The structural basis of airways hyperresponsiveness in asthma.

We hypothesized that structural airway remodeling contributes to airways hyperresponsiveness (AHR) in asthma. Small, medium, and large airways were analyzed by computed tomography in 21 asthmatic volunteers under baseline conditions (FEV1 = 64% predicted) and after maximum response to albuterol (FEV1 = 76% predicted). The difference in pulmonary function between baseline and albuterol was an estimate of AHR to the baseline smooth muscle tone (BSMT). BSMT caused an increase in residual volume (RV) that was threefold greater than the decrease in forced vital capacity (FVC) because of a simultaneous increase in total lung capacity (TLC). The decrease in FVC with BSMT was the major determinant of the baseline FEV1 (P < 0.0001). The increase in RV correlated inversely with the relaxed luminal diameter of the medium airways (P = 0.009) and directly with the wall thickness of the large airways (P = 0.001). The effect of BSMT on functional residual capacity (FRC) controlled the change in TLC relative to the change in RV. When the FRC increased with RV, TLC increased and FVC was preserved. When the relaxed large airways were critically narrowed, FRC and TLC did not increase and FVC fell. With critical large airways narrowing, the FRC was already elevated from dynamic hyperinflation before BSMT and did not increase further with BSMT. FEV1/FVC in the absence of BSMT correlated directly with large airway luminal diameter and inversely with the fall in FVC with BSMT. These findings suggest that dynamic hyperinflation caused by narrowing of large airways is a major determinant of AHR in asthma.

Adrenergic beta-Agonists↗

PubMedDate not supplied

Value of spirometry in detecting volume restriction in interstitial lung disease patients. Spirometry in interstitial lung diseases.

BACKGROUND: Restriction is a typical functional abnormality in interstitial lung disease (ILD) patients, but is not always present, especially in the early stage of the disease. The greater reduction of vital capacity (VC; %pred.) than total lung capacity (TLC; %pred.) is regarded as a typical pattern of lung function disturbances in ILD patients. STUDY OBJECTIVES: To explore the diagnostic value of spirometry in a detection restrictive pattern the relative volume loss assessed by TLC and VC in large series of patients with a diagnosis of ILD referred for lung function tests was evaluated. METHODS: Retrospective, cross-sectional analysis of pulmonary function data was done. The sampleconsisted of 1,173 patients with the diagnosis of different interstitial lung diseases investigated during a period of 5 years. Only patients without airway obstruction (normal FEV1%VC) were included. In all cases spirometry and whole body plethysmography were performed by experienced staff using MasterLab - 'Jaeger' equipment according to ERS standards. Reference values according to ERS guidelines were applied. RESULTS: The mean value of TLC expressed as %pred. was significantly (p < 0.001) lower than VC in all patients (93.7 +/- 18.6 vs. 98.0 +/- 21.4%pred.). The frequency of abnormal (lowered) TLC results was also higher than lowered VC (22.8 vs. 17.8%). Sensitivity of VC reached 69.3% and the positive predictive value was 88.5% in detecting volume restriction as compared to TLC measurement. CONCLUSION: The relative loss of TLC was greater than VC in our large group of patients. Measurement of TLC should be part of functional assessment of ILD patients, irrespective of whether they present or do not present a restrictive pattern in spirometry.

Adolescent↗

PubMed1981

Inhaled atropine sulfate in acute asthma.

We administered inhaled atropine sulfate to acute asthmatics already receiving therapeutic doses of adrenergic agonists, theophylline, and corticosteroids. Following atropine, hyperinflation diminished whereas vital capacity and expiratory flow rates breathing air and helium-oxygen increased (p less than 0.025 - p less than 0.005). Initial density dependence correlated inversely with changes in density dependence after atropine (r = -0.69, p less than 0.001). We conclude that: (1) inhaled atropine sulfate was effective therapy for acutely ill asthmatics already being treated with multiple antiasthmatic agents; (2) atropine caused large and peripheral airways bronchodilatation, and (3) the predominant site of bronchodilatation after atropine was related to the site of flow limitation before atropine.

Acute Disease↗

PubMed1986

Pulmonary function tests in the detection of left heart failure: correlation with pulmonary artery wedge pressure.

