Chronic respiratory diseases: a global view

Endotyping Chronic Respiratory Diseases: T2 Inflammation in the United Airways Model

Over the past 15 years, the paradigm of viewing the upper and lower airways as a unified system has progressively shifted the approach to chronic respiratory diseases (CRDs). As the global prevalence of CRDs continues to increase, it becomes evident that acknowledging the presence of airway pathology as an integrated entity could profoundly impact healthcare resource allocation and guide the implementation of pharmacological and rehabilitation strategies. In the era of precision medicine, endotyping has emerged as another novel approach to CRDs, whereby pathologies are categorized into distinct subtypes based on specific molecular mechanisms. This has contributed to the growing acknowledgment of a group of conditions that, in both the upper and lower airways, share a common type 2 (T2) inflammatory signature. These diverse pathologies, ranging from allergic rhinitis to severe asthma, frequently coexist and share diagnostic and prognostic biomarkers, as well as therapeutic strategies targeting common molecular pathways. Thus, T2 inflammation may serve as a unifying endotypic trait for the upper and lower airways, reinforcing the practical significance of the united airways model. This review aims to summarize the literature on the role of T2 inflammation in major CRDs, emphasizing the value of common biomarkers and integrated treatment strategies targeting shared molecular mechanisms.

Respiratory diseases and gut microbiota: relevance, pathogenesis, and treatment

Preclinical evidence has firmly established a bidirectional interaction among the lung, gut, and gut microbiome. There are many complex communication pathways between the lung and intestine, which affect each other's balance. Some metabolites produced by intestinal microorganisms, intestinal immune cells, and immune factors enter lung tissue through blood circulation and participate in lung immune function. Altered gut-lung-microbiome interactions have been identified in rodent models and humans of several lung diseases such as pulmonary fibrosis, chronic obstructive pulmonary disease, lung cancer, asthma, etc. Emerging evidence suggests that microbial therapies can prevent and treat respiratory diseases, but it is unclear whether this association is a simple correlation with the pathological mechanisms of the disease or the result of causation. In this review, we summarize the complex and critical link between the gut microbiota and the lung, as well as the influence and mechanism of the gut microbiota on respiratory diseases, and discuss the role of interventions such as prebiotics and fecal bacteria transplantation on respiratory diseases. To provide a reference for the rational design of large-scale clinical studies, the direct application of microbial therapy to respiratory-related diseases can reduce the incidence and severity of diseases and accompanying complications.

Exploring the role of the ocular surface in the lung-eye axis: Insights into respiratory disease pathogenesis

Chronic respiratory diseases (CRDs) represent a significant proportion of global health burden, with a wide spectrum of varying, heterogenic conditions largely affecting the pulmonary system. Recent advances in immunology and respiratory biology have highlighted the systemic impact of these diseases, notably through the elucidation of the lung-eye axis. The current review focusses on understanding the pivotal role of the lung-eye axis in the pathogenesis and progression of chronic respiratory infections and diseases. Existing literature published on the immunological crosstalk between the eye and the lung has been reviewed. The various roles of the ocular microbiome in lung health are also explored, examining the eye as a gateway for respiratory virus transmission, and assessing the impact of environmental irritants on both ocular and respiratory systems. This novel concept emphasizes a bidirectional relationship between respiratory and ocular health, suggesting that respiratory diseases may influence ocular conditions and vice versa, whereby this conception provides a comprehensive framework for understanding the intricate axis connecting both respiratory and ocular health. These aspects underscore the need for an integrative approach in the management of chronic respiratory diseases. Future research should further elucidate the in-depth molecular mechanisms affecting this axis which would pave the path for novel diagnostics and effective therapeutic strategies.

Pharmaceutical care in respiratory diseases: Current situation and opportunities for Hospital Pharmacy in Spain

OBJECTIVE

Respiratory diseases present a challenge for the healthcare system due to their prevalence and clinical impact. The aim of this study was to explore the current situation of hospital pharmacy in the field of respiratory diseases.

METHOD

Observational, cross-sectional study, with a national scope, divided into 2 parts. In an initial phase, the activity and level of pharmaceutical care in respiratory diseases was evaluated through an online questionnaire using REDCap. The survey was addressed to department chiefs and consisted of 17 items, divided into 2 modules: general data and general activity. The second phase was open to hospital pharmacists, with the aim of exploring their opinion on care, training, and improvement needs. The number of items in this phase was 19, divided into 5 modules: general data, pharmaceutical care, competencies, training and degree of satisfaction.

RESULTS

In the first phase, 23 hospitals were included. Most of them (n=20) had a pharmacist in charge of respiratory diseases. However, a large proportion of them dedicated less than 40% of their working day to this activity. The pharmacist's activity occurred at the level of external patients (n=20), hospitalized patients (n=16), and secondarily in management (n=8). Integration is greater in pathologies such as asthma, IPF, pulmonary hypertension, and bronchiectasis. Participation in committees was present in 15 hospitals, with variability in pathologies and degree of involvement. In the second phase, 164 pharmacists participated, who considered pharmaceutical care in cystic fibrosis, asthma and lung transplant as a priority. Fifty-one percent considered integration to be adequate and 91% considered it necessary to implement prioritization criteria. Professional competencies ranged from 6.5-6.9 out of 10 points. Only 45% of participants had received specific training in the last four years, indicating greater priority for asthma, pulmonary hypertension and IPF.

CONCLUSIONS

Most centers have pharmacists specialized in respiratory diseases. However, there is room for improvement in terms of sub specialization, participation in multidisciplinary committees, implementation of prioritization criteria, diversification in pathologies treated, as well as greater specific training in this area.

[Translated article] Pharmaceutical care in respiratory diseases: Current situation and opportunities for hospital pharmacy in Spain

OBJECTIVE

Respiratory diseases present a challenge for the healthcare system due to their prevalence and clinical impact. The aim of this study was to explore the current situation of hospital pharmacy in the field of respiratory diseases.

METHOD

Observational, cross-sectional study, with a national scope, divided into 2 parts. In an initial phase, the activity and level of pharmaceutical care in respiratory diseases was evaluated through an online questionnaire using REDCap. The survey was addressed to department chiefs and consisted of 17 items, divided into 2 modules: general data and general activity. The second phase was open to hospital pharmacists, with the aim of exploring their opinion on care, training, and improvement needs. The number of items in this phase was 19, divided into 5 modules: general data, pharmaceutical care, competencies, training, and degree of satisfaction.

RESULTS

In the first phase, 23 hospitals were included. Most of them (n=20) had a pharmacist in charge of respiratory diseases. However, a large proportion of them dedicated less than 40% of their working day to this activity. The pharmacist's activity occurred at the level of external patients (n=21), hospitalised patients (n=16), and secondarily in management (n=8). Integration is greater in pathologies such as asthma, IPF, pulmonary hypertension, and bronchiectasis. Participation in committees was present in 15 hospitals, with variability in pathologies and degree of involvement. In the second phase, 164 pharmacists participated, who considered pharmaceutical care in cystic fibrosis, asthma, and lung transplant as a priority. 51% considered integration to be adequate and 91% considered it necessary to implement prioritisation criteria. Professional competencies ranged from 6.5 to 6.9 out of 10 points. Only 45% of participants had received specific training in the last 4 years, indicating greater priority for asthma, pulmonary hypertension, and IPF.

CONCLUSIONS

Most centers have pharmacists specialised in respiratory diseases. However, there is room for improvement in terms of subspecialisation, participation in multidisciplinary committees, implementation of prioritisation criteria, diversification in pathologies treated, as well as greater specific training in this area.

Chronic respiratory disease in Indigenous peoples: a framework to address inequity and strengthen respiratory health and health care globally

Indigenous peoples around the world bear a disproportionate burden of chronic respiratory diseases, which are associated with increased risks of morbidity and mortality. Despite the imperative to address global inequity, research focused on strengthening respiratory health in Indigenous peoples is lacking, particularly in low-income and middle-income countries. Drivers of the increased rates and severity of chronic respiratory diseases in Indigenous peoples include a high prevalence of risk factors (eg, prematurity, low birthweight, poor nutrition, air pollution, high burden of infections, and poverty) and poor access to appropriate diagnosis and care, which might be linked to colonisation and historical and current systemic racism. Efforts to tackle this disproportionate burden of chronic respiratory diseases must include both global approaches to address contributing factors, including decolonisation of health care and research, and local approaches, co-designed with Indigenous people, to ensure the provision of culturally strengthened care with more equitable prioritisation of resources. Here, we review evidence on the burden of chronic respiratory diseases in Indigenous peoples globally, summarise factors that underlie health disparities between Indigenous and non-Indigenous people, propose a framework of approaches to improve the respiratory health of Indigenous peoples, and outline future directions for clinical care and research.

A review of the safety profile, antioxidant, anti-inflammatory, and bronchorelaxant activities of Waltheria indica Linn (Malvaceae): A potential antiasthmatic phytomedicine

Introduction

Waltheria indica Linn (Malvaceae) is a widely distributed plant in West Africa. It is commonly used in Burkina Faso to treat inflammation-related diseases, including asthma. Previous reviews have focused on the ethnobotanical, traditional uses, phytochemistry, and pharmacological properties of Waltheria indica. This report aims to compile the biological and pharmacological activities that highlight the anti-asthmatic properties of Waltheria indica L. (W. indica).

Method

Electronic databases, such as PubMed, Scopus, Hinari, SciFinder, Google Scholar, and ScienceDirect, were used to gather data on Watheria indica. Data on the toxicological, anti-inflammatory, antioxidant, and bronchorelaxant effects of W. indica were collected.

Results

Twenty-three studies describing the biological and pharmacological activities relevant to assessing the anti-asthmatic properties of W. indica were found. Nine articles investigated the anti-inflammatory effects, and three manuscripts were found to have bronchorelaxant activity. Five publications reported the antioxidant activity of the plant extracts. Research on the extracts revealed a tolerable safety profile in rats and mice with an LD50 ranging from 300 to 5000 mg/kg body weight, depending on the parts of the plant used. Phenolic compounds, particularly flavonoids, alkaloids, and saponins, were found to be responsible for the activities involved in the assessment of anti-asthmatic properties.

Conclusion

The results of this review suggest that W. indica could be a valuable resource for the treatment of asthma and other respiratory diseases. However, further chemical and pharmacological investigations are needed to understand its mechanism of action in treating asthma.

Optimized lipid nanoparticles (LNPs) for organ-selective nucleic acids delivery in vivo

Nucleic acid therapeutics offer tremendous promise for addressing a wide range of common public health conditions. However, the in vivo nucleic acids delivery faces significant biological challenges. Lipid nanoparticles (LNPs) possess several advantages, such as simple preparation, high stability, efficient cellular uptake, endosome escape capabilities, etc., making them suitable for delivery vectors. However, the extensive hepatic accumulation of LNPs poses a challenge for successful development of LNPs-based nucleic acid therapeutics for extrahepatic diseases. To overcome this hurdle, researchers have been focusing on modifying the surface properties of LNPs to achieve precise delivery. The review aims to provide current insights into strategies for LNPs-based organ-selective nucleic acid delivery. In addition, it delves into the general design principles, targeting mechanisms, and clinical development of organ-selective LNPs. In conclusion, this review provides a comprehensive overview to provide guidance and valuable insights for further research and development of organ-selective nucleic acid delivery systems.

Comprehensive analysis of environmental exposure to hazardous trace elements and lung function: a national cross-sectional study

BACKGROUND

There is growing interest in the joint effects of hazardous trace elements (HTEs) on lung function deficits, but the data are limited. This is a critical research gap given increased global industrialisation.

METHODS

A national cross-sectional study including spirometry was performed among 2112 adults across 11 provinces in China between 2020 and 2021. A total of 27 HTEs were quantified from urine samples. Generalised linear models and quantile-based g-computation were used to explore the individual and joint effects of urinary HTEs on lung function, respectively.

RESULTS

Overall, there were negative associations between forced expiratory volume in 1 s (FEV1) and urinary arsenic (As) (z-score coefficient, -0.150; 95% CI, -0.262 to -0.038 per 1 ln-unit increase), barium (Ba) (-0.148, 95% CI: -0.258 to -0.039), cadmium (Cd) (-0.132, 95% CI: -0.236 to -0.028), thallium (Tl) (-0.137, 95% CI: -0.257 to -0.018), strontium (Sr) (-0.147, 95% CI: -0.273 to -0.022) and lead (Pb) (-0.121, 95% CI: -0.219 to -0.023). Similar results were observed for forced vital capacity (FVC) with urinary As, Ba and Pb and FEV1/FVC with titanium (Ti), As, Sr, Cd, Tl and Pb. We found borderline associations between the ln-quartile of joint HTEs and decreased FEV1 (-20 mL, 95% CI: -48 to +8) and FVC (-14 mL, 95% CI: -49 to+2). Ba and Ti were assigned the largest negative weights for FEV1 and FVC within the model, respectively.

CONCLUSION

Our study investigating a wide range of HTEs in a highly polluted setting suggests that higher urinary HTE concentrations are associated with lower lung function, especially for emerging Ti and Ba, which need to be monitored or regulated to improve lung health.

MAPK15 controls cellular responses to oxidative stress by regulating NRF2 activity and expression of its downstream target genes

Oxidation processes in mitochondria and different environmental insults contribute to unwarranted accumulation of reactive oxygen species (ROS). These, in turn, rapidly damage intracellular lipids, proteins, and DNA, ultimately causing aging and several human diseases. Cells have developed different and very effective systems to control ROS levels. Among these, removal of excessive amounts is guaranteed by upregulated expression of various antioxidant enzymes, through activation of the NF-E2-Related Factor 2 (NRF2) protein. Here, we show that Mitogen Activated Protein Kinase 15 (MAPK15) controls the transactivating potential of NRF2 and, in turn, the expression of its downstream target genes. Specifically, upon oxidative stress, MAPK15 is necessary to increase NRF2 expression and nuclear translocation, by inducing its activating phosphorylation, ultimately supporting transactivation of cytoprotective antioxidant genes. Lungs are continuously exposed to oxidative damages induced by environmental insults such as air pollutants and cigarette smoke. Interestingly, we demonstrate that MAPK15 is very effective in supporting NRF2-dependent antioxidant transcriptional response to cigarette smoke of epithelial lung cells. Oxidative damage induced by cigarette smoke indeed represents a leading cause of disability and death worldwide by contributing to the pathogenesis of different chronic respiratory diseases and lung cancer. Therefore, the development of novel therapeutic strategies able to modulate cellular responses to oxidative stress would be highly beneficial. Our data contribute to the necessary understanding of the molecular mechanisms behind such responses and identify new potentially actionable targets.

Improving the Diagnosis and Treatment of Paediatric Bronchiectasis Through Research and Translation

Bronchiectasis, particularly in children, is an increasingly recognised yet neglected chronic lung disorder affecting individuals in both low-to-middle and high-income countries. It has a high disease burden and there is substantial inequity within and between settings. Furthermore, compared with other chronic lung diseases, considerably fewer resources are available for children with bronchiectasis. The need to prevent bronchiectasis and to reduce its burden also synchronously aligns with its high prevalence and economic costs to health services and society. Like many chronic lung diseases, bronchiectasis often originates early in childhood, highlighting the importance of reducing the disease burden in children. Concerted efforts are therefore needed to improve disease detection, clinical management and equity of care. Modifiable factors in the causal pathways of bronchiectasis, such as preventing severe and recurrent lower respiratory infections should be addressed, whilst also acknowledging the role played by social determinants of health. Here, we highlight the importance of early recognition/detection and optimal management of bronchiectasis in children, and outline our research, which is attempting to address important clinical knowledge gaps discussed in a recent workshop. The research is grouped under three themes focussing upon primary prevention, improving diagnosis and disease characterisation, and providing better management. Our hope is that others in multiple settings will undertake additional studies in this neglected field to further improve the lives of people with bronchiectasis. We also provide a resource list with links to help inform consumers and healthcare professionals about bronchiectasis and its recognition and management.

Barriers to Pulmonary Rehabilitation

Pulmonary rehabilitation (PR) is one of the most effective therapies for chronic respiratory diseases, yet it is significantly underutilized. There are several patient-related, geographic, societal, and health system-related barriers to PR. People with chronic respiratory disease face a collectively high burden of treatments including health care provider visits, medications, oxygen and other durable medical equipment, and providers' recommendation to undertake PR may be considered an added burden more than a likely benefit. Transportation difficulties, lack of insurance coverage, competing time priorities, low knowledge of PR, lack of perceived likely benefit, comorbidities, and other factors also pose obstacles to participation in PR for patients. Geographic availability of PR is heterogenous; in the United States, out-patient center-based PR programs are often not available within close proximity to patients' residence, posing barriers to patients' access to it. PR programs are lacking altogether in many areas; rural areas are particularly affected. Existing PR programs are often poorly funded and underresourced. Socioeconomic and racial disparities also influence patients' likelihood of receiving PR. Also, health care professionals (HCPs) often do not refer their patients with chronic respiratory disease to PR, owing to a lack of knowledge and awareness of its content and benefits, patient candidacy, or of the referral process. A limited number of multidisciplinary HCPs trained in PR likely also contributes to limited access to PR for patients. Collectively, these multifaceted barriers to PR create unacceptable health care disparities. Strategies to address barriers to PR are urgently needed in order to enable individuals who need to receive it.

Genetic variations in anti-diabetic drug targets and COPD risk: evidence from mendelian randomization

BACKGROUND

Previous research has emphasized the potential benefits of anti-diabetic medications in inhibiting the exacerbation of Chronic Obstructive Pulmonary Disease (COPD), yet the role of anti-diabetic drugs on COPD risk remains uncertain.

METHODS

This study employed a Mendelian randomization (MR) approach to evaluate the causal association of genetic variations related to six classes of anti-diabetic drug targets with COPD. The primary outcome for COPD was obtained from the Global Biobank Meta-analysis Initiative (GBMI) consortium, encompassing a meta-analysis of 12 cohorts with 81,568 cases and 1,310,798 controls. Summary-level data for HbA1c was derived from the UK Biobank, involving 344,182 individuals. Positive control analysis was conducted for Type 2 Diabetes Mellitus (T2DM) to validate the choice of instrumental variables. The study applied Summary-data-based MR (SMR) and two-sample MR for effect estimation and further adopted colocalization analysis to verify evidence of genetic variations.

RESULTS

SMR analysis revealed that elevated KCNJ11 gene expression levels in blood correlated with reduced COPD risk (OR = 0.87, 95% CI = 0.79-0.95; p = 0.002), whereas an increase in DPP4 expression corresponded with an increased COPD incidence (OR = 1.18, 95% CI = 1.03-1.35; p = 0.022). Additionally, the primary method within MR analysis demonstrated a positive correlation between PPARG-mediated HbA1c and both FEV1 (OR = 1.07, 95% CI = 1.02-1.13; P = 0.013) and FEV1/FVC (OR = 1.08, 95% CI = 1.01-1.14; P = 0.007), and a negative association between SLC5A2-mediated HbA1c and FEV1/FVC (OR = 0.86, 95% CI = 0.74-1.00; P = 0.045). No colocalization evidence with outcome phenotypes was detected (all PP.H4 < 0.7).

CONCLUSION

This study provides suggestive evidence for anti-diabetic medications' role in improving COPD and lung function. Further updated MR analyses are warranted in the future, following the acquisition of more extensive and comprehensive data, to validate our results.

Impact of lung transplantation on diastolic dysfunction in recipients with pretransplant pulmonary hypertension

OBJECTIVE

Pulmonary hypertension can cause left ventricular diastolic dysfunction through ventricular interdependence. Moreover, diastolic dysfunction has been linked to adverse outcomes after lung transplant. The impact of lung transplant on diastolic dysfunction in recipients with pretransplant pulmonary hypertension is not defined. In this cohort, we aimed to assess the prevalence of diastolic dysfunction, the change in diastolic dysfunction after lung transplant, and the impact of diastolic dysfunction on lung transplant outcomes.

METHODS

In a large, single-center database from January 2011 to September 2021, single or bilateral lung transplant recipients with pulmonary hypertension (mean pulmonary artery pressure > 20 mm Hg) were retrospectively identified. Those without a pre- or post-transplant echocardiogram within 1 year were excluded. Diastolic dysfunction was diagnosed and graded according to the American Society of Echocardiography 2016 guideline on assessment of diastolic dysfunction (present, absent, indeterminate). McNemar's test was used to examine association between diastolic dysfunction pre- and post-transplant. Kaplan-Meier and Cox regression analysis were used to assess associations between pre-lung transplant diastolic dysfunction and post-lung transplant 1-year outcomes, including mortality, major adverse cardiac events, and bronchiolitis obliterans syndrome grade 1 or higher-free survival.

RESULTS

Of 476 primary lung transplant recipients, 205 with pulmonary hypertension formed the study cohort (mean age, 56.6 ± 11.9 years, men 61.5%, mean pulmonary artery pressure 30.5 ± 9.8 mm Hg, left ventricular ejection fraction < 55% 9 [4.3%]). Pretransplant, diastolic dysfunction was present in 93 patients (45.4%) (grade I = 8, II = 84, III = 1), absent in 16 patients (7.8%), and indeterminate in 89 patients (43.4%), and 7 patients (3.4%) had missing data. Post-transplant, diastolic dysfunction was present in 7 patients (3.4%) (grade I = 2, II = 5, III = 0), absent in 164 patients (80.0%), and indeterminate in 15 patients (7.3%), and 19 patients (9.3%) had missing data. For those with diastolic dysfunction grades in both time periods (n = 180), there was a significant decrease in diastolic dysfunction post-transplant (148/169 patients with resolved diastolic dysfunction; McNemar's test P < .001). Pretransplant diastolic dysfunction was not associated with major adverse cardiac events (hazard ratio [HR], 1.08, 95% CI, 0.72-1.62; P = .71), bronchiolitis obliterans syndrome-free survival (HR, 0.67, 95% CI, 0.39-1.56; P = .15), or mortality (HR, 0.70, 95% CI, 0.33-1.46; P = .34) at 1 year.

CONCLUSIONS

Diastolic dysfunction is highly prevalent in lung transplant candidates with normal left ventricular systolic function and pulmonary hypertension, and resolves in most patients after lung transplant regardless of patient characteristics. Pre-lung transplant diastolic dysfunction was not associated with adverse lung or cardiac outcomes after lung transplant. Collectively, these findings suggest that the presence of diastolic dysfunction in lung transplant recipients with pulmonary hypertension has no prognostic significance, and as such diastolic dysfunction and the associated clinical syndrome of heart failure with preserved ejection fraction should not be considered a relative contraindication to lung transplant in such patients.

Call to action: Addressing asthma diagnosis and treatment gaps in India

In comparison to the worldwide burden of asthma, although India contributes to 13% of the total asthma prevalence, it has a threefold higher mortality rate and more than twofold higher DALYs, indicating a substantial gap in asthma diagnosis and treatment. Asthma causes significant suffering, affecting people's quality of life and draining the country's resources; therefore, we must devise ways and means to fill these gaps. The most successful and cost-efficient strategy to battle asthma is to form strong partnerships between patients, the general public, the government, the pharmaceutical industry and non-governmental organisations. This necessitates a comprehensive approach that involves raising awareness, developing universally applicable recommendations, increasing access to high-quality asthma care, and other measures. The purpose of this article was to review the existing scenario of asthma management in India and the factors that contribute to it and devise unique and all-encompassing strategies to fill these gaps.

Association of the oxidation balance score with the prevalence of chronic obstructive pulmonