Obstructive Ventilatory Defect Research Articles

Fractional exhaled nitric oxide distribution and its relevant factors in the general adult population and its healthy subpopulation

Measurement of fractional exhaled nitric oxide (Feno) has been used in the diagnosis and management of asthma. Understanding the distribution of Feno in a larger resident population and its "healthy" subpopulation would contribute to the interpretation of Feno in clinical practice. This study aimed to investigate the distribution and its associated factors in the adult population and its healthy subpopulations. We conducted a cross-sectional study of 8,638 men and 17,288 women aged 20 years or older living in Miyagi prefecture, Japan. We investigated the distribution of Feno and its associated factors in all subjects, a subpopulation with no history of upper and lower airway diseases (healthy subpopulation 1), and a subpopulation with no history of upper and lower airway diseases, normal lung function, and no positivity for other biomarkers of type 2 inflammation (healthy subpopulation 2). The distribution of Feno in healthy subpopulations, especially in healthy subpopulation 2 (median [interquartile range], 17 [12-23] with 95th percentile of 36 ppb) was lower than in all subjects (19 [13-26] ppb with 95th percentile of 47 ppb). In healthy subpopulation 1, 10.3% had elevated Feno (≥35 ppb), and elevated Feno was positively associated with factors including obstructive ventilatory defect, blood eosinophilia, house dust mite-specific IgE positivity, and history of hypertension. Male sex was associated with elevated Feno in all subjects and healthy subpopulations. The distribution of Feno in the healthy subpopulation supports the validity of the criteria (≥35 ppb) currently used in Japan for the diagnosis of asthma.

Case Report: Unusual pulmonary involvement in a patient with Costello syndrome

Costello syndrome (CS) is a rare disease with intellectual disability, characterized by failure to thrive, short stature, joint laxity, loose soft skin, and distinctive facial features. This disease is caused by heterozygous germline mutations in the HRAS proto-oncogene. Cardiac and neurological abnormalities are the most common. Cardiovascular manifestations include valvular pulmonary stenosis, arrhythmia and hypertrophic cardiomyopathy. Neurological manifestations are dominated by hydrocephalus, seizures, and tethered spinal cord. Respiratory system manifestations have been reported in people with CS, but a full description of the different lung involvement and respiratory symptoms in these patients is not available. We report the case of a 19-year-old non-smoking man, followed for a Costello syndrome since the age of 8 months, who complained of exertional dyspnea and chest pain for over 18 months. The chest CT scan showed bullous emphysema of the left lung with a giant bulla in the left upper lobe measured than 20 cm long axis responsible for passive atelectasis. Pulmonary function tests revealed a severe non-reversible obstructive ventilatory defect. Faced with the worsening of his dyspnea despite treatment with bronchodilators and recurrent respiratory infections, it was decided to surgically remove the the giant emphysematous bulla. After bullectomy, a clinical and functional respiratory improvement was noted.

Environmental pollutants increase the risks of acute exacerbation in patients with chronic airway disease.

Respiratory infections are a common cause of acute exacerbations in patients with chronic airway disease, however, environmental factors such as air pollution can also contribute to these exacerbations. The study aimed to determine the correlation between pollutant levels and exacerbation risks in areas exposed to environmental pollution sources. From 2015 to 2016, a total of 788 patients with chronic airway diseases were enrolled in a study. Their medical records, including hospital visits due to acute exacerbations of varying severity were analyzed. Additionally, data on daily pollutant levels from the Air Quality Monitoring Network from 2014 to 2016 was also collected and analyzed. Patients with chronic airway disease and poor lung function (FEV1 < 50% or obstructive ventilatory defect) have a higher risk of severe acute exacerbations and are more likely to experience more than two severe acute exacerbations within a year. The study found that in areas exposed to environmental pollution sources, there is a significant correlation between NO2, O3, and humidity with the main causes of severe acute exacerbation. When the levels of NO2 were higher than 16.65 ppb, O3 higher than 35.65 ppb, or humidity higher than 76.95%, the risk of severe acute exacerbation in patients with chronic airway disease increased. Acute exacerbations of chronic airway disease can be triggered by both the underlying disease state and the presence of air pollution. Computer simulations and early warning systems should be developed to predict acute exacerbations of chronic airway disease based on dynamic changes in air pollution.

