Restrictive Lung Function Research Articles

Eventration of Right Hemidiaphrgm – A Post Covid -19 Infection Complication

Introduction and Significance: Diaphragmatic eventration is an uncommon disorder marked by partial or complete thinning of the diaphragm's muscle tissue. In this condition, the diaphragm, which is normally flexible and moves downward during inhalation, instead moves upward in a paradoxical manner. This abnormal movement leads to restricted lung function. The condition can be congenital or acquired, with acquired cases often resulting from trauma to the phrenic nerve, either from mechanical or surgical causes, compression by thoracic space-occupying lesions, or various infectious or inflammatory conditions impacting the phrenic nerve. Many individuals with this condition may remain asymptomatic for long periods, leading to frequent underdiagnosis. Clinical suspicion should prompt chest X-rays, and the diagnosis can be confirmed with chest computed tomography (CT).  Case Presentation: We report the case of a 65-year-old male who exhibited right-sided hemi-diaphragmatic eventration and experienced dyspnea over the past two years. The patient underwent a multilayer surgical plication of the right hemidiaphragm, which resulted in a successful outcome.  Clinical Discussion: The choice to proceed with surgical intervention for diaphragmatic eventration is influenced by the severity of associated complications. Patients who are symptomatic and exhibit compromised respiratory, cardiovascular, or gastrointestinal function generally require diaphragmatic plication.  Conclusion: Despite its rarity, diaphragmatic eventration is a condition that warrants careful evaluation by clinicians. Early detection and surgical intervention are key to managing and repairing this condition effectively.

Poor correlation between diaphragm ultrasound and invasive gold standard technique derived respiratory muscle strength assessment in patients after hospitalization for COVID-19.

Individuals who survive acute coronavirus disease 2019 (COVID-19) might experience diaphragm muscle weakness. Diaphragm ultrasound may be an easy-to-obtain bedside tool for determining diaphragm function. However, twitch transdiaphragmatic pressure (twPdi) following magnetic stimulation (MS) of the phrenic nerves is the gold standard for non-volitional assessment of diaphragm strength. This study investigated whether diaphragm thickening ratio (DTR) measured on diaphragm ultrasound reflects diaphragm strength as measured by twPdi following MS of the phrenic nerves or other (volitional) invasively obtained pressure values and could therefore be used to accurately diagnose diaphragm weakness. One year after discharge, 50 individuals (14 female, age 58±12 years) who had been hospitalised and treated for moderate-severe COVID-19 underwent standard spirometry and diaphragm ultrasound. TwPdi following cervical MS of the phrenic nerve and volitional inspiratory manoeuvres (Sniff and Mueller manoeuvre) were measured using oesophageal and gastric balloon catheters after transnasal placement. At follow-up, no clinically meaningful restrictive lung function impairment was evident on spirometry. On diaphragm ultrasound, diaphragm dysfunction, i. e. an impaired diaphragm thickening ratio was detected in 24% (12/50) of participants. An objective diagnosis of diaphragm dysfunction, defined as twPdi <16 cmH2O, was made in 60% (30/50) of participants. The measurement results of the two methods did not agree, given that there were many false negative, but also false positive results, so diaphragm ultrasound diagnosed in parts other patients with diaphragm dysfunction than TwPdi. Diaphragm ultrasound had a sensitivity of 26.67% and a specificity of 80.0% in the detection of diaphragm dysfunction (Positive predictive value 66.67%, negative predictive value 42.10%). Diagnosis of diaphragm weakness in individuals who have recovered from COVID-19 cannot be made accurately on diaphragm ultrasound (via DTR), but requires twPdi as the gold standard for assessment of diaphragm strength.

Experimental and modeling approaches to determine drug diffusion coefficients in artificial mucus

