Airflow Obstruction Research Articles

Impact of Pharmacist-Led Intervention on Adherence to Inhalers, Inhalation Technique, and Disease Control Among Asthma/COPD Patients in a Resource Limited Center: An Interventional Study.

Asthma and Chronic obstructive pulmonary disease (COPD) are chronic respiratory conditions characterized by airflow obstruction and respiratory symptoms. Adherence to prescribed inhaler therapy and correct inhalation technique are essential for effective disease management and optimal disease control. However, non-adherence and incorrect inhalation technique are common challenges faced by patients with asthma and COPD, leading to suboptimal treatment outcomes and increased healthcare burden. To study the impact of a pharmacist-led intervention on inhaler adherence, inhalation technique, and disease control among patients with asthma and COPD. A pre-post interventional design assessed the effects of pharmacist-led intervention on inhaler adherence, inhalation techniques, and disease control in asthma and COPD patients at Dhulikhel Hospital in Nepal. Inclusion criteria: adult patient clinically diagnosed with asthma or COPD patients of all genders. The intervention comprised counseling patients with aids like videos, and informational leaflets. Impact was measured using checklist method for inhalation technique, the Test of Adherence to Inhaler (TAI) questionnaire for adherence to inhaler, and "Asthma Control Test (ACT)" or "COPD Assessment Test (CAT)" for disease control. The pharmacist-led intervention significantly increased adherence to inhalers, evidenced by a notable rise in the proportion of patients with good adherence (P<0.001). Sporadic, deliberate, and unwitting noncompliance pattern also improved significantly after the intervention (P<0.001, P<0.001 and P=0.001). Inhalation technique exhibited substantial improvement after intervention (P<0.001). The analysis indicated significant moderate negative correlations between "TIA" and "CAT" [ρ=-0.31; P=0.01], and between "inhalation technique score" and "CAT score" [ρ=-0.31; P=0.01] suggesting that as adherence to inhaler usage and inhalation technique improve, CAT scores tend to decrease, indicating reduced disease impact on the patient. This study shows the potential efficacy of pharmacist-led intervention in enhancing adherence to inhaler, inhalation technique, and disease control in respiratory conditions such as asthma and COPD.

Mechanisms of osteoporosis associated with chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a disease characterized by chronic respiratory symptoms due to inflammatory and destructive changes of the lung leading to progressive airflow obstruction. Fragility fractures associated with osteoporosis are among major comorbidities and have significant impacts on quality of life and prognosis of patients with COPD. Evidence suggests that both decreased bone mineral density (BMD) and impaired bone quality contribute to bone fragility and resultant fractures in COPD. Although various clinical risk factors of osteoporosis have been described, mechanisms of COPD-associated osteoporosis are still largely unknown. In addition, its specific treatment has not been established, either. Previous studies have suggested involvement of low BMI and sarcopenia in the pathogenesis of COPD-associated osteoporosis. In this narrative review, we will propose critical roles of vitamin D deficiency and inflammation, both of which are often present in COPD and may underlie the development of osteosarcopenia and impaired bone quality, ultimately causing fractures in COPD patients.

Numerical investigation of multiple affecting parameters on mixed convective heat transfer for arrays of buildings

This study aims to explore relationships between wind speed, wind direction, exterior surface roughness, temperature difference, plan area density and convective heat transfer coefficients (CHTCs) for external surfaces of arrays of buildings. The present investigation provides correlations for CHTCs at the windward, leeward, top, left, and right lateral surfaces. Three different plan area densities of 0.25, 0.111 and 0.027 are considered and 249 numerical simulations are conducted to investigate the influential parameters including density (λp), wind angle (θ), wind speed (U10), temperature difference (ΔT), and surface roughness (ε). Findings reveal that higher plan area density results in lower CHTC due to heightened airflow obstruction. Increase of the wind angle amplifies CHTC on leeward and right lateral facades while reduces it on the left lateral side. With increased wind speed, CHTC experiences significant increase. The results also shows that the temperature difference's impact is pronounced at lower air velocities, leading to heightened CHTC. Besides, increased surface roughness enhances heat transfer coefficients. Finally, the present study employs extensive simulations to present correlations for different facades of the buildings in the studied arrays offering insights into CHTC variations in terms of plan area density, wind angle, speed, temperature difference, and roughness height.