Association of spirometric restriction with mortality in the silicotics: a cohort study

BackgroundRestrictive spirometry pattern (RSP), defined as reduced forced vital capacity (FVC) in absence of airflow obstruction (AFO), is associated with increased risk of mortality in general population. However, evidence in the patients with silicosis is limited. This study was aimed to investigate the relationship between RSP and the risk of death in a silicotic cohort.MethodThis retrospective cohort study used data from the Pneumoconiosis Clinic, Hong Kong Department of Health that containing 4315 patients aged 18–80 years and diagnosed with silicosis during 1981–2019, with a follow-up till 31 December 2019. Spirometry was carried out at the diagnostic examination of silicosis. Lung function categories were classified as normal spirometry (FEV1/FVC ≥ 0.7, FVC ≥ 80% predicted), RSP only (FEV1/FVC ≥ 0.7, FVC < 80% predicted), AFO only (FEV1/FVC < 0.7, FVC ≥ 80% predicted), and RSP&AFO mixed (FEV1/FVC < 0.7, FVC < 80% predicted). The hazard ratio (HR) and 95% confidence intervals (95% CI) were computed using a Cox proportional hazards model adjusting for age, body mass index, history of tuberculosis, smoking status, pack-years, and radiographic characteristics of silicotic nodules.ResultsAmong the 4315 patients enrolled in the study, the prevalence of RSP was 24.1% (n = 1038), including 11.0% (n = 473) with RSP only and 13.1% (n = 565) with mixed RSP and AFO. During the follow-up period, a total of 2399 (55.6%) deaths were observed. Compared with the silicotics with normal spirometry, those with RSP only had significantly increased risk of all-cause mortality (HR = 1.63, 95% CI 1.44–1.85) and respiratory-related mortality (HR = 1.56, 95% CI 1.31–1.85). Notably, a higher risk of mortality was observed in silicotics with mixed ventilatory defects of both RSP and AFO (all-cause mortality: HR = 2.22, 95% CI 1.95–2.52; respiratory-related mortality: HR = 2.59, 95% CI 2.18–3.07) than in those with RSP only.ConclusionRSP is significantly associated with increased risk of all-cause and respiratory-related mortality in the silicotics, and patients with mixed restrictive and obstructive ventilatory defect have higher risk of mortality than those with single RSP or AFO. These findings emphasize the importance of recognizing RSP in the occupational settings, especially for the silicotic patients with mixed ventilatory defect.

Home noninvasive ventilation use in patients hospitalized with COPD.

The study objective was to estimate the prevalence of chronic hypercapnic respiratory failure (CHRF) and home noninvasive ventilation (NIV) use in a high-risk population, individuals with a history of at least one COPD-related hospitalizations. We retrospectively analyzed electronic medical record data of patients with at least one COPD-related hospitalization between October 1, 2011, and September 30, 2017, to the Iowa City VA Medical Center. We excluded individuals with no obstructive ventilatory defect. Of 186 patients, the overall prevalence of compensated hypercapnic respiratory failure (CompHRF), defined as PaCO2 > 45 mmHg with a pH =7.35-7.45, was 52.7%, while the overall prevalence of home NIV was 4.3%. The prevalence of CompHRF was 43.6% and home NIV was 1.8% in those with one COPD-related hospitalization. Among those with ≥4 COPD-related hospitalizations, the prevalence of CompHRF was 77.8% (14 of 18), and home NIV was 11.1% (2 of 18). Approximately half of individuals with at least one COPD-related hospitalization have CompHRF, but only 8.2% of those use home NIV. Future studies should estimate CHRF rates and the degree of underutilization of home NIV in larger multicenter samples.

Relevance of serum levels of the endoplasmic reticulum stress protein GRP78 (glucose-regulated protein 78 kDa) as biomarker in pulmonary diseases