Asthma, usually characterized by inflammation and mucus accumulation, causes restricted airflow and impaired lung function. The physiological and biochemical characteristics of mucus pose a strong barrier for drugs administered orally or via the pulmonary route for asthma treatment. In this study, two drugs commonly employed in the treatment of asthma, theophylline and albuterol, were placed in contact with an artificial mucus layer, measuring their interface concentrations, and modeling the concentration profiles to determine their diffusion coefficients. To monitor the diffusion process, the upper surface of a mucus layer was placed in contact with the drug solutions and the lower mucus surface was in contact with a zinc selenide crystal to allow for time-resolved Fourier transform infrared spectroscopy (FTIR) measurements. FTIR spectra were collected at constant time intervals and monitored for quantitative changes in spectral peaks corresponding to functional groups specific to each of these drugs. Changes in peak heights were correlated to concentration via Beer's Law. Fick's 2nd Law of Diffusion was used along with Crank's trigonometric series solution for a planar semi-infinite sheet to analyze the concentration data and determine diffusion coefficients. Using this method, fitting the experimental data resulted in diffusivity coefficients of D = 6.56 x 10−6 cm2/s for theophylline and D = 4.66 x 10−6 cm2/s for albuterol through artificial mucus. The drug diffusivity coefficients align closely with literature reports, wherein, diffusivity data was obtained experimentally using a rotating-disk apparatus and intrinsic dissolution technique. By coupling analytical and experimentally determined drug diffusion data, this approach provides a fast, non-invasive method for quickly assessing drug diffusion profiles through complex media.

Analysis of Risk Factors and The Impact of Nitric Oxide (NO) and Carbon Monoxide (CO) Levels on Lung Function: A Comparative Study of Palm Oil Factory Workers and the Community in Kuantan Mudik District, Riau, Indonesia

Background: Air pollution, particularly from industrial sources like palm oil factories, poses a significant risk to respiratory health. This study aimed to investigate the impact of nitric oxide (NO) and carbon monoxide (CO) exposure on lung function in palm oil factory workers and compare it to the lung function of individuals in the surrounding community. Methods: A cross-sectional study was conducted in Kuantan Mudik District, Riau, Indonesia. One hundred palm oil factory workers with a minimum of two years of employment and 100 community members not occupationally exposed to NO and CO were recruited. Lung function was assessed using spirometry, and NO and CO levels were measured using specialized analyzers. Participants completed the European Community Respiratory Health Survey (ECRHS) questionnaire, and demographic and clinical data were collected. Statistical analyses included univariate, bivariate, and multivariate logistic regression. Results: Factory workers exhibited significantly higher levels of NO (p=0.000) and a higher prevalence of restrictive lung function (17%) compared to the community members (3%). Multivariate analysis identified NO exposure as the most significant risk factor for restrictive lung function (p=0.005). Each unit increase in NO was associated with a 1.12-fold increased risk of restrictive lung function. CO exposure, age, gender, smoking history, and the use of personal protective equipment (PPE) were not significantly associated with lung function impairment in this study. Conclusion: Occupational exposure to NO in palm oil factories is a significant risk factor for restrictive lung function impairment. Regular monitoring of NO levels and the implementation of effective control measures are crucial to protect the respiratory health of palm oil factory workers.

Individual and mixture analyses of the associations of phenols and phthalates with lung function among US adults

ABSTRACT The effects of endocrine disruptors including phenols and phthalates on adult lung function remain unclear. In the present study, data from 2007–2012 National Health and Nutrition Examination Survey (NHANES) were extracted, and 4338 participants were included in the final analyses. The associations of three phenols and four phthalate metabolites with six lung function parameters were investigated. In generalized linear regression models (GLM) and restricted cubic spline (RCS) analyses, bisphenol A (BPA) was associated with decreased forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC), and 2,5-dichlorophenol (DCP) was associated with reduced FEV1, FVC and peak expiratory flow rate (PEF), and increased prevalence of restrictive lung function (RLF) in adults. Furthermore, weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) models demonstrated that mixed exposures to phenols and phthalates were linked to reduced FEV1, FVC and PEF and increased prevalence of RLF, and these associations were mainly driven by BPA and 2,5-DCP. In conclusion, mixed exposure to phenols and phthalates was linked to compromised and a restrictive pattern of lung function. The mechanisms of the effects of phenol and phthalate exposures on lung function and respiratory diseases need to be further investigated.

