Measurement Of Static Lung Volumes Research Articles

Static lung volumes and diffusion capacity in adults 30 years after being diagnosed with asthma

BackgroundLong-term follow-up studies of adults with well-characterized asthma are sparse. We aimed to explore static lung volumes and diffusion capacity after 30 + years with asthma.MethodsA total of 125 adults with an objectively verified diagnosis of asthma between 1974–1990 at a Danish respiratory outpatient clinic completed a follow-up visit 2017–19. All participants (age range 44–88 years) completed a comprehensive workup and were, based on these assessments, classified as having either active asthma or being in complete remission. The examination program included measurements of static lung volumes and diffusion capacity.ResultsParticipants with active asthma were hyperinflated (residual volume/total lung capacity ratio 0.43, 95% CI 0.41—0.45) (RV/TLC ratio) compared with those in remission (RV/TLC ratio 0.38, 95% CI 0.36—0.41) (p < 0.03). A tendency towards higher diffusion capacity per liter lung volume was seen in participants with active asthma (KCO 100% predicted, 95% CI 97—104) compared with those in remission (KCO 94% pred., 95% CI 89—99) (P = 0.10). Longer asthma duration was associated with a higher KCO 0.47% pred./year (95% CI 0.14—0.80), adjusted for age and smoking. Patients on GINA step 4 and 5 treatment were more hyperinflated (Delta RV 14% pred., 95% CI 3—27) and had higher airway resistance (mean 53% pred., 95% CI 9—97) than participants on lower GINA steps. Patients with uncontrolled disease had substantially higher airway resistance (72% pred. 95% CI 20—124) than well-controlled patients.ConclusionThirty years after a confirmed diagnosis of asthma, those continuing to have active asthma and those having severe asthma, have higher diffusion capacity and more hyperinflation than patients in remission.

The bronchodilator test in patients with airway obstruction: the responsiveness of lung function parameters

Interpretation of bronchodilator (BD) test based on reaction of forced expiratory in one second (FEV 1). For assessing bronchodilator responsiveness of lung volumes, airway resistance remains largely unexplored. Therefore, we assessed the response of pulmonary function parameters to BD to reveal the most responsive parameter. 90 patients with chronic airway obstruction (61 male and 29 female; aged 55±11; post- BD FEV 1 was 63.1+18.3 % predicted) performed spirometry and static lung volume measurements before and after inhalation of BD. We calculated effect size (ES) for each parameter from the difference between two means divided by the standard deviation of baseline score. There was a significant increase both FVC and FEV 1by 8.2 and 12.3 % from baseline (p&lt;0.001). ES were 0.34 for FEV1 and 0.26 for FVC. The ES for lung volumes were from -0.07 (total lung capacity) to -0.31 (residual volume). The ES for sRtot (specific airway resistance) was -0.5 and ES for sGeff (specific effective airway conductance) was 0.95. The parameters of airway resistance and conductance were more responsive for the assessment of pulmonary function changes than spirometry and lung volumes parameters in patients with chronic airway obstruction.

Longitudinal lung function measurements in single lung transplant recipients with chronic lung allograft dysfunction