Worse pulmonary function in association with cumulative exposure to nanomaterials. Hints of a mediation effect via pulmonary inflammation

BackgroundToday, nanomaterials are broadly used in a wide range of industrial applications. Such large utilization and the limited knowledge on to the possible health effects have raised concerns about potential consequences on human health and safety, beyond the environmental burden. Given that inhalation is the main exposure route, workers exposed to nanomaterials might be at risk of occurrence of respiratory morbidity and/or reduced pulmonary function. However, epidemiological evidence regarding the association between cumulative exposure to nanomaterials and respiratory health is still scarce. This study focused on the association between cumulative exposure to nanomaterials and pulmonary function among 136 workers enrolled in the framework of the European multicentric NanoExplore project.ResultsOur findings suggest that, independently of lifelong tobacco smoking, ethnicity, age, sex, body mass index and physical activity habits, 10-year cumulative exposure to nanomaterials is associated to worse FEV1 and FEF25 − 75%, which might be consistent with the involvement of both large and small airway components and early signs of airflow obstruction. We further explored the hypothesis of a mediating effect via airway inflammation, assessed by interleukin (IL-)10, IL-1β and Tumor Necrosis Factor alpha (TNF-α), all quantified in the Exhaled Breath Condensate of workers. The mediation analysis results suggest that IL-10, TNF-α and their ratio (i.e., anti-pro inflammatory ratio) may fully mediate the negative association between cumulative exposure to nanomaterials and the FEV1/FVC ratio. This pattern was not observed for other pulmonary function parameters.ConclusionsSafeguarding the respiratory health of workers exposed to nanomaterials should be of primary importance. The observed association between cumulative exposure to nanomaterials and worse pulmonary function parameters underscores the importance of implementing adequate protective measures in the nanocomposite sector. The mitigation of harmful exposures may ensure that workers can continue to contribute productively to their workplaces while preserving their respiratory health over time.

The relevance of eosinophils in chronic obstructive pulmonary disease: inflammation, microbiome, and clinical outcomes.

Chronic obstructive pulmonary disease is caused by the inhalation of noxious particles such as cigarette smoke. The pathophysiological features include airway inflammation, alveolar destruction, and poorly reversible airflow obstruction. A subgroup of patients with chronic obstructive pulmonary disease has higher blood eosinophil counts, associated with an increased response to inhaled corticosteroids and increased biomarkers of pulmonary type 2 inflammation. Emerging evidence shows that patients with chronic obstructive pulmonary disease with increased pulmonary eosinophil counts have an altered airway microbiome. Higher blood eosinophil counts are also associated with increased lung function decline, implicating type 2 inflammation in progressive pathophysiology in chronic obstructive pulmonary disease. We provide a narrative review of the role of eosinophils and type 2 inflammation in the pathophysiology of chronic obstructive pulmonary disease, encompassing the lung microbiome, pharmacological targeting of type 2 pathways in chronic obstructive pulmonary disease, and the clinical use of blood eosinophil count as a chronic obstructive pulmonary disease biomarker.

Symptoms of COPD in the absence of airflow obstruction are more indicative of pre-COPD than overdiagnosis.

Dysfunction of the small airways is a precursor of COPD but is not detectable on standard spirometric testing until significant destruction has occurred. A proportion of COPD patients have a forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <0.7 which is greater than the lower limit of normal (LLN), when adjusted for their age and sex. It is not understood whether this group of patients, known as "discordant COPD", are representative of "early COPD" or overdiagnosis. We sought to characterise discordant COPD (disCOPD) using radiology, lung function, serum biomarkers, activity monitoring and quality-of-life scores, comparing with COPD patients with an FEV1/FVC <0.7 and <LLN and healthy, age-matched controls. Six out of eight serum biomarkers were significantly different in the disCOPD group versus healthy controls, as were the scores of all four quality-of-life questionnaires. Activity monitoring revealed similar levels of sedentary time between the disCOPD group and concordant COPD (conCOPD). Computed tomography analysis showed less involvement of small airway dysfunction and emphysema in the disCOPD group versus conCOPD. Collectively, our findings support the hypothesis that disCOPD is a clinically relevant phenomenon that represents a pre-COPD state. Identification of such patients is important for early intervention and management before progression to fully established COPD.