Reduced sensitivity to thyroid hormones is associated with lung function in euthyroid individuals

BackgroundThe thyroid gland exhibits a subtle interconnection with the lungs. We further investigated the correlation between thyroid hormone sensitivity and lung function in euthyroid individuals. MethodsData on spirometry and mortality for participants aged 19–79 years were extracted from the NHANES database. Obstructive lung function was defined as a forced expiratory volume in 1 s to forced vital capacity ratio (FEV1/FVC) < 0.70, while restrictive lung function was considered when FEV1/FVC ≥0.70 and baseline FVC <80 % predicted. Central and peripheral sensitivities to thyroid hormones were mainly evaluated by Thyroid Feedback Quantile-based Index (TFQI) and Free Triiodothyronine/Free thyroxine (FT3/FT4) ratio. Logistic regression and subgroup analysis were used to examine potential associations between thyroid hormone sensitivity and lung function. The association between TFQI and all-cause mortality risk was also investigated. ResultsA total of 6539 participants were analyzed, 900 with obstructive lung function and 407 with restrictive lung function. The prevalence of impaired lung function, both obstructive and restrictive, increased with higher TFQI levels. Logistic regression analysis showed that increased TFQI and decreased FT3/FT4 levels were independent risk factors for obstructive and restrictive lung function (P < 0.05). After adjusting for the impact of lung function, TFQI (HR = 1.25, 95 % CI 1.00–1.56, P = 0.048) was an independent risk factor for all-cause mortality. ConclusionReduced sensitivity to thyroid hormones has been linked to impaired lung function. TFQI and FT3/FT4 are potential epidemiological tools to quantify the role of central and peripheral thyroid resistance in lung function.

Pulmonary Function and Diffusing Capacity of Carbon Monoxide in Hypersensitivity Pneumonitis: An Observational Study of 152 Patients.

Hypersensitivity pneumonitis (HP) is an inflammatory and/or fibrotic lung disease. The restrictive lung function with low diffusing capacity of carbon monoxide (DLCO) is common in interstitial lung diseases (ILD). There are limited data on pulmonary function test (PFT) in HP and its role for diagnosis is questionable. We analyzed the data of 152 HP patients for type of defect, lung volume, and DLCO. The present study is a retrospective analysis of 152 patients at one of the tertiary chest institutes in India. All diagnosed cases with at least spirometry were included. PFT findings were classified and graded as obstructive, restrictive, and mixed patterns. The correlation of PFT was calculated with disease duration and 6MWT distance. The majority were female [106 (70%)], with a mean age of 47.8 ± 12.3 years. Spirometry with lung volume data were available for 97% patients. PFT was abnormal in 118 (80%) cases. Among the patterns of abnormality, the most common type was restrictive (74%) followed by mixed (15%) and obstructive (11%) with the majority in the severe to very severe grade. The mean total lung capacity (TLC) and residual volume (RV) were reduced, with the grade more severe when the pattern of abnormality was restrictive while the RV/ TLC was higher suggestive of air tapping. DLCO data were available for 132 (87%) cases, with levels decreased in 67%. The severity of DLCO was highest when the pattern of abnormality was restrictive. One of the PFT parameters was abnormal in 137 (90%) cases, with isolated decreased DLCO levels seen in 16 (10%) cases. Forced vital capacity (FVC), TLC, and DLCO showed positive correlation with 6MWT distance (FVC r = .22, P = .02; TLC r = .28, P = .003; DLCO r = .30, P = .002). The PFT abnormality is seen in >80% of HP patients. All types of abnormality were seen, with the restrictive pattern being the most common. Isolated decreased DLCO levels were seen in 10% of cases. We advised to do full PFT for diagnosis and followup of HP.

Long term management of people with post-tuberculosis lung disease.

Post-tuberculosis lung disease (PTLD) is emerging as a significant area of global interest. As the number of patients surviving tuberculosis (TB) increases, the subsequent long-term repercussions have drawn increased attention due to their profound clinical and socioeconomic impacts. A primary obstacle to its comprehensive study has been its marked heterogeneity. The disease presents a spectrum of clinical manifestations which encompass tracheobronchial stenosis, bronchiectasis, granulomas with fibrosis, cavitation with associated aspergillosis, chronic pleural diseases, and small airway diseases-all persistent consequences of PTLD. The spectrum of symptoms a patient may experience varies based on the severity of the initial infection and the efficacy of the treatment received. As a result, the long-term management of PTLD necessitates a detailed and specific approach, addressing each manifestation individually-a tailored strategy. In the immediate aftermath (0-12 months after anti-TB chemotherapy), there should be an emphasis on monitoring for relapse, tracheobronchial stenosis, and smoking cessation. Subsequent management should focus on addressing hemoptysis, managing infection including aspergillosis, and TB-associated chronic obstructive pulmonary disease or restrictive lung function. There remains a vast expanse of knowledge to be discovered in PTLD. This review emphasizes the pressing need for comprehensive, consolidated guidelines for management of patients with PTLD.