Phenotyping chronic lung allograft dysfunction (CLAD) in single lung transplant (SLTX) recipients is challenging. The aim of this study was to assess the diagnostic and prognostic value of longitudinal lung function tests in SLTX recipients with CLAD. A total of 295 SLTX recipients were analyzed and stratified according to native lung physiology. In addition to spirometry, measurements of static lung volumes and lung capacities were used to phenotype patients and to assess their prognostic value. Outcome was survival after CLAD onset. Patients with insufficient clinical information were excluded (n = 71). Of 224 lung transplant recipients, 105 (46.9%) developed CLAD. Time to CLAD onset (hazard ratio [HR]: 0.82, 95% CI: 0.74-0.90; p < 0.001), severity of CLAD at onset (HR: 0.97, 95% CI: 0.94-0.99; p = 0.009), and progression after onset of CLAD (HR: 1.03, 95% CI: 1.00-1.05; p = 0.023) were associated with outcome. Phenotypes at onset were bronchiolitis obliterans syndrome (BOS) (59.1%), restrictive allograft syndrome (RAS) (12.4%), mixed phenotype (6.7%), and undefined phenotype (21.9%). Survival estimates differed significantly between phenotypes (p = 0.004), with RAS and mixed phenotype being associated with the worst survival, followed by BOS and undefined phenotype. Finally, a higher hazard for mortality was noticed for RAS (HR: 2.34, 95% CI: 0.99-5.52; p = 0.054) and mixed phenotype (HR: 3.30, 95% CI: 1.20-9.11; p = 0.021) while controlling for time to CLAD onset and severity of CLAD at onset. Phenotyping CLAD in SLTX remains challenging with a high number of patients with an undefined phenotype despite comprehensive lung function testing. However, phenotyping is of prognostic value. Furthermore, early, severe, and progressive CLADs are associated with worse survival.

LONG-TERM RESPIRATORY OUTCOMES FOLLOWING PRETERM BIRTH

Preterm birth interrupts the normal development of the respiratory system. Taken together with the lung injury that can occur antenatally such as from chorioamnionitis or postnatally by interventions such as mechanical ventilation and oxygen therapy, survivors are at risk of developing long term deficits of their respiratory system. Decrements of lung spirometry have been regularly reported in those born preterm across all gestational ages. Those who develop chronic lung disease of prematurity (also called bronchopulmonary dysplasia) are the most affected, but lung function decrements are also seen in those born at later gestation of between 33 and 36 weeks, a population that generally does not require respiratory support in the neonatal period. Besides spirometry, many other techniques have been used to assess the status of the respiratory system including measurement of static lung volumes, airway resistance and compliance, bronchial hyperresponsiveness, diffusing capacity, exhaled nitric oxide and newer imaging techniques including hyperpolarised 3-helium magnetic resonance imaging. Discussed in this review are the findings from such methods to delineate the respiratory outcomes that occur after preterm birth.

Obstructive and restrictive pulmonary dysfunction in long-term lymphoma survivors after high-dose therapy with autologous stem cell transplantation

Background: Obstructive and restrictive dysfunction in long-term lymphoma survivors (LSs) after high-dose therapy with autologous stem-cell transplantation (HDT-ASCT) has not been addressed systematically previously.Material and methods: LSs treated in Norway 1987–2008 with HDT-ASCT who performed spirometry, measurement of static lung volumes and echocardiography 2012–2014 at either Oslo or St. Olavs University Hospitals was eligible. Smoking data were recorded by questionnaire. Treatment data were collected from medical records or hospital databases. Factors associated with obstructive and restrictive impairments (dichotomous outcomes) were examined by Poisson regression. Linear regression with the margins post-estimation command was used to derive adjusted mean values of forced expiratory volume in 1 s (FEV1). We used the normative reference data recommended by the European Respiratory Society for calculating percent predicted values.Results: A total of 226 LSs were studied, of whom 11.5 and 5.8% had obstructive and restrictive impairment, respectively. For women and men, mean FEV1 was 2.31 and 3.34 l corresponding to 11.4%- and 11.1%-points below that predicted from norms, respectively. In multivariable regression analyses, cumulative doxorubicin dose (400–775 mg/m2) and current smoking were associated with increased risk of obstructive impairment, and chest RT (>13–66 Gy) was associated with increased risk of restrictive impairment. Currently smoking LSs within the highest doxorubicin category (400–775 mg/m2), had the lowest adjusted mean FEV1.Conclusions: Despite intensive cancer treatment, our analysis showed modest reductions in obstructive parameters among long-term LSs after HDT-ASCT compared to normative reference data. To limit obstructive impairments in LSs after HDT-ASCT, we suggest that targeted smoking-cessation advice is directed towards patients who have received high cumulative doses of doxorubicin.