Standard pulmonary function tests, including lung volumes measured by three fundamentally different techniques, were performed in 40 patients undergoing cardiac catheterization. These were compared with clinical and radiologic evaluations in detecting left heart failure (LHF). Patients with elevation in mean pulmonary artery wedge pressure (PAWM) greater than or equal to 20 mm Hg had significant restrictive changes with reduction in vital capacity (VC), forced expiratory volume in 1 s (FEV1.0), and total lung capacity (TLC) measured by helium dilution and body plethysmography. Radiographic TLC was not reduced in these patients or correlated with PAWM. Obstructive changes were not present. Radiologic gradings by 5 different observers were reasonably accurate in detecting LHF but varied between observers. VC and TLC measured by helium dilution and body plethysmography were slightly less sensitive but more specific in detecting PAWM elevation. Clinical classification was sensitive but nonspecific; in addition, clinical signs were not reliable indicators of elevated PAWM. We conclude that pulmonary function testing may provide objective, accurate, and useful information in the evaluation of cardiac patients for LHF. However, radiographic measurement of thoracic cage volume does not reflect the changes in lung gas volume measured by gas dilution or plethysmographic techniques in patients with chronic congestive heart failure.

Adult↗

PubMed1997

Inspiratory maneuver effects on peak expiratory flow. Role of lung elastic recoil and expiratory pressure.

We investigated the effects of two different inspiratory maneuvers (fast or slow) on the ability of normal subjects to generate peak expiratory flows (PEF) and maximal dynamic expiratory pressures (Pexp) during the performance of a forced vital capacity maneuver. During the fast maneuver (F), the subject inspired rapidly to total lung capacity (TLC) and immediately performed a maximal expiration, whereas in the slow maneuver (S) the subject inspired slowly to TLC, paused for 4-5 s at TLC and then performed a maximal expiration. Ten normal subjects performed a series of such maneuvers. In addition to PEF and Pexp, we measured EMG activity of abdominal (EMGabd) and rib cage muscles, and lung elastic recoil pressure (PesL). Overall, F yielded higher PEF values than S (by approximately 7%); in addition, PesL, Pexp, rate of rise of Pexp (dPexp/dt), and EMGabd were similarly higher with F than with S (p < 0.05 for all). Analysis of individual data showed that the intermaneuver differences in PEF were largely explained by differences in PesL, Pexp or dPexp/dt. Our data suggest that, in comparison with the slow maneuver, the fast maneuver induces a greater change in both the lung elastic recoil and expiratory muscle activation which account for differences in PEF between the two maneuvers. The enhanced expiratory muscle activation with the fast maneuver suggests a specific inspiratory-expiratory muscle interaction analogous to agonist-antagonist interactions described for skeletal muscles.

Adult↗

PubMed1998

Lung volume reduction surgery and airflow limitation.

Interest has recently been renewed in lung volume reduction surgery (LVRS) for end-stage emphysema. However, numerous questions about its role in the treatment of emphysema remain, including the clinical characteristics of optimal candidates and its mechanism of improvement in pulmonary function. In this report, we develop a mathematical analysis and graphic depiction of the mechanism of improvement in expiratory airflow and vital capacity. This analysis is based on consideration of the interaction between lung function and respiratory muscle function. We also reexamine previously published pulmonary mechanics in patients with alpha1-antitrypsin deficiency, chronic obstructive pulmonary disease, and asthma. We find a major determinant of airflow limitation common to these diseases is the ratio of residual volume to total lung capacity (RV/TLC). Moreover, RV/TLC is found to be the single most important determinant of the improvement in pulmonary function after LVRS. Regardless of the specific underlying lung disease, the impairment of airflow is due primarily to mismatch between the sizes of the lung and the chest wall, and the effects of LVRS are almost exclusively due to improvement of that match. This analysis can be used to develop testable hypotheses to guide patient selection for this procedure.

Algorithms↗

PubMed1989

Intraindividual variability in serial measurements of DLCO and alveolar volume over one year in eight healthy subjects using three independent measuring systems.