The Effect of Ferritin Level on Respiratory Functions in Patients with β-Thalassemia Major

Introduction-Purpose β-thalassemia major (β-TM) is an autosomal recessive disorder caused by mutations in the β-globin gene of hemoglobin. The disease is characterized by splenomegaly due to ineffective erythropoiesis, iron accumulation signs in tissues as a result of increased iron absorption, bone expansion due to increased erythropoietic activity, and decreased tissue oxygenation. One of the effected organ can be the lungs due to excessive iron deposition in these patients. The current study aimed to investigate the effect of serum ferritin level, which is known as a marker of iron accumulation in tissues, on pulmonary function tests (PFT) in patients with β-TM. Methods and Materials Patients aged ≥6 years who were regularly followed in the pediatric hematology section of Mersin City Research and Training Hospital with a diagnosis of β-TM were included. All patients received regular blood transfusion and iron chelation therapy. Study participants underwent PFT prior to blood transfusion in the pediatric pulmonology section Results A total of 43 patients with β-TM were studied. Included patients were divided into two groups according to the mean annual ferritin level; low ferritin group if below 2000 ml/ng and high ferritin group if above 2000 ml/ng. The low ferritin group was consisted of 19 patients and the high ferritin group was consisted of 24 patients. The characteristics of these two groups are shown in Table 1. There were no statistical significance in age, gender, body mass index, age at diagnosis, mean annual hemoglobin, splenectomy, cardiac involvement and oxygen saturation among both groups, but the number of annual transfusion was significantly higher in the high ferritin group than lower ferritin group. When PFT parameters of both groups were compared, FVC (forced vital capacity) was statistically lower in the high ferritin group compared to the low ferritin group. Other parameters included FEV 1 (forced expiratory volume in 1 second), FEV 1/FVC ratio, PEF (peak expiratory flow) and FEF 25-75 (forced expiratory flow between 25% and 75% of vital capacity) were similar among groups. (Table 2) Discussion Patients with β-TM may accumulate iron in the interstitial area of the lungs which can lead fibrosis and impaired lung function over time. There are several studies investigated lung dysfunction and its etiology in these patients. Although the results of the studies are varied, the majority of them reported a restrictive pattern of respiratory dysfunction in thalassemia patients. Additionally, some studies showed the presence of mild or moderate obstruction in small airways and decrease in diffusion capacity with the increase of alveolar-capillary membrane thickness at advanced ages. In the present study, we found that patients with β-TM who had high ferritin level showed restrictive type lung function compared to those with low ferritin level. There were no difference among the groups in obstructive parameters (i.e. FEV 1, FEV 1/FVC, FEF 25-75) of PFT. In the literature, studies investigating PFT in patients with high ferritin levels had variable results, impaired or no change, in pulmonary status. In conclusion, loss of respiratory function and impaired tissue oxygenation in patients with β-TM may develop over time due to iron deposition in the interstitial area. PFT assessment of these patients is essential and recommended for the detection of early lung disease. Routine PFT follow in patients with β-TM of high ferritin values is highly important.

Radiological appearance and lung function six months after invasive ventilation in ICU for COVID-19 pneumonia: An observational follow-up study.

Respiratory functional sequelae in COVID-19 patients admitted to the intensive care unit for invasive ventilation are sparsely reported. The aim of this study was to investigate the radiological lung appearance, lung function and their association at 6 months after hospital discharge. It was hypothesized that the degree of pathological morphology on CT scans would correlate with lung function at the time of follow-up. In this single-centre prospective observational study, 86 from 154 patients admitted to ICU due to COVID-19 between March 2020 and May 2021 were followed up at 6 months post discharge with computed tomography (CT) of the chest and pulmonary function tests (PFTs). The PFT results were expressed as z-scores calculated as the difference between the measured and predicted values divided by the standard deviation obtained from a reference population. Correlations were evaluated by Spearman's rho including the 95% confidence interval. Pathological changes on CT were found in 78/85 participants with fibrous parenchymal bands being the most prevalent finding (91%) followed by traction bronchiectasis (64%) and ground glass opacities (41%). Sixty-five participants performed PFTs, and a restrictive pattern was the most prevalent abnormality (34%). Diffusing capacity of the lung for carbon monoxide (DLCO) was reduced in 66% of participants. The CT severity score weakly correlated with forced vital capacity (FVC) z-score (0.295, p = 0.006), DLCO z-score (-0.231, p = 0.032) and alveolar volume (VA) z-score (0.253, p = 0.019). Most patients showed persistent radiological abnormalities on CT and reduced lung volumes, impaired diffusion capacity and patterns of restrictive lung function at 6 months post discharge from the ICU. The correlations between abnormalities on CT and lung function tests were weak. Further, studies with a long-term follow-up of lung function in this group of patients are needed.