Cellular stress and inflammation contribute to the initiation and progression of a variety of pulmonary diseases. Endoplasmic reticulum (ER) stress and its main regulator GRP78 (glucose-regulated protein 78 kDa) appear to be involved in the pathogenesis of pulmonary diseases, and GRP78 was found to be a biomarker in a wide range of inflammatory diseases. The aim of this study was to investigate the relevance of serum GRP78 in pulmonary disorders.In this prospective cohort study, 78 consecutive patients with chronic obstructive pulmonary disease (COPD, n = 28), asthma (n = 38) or interstitial lung disease (ILD, n = 12) underwent measurement of serum GRP78 levels by ELISA.The mean age of patients was 59.8 ± 12.4 years, 48.7% were female. Patients with elevated GRP78 levels (> median) offered a significantly better oxygenation status (capillary pO2: 75.3 ± 11.7 mmHg vs. 67.8 ± 15.9 mmHg, p = 0.02). Significant correlations were observed between GRP78, on the one hand, and haemoglobin, high-sensitivity C-reactive protein (hs-CRP) and eosinophil counts, on the other hand (haemoglobin: Pearson’s r = −0.25, hs-CRP: r = 0.30, eosinophils: r = 0.63).Subsequently, we evaluated GRP78 measurements in function of severity stratifiers of the specific underlying pulmonary disease. ILD patients with a severe diffusion impairment (DLCO< 40% of predicted), exhibited a significant decrease in GRP78 levels (p = 0.01). In COPD and asthma, both characterized by obstructive ventilatory defects, a forced expiratory volume in one second (FEV1) <30% of predicted was accompanied by significantly lower GRP78 (p = 0.0075).In both obstructive and restrictive pulmonary disorders, GRP78 protein concentrations were reduced with increasing disease severity. These data suggest a prevalent role of GRP78 in the presently studied pulmonary disorders.

Respiratory muscle metabolic activity on PET/CT correlates with obstructive ventilatory defect severity and prognosis in patients undergoing lung cancer surgery.

Respiratory muscle activity is increased in patients with chronic respiratory disease. 18 F-FDG-PET/CT can assess respiratory muscle activity. We hypothesized that respiratory muscles metabolism was correlated to lung function impairment and was associated to prognosis in patients undergoing lung cancer surgery based on the research question whether respiratory muscle metabolism quantitatively correlates with the severity of lung function impairment in patients? Does respiratory muscle hypermetabolism have prognostic value? Patients undergoing 18 F-FDG-PET/CT and pulmonary function tests prior to lung cancer surgery were identified. Maximum Standardized Uptake Value (SUVm) were measured in each respiratory muscle group (sternocleidomastoid, scalene, intercostal, diaphragm), normalized against deltoid SUVm. Respiratory muscle hypermetabolism was defined as SUVm >90th centile in any respiratory muscle group. Clinical outcomes were collected from a prospective cohort. One hundred fifty-six patients were included, mostly male [110 (71%)], 53 (34%) with previous diagnosis of COPD. Respiratory muscle SUVm were: scalene: 1.84 [1.51-2.25], sternocleidomastoid 1.64 [1.34-1.95], intercostal 1.01 [0.84-1.16], diaphragm 1.79 [1.41-2.27]. Tracer uptake was inversely correlated to FEV1 for the scalene (r=-0.29, p < 0.001) and SCM (r=-0.17, p=0.03) respiratory muscle groups and positively correlated to TLC for the scalene (r=0.17, p=0.04). Respiratory muscle hypermetabolism was found in 45 patients (28.8%), who had a lower VO2 max (15.4 [14.2-17.5] vs. 17.2 mL/kg/min [15.2-21.1], p=0.07) and poorer overall survival when adjusting to FEV1% (p < 0.01). Our findings show respiratory muscle hypermetabolism is associated with lung function impairment and has prognostic significance. 18 F-FDG/PET-CT should be considered as a tool for assessing respiratory muscle activity and to identify high-risk patients.

Morphological Characteristics and Pulmonary Function of Naval Saboteurs and Ground Special Forces of the Armed Forces of Montenegro

The results of numerous medical and kinesiological studies indicate the existence of differences in pulmonary function in relation to age, body height, and the relationship between certain parameters of body composition. The aim of this study was to determine the state of morphological characteristics and pulmonary function of naval saboteurs and ground Special Forces of the Armed Forces of Montenegro. The sample of participants included 30 naval saboteurs aged 30.3±6 years and 30 members of the ground special forces aged 25.6±5 years. The sample of measuring instruments included 4 indicators each for the evaluation of longitudinal dimensionality, transversal dimensionality, mass and body volume, subcutaneous fat, body composition, and pulmonary function. The central and dispersion parameters of the variables were calculated. The specificities of body composition of the naval saboteurs and members of the ground Special Forces of the AF of Montenegro were determined, while the parameters of lung volume and capacity and the parameters of airway flow indicated an excellent state of their respiratory function. Furthermore, it was determined that the studied members of the armed forces had no individual health risks in the sense of the onset of obesity or obstructive ventilatory defects. The results obtained indicate the need for further studies which would predominantly focus on the impact of individual morphological measurements and parameters of body composition on pulmonary function. This would provide important data both for the armed forces in the sense of improving the training system and the realization of specific tasks, as well as for kinesiology as a science from the aspect of determining certain regularities in the functioning of the human body in specific living and working conditions in the armed forces.