To evaluate intraindividual and between-machine variability in DLCO, one technician performed triplicate measurement of DLCO in eight healthy subjects on three consecutive days using three different systems (Collins [C], Gould [G], SRL [S]) on five separate occasions over the course of 1 yr. For each subject and machine, we calculated the coefficient of variation (CV) of the DLCO and its associated alveolar volume (VA) and inspiratory vital capacity (IVC) over the five different measurement periods using the mean value for each period. CV (in %) for DLCO in each of the eight subjects for each machine varied from 2.4 to 7.1% for machine C, 4.1 to 10.5% for machine G, and 2.5 to 8.7% for machine S. Two-way ANOVA showed significant differences in CV for DLCO and IVC but not for VA across subjects (p less than 0.01) and for DLCO, VA, and IVC across machines (p less than 0.03): CV for DLCO was higher for G than for C or S; CV for VA and IVC was lower for C than for G or S. Multiple regression did not show a significant relationship between within-individual CV for DLCO and that for VA or IVC. We conclude that variability in DLCO measurements is affected by both subject and machine, but, at least in healthy cooperative subjects, it does not appear to be affected by variability in VA or IVC. For the average subject and the two less variable machines we tested, DLCO measurements could vary within the same subject as much as +/- 9.6% (two-tailed 95% confidence interval) with repeated measurements over 1 yr.

Adult↗

PubMed1990

Resting energy expenditure in interstitial lung disease.

Because interstitial lung disease increases the work of breathing, the aim of this study was to determine if this condition is associated with increased energy requirements. A group of 12 clinically stable patients with interstitial lung disease was studied. Patients with a history of weight loss had significantly more severe lung volume restriction. Regression analysis showed that 42% of body weight variation was explained by vital capacity (p less than 0.025). Resting energy expenditure was measured by standard methods of indirect calorimetry. The measurements were performed with a ventilated hood during prolonged steady-state periods after an overnight fast. We found that resting energy expenditure was increased to 117.3 and 118.7% of the predicted basal metabolic rate, according to Fleisch and to Harris and Benedict reference values, respectively (p less than 0.001). Furthermore, resting energy expenditure was increased to 120.8% of the predicted value according to body fat-free mass (p less than 0.001). This extra energy expenditure in patients with interstitial lung disease is similar to that recently reported in patients with chronic obstructive pulmonary disease.

Adult↗

PubMed1976

The effect of smoking cessation and modification on lung function.

The purpose of this study was to obtain more information about the effect on lung function of stopping smoking or of modifying the smoking habit and to determine the time course of change. We followed a group of 75 cigarette smokers who attended a smoking cessation clinic in May 1973, using a respiratory symptom questionnaire, spirometry, closing volumes, and the slope of the alveolar plateau of the single-breath nitrogen test. Subjects were tested before stopping smoking and at 1, 3, 6, and 12 months after the initial testing. We found a significant (P less than 0.05) improvement in closing volume as a percentage of vital capacity and closing capacity as a percentage of total lung capacity at 6 and 12 months and in the slope of the alveolar plateau at 1, 6, and 12 months in those who stopped smoking. There was also a dramatic decrease in respiratory symptoms in those who stopped smoking, a moderate decrease in those who reduced their consumption by at least 25 per cent, and very little change in those who did not appreciably modify their smoking consumption.

Adult↗

PubMed1979

Maximal expiratory flows after postural drainage.

Flows measured from maximal expiratory flow-volume (MEFV) curves were used to evaluate the efficacy of postural drainage in improving ventilatory function acutely. Maximal expiratory flow-volume curves were obtained for 9 cystic fibrosis subjects and 10 subjects with chronic bronchitis before and 5, 15, and 45 min after a 30-min session of postural drainage with percussion, vibration, and coughing. Forced vital capacity (FVC) was significantly increased 45 min after drainage for the combining group. Flows at high lung volumes were different for the 2 subgroups. Subjects with cystic fibrosis demonstrated a significant increase in peak expiratory flow rates 45 min after drainage and an increase in forced expiratory volume in one sec at all time intervals. The subjects with chronic bronchitis had a decreased peak expiratory flow rate 5 min after drainage, but by 45 min, it had returned to baseline. There was no significant change in one-sec forced expiratory volume at any time interval for the chronic bronchitis subgroup. Changes in flows at low lung volumes were similar for the 2 subgroups. Forty-five min after drainage there was an increase in flow rates near 50 per cent of FVC. Flows near 25 per cent of FVC were increased 15 and 45 min after drainage. This study demonstrated that postural drainage with coughing resulted in significant improvement in flows at low lung volumes. Changes in flows at high lung volumes were less consistent.

Adolescent↗

PubMed1986

The relationship between pleural pressures and changes in pulmonary function after therapeutic thoracentesis.