Association of lung function by spirometry with serum ferritin in transfusion-dependent thalassemia patients in a tertiary care centre

Background: β-thalassemia major is an inherited, transfusion-dependent chronic anemia which is caused by decreased production of β-globin chains required for formation of hemoglobin. Regular blood transfusion is most important factors that help in improving the survival of patients with TM; however, it leads to iron deposition in many organs such as lung. Most studied concerned about effect of iron on lung functions, revealed abnormalities, but limited data were observed. The aim of our study was to determine pulmonary function abnormalities in children with thalassemia major and assess the relation between these abnormalities and iron overload. Methods: This study had included 51 children in each group, aged between 6 and 18 years (28 males and 23 females) with TM. All included children were subjected to full clinical examination and laboratory investigations including complete blood counts and serum ferritin. Pulmonary function tests (PFTs) were assessed in all included children using spirometry. Results: 31.4% patients had restrictive lung functions. Spirometer parameters i.e., FEF25-75% (p value≤0.0001) and PEFR (%pred) (p value≤0.0001) had significant difference in both groups. FEF25-75% and PEFR had no effect of serum ferritin. Conclusions: The lung may be considered a site for organ damage, and alteration of pulmonary function may be expected in transfusion-dependent patients in spite of no pulmonary symptoms or normal chest X-ray.

Measuring Expiratory Diaphragm Activity: An Electrifying Tool to Guide Positive End-Expiratory Pressure Strategy in Critically Ill Children?

Measuring Expiratory Diaphragm Activity: An Electrifying Tool to Guide Positive End-Expiratory Pressure Strategy in Critically Ill Children?

Global, Race-Neutral Reference Equations and Pulmonary Function Test Interpretation

Race and ethnicity are routinely used to inform pulmonary function test (PFT) interpretation. However, there is no biological justification for such use, and it may reinforce health disparities. To compare the PFT interpretations produced with race-neutral and race-specific equations. In this cross-sectional study, race-neutral reference equations recently developed by the Global Lung Function Initiative (GLI) were used to interpret PFTs performed at an academic medical center between January 2010 and December 2020. The interpretations produced with these race-neutral reference equations were compared with those produced using the race and ethnicity-specific reference equations produced by GLI in 2012. The analysis was conducted from April to October 2022. The primary outcomes were differences in the percentage of obstructive, restrictive, mixed, and nonspecific lung function impairments identified using the 2 sets of reference equations. Secondary outcomes were differences in severity of these impairments. PFTs were interpreted from 2722 Black (686 men [25.4%]; mean [SD] age, 51.8 [13.9] years) and 5709 White (2654 men [46.5%]; mean [SD] age, 56.4 [14.3] years) individuals. Among Black individuals, replacing the race-specific reference equations with the race-neutral reference equations was associated with an increase in the prevalence of restriction from 26.8% (95% CI, 25.2%-28.5%) to 37.5% (95% CI, 35.7%-39.3%) and of a nonspecific pattern of impairment from 3.2% (95% CI, 2.5%- 3.8%) to 6.5% (95% CI, 5.6%-7.4%) and no significant change in the prevalence of obstruction (19.9% [95% CI, 18.4%-21.4%] vs 19.5% [95% CI, 18.0%-21.0%]). Among White individuals, replacing the race-specific reference equations with the race-neutral reference equations was associated with a decrease in the prevalence of restriction from 22.6% (95% CI, 21.5%-23.6%) to 18.0% (95% CI, 17.0%-19.0%), a decrease in the prevalence of a nonspecific pattern of impairment from 8.7% (95% CI, 7.9%-9.4%) to 4.0% (95% CI, 3.5%-4.5%), and no significant change in the percentage with obstruction from 23.9% (95% CI, 22.8%-25.1%) to 25.1% (95% CI, 23.9%- 26.2%). The race-neutral reference equations were associated with an increase in severity in 22.8% (95% CI, 21.2%-24.4%) of Black individuals and a decrease in severity in 19.3% (95% CI, 18.2%-20.3%) of White individuals vs the race-specific reference equations. In this cross-sectional study, the use of race-neutral reference equations to interpret PFTs resulted in a significant increase in the number of Black individuals with respiratory impairments along with a significant increase in the severity of the identified impairments. More work is needed to quantify the effect these reference equations would have on diagnosis, referral, and treatment patterns.