The noninvasive ventilation outcomes score in patients requiring NIV for COPD exacerbation without prior evidence of airflow obstruction.

Exacerbation of COPD complicated by respiratory acidaemia is the commonest indication for noninvasive ventilation (NIV). The NIV outcomes (NIVO) score offers the best estimate of survival for those ventilated. Unfortunately, two-thirds of cases of COPD are unrecognised, and patients may present without COPD having been confirmed by spirometry. In the 10-centre NIVO validation study there was no pre-admission spirometry in 111 of 844 consecutive patients (termed "clinical diagnosis" patients). We compared the performance of the NIVO, DECAF and CURB-65 scores for in-hospital mortality in the clinical diagnosis cohort. Usual clinical practice was not influenced, but confirmation of COPD in the year following discharge was captured. In the clinical diagnosis cohort, in-hospital mortality was 19.8% and rose incrementally across the NIVO risk categories, consistent with the NIVO validation cohort. NIVO showed good discrimination in the clinical diagnosis cohort: area under the receiver operating curve 0.724, versus 0.79 in the NIVO validation cohort. At 1 year after discharge, 41 of 89 clinical diagnosis patients had undertaken diagnostic spirometry; 33 of 41 had confirmation of airflow obstruction (forced expiratory volume in 1 s/(forced) vital capacity <0.7), meaning the diagnosis of COPD was incorrect in 19.5% of cases. These data support the use of the NIVO score in patients with a "clinical diagnosis" of COPD. NIVO can help guide shared decision-making, assess risk-adjusted outcomes by centre and challenge prognostic pessimism. Accurate diagnosis is critical to ensure that acute and long-term treatment is optimised; this study highlights failings in the follow-up of such patients.

The challenges of identifying pulmonary embolism in patients hospitalized for exacerbations of COPD

BackgroundChronic obstructive pulmonary disease (COPD) is associated with airflow obstruction that threatens global health. During the hospitalization of patients with acute exacerbations of COPD (AECOPD), the high prevalence of pulmonary embolism (PE) seriously affects the prognosis of disease. This study aims to assess the differences in clinical data between patients with AECOPD and patients with AECOPD-PE, and to identify the relevant factors of PE. MethodsWe performed a retrospective case-control study in AECOPD patients between January 2018 and December 2021. Due to suspected PE, all patients underwent radiological examination. Patients without PE were included as controls. Clinical data and laboratory tests were recorded. Univariate analysis and multivariate logistic regression analysis were used to investigate the independent predictors of PE. Receiver operating characteristics (ROC) curves was performed to evaluate the effect of risk factors on PE prediction. ResultsA total of 191 patients were included for analysis, divided into the AECOPD group (96 cases) and AECOPD-PE group (95 cases). No statistic differences were detected in demographic characteristics between patients with AECOPD and patients with AECOPD and PE. Average PO2 and PCO2 levels, lung function, and Echocardiographic indicator were not associated with PE. The concentration of D-dimer, the proportion of simplified wells score ≥ 2, and the incidence rate of lower extremity deep vein thrombosis (DVT) remarkably increased in AECOPD-PE group than AECOPD individuals. At multivariate analysis, the above three indicators were closely relevant to the occurrence of PE. The AUC value for D-dimer combined with lower extremity DVT and Simplified Wells Score was 0.729. ConclusionsD-dimer, lower extremity DVT, and simplified wells score ≥ 2 were relevant to higher risks of PE, which will help to improve clinicians’ understanding of PE secondary to AECOPD.