Nocturnal continuous positive airway pressure offers symptomatic benefit in excessive dynamic airway collapse despite normal sleep study.

Excessive dynamic airway collapse (EDAC) and tracheobronchomalacia (TBM) cause debilitating symptoms yet are often misdiagnosed as asthma or chronic obstructive pulmonary disease (COPD). EDAC/TBM should be considered in all cases of obstructive ventilatory defect refractory to medical management. Diagnosis is made with flexible bronchoscopy and/or inspiratory and expiratory phase computed tomography (CT) scans. Treatment should be individualised and "pneumatic stenting" with the use of continuous positive airway pressure (CPAP) may lead to symptomatic relief, and in some cases regardless of the degree of collapse or absence of sleep disordered breathing in overnight oximetry. The case of a 63-year-old female referred to a tertiary respiratory department for a trial of CPAP due to EDAC is presented. Over the course of a few months, she had presented frequently to hospital with cough and shortness of breath which had been attributed to asthma. As she had not responded to treatment, an inpatient flexible bronchoscopy was performed which identified EDAC of the right main bronchus and she was referred to a tertiary ventilation department. Despite a normal sleep study whilst self-ventilating, nocturnal CPAP therapy significantly improved quality and duration of sleep, daytime symptoms and therefore quality of life. She was discharged with nocturnal CPAP and remains adherent to treatment.

Impact of preheart transplant spirometry and DLCO measurement on post-transplant pulmonary outcomes

Pulmonary function tests (PFT) are a frequent component of heart transplant evaluation. In cardiac surgery abnormal PFTs, especially reduced DLCO, have been associated with poor outcomes. We sought to evaluate the impact of pretransplant PFTs on post-transplant pulmonary outcomes and patient survival. Among the 652 adult heart transplant recipients between January 1, 2010 and July 31, 2021, 462 had PFTs and constituted the patient cohort. Obstructive ventilatory defects (OVD), restrictive ventilatory defects (RVD), and reduced DLCO were defined according to established criteria. The primary outcome was the combined endpoint of a post-transplant pulmonary complication defined as reintubation, postoperative pneumonia, prolonged intubation, or tracheostomy. Secondary outcomes included 90-day all-cause mortality, length of stay, and the odds of individual pulmonary complications. Kaplan-Meier survival analysis, multivariable Cox proportional-hazards regression, and multivariable logistic regression were performed to compare outcomes between the groups. Patients with severe OVD (OR 1.48, 95% CI 1.18-5.23, p=0.02) or severely reduced DLCO (OR 1.95, 95% CI 1.19-3.20, p=0.008) had increased odds of post-transplant pulmonary complications. Following multivariable adjustment, severe OVD (aOR 2.67, 95% CI 1.15-6.19, p=0.02) and severely reduced DLCO (aOR 1.79, 95% CI 1.05-3.04) remained strongly associated with post-transplant pulmonary complications. Patients with any degree of extrinsic RVD, moderate or less OVD, or moderately reduced DLCO or less did not have increased odds of post-transplant pulmonary complications. Ninety-day post-transplant survival was significantly reduced for both severe OVD (97.2% vs 86.5%, p=0.04) and severely reduced DLCO (97.3% vs 90.4%, p=0.004). Post-transplant ICU and hospital length of stay were nominally longer for both groups as well. Severe OVD or severely reduced DLCO on preheart transplant PFTs were associated with increased odds of post-transplant pulmonary complications and early mortality.

Tracheobronchial Compression by Right-sided Aortic Arch in a Middle Aged Male

Exertional dyspnoea is a common symptom among middle-aged population. Diagnostic evaluation of such patients is often challenging and confusing. We report a patient presenting with exertional dyspnoea and an obstructive ventilatory defect on spirometry that was refractory to bronchodilator therapy. Careful review of the chest radiograph and spirometry pointed towards variable intra-thoracic airways obstruction as a cause of dyspnoea. Contrast enhanced computed tomography (CECT) of the thorax and bronchoscopy established the diagnosis of a right-sided aortic arch resulting in tracheobronchial compression and tracheomalacia.