The purpose of this study was to determine whether changes in pulmonary function after therapeutic thoracentesis are related to the pleural pressure or to changes in pleural pressure during thoracentesis. Spirometry was obtained before and 24 h after thoracentesis in 26 patients. Pleural pressures were measured with a U-shaped manometer initially and after each 400-ml aliquot of pleural fluid was removed. Thoracentesis was continued until the patient developed severe symptoms (chest pain or coughing), the pleural pressure dropped below -20 cm H2O, or no more fluid could be obtained. The mean vital capacity improved 410 +/- 390 ml in this group of patients who had 1,740 +/- 900 ml fluid removed. The improvement in the VC most closely correlated with the pleural pressure after 800 ml fluid had been withdrawn (r = 0.57, p less than 0.005). The ratio of the improvement in the VC to the amount of fluid removed most closely correlated with the pressure change after 800 ml fluid had been removed (r = -0.43, p less than 0.05). From this study we conclude that the improvement in the FVC after therapeutic thoracentesis is small relative to the amount of fluid withdrawn. Patients with higher pleural pressures after the removal of 800 ml pleural fluid and patients with smaller decreases in the pleural pressure after removal of 800 ml pleural fluid have greater improvements in their pulmonary functions after thoracentesis.

Drainage↗

PubMed2002

Steroid treatment based on the findings of transbronchial biopsy in idiopathic interstitial pneumonia.

This study was performed to find the rationale for administering steroids to patients with idiopathic interstitial pneumonia (IIP), which was unlikely to be usual interstitial pneumonia (UIP) but was not surgically biopsied. Among IIP patients in the file of the departments, nine patients who met the following criteria were selected for this study ("non-UIP" group): 1) transbronchial lung biopsy showed dense mononuclear cell infiltration in thickened alveolar septa; 2) chest radiograph and computed tomography showed irregular linear, reticular or ground-glass opacities with alveolar consolidation without honeycombing in the lung base; and 3) spirometry was performed before and after steroid therapy. Ten patients with pathologically confirmed nonspecific interstitial pneumonia ("NSIP" group) were also selected for the comparison. Baseline values and percentage increase of vital capacity (VC) after steroid therapy were plotted. Steroids improved VC in both groups of patients. After 1 yr of steroid therapy, percentage increase of VC in "non-UIP" was 28.8+/-7.7%, which was not significantly different from that in NSIP (30.0+/-11.7%). One "non-UIP" patient and one NSIP patient died after 6.4 and 4.3 yrs of follow-up, respectively. Patients with idiopathic interstitial pneumonia presenting cellular interstitial pneumonia in transbronchial lung biopsy, in addition to radiographic findings not typical for usual interstitial pneumonia, could expect a beneficial effect of steroids without undergoing surgical biopsy.

Aged↗

PubMed2002

Pertechnegas lung clearance in different forms of interstitial lung disease.

Interstitial lung diseases (ILD) are characterized by an acute or chronic inflammation of the alveolar capillary membrane, which affects the permeability of this membrane. A possible way to measure the permeability of the membrane is by radionuclide aerosol imaging. Pertechnegas, a gas composed of technetium-labelled carbon particles, has recently been proposed as a new ventilation agent to measure this lung clearance. The clearance by pertechnegas in the four most common forms of ILD (eight patients with connective tissue disease, 10 with hypersensitivity pneumonitis, nine with idiopathic interstitial pneumonia and 10 with sarcoidosis) was measured and compared with 10 nonactive smoking controls. Because forced vital capacity (FVC), total lung capacity (TLC) and carbon monoxide diffusing capacity of the lung (DL,CO) are used in the assessment of functional severity of the ILD, the pertechnegas clearance was correlated with these lung-function indices. It was found that the time to half clearance of pertechnegas of the lung is significantly decreased in idiopathic interstitial pneumonia (p<0.0001), hypersensitivity pneumonitis (p=0.0005) and connective tissue disease (p=0.002) but not in sarcoidosis when compared with 10 nonsmoking controls. A significant correlation is also found between time to half clearance and FVC (r=0.76; p<0.0001), TLC (r=0.63; p<0.0001) and DL,CO (r=0.75; p<0.0001) for all groups together. For all subjects as a group, the time to half clearance is shorter in the upper lung zones than in the lower zones (p<0.0001) and the ratio between both zones is not significantly different between the different types of disease. These results indicate that pertechnegas clearance is increased in idiopathic interstitial pneumonia, hypersensitivity pneumonitis and connective tissue disease, but not in sarcoidosis and is related to the functional severity of the disease.

Adolescent↗