Association between dietary niacin intake and lung function among American adults: A cross-sectional analysis from national health and nutrition examination survey, 2007–2012

BackgroundThe pathogenesis of pulmonary senescence involves immune system dysregulation, oxidative stress, and mitochondrial dysfunction. The effects on lung function of niacin, an essential coenzyme involved in mitochondrial energy metabolism with known antioxidant properties, are poorly understood. MethodsThis cross-sectional study used data from the 2007–2012 National Health and Nutrition Examination Survey, including spirometry data and niacin intake information of 9706 adults. This study investigated various spirometry measures, such as forced expiratory volume in 1 s, forced vital capacity, pulse expiratory flow, (forced expiratory volume in 1 s)/(forced vital capacity)ratio, and predicted forced expiratory volume in 1 s and forced vital capacity percentages. Additionally, a secondary analysis was conducted using Global Initiative for Chronic Obstructive Lung Disease and chronic obstructive pulmonary disease. Foundation Spirometry Grade criteria to assess the relationship between niacin intake, airflow limitation, and obstruction. Multivariate regression models were used to adjust for relevant covariates. ResultsThe study included 9706 U S. adults (4788 men and 4918 women) with a median age of 46.2 years. After adjusting for relevant factors, a positive correlation was observed between niacin intake and lung function. Compared to the lowest quintile of niacin intake (Q1, ≤14.5 mg/day), individuals in the highest quintile (Q5, >34.5 mg/day) exhibited significant increases in lung function parameters, including forced expiratory volume in 1s (69.84 mL, p = 0.003), pulse expiratory flow (254.48 mL, p < 0.001), (forced expiratory volume in 1 s)/(forced vital capacity)(0.01, p = 0.041), percent predicted forced expiratory volume in 1 s(2.05, p = 0.002), and percent predicted forced vital capacity(1.29, p = 0.042).Subset analyses of individuals with spirometry-defined airflow obstruction showed associations of high niacin intake with significantly improved forced expiratory volume, pulse expiratory flow, and percent predicted pulse expiratory flow and an interaction among race, education, and smoking status with respect to the relationship between niacin intake and lung function parameters. ConclusionsHigher niacin intake was associated with increased measures of lung function. A diet rich in niacin-containing foods may play a role in improving lung health.

Effects of Daily Physical Activity on Exercise Capacity in Chronic Obstructive Pulmonary Disease.

Background and Objectives: In adults, 150 to 300 min a week of moderate-intensity physical activity is the recommended daily level to maintain or improve fitness. In subjects with chronic obstructive pulmonary disease (COPD), reductions in daily physical activity (DPA) amounts are related to clinically significant outcomes. In this study, we ascertain whether or not COPD patients, when clustered into active (DPA ≥ 30 min a day, 5 days a week) and inactive (DPA < 30 min a day, 5 days a week), may differ in exercise capacity, as assessed by a cardiopulmonary exercise test (CPET). Materials and Methods: A large sample of clinically stable COPD patients was retrospectively recruited and then underwent spirometry and an incremental ramp protocol 5-15 watts/min CPET. DPA was assessed by a questionnaire. Results: A total of 83 (female 25%, age range 41-85 y) active and 131 (female 31%, age range 49-83 y) inactive participants were enrolled. They were similar in age, sex distribution, body mass index (BMI) and in spirometry. The two groups were significantly different in dyspnea on exertion, as assessed by the modified Medical Research Council (mMRC), and in cardio-metabolic parameters, but not in ventilatory ones, as confirmed by the CPET. Conclusions: COPD patients experiencing physical activity of at least 30 min a day, 5 days a week, showed a greater exercise capacity and an improved cardiovascular response to exercise, when compared to inactive ones. Active and inactive participants did not differ in terms of airflow obstruction severity as well as in dynamic hyperinflation and ventilatory inefficiency during exercise. This study further suggests the benefits of regular physical activity in COPD.

Efficacy of tezepelumab in patients with severe asthma and persistent airflow obstruction

Efficacy of tezepelumab in patients with severe asthma and persistent airflow obstruction

Role of exhaled carbon monoxide in assessment of chronic obstructive airway disease severity