Combined pulmonary fibrosis and emphysema: A new horizon of smoker’s lung disease with obstructive and restrictive lung functions!

Combined pulmonary fibrosis and emphysema (CPFE) is underestimated chronic lung disease presenting with a combo of emphysema plus interstitial lung disease. CPFE is a heterogeneous lung disease documented usually in smokers which includes emphysema in the upper lobes and pulmonary fibrosis in the lower lobes. Although CPFE is commonly called as Smoker’s lung disease , a proportionate number of cases are having concurrent connective tissue disease. High-Resolution Computed Tomography (HRCT thorax) is a gold standard investigation to evaluate CPFE due less reliability of conventional chest radiography. Pulmonary hypertension and lung cancer are two comorbidities associated with poor outcome in CPFE. Echocardiography, diffusion coefficient, and body plethysmography have documented a role in composite assessment of CPFE. Combination of bronchodilators, oxygen supplementation during rest and ambulation in selected cases and antifibrotics is having a “game changer” role in the management of CPFE.

Poor Outcome and Mortality in Patients with Lower Lung-Dominant Sarcoidosis.

Pulmonary sarcoidosis predominantly affects the upper lung zones but sometimes affects the lower lung zones. We hypothesised that patients with lower lung zone-dominant sarcoidosis had lower baseline forced vital capacity, progressive restrictive lung function decline, and higher long-term mortality. We retrospectively reviewed clinical data including the pulmonary function tests of 108 consecutive patients with pulmonary sarcoidosis pathologically confirmed by lung and/or mediastinal lymph node biopsy from 2004 to 2014 from our database. Eleven patients (10.2%) with lower lung zone-dominant sarcoidosis were compared with 97 patients with nonlower lung zone-dominant sarcoidosis. The median age of the patients with lower dominance was significantly older (71 vs. 56, p = 0.0005). The patient with lower dominance had a significantly lower baseline percent forced vital capacity (FVC) (96.0% vs. 103%, p = 0.022). The annual change in FVC was -112 mL in those with lower dominance vs. 0 mL in nonlower dominance (p = 0.0033). Fatal acute deterioration was observed in three patients (27%) in the lower dominant group. Overall survival in the lower dominant group was significantly worse. Patients with lower lung zone-dominant sarcoidosis had an older age and lower baseline FVC with disease progression and acute deterioration associated with higher long-term mortality.

Pulmonary function in patients with transfusion-dependent thalassemia and its associations with iron overload

In patients with transfusion-dependent thalassemia (TDT), pulmonary function impairment has been reported but data are conflicting. Moreover, it remains unclear whether pulmonary dysfunction is associated with iron overload. This study aimed to evaluate the pulmonary function in patients with TDT and to investigate the associations between pulmonary dysfunction and iron overload. It was a retrospective observational study. 101 patients with TDT were recruited for lung function tests. The most recent ferritin levels (pmol/L) and the magnetic resonance imaging (MRI) measurements of the myocardial and liver iron status, as measured by heart and liver T2* relaxation time (millisecond, ms) respectively, were retrieved from the computerized medical records. Only data within 12 months from the lung function measurement were included in the analysis. The serum ferritin, and the cardiac and liver T2* relaxation time were the surrogate indexes of body iron content. The threshold of abnormality in lung function was defined as under 80% of the predicted value. 101 subjects were recruited with a mean age of 25.1 years (standard deviation (SD) 7.9 years). Thirty-eight (38%) and five (5%) demonstrated restrictive and obstructive lung function deficits, respectively. A weak correlation of FVC %Predicted and TLC %Predicted with MRI myocardial T2* relaxation time (rho = 0.32, p = 0.03 and rho = 0.33, p = 0.03 respectively) was observed. By logistic regression, MRI cardiac T2* relaxation time was negatively associated with restrictive lung function deficit (B − 0.06; SE 0.03; Odds ratio 0.94; 95% confidence interval (CI) 0.89–0.99; p = 0.023) after adjusting for age, sex and body mass index. Restrictive pulmonary function deficit was commonly observed in patients with TDT, and the severity potentially correlates with myocardial iron content. Monitoring of lung function in this group of patients, particularly for those with iron overload, is important.