Pulmonary Function Standards: A Work in Progress

In this issue of Respiratory Care, a report by Borg and Thompson[1][1] examines an aspect of the measurement of static lung volumes according to recommendations in the 2005 American Thoracic Society (ATS)/European Respiratory Society (ERS) Standardisation of Lung Function Testing.[2][2]–[6][3] The

The Measurement of Lung Volumes Using Body Plethysmography: A Comparison of Methodologies

The statement of the American Thoracic Society and European Respiratory Society on the measurement of static lung volumes (SLV) suggests a preferred and alternate method for measuring and calculating SLV. To determine if differences in functional residual capacity (FRC), vital capacity (VC), residual volume (RV), and total lung capacity (TLC), obtained using preferred and alternate measurement and calculation methodologies, exist in a clinical setting. Patients attending for SLV at a hospital-based laboratory were recruited. Following spirometry, SLV was measured via body plethysmography, using the preferred and alternate methods in random order. Volumes were calculated using the preferred and alternate calculation methods. Subjects were classified according to standard ventilatory function interpretative strategies. Differences of the means between the measurement methods, and calculation methods were assessed. One hundred eight data sets were analyzed. Significant, but small differences (< 150 mL) in the means for VC and TLC, and RV and TLC were found in the normal and restricted groups, respectively. No significant differences in SLV parameters were found in subjects with air-flow obstruction. Twelve of the 108 changed ventilatory function classification between methods, with the alternate method delivering a lower inspiratory capacity and TLC without a change in RV in 66% of this subgroup. Identical results were obtained when data were analyzed using both calculation methods. Differences in FRC, VC, RV, and TLC obtained using the preferred and alternate measurement methodologies exist in the clinical setting in select classification groups and individuals. Differing calculation methods dependent on measurement method used may be unnecessary.

Underdiagnosis of Obstructive Airways Disease by Spirometry

PURPOSE: Spirometry is commonly utilized to diagnose obstructive airways defect(OAD). As per spirometric criteria OAD is defined as FEV1/FVC% < LLN based on NHANES III reference equations. However as per ATS/ERS 2005 interpretation strategy, OAD is diagnosed by low FEV1/ best VC (often SVC). Normally FVC > SVC in many patients with OAD because of dynamic airway collapse resulting in air-trapping and lung hyperinflation. This results in discrepant ratios with normal FEV1/FVC but reduced FEV1/SVC ratio. This results in missed diagnosis of OAD, if only FEV1/FVC is utilized for diagnosis. It is a standard practice to measure only FVC during spirometry. SVC is measured only during static lung volume measurements. To identify the prevalence of missed diagnosis of OAD, based on FEV1/FVC ratio during spirometry when compared to FEV1/ SVC during static lung volume measurements.

Explorations fonctionnelles respiratoires dans la bronchopneumopathie chronique obstructive

The diagnosis of chronic obstructive pulmonary disease (COPD) relies on the presence of chronic airflow limitation poorly reversible or not reversible at all, defined by an FEV1/FVC ratio less than 70%. Stages of severity of COPD are defined according to the level of post-bronchodilator FEV1: > 80% of the predicted value (stage I); 50-80% (stage II); 30-50% (stage III); < 30% (stage IV). Accordingly, the measurement of pulmonary volumes (spirometry) is required for the diagnosis but also for the follow-up of COPD patients. The investigations which are required depend on the severity of COPD: spirometry and flow-volume curves during forced expiration are sufficient in stage I; measurement of static lung volumes and bronchodilator reversibility testing are required in stage II. Arterial blood gases should be measured in stages III and IV. Pulse oxymetry and 6minute walk test (6MWT) are recommended from stage II. For appreciating the severity of COPD and for the follow-up of patients it is recommended to evaluate other variables than FEV1: results of the 6MWT, level of dyspnea, body mass index. The results of FEV1 and of these variables are included in the recently developed BODE index. Measurement of CO transfer capacity is recommended in the presence of emphysema; cardiopulmonary exercise testing (bicycle) is recommended before initiating exercise training.