Lung function impairment and risk of incident heart failure: the NHLBI Pooled Cohorts Study.

The aim is to evaluate associations of lung function impairment with risk of incident heart failure (HF). Data were pooled across eight US population-based cohorts that enrolled participants from 1987 to 2004. Participants with self-reported baseline cardiovascular disease were excluded. Spirometry was used to define obstructive [forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.70] or restrictive (FEV1/FVC ≥0.70, FVC <80%) lung physiology. The incident HF was defined as hospitalization or death caused by HF. In a sub-set, HF events were sub-classified as HF with reduced ejection fraction (HFrEF; EF <50%) or preserved EF (HFpEF; EF ≥50%). The Fine-Gray proportional sub-distribution hazards models were adjusted for sociodemographic factors, smoking, and cardiovascular risk factors. In models of incident HF sub-types, HFrEF, HFpEF, and non-HF mortality were treated as competing risks. Among 31 677 adults, there were 3344 incident HF events over a median follow-up of 21.0 years. Of 2066 classifiable HF events, 1030 were classified as HFrEF and 1036 as HFpEF. Obstructive [adjusted hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.07-1.27] and restrictive physiology (adjusted HR 1.43, 95% CI 1.27-1.62) were associated with incident HF. Obstructive and restrictive ventilatory defects were associated with HFpEF but not HFrEF. The magnitude of the association between restrictive physiology and HFpEF was similar to associations with hypertension, diabetes, and smoking. Lung function impairment was associated with increased risk of incident HF, and particularly incident HFpEF, independent of and to a similar extent as major known cardiovascular risk factors.

Impact of Pre-Heart Transplant Pulmonary Function Tests on Post-Transplant Pulmonary Outcomes

<h3>Purpose</h3> Pulmonary function tests (PFT) are a component of heart transplant (HT) evaluation. In cardiac surgery, abnormal PFTs, especially reduced DLCO, are associated with poor outcomes. We sought to evaluate the impact of pre-HT PFTs on post-HT pulmonary outcomes. <h3>Methods</h3> We retrospectively reviewed 235 consecutive HT recipients and collected pre-HT data including PFTs. PFT patterns were classified according to ATS/ERS standards (Severe restrictive ventilatory defect (RVD): [FEV1/FVC≥70%, FVC<80% & FEV1<50%], Severe obstructive ventilatory defect (OVD): [FEV1/FVC<70% & FEV1<80%]). The combined endpoint included reintubation, prolonged intubation (greater than 5 days), tracheostomy, or post-HT treated pneumonia. <h3>Results</h3> 151 patients had pre-HT PFT data. The mean age was 55±12 years, 75% were male, 59% were bridged with a LVAD, and 52% were former smokers. 28 patients (18%) had normal PFTs, 81 (53%) had RVD (10 severe), and 42 (29%) had OVD (10 severe). Among 136 patients with DLCO data, 30 (22%) had a severely reduced DLCO (<40% predicted). Overall, 37 patients (24.5%) experienced an adverse pulmonary event. Among those with severely reduced DLCO, 40% met the combined endpoint (vs 23.6% with mild-moderate DLCO reduction, P=0.07). Among the 10 patients with severe OVD, 6 (60%) experienced the combined endpoint (vs. 31.3% of those with mild-moderate OVD p=0.14). 40% with severe RVD experienced the combined endpoint (vs. 22% with mild-moderate RVD, p=0.20). Those with severe lung disease (OVD, RVD, DLCO) had a 3.1 fold increased odds of post-HT pulmonary complications (95% CI 1.2-8.0, p=0.03). Similarly, post-HT ICU length of stay was significantly longer 16.2±19.9 vs. 7.3±8.6 days (p=0.03) and 90 day survival was significantly reduced 66.7% vs. 94.7, p=0.002 (Figure). <h3>Conclusion</h3> Severe abnormalities of pre-HT PFTs are associated with increased odds of post-HT pulmonary complications, ICU length of stay, and 90 day mortality. Severely reduced DLCO seems to be the strongest predictor among PFT variables.