Prevalence of restrictive lung function in children and adults in the general population

BackgroundRestrictive lung function (RLF) is characterized by a reduced lung expansion and size. In the absence of lung volume measurements, restriction can be indirectly assessed with restrictive spirometric patterns (RSP) by spirometry. Prevalence data on RLF by the golden standard body plethysmography in the general population are scarce. Therefore, we aimed to evaluate the prevalence of RLF and RSP in the general population by body plethysmography and to determine factors influencing RLF and RSP. MethodsPre-bronchodilation lung function data of 8891 subjects (48.0% male, age 6–82 years) have been collected in the LEAD Study, a single-centered, longitudinal, population-based study from Vienna, Austria. The cohort was categorized in the following groups based on the Global Lung Initiative reference equations: normal subjects, RLF (TLC < lower limit of normal (LLN)), RSP (FEV1/FVC ≥ LLN and a FVC < LLN), RSP only (RSP with TLC ≥ LLN). Normal subjects were considered those with FEV1, FVC, FEV1/FVC and TLC between LLN and ULN (upper limit of normal). ResultsThe prevalence of RLF and RSP in the Austrian general population is 1.1% and 4.4%. Spirometry has a positive and negative predictive value of 18.0% and 99.6% to predict a restrictive lung function. Central obesity was associated with RLF. RSP was related to smoking and underweight. ConclusionsThe prevalence of true restrictive lung function and RSP in the Austrian general population is lower than previously estimated. Our data confirm the need for direct lung volume measurement to diagnose true restrictive lung function.

Lung function decline preceding chronic respiratory failure in spinal muscular atrophy: a national prospective cohort study

BackgroundProgressive lung function decline, resulting in respiratory failure, is an important complication of spinal muscular atrophy (SMA). The ability to predict the need for mechanical ventilation is important. We assessed longitudinal patterns of lung function prior to chronic respiratory failure in a national cohort of treatment-naïve children and adults with SMA, hypothesizing an accelerated decline prior to chronic respiratory failure.MethodsWe included treatment-naïve SMA patients participating in a prospective national cohort study if they required mechanical ventilation because of chronic respiratory failure and if lung function test results were available from the years prior to initiation of ventilation. We analyzed Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 s (FEV1), Peak Expiratory Flow (PEF) and Maximum Expiratory Pressure (PEmax). We studied the longitudinal course using linear mixed-effects models. We compared patients who electively started mechanical ventilation compared to patients who could not be weaned after acute respiratory failure.ResultsWe analyzed 385 lung function tests from 38 patients with SMA types 1c–3a. At initiation of ventilation median age was 18.8 years (IQR: 13.2–30.1) and median standardized FVC, FEV1 and PEF were 28.8% (95% CI: 23.5; 34.2), 28.8% (95% CI: 24.0; 33.7) and 30.0% (95% CI: 23.4; 36.7), with an average annual decline of 1.75% (95% CI: 0.86; 2.66), 1.72% (95% CI: 1.04; 2.40) and 1.65% (95% CI: 0.71; 2.59), respectively. Our data did not support the hypothesis of an accelerated decline prior to initiation of mechanical ventilation. Median PEmax was 35.3 cmH2O (95% CI: 29.4; 41.2) at initiation of mechanical ventilation and relatively stable in the years preceding ventilation. Median FVC, FEV1, PEF and PEmax were lower in patients who electively started mechanical ventilation (p < 0.001).ConclusionsPatterns of lung function decline cannot predict impending respiratory failure: SMA is characterized by a gradual decline of lung function. We found no evidence for an accelerated deterioration. In addition, PEmax remains low and stable in the years preceding initiation of ventilation. Patients who electively started mechanical ventilation had more restrictive lung function at initiation of ventilation, compared to patients who could not be weaned after surgery or a respiratory tract infection.