BackgroundChronic obstructive pulmonary disease (COPD) is a critical public health issue. Spirometric measurements are used to diagnose chronic obstructive lung disease, as per the guidelines of the GOLD initiative. Post-bronchodilator forced expiratory volume in 1 s (FEV1) is a predictor of mortality from COPD and helps to classify the disease’s severity. Smoking contributes to the high levels of exhaled CO. Evidence suggests that the exhaled CO level in COPD patients varies with degree of blockage and can be used to assess treatment response. Estimating the exhaled CO level can help assess airway inflammation and severity of airflow obstruction in individuals with COPD.AimEvaluate role of exhaled CO in assessment of severity of COPD.Materials and methodsThis cross-sectional study included 132 patients who visited the outpatient clinics or were admitted to the Chest Department, Kasr Alainy Hospital, Faculty of Medicine, Cairo University. The study participants were divided into three groups: group 1 nonsmoker healthy control, group 2 smoker non-COPD, and group 3 smoker COPD which further divided according to GOLD 2023 into mild, moderate, and severe COPD. The smoking status, exhaled CO, and spirometry test including FEV1/FVC and FEV1 were measured for each patient.ResultsExhaled CO was significantly increased in the smoker group (mean 9.69, SD 3.11) compared to the nonsmoker group (mean 2.19, SD 0.98) with p-value < 0.001. Exhaled CO was also statistically significantly higher in the smoker COPD group (mean 10.45, SD 3.03) compared to the smoker non-COPD group (mean 7.05, SD 1.56) with p-value < 0.001. Although exhaled CO was increased in the severe COPD group compared to the mild and moderate group, there is no statistically significant difference between them.ConclusionExhaled CO is a fast, sensitive, noninvasive, and well-established method test that can be used to identify smokers from nonsmokers with 98.9% sensitivity at 4.5 cutoff value. Also, exhaled CO levels in COPD patients vary with different degrees of airway obstruction.

The impact of traditional mind-body exercises on pulmonary function, exercise capacity, and quality of life in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis of randomized controlled trials.

Chronic Obstructive Pulmonary Disease (COPD) is a chronic condition characterized primarily by airflow obstruction, significantly impacting patients' quality of life. Traditional mind-body exercises, as a non-pharmacological intervention for COPD, have become a new research focus. To assess the impact of traditional mind-body exercises (Tai Chi, Qigong, Yoga) on pulmonary function, exercise capacity, and quality of life in COPD patients. Additionally, to identify the most suitable form of traditional mind-body exercise for different indicators. Searches were conducted in databases such as Web of Science, PubMed, EBSCOhost, CNKI, etc., to collect randomized controlled trials (RCTs) evaluating the intervention of traditional mind-body exercises (Tai Chi, Yoga, Qigong) in COPD. The Cochrane evaluation tool was applied for methodological quality assessment of the included literature. Statistical analysis and sensitivity analysis were performed using Revman 5.4 software, while publication bias was assessed using R software. This study included 23 studies with a total of 1862 participants. Traditional mind-body exercises improved patients' FEV1% index (WMD = 4.61, 95%CI [2.99, 6.23]), 6-min walk distance (SMD = 0.83, 95%CI [0.55, 1.11]), and reduced patients' SGRQ score (SMD = -0.79, 95%CI [-1.20, -0.38]) and CAT score (SMD = -0.79, 95%CI [-1.20, -0.38]). Qigong showed the most significant improvement in FEV1% and 6MWT, while Tai Chi primarily improved 6MWT, and the effect of Yoga was not significant. Sensitivity analysis indicated stable and reliable research conclusions. Traditional mind-body exercises are effective rehabilitation methods for COPD patients, significantly improving pulmonary function, exercise capacity, and quality of life. They are suitable as complementary interventions for standard COPD treatment. [https://www.crd.york.ac.uk/prospero/display-record.php?ID=CRD42023495104], identifier [CRD42023495104].

Sex differences in asthma control, lung function and exacerbations: the ATLANTIS study

BackgroundAsthma is a heterogeneous disease with a prevalence and severity that differs between male and female patients.QuestionWhat are differences between male and female patients with asthma with regard to asthma...

Role of exosomes in exacerbations of asthma and COPD: a systematic review.

Asthma and chronic obstructive pulmonary disease are chronic respiratory disorders characterized by airways obstruction and chronic inflammation. Exacerbations lead to worsening of symptoms and increased airflow obstruction in both airways diseases, and they are associated with increase in local and systemic inflammation. Exosomes are cell-derived membrane vesicles containing proteins, lipids, and nucleic acids that reflect their cellular origin. Through the transfer of these molecules, exosomes act as mediators of intercellular communication. Via selective delivery of their contents to target cells, exosomes have been proved to be involved in regulation of immunity and inflammation. Although, exosomes have been extensively investigated in different diseases, little is currently known about their role in asthma and COPD pathogenesis, and particularly in exacerbations. This review aims to systemically assess the potential role of exosomes in asthma and COPD exacerbations.