Comparison of Lung Volume Measurements In Individuals With Spinal Cord Injury By Two Different Methods

Background/Objective: Few detailed studies have been performed among subjects with spinal cord injury (SCI) using whole body plethysmography for measurement of static lung volumes. Because abdominal gas volumes and respiratory patterns among subjects with varying Ieveis of SCI may differ significantly from able-bodied individuals, methodological concerns related to this technique could conceivably Iead to inaccuracies in lung volume measurements. The purpose of this study was to compare lung volume parameters obtained by whole body plethysmography with those determined by the commonly used nitrogen washaut technique among individuals with SCI.Participants: Twenty-nine clinically stable men, 14 with chronic tetraplegia (injury C4-C7) and 15 with paraplegia (injury below T5) participated in the study.Methods: Lung volumes were obtained using whole body plethysmography and the open-circuit nitrogen washout technique. Within both study groups, data were evaluated by the paired Student’st test and by determination of correlation coefficients.Results: No statistically significant differences for any lung volume parameter were found within either group. ln subjects with tetraplegia on paraplegia, respectively, strong correlation coefficients were found for measurements of totallung capacity (.8 6 and .97), functional residual capacity (.87 and .96), and residual volume (.77 and .85).Conclusion: These findings indicate that body plethysmography is a valid technique for determining lung volumes among subjects with SCI. Because airway resistance measurements can also be obtained du ring same study sessions for assessment of airway caliber and bronchial responsiveness, body plethysmography is a useful tool for examining multiple aspects of pulmonary physiology in this population.

Static Lung Volumes: Reference Values from a Latin Population of Spanish Descent

Background and Objectives: The aim of this study was to develop a set of prediction equations and 90% confidence intervals for static lung volumes using the multibreath helium equilibration method from a sample of asymptomatic Caucasian subjects of Spanish descent. Moreover, these equations were compared with those of previous studies. Methods: Measurements of static lung volumes using techniques recommended by the American Thoracic Society and the European Community for Steel and Coal were carried out on a selected sample of 591 healthy nonsmoking volunteers (305 men and 286 women) aged 18–88 years, living in the metropolitan area of Valencia, on the east coast of Spain. Multiple regression analysis using height, age and weight as independent variables were used to provide predicted values for both sexes. These reference values were compared with other sets of prediction equations reported in the literature using an independent sample of 69 subjects (32 men and 37 women). Results: Simple linear regression equations using age, height and body weight predicted all the subdivisions of lung volumes (vital capacity, expiratory reserve volume (ERV), inspiratory capacity, functional residual capacity (FRC), residual volume (RV), total lung capacity (TLC), FRC/TLC and RV/TLC) as well as more complex equational models. The distribution of residuals fulfilled the assumptions of multiple regression analysis (independence, homoscedasticity and Gaussian distribution of residuals), except for ERV, using simple linear models. The derived equations did not differ significantly from most of the previously reported equations and were usually superior in their ability to predict the lung volumes. Conclusions: The use of the present prediction equations is recommended in the Latin population of Spanish descent and in populations with similar Caucasian characteristics.

Lung Volumes in 4,774 Patients With Obstructive Lung Disease

To determine the correlates of static lung volumes in patients with airways obstruction, and to determine if static lung volumes differ between asthma and COPD. We examined the data from all of the adult patients (mean age of 69) who were referred to a pulmonary function laboratory from January 1990 through July 1994 with an FEV1/FVC ratio of < 0.70 and tested using a body plethysmograph. Correlates were determined using regression analysis. Of the 4,774 patients observed with evidence of airways obstruction, 61% were men. Self-reported diagnoses included asthma, 19%; emphysema or COPD, 23%; chronic bronchitis, 1.5%; and alpha1-antiprotease deficiency, 0.6%. Fifty-six percent of the patients did not report a respiratory disease. The degree of hyperinflation, as determined by the residual volume (RV)/total lung capacity (TLC) ratio, or the RV % predicted (but not the TLC % predicted), was strongly associated with the degree of airways obstruction (the FEV1 % predicted). Patients with moderate to severe airways obstruction and high RV and TLC levels were more likely to have COPD than asthma. Of the 1,872 patients with a reduced vital capacity determined by spirometry testing, 87% had hyperinflation as defined by the RV/TLC, and 9.5% had a low TLC (with less severe airways obstruction). In patients found to have airways obstruction by spirometry, the additional measurement of static lung volumes added little to the clinical interpretation.