Mortality and lung function decline in patients who develop chronic pulmonary aspergillosis after lung cancer surgery

BackgroundLung cancer surgery is reported as a risk factor for chronic pulmonary aspergillosis (CPA). However, limited data are available on its clinical impact. We aimed to determine the effect of developed CPA after lung cancer surgery on mortality and lung function decline.MethodsWe retrospectively identified the development of CPA after lung cancer surgery between 2010 and 2016. The effect of CPA on mortality was evaluated using multivariable Cox proportional hazard analyses. The effect of CPA on lung function decline was evaluated using multiple linear regression analyses.ResultsDuring a median follow-up duration of 5.01 (IQR, 3.41–6.70) years in 6777 patients, 93 developed CPA at a median of 3.01 (IQR, 1.60–4.64) years. The development of CPA did not affect mortality in multivariable analysis. However, the decline in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) were greater in patients with CPA than in those without (FVC, − 71.0 [− 272.9 to − 19.4] vs. − 10.9 [− 82.6 to 57.9] mL/year, p < 0.001; FEV1, − 52.9 [− 192.2 to 3.9] vs. − 20.0 [− 72.6 to 28.6] mL/year, p = 0.010). After adjusting for confounding factors, patients with CPA had greater FVC decline (β coefficient, − 103.6; 95% CI − 179.2 to − 27.9; p = 0.007) than those without CPA. However, the FEV1 decline (β coefficient, − 14.4; 95% CI − 72.1 to 43.4; p = 0.626) was not significantly different.ConclusionAlthough the development of CPA after lung cancer surgery did not increase mortality, the impact on restrictive lung function deterioration was profound.

Stratification in systemic sclerosis according to autoantibody status versus skin involvement: a study of the prospective EUSTAR cohort.

The current subclassification of systemic sclerosis into cutaneous subtypes does not fully capture the heterogeneity of the disease. We aimed to compare the performances of stratification into LeRoy's cutaneous subtypes versus stratification by autoantibody status in systemic sclerosis. For this cohort study, we assessed people with systemic sclerosis in the multicentre international European Scleroderma Trials and Research (EUSTAR) database. Individuals positive for systemic-sclerosis autoantibodies of two specificities were excluded, and remaining individuals were classified by cutaneous subtype, according to their systemic sclerosis-specific autoantibodies, or both. We assessed the performance of each model to predict overall survival, progression-free survival, disease progression, and different organ involvement. The three models were compared by use of the area under the curve (AUC) of the receiver operating characteristic and the net reclassification improvement (NRI). Missing data were imputed. We assessed the database on July 26, 2019. Of 16 939 patients assessed for eligibility, 10 711 patients were included: 1647 (15·4%) of 10 709 were male, 9062 (84·6%) were female, mean age was 54·4 (SD 13·8) years, and mean disease duration was 7·9 (SD 8·2) years. Information regarding cutaneous subtype was available for 10 176 participants and antibody data were available for 9643 participants. In the prognostic analysis, there was no difference in AUC for overall survival (0·82, 95% CI 0·81-0·84 for cutaneous only vs 0·84, 0·82-0·85 for antibody only vs 0·84, 0·83-0·86 for combined) or for progression-free survival (0·70, 0·69-0·71 vs 0·71, 0·70-0·72 vs 0·71, 0·70-0·72). However, at 4 years the NRI showed substantial improvement for the antibody-only model compared with the cutaneous-only model in prediction of overall survival (0·57, 0·46-0·71 for antibody only vs 0·29, 0·19-0·39 for cutaneous only) and disease progression (0·36, 0·29-0·46 vs 0·21, 0·14-0·28). The antibody-only model did better than the cutaneous-only model in predicting renal crisis (AUC 0·72, 0·70-0·74 for antibody only vs 0·66, 0·64-0·69 for cutaneous only) and lung fibrosis leading to restrictive lung function (AUC 0·76, 0·75-0·77 vs 0·71, 0·70-0·72). The combined model improved the prediction of digital ulcers and elevated systolic pulmonary artery pressure, but did poorly for cardiac involvement. The autoantibody-only model outperforms cutaneous-only subsetting for risk stratifying people with systemic sclerosis in the EUSTAR cohort. Physicians should be aware of these findings at the time of decision making for patient management. World Scleroderma Foundation.