Muscle fibre satellite cells are located at a greater distance from capillaries in patients with COPD compared with healthy controls.

COPD is a disease characterised by skeletal muscle dysfunction. A spatial relationship exists between satellite cells and muscle fibre capillaries, which has been suggested to be of major importance for satellite cell function. In the present study we compared the spatial relationship between satellite cells and capillaries in patients with COPD and age-matched healthy older adults. Muscle biopsies were obtained from the vastus lateralis of n=18 patients with COPD (8 female, 10 male; age 66±5 years, mild-to-severe airflow obstruction) and n=18 age-, sex- and body mass index-matched healthy control adults (8 female, 10 male; age 68±5 years). Immunohistochemistry was used to assess type I/II muscle fibre size, distribution, myonuclear content, satellite cell number and fibre capillarisation. In addition, type I/II muscle fibre satellite cell distance to its nearest capillary was assessed. The percentage of type II muscle fibres was significantly greater in patients with COPD (62±10%) compared with controls (50±12%, p<0.05). Muscle fibre capillarisation was significantly lower in patients with COPD compared with controls (p<0.05). While satellite cell content was not different between groups, type I and type II satellite cell distance to its nearest capillary was significantly greater in patients with COPD (type I: 21.3±4.8 µm; type II: 26.7±9.3 µm) compared with controls (type I: 16.1±3.5 µm; type II: 22.7±5.8 µm; p<0.05). Satellite cells are located at a greater distance from their nearest capillary in patients with COPD compared with age-matched controls. This increased distance could play a role in impaired satellite cell function in patients with COPD.

Predicting COPD exacerbations based on quantitative CT analysis: an external validation study.

Quantitative computed tomography (CT) analysis is an important method for diagnosis and severity evaluation of lung diseases. However, the association between CT-derived biomarkers and chronic obstructive pulmonary disease (COPD) exacerbations remains unclear. We aimed to investigate its potential in predicting COPD exacerbations. Patients with COPD were consecutively enrolled, and their data were analyzed in this retrospective study. Body composition and thoracic abnormalities were analyzed from chest CT scans. Logistic regression analysis was performed to identify independent risk factors of exacerbation. Based on 2-year follow-up data, the deep learning system (DLS) was developed to predict future exacerbations. Receiver operating characteristic (ROC) curve analysis was conducted to assess the diagnostic performance. Finally, the survival analysis was performed to further evaluate the potential of the DLS in risk stratification. A total of 1,150 eligible patients were included and followed up for 2 years. Multivariate analysis revealed that CT-derived high affected lung volume/total lung capacity (ALV/TLC) ratio, high visceral adipose tissue area (VAT), and low pectoralis muscle cross-sectional area (CSA) were independent risk factors causing COPD exacerbations. The DLS outperformed exacerbation history and the BMI, airflow obstruction, dyspnea, and exercise capacity (BODE) index, with an area under the ROC (AUC) value of 0.88 (95%CI, 0.82-0.92) in the internal cohort and 0.86 (95%CI, 0.81-0.89) in the external cohort. The DeLong test revealed significance between this system and conventional scores in the test cohorts (p < 0.05). In the survival analysis, patients with higher risk were susceptible to exacerbation events. The DLS could allow accurate prediction of COPD exacerbations. The newly identified CT biomarkers (ALV/TLC ratio, VAT, and pectoralis muscle CSA) could potentially enable investigation into underlying mechanisms responsible for exacerbations.