Prevalence of a decreased FEV3/FEV6 ratio in symptomatic smokers with preserved lung function

BackgroundThe ratio of forced expiratory volume in 3 seconds to forced expiratory volume in 6 seconds (FEV3/FEV6) has been proposed as an index of peripheral airway disease, and could be decreased in patients at risk for COPD. However, the prevalence of FEV3/FEV6 decrease has never been assessed in patients attending a pneumology clinic. Here we set out to assess the prevalence of a decreased FEV3/FEV6 in smokers with symptoms of chronic bronchitis, and to test its predictive value for COPD diagnosis. MethodsWe performed a retrospective analysis of databased pulmonary function tests (PFTs) for smokers and ex-smokers aged >40 years old, with symptoms of chronic bronchitis and a normal FEV1/FVC ratio. Clinical data were retrieved from the hospital records. Patients presenting with clinical conditions liable to interfere with PFT results were excluded. For those included, we controlled for onset of an obstructive ventilatory defect 1 year later. ResultsThe dataset included 67 patients (median age: 64 years [interquartile range: 53–72], 61% current smokers). FEV1/FVC was above lower limit of normal but lower than 0.7 in 18 patients (27%). FEV3/FEV6 was decreased below the lower limit of normal in 45 patients (67%). The latter did not differ from others patients in clinical data and PFTs except for a lower lung diffusion capacity (DLCO). We found a weak correlation between FEV3/FEV6 and DLCO (r=0.33, p=0.004). PFTs were repeated in 35 patients at 11 [7–12] months, and 20 (54%) presented with obstructive ventilatory defect defined by FEV1/FVC ratio <0.7. A reduction of FEV3/FEV6 was predictive of COPD onset one year later (p=0.04). These results may be biased by a discrepancy between the normality cut-offs used at inclusion and during follow-up (i.e. lower limit of normal and 0.7). ConclusionsDecreased FEV3/FEV6 suggestive of peripheral airway disease is highly prevalent in smokers with symptoms of chronic bronchitis and preserved pulmonary function. Altered FEV3/FEV6 is predictive of reduced FEV1/FVC ratio in the mid-term. A larger prospective study is needed to determine whether decreased FEV3/FEV6 could be used to detect patients at risk for COPD.

Differences between FEV6, FVC and VC at the diagnosis of obstructive ventilatory defect

IntroductionThe diagnosis of airway obstruction can be made through FEV1/FVC ratio <0.7 or FEV1/VC ratio < lower limit of normality (LLN). Several authors advocate that FEV1/FEV6 ratio is an alternative to diagnosing obstructive ventilatory defect, while others have determined that the best cut-off for this ratio (best combined sensitivity and specificity) is 0.73. ObjectiveTo evaluate the non-inferiority of FEV1/FEV6 ratio < 0.73 when compared to FEV1/FVC ratio < 0.7 and FEV1/VC < LLN in diagnosing airway obstruction. MethodsA retrospective analysis of the medical records from patients who underwent spirometry or plethysmography in a university central hospital from June 1st to December 31st, 2018 was carried out. Only medical records which included FEV1/FVC < 0.7 or FEV1/VC < LLN were selected, and these results were compared to FEV1/FEV6 ratio. ResultsA total of 526 patients with obstructive ventilatory defect were identified by one of the two ratios described. Of these, 95.1%, 87.4% and 88.6% were obstructive by FEV1/FVC, FEV1/VC, and FEV1/FEV6 ratio, respectively. The positive predictive value (PPV) of FEV1/FEV6 in relation to FEV1/FVC ratio was 99.6% (p < 0.001) with a diagnostic efficacy of 92.8%, whereas the PPV of FEV1/FEV6 in relation to FEV1/VC was 91.0% (p < 0.001) and diagnostic efficacy was 85.2%. Most false negatives, comparing FEV6 with the other two tests, were found in patients with FEV1 > 70% (mild obstruction) and in individuals aged >50 years. ConclusionsFEV1/FEV6 < 0.73 may be a good alternative ratio, as it is non-inferior to FEV1/VC and FEV1/FVC in diagnosing obstructive ventilatory defect.

Delayed lung function testing after COVID-19 to detect persistent lung function abnormalities - The DELTA - COVID-19 lung function study.