Lung volumes and respiratory muscle strength in adult patients with childhood- or adult-onset growth hormone deficiency: effect of 12 months' growth hormone replacement therapy.

We have described impairment of the respiratory function in adult patients with childhood-onset growth hormone (GH) deficiency. The aim of the present study was to evaluate lung volumes and respiratory muscle strength in patients diagnosed as GH deficient before and after 6 and 12 months of recombinant GH treatment. Ten adults diagnosed as GH deficient in childhood, ten adults diagnosed as GH deficient in adulthood and ten healthy subjects entered the study. For each subject, evaluation of respiratory function followed the same standard approach, consisting of respiratory muscle strength assessment, record of flow-volume curves, measurement of static lung volumes and lung diffusing capacity. Childhood-onset GH-deficient patients had a significant reduction of maximal inspiratory (p < 0.01) and maximal expiratory (p < 0.05) mouth pressures. Total lung capacity, vital capacity and functional residual capacity were significantly reduced compared to healthy subjects (p < 0.05). Conversely, residual volume and diffusing lung capacity did not show any significant change. No significant change of the ratio between the percentage forced expiratory volume in 1 s and the forced vital capacity was observed. The decrease of respiratory mouth pressures was not correlated to the decrease of lung volumes. Adult-onset GH-deficient patients had only a significant reduction of maximal expiratory pressure compared to healthy subjects (p < 0.05). After 6 months of treatment no significant differences in any of the evaluated parameters were found. After 12 months of treatment patients with childhood-onset GH deficiency show a significant improvement of lung volumes (p < 0.01) and maximal respiratory mouth pressures (p < 0.005), whereas adult-onset GH-deficient patients show a significant improvement of maximal expiratory pressure (p < 0.05). In conclusion, the results of this study showed that adult patients affected with childhood-onset GH deficiency suffer from an impairment of the ventilatory function due to a reduction of lung volumes and a decrease of respiratory pressures probably due to a reduction of respiratory muscle strength. This impairment was reversed after 12 months of treatment with recombinant GH. Conversely, adult-onset GH-deficient patients had only an impairment of the maximal expiratory pressure, probably due to respiratory muscle weakness re-established after 12 months of GH therapy.

Impairment of lung volumes and respiratory muscle strength in adult patients with growth hormone deficiency

Little is known of the respiratory function in patients with growth hormone (GH) deficiency. The aim of the present study was to evaluate lung volumes and respiratory muscle strength in patients diagnosed as GH deficient in childhood. Ten patients diagnosed as GH deficient in childhood and ten healthy subjects entered the study. For each subject the evaluation of respiratory function followed the same standard approach, consisting of respiratory muscle strength assessment, recording of flow-volume curves, measurement of static lung volumes and lung diffusing capacity. Both maximal inspiratory and expiratory mouth pressures were decreased in GH deficiency. Vital capacity, N2 functional residual capacity and total lung capacity were significantly reduced when compared to healthy subjects. Conversely, the residual volume and diffusing lung capacity to CO did not show any significant change. No significant change of percentage forced expiratory volume in 1 s/forced vital capacity ratio was observed. The decrease of respiratory mouth pressures was not correlated to the decrease of lung volumes. In conclusion, the results of this study show that adult patients affected with childhood onset GH deficiency suffer from impairment of ventilatory function and a decrease of respiratory muscle pressures, probably due to reduction of respiratory muscle strength.

Can Concomitant Restriction Be Detected in Adult Men with Airflow Obstruction?