Computational analysis of nasal airflow and its alteration by a nasal dilator

Nasal airflow obstruction correlates with several ailments, such as higher patency, increased friction at the mucosal wall or the so-called Little's area, improper air conditioning, and snoring. Nasal dilators are frequently employed, mainly due to their ease of access and use, combined with their non-permanent and non-surgical nature. Their overall efficacy, however, has not been clearly demonstrated so far, with some studies reporting conflicting outcomes, mainly because being based on subjective evaluations. This study employs Computational Fluid Dynamics simulations to analyze the flow inside a real nose, performs an objective assessment of a nasal dilator's effect in terms of airflow and air conditioning, reporting flow paths, friction levels, heat and water fluxes and detailed temperature and humidity distributions. Coincidentally, the studied nose presents a septal deviation, with one nostril being wider than the other. The tubes of the dilator used in both nostrils are identical, as with any standard commercial dilator. Consequently, the dilator widens one nostril, as intended, but results in an obstruction in the other. This allows simultaneously addressing two situations, the nominal function of the dilator, as well as an off-design case. Results indicate a 24 % increase in nasal patency in the design situation. The effect, however, is limited, as quantified by appropriate measures, such as the flow-generated friction at the nose surfaces and the temperature fluxes. Hence, the effect of such a dilator in nominal conditions is perhaps not as large as might be hoped. In the off-design situation, nasal resistance increases by 62 %, an undesirable effect, illustrating the consequences of using an inappropriate dilator.

The roles of bacteria and viruses in COPD-Bronchiectasis association: A prospective cohort study

BackgroundExacerbations are implicated in bronchiectasis and COPD, which frequently co-exist [COPD-Bronchiectasis association (CBA)]. We aimed to determine the bacterial and viral spectrum at stable-state and exacerbation onset of CBA, and their association with exacerbations and clinical outcomes of CBA as compared with bronchiectasis. MethodsWe prospectively collected spontaneous sputum from adults with CBA, bronchiectasis with (BO) and without airflow obstruction (BNO) for bacterial culture and viral detection at stable-state and exacerbations. ResultsWe enrolled 76 patients with CBA, 58 with BO, and 138 with BNO (711 stable and 207 exacerbation visits). Bacterial detection rate increased from BNO, CBA to BO at steady-state (P = 0.02), but not at AE onset (P = 0.91). No significant differences in viral detection rate were found among BNO, CBA and BO. Compared with steady-state, viral isolations occurred more frequently at exacerbation in BNO (15.8 % vs 32.1 %, P = 0.001) and CBA (19.5 % vs 30.6 %, P = 0.036) only. In CBA, isolation of viruses, human metapneumovirus and bacteria plus viruses was associated with exacerbation. Repeated detection of Pseudomonas aeruginosa (PA) correlated with higher modified Reiff score (P = 0.032) in CBA but not in BO (P = 0.178). Repeated detection of PA yielded a shorter time to the first exacerbation in CBA [median: 4.3 vs 11.1 months, P = 0.006] but not in BO (median: 8.4 vs 7.6 months, P = 0.47). ConclusionsIsolation of any viruses, human metapneumovirus and bacterialplus viruses was associated with CBA exacerbations. Repeated detection of PA confers greater impact of future exacerbations on CBA than on BO.

Pulmonary function, genetic predisposition, and the risk of cirrhosis: A prospective cohort study

ObjectivePulmonary function is associated with the development of chronic liver disease. However, evidence of the association between pulmonary function and cirrhosis risk is still lacking. This study aimed to investigate the longitudinal associations of pulmonary function with the development of cirrhosis, and to explore whether genetic predisposition to cirrhosis could modify these associations. MethodsOf 294,835 participants free of cirrhosis and had undergone spirometry at baseline from the UK Biobank were included. Cirrhosis diagnoses were ascertained through linked hospital records and death registries. Cox proportional hazard models were employed to investigate the longitudinal associations between pulmonary function, genetic predisposition, and cirrhosis risk. ResultsDuring a median follow-up of 12.0 years, 2598 incident cirrhosis cases were documented. Compared to individuals with normal spirometry findings, those with preserved ratio impaired spirometry (PRISm) findings (hazard ratio [HR] and 95% confidence interval [CI]: 1.32 [1.18, 1.48]) and airflow obstruction (HR [95%CI]: 1.19 [1.07, 1.31]) had a higher risk of developing cirrhosis after adjustments. These associations were consistent across all categories of genetic predisposition, with no observed modifying effect of genetic predisposition. In joint exposure analyses, the highest risk was observed in individuals with both a high genetic predisposition for cirrhosis and PRISm findings (HR [95% CI]: 1.74 [1.45, 2.08]). ConclusionsOur findings indicate that worse pulmonary function is a significant risk factor of cirrhosis, irrespective of genetic predisposition. Early identification and appropriate intervention for pulmonary function may lead to more effective healthcare resource utilization and reduce the burden associated with cirrhosis.