Coronavirus disease 2019 (COVID-19) has made its presence felt as the worst pandemic witnessed till date in the 21st century. The mortality and morbidity associated with COVID-19 does not end with the acute pneumonia and respiratory failure and consequences extend well into the subsequent weeks to months in a minority. After recovery from severe disease, symptoms, lung function abnormalities and radiological changes are known to persist for varying length of time in a small proportion of patients. Various studies report different incidences of lung function abnormalities post-COVID-19. The present study describes the occurrence, severity, pattern and risk factors for persistent lung function abnormalities post-COVID-19 patients. The present study was aimed to find out the occurrence of persistent lung function abnormalities in patients hospitalised with COVID-19 at three months of discharge who had normal previous lung function prior to COVID-19. In those with persisting abnormal lung function, the severity, pattern and risk factors for persistent lung function abnormalities were also studied. The present study was a retrospective study in patients hospitalised with COVID-19 who had radiological evidence of pneumonia at admission. Patients with prior abnormal lung function were excluded from the study. Lung function was analysed with spirometry, 6-min walk test and diffusion capacity between day 85 and 95 of hospital discharge and the occurrence, severity and pattern of impairment was described. Lung function impairment was correlated with baseline characteristics and univariate regression analysis was done to identify risk factors for persisting functional impairment. 39 patients were included in the study. Spirometry at follow up showed a restrictive ventilatory defect in 26 out of 39 patients (64%) and a normal study was noted in 12 patients. One patient had an obstructive ventilatory defect. Diffusion impairment was present in 27 patients and normal transfer factor was seen in 12 patients. The degree of diffusion impairment was mild in 16 patients and moderate in 11 patients. Univariate regression analysis revealed that age, history of systemic hypertension, severe hypoxia at presentation, and extent of lung involvement by CT chest were associated with lung function impairment. Almost two-thirds of patients hospitalised with COVID-19 pneumonia have persistent lung function abnormalities at three months post-discharge. Advanced age, severe disease and medical comorbidities increase the risk of persistent functional abnormalities.

THE MAIN EPIDEMIOLOGICAL AND DIAGNOSTICAL FEATURES OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE IN SERVICEMEN OF THE ARMED FORCES OF UKRAINE IN THE CONDITIONS OF JOINT FORCES OPERATION

The aim: The aim of the work was to determine the leading epidemiological, diagnostical features, disturbance of spirometric indices, changes in the immune system in servicemen with COPD, who take part in Joint Forces Operation (JFO). Materials and methods: 89 male patients were examined, who sought medical help for COPD, group B. They were divided into two groups. 1 group (42 patients) − with COPD, who took part in the JFO not more than 6 month, the 2 group consisted of 47 patients with COPD, who took part in the JFO during the period more than 6 month. Results: The patients in the group 2 had veraciously more points of cough and sputum expectoration in daily amount of 30 and more ml. The type of sputum in 53.2% patients was predominantly mucus-pus. There were also more percentage of patients with feeling short of breath and the high point, achieved at CAT. There were significant differences in systolic and diastolic blood pressure levels, LV mass index between two groups. Conclusions: It was found that servicemen who took part in JFO for more than 6 months had a more severe course of COPD with a higher score in the CAT and probably lower obstructive ventilatory indices, in a probably higher percentage of cases there were detected such a concomitant pathology as AH stage II and GERD. They had Th17 immune response predomination with significant elevation of IL-17, TGF-β, IL-6 concentrations in serum and high concentration of soluble adhesion molecules. KEY WORDS: Obstructive ventilatory defects, immune, external respiration function, fuel combustion products

Z-alpha1-antitrypsin polymers and small airways disease: a new paradigm in alfa-1 anti-trypsin deficiency-related COPD development?

The presence of Alpha1-Antitrypsin (AAT) polymers, known to promote a sustained pro-inflammatory activity, has been previously demonstrated in bronchial biopsies of subjects with Z-AAT deficiency (AATD) suggesting a possible role in the development of COPD through a small airway disease impairment. The study aimed to assess the presence of small airways dysfunction and the potential correlation with the presence of Z-AAT polymers obtained by Exhaled Breath Condensate (EBC) collection in PiZZ subjects, as compared with matched healthy PiMM subjects. We enrolled 19 asymptomatic, never smoker subjects: 9 PiZZ and 10 PiMM as controls, without obstructive ventilatory defect (i.e., normal FEV1/VC% ratio). All subjects underwent complete pulmonary function tests (PFT). EBC was collected in all subjects. ELISA test was applied to search for Z-AAT polymers. The PiZZ subjects showed normal lung volumes and DLCO values. However, in comparison with PiMM subjects, the single breath test N2 wash-out revealed significant differences regarding the phase III slope (1.45±0.35 N2/L vs. 0.96±0.40 N2/L) (p<0.02) in the PiZZ subjects, while the closing volume/vital capacity ratio (14.3±4.5 % vs. 11.3±6.3 %) was not significantly increased. The ELISA test detected the presence of Z-AAT polymers in 44% of PiZZ patients. Asymptomatic, never smoker PiZZ subjects with normal spirometry and lung diffusion capacity showed airways impairment when compared to PiMM subjects. Although Z-AAT polymers were found only in 44% of PiZZ subjects, these findings suggest the possibility that chronic bronchiolitis can develop as a result of the long-term pro-inflammatory activity of Z-AAT polymers in subjects with Z-related AATD.

843 Paradoxical Waking Hypoxemia that Improves with Sleep

Abstract Introduction We present a case of paradoxically worsened hypoxia during wake phase of polysomnography while undergoing a CPAP titration study. Nighttime hypoxemia is a common feature in obstructive sleep apnea, due to obstructive events that manifest while sleeping. Excluding OSA, there remains an extensive differential for disease processes that cause hypoxemia while asleep; however, none of these processes can explain waking hypoxemia that improves upon sleeping. Report of case(s) A 70 year old male with severe OSA diagnosed by home sleep test (REI 46.5, nadir O2=76%) underwent polysomnography with PAP titration and demonstrated several hours of interrupted sleep without hypoxia and minimal obstructive events on CPAP 9–13 cmH2O. During the study, while awake at CPAP of 14 cmH2O, he developed hypoxia to mid-high 80s and supplemental oxygen bleed in was added starting at 3L and increased to 5L during a prolonged period of wakefulness. On CPAP 15 cmmH2O with 5L bleed-in, the patient fell asleep and oxygen saturation again increased to low 90s. He underwent an extensive workup for other cardiopulmonary causes of hypoxemia, with pulmonary function testing showing moderate obstructive ventilatory defect and mild DLCO impairment. An echocardiogram with saline contrast bubble study was relatively unremarkable, without evidence of right to left shunting. He underwent a chest CTA which was negative for pulmonary embolism, though it did reveal an enlarged pulmonary artery consistent with pulmonary hypertension. His chronic hypoxemia was treated with 2L supplemental oxygen during the day and bleed-in with CPAP at night. Conclusion Though nocturnal hypoxemia is common with OSA, polysomnography with paradoxical hypoxemia during wake phase has not been reported. Notably, the patient was without prolonged hypoxia during his sleep phase while on CPAP treatment with minimal apneic/hypopneic events. Pulmonary hypertension can also present as nocturnal hypoxemia, but it should worsen with sleep, rather than improve. There are case reports of right to left shunting worsened by PAP, though his hypoxemia persisted despite PAP. His paradoxical worsening hypoxemia with wakefulness is still unexplained. Support (if any):

Maximal Voluntary Breath-Holding Tele-Inspiratory Test in Patients with Chronic Obstructive Pulmonary Disease.

Maximal voluntary inspiratory breath-holding time (MVIBHT) has proved to be of clinical utility in some obstructive ventilatory defects. This study aims to correlate the breath-holding time with pulmonary function tests in patients with chronic obstructive pulmonary disease (COPD) and to determine the feasibility of using a breath-holding test in assessing the severity of COPD.A cross-sectional study including male patients with stable COPD were conducted. Patients with respiratory comorbidities and severe or unstable cardiac diseases were excluded. Patients were interviewed and examined. Six-minute walk test (6MWT) and plethysmography were performed.For MVIBHT collection, the subject was asked to inspire deeply and to hold the breath as long as possible at the maximum inspiratory level. This maneuver was repeated three times. The best value was used for further analysis.A total of 79 patients (mean age: 64.2 ± 8) were included in this study. The mean value of MVIBHT was 24.2 ± 8.5 s. We identified a positive and significant correlations between MVIBHT and forced vital capacity (r = .630; p < .001) as well as MVIBHT and forced expiratory volume in 1 s (FEV1%) (r = .671; p < .001). A significant inverse correlation with total lung capacity (r = −.328; p = .019) and residual volume to total lung capacity ratio (r = −.607; p < .001) was noted. MVIBHT was significantly correlated to the distance in the 6MWT (r = .494; p < .001). The mean MVIBHT was significantly different within spirometric grades (p < .001) and GOLD groups (p = .002). At 20.5 s, MVIBHT had a sensitivity of 72% and specificity of 96% in determining COPD patients with FEV1 <50%.Our results provide additional evidence of the usefulness of MVIBHT in COPD patients as a pulmonary function parameter.