A reduction in lung volume is used to diagnose physiologic restriction in the pulmonary function tests of patients with lung disease. Airflow obstruction is commonly associated with hyperinflation of static lung volume. Because restriction and obstruction exert opposite effects on lung volumes, we questioned whether the lack of hyperinflation of static lung volumes could indicate the presence of concomitant restriction in patients with airflow obstructive ventilatory defects. To assess this, we evaluated by pulmonary function tests and chest roentgenograms of 58 patients with airflow obstruction (group 1), 18 of whom then sustained various types of resection for lung cancer (group 2) as a type of superimposed restriction. We selected 80 percent of predicted as the lower limit of "normal" frequently used by clinical pulmonary function laboratories. Despite a statistically significant decrease in total lung capacity (p less than 0.05) for the postpneumonectomy patients, when the static lung volume measurements of the patients with resection were evaluated, no one lung volume showed a consistent reduction sufficient to detect the superimposed restriction in all these patients. Using 80 percent of predicted as "normal," 61 percent of our patients with airflow obstruction and superimposed restriction would have been missed. We conclude that it is clinically difficult, based on only static lung volume measurements alone, to detect restriction superimposed on the hyperinflation of airflow obstruction unless these lung volumes are reduced to below accepted "normal" limits.

The Determination of Static Lung Volumes Report of the Section on Respiratory Pathophysiology

The measurement of static lung volumes in the course of pulmonary function testing facilitates the interpretation of the results obtained from the analysis of the forced vital capacity maneuver. It provides additional information regarding the mechanical properties of the ventilatory apparatus and the nature and extent of impairments in lung function.

Effects of neuromuscular blockade on respiratory mechanics in conscious man.

The effect of submaximal neuromuscular blockade (SMNB) on lung and chest wall mechanics was studied in six normal, awake subjects infused with pancuronium. Measurements of static lung volumes, specific airway conductance (sGaw), maximum expiratory and inspiratory flow-volume (MEFV, MIFV) curves, and static pressure-volume (PV) curves of the lung and of the relaxed chest wall were obtained after lung recoil pressure (Pst(L)) at full inflation had been reduced to 60 +/- 10% of control. Inspiratory capacity was decreased, but residual volume was not increased. Inspiratory PV curve of the lung was not modified, and the observed decrease in expiratory compliance and the slight increase in Pst(L) during deflation were compatible with the altered lung volume history. SMNB did not modify sGaw nor the relationship between Pst(L) and MEF; by contrast it markedly reduced MIF rates. Finally, SMNB transposed the chest wall PV curve to higher levels on the pressure axis (it decreased the outward pull of the chest wall) without greatly affecting its slope, and thereby it reduced the resting level of the respiratory system. We conclude that 1) muscle weakness per se does not affect the eleastic properties of the lungs and airways, and 2) involuntary respiratory muscle activity influences the elastic recoil of the chest wall. We believe this muscle activity originates from muscle spindles, and lies essentially in the inspiratory portion of the intercostal musculature.

Relationship of lung recoil to lung volume and maximum expiratory flow in normal children.

Thirty-one normal children, aged 6--18 yr, were studied by measurements of static lung volumes, static expiratory pressure-volume (PV) curves, and maximum expiratory flow-volume (MEFV) curves. A theoretical standard volume was used to compare children of differing size and this showed that total lung capacity (TLC) is also a valid standard volume. The shape of the PV curve was found to change so that static elastic recoil at a fixed proportion of TLC was higher in older than in younger children. This was also true of static recoil at functional residual capacity (FRC) and an associated increase in the ratio of FRC to TLC was interpreted as evidence for increase in outward recoil of the chest wall during childhood. Since static recoil at "closing capacity" (CC) remained constant, a decrease in the ratio of CC to TLC was quantitatively explained by the PV shift during childhood. Although maximum expiratory flow at various lung volumes increased in constant proportion to TLC, "upstream conductance" decreased relative to TLC. It was concluded that maturation of the respiratory system is disproportionate in several features during childhood and that these disproportions are likely to be even more prominent during infancy and early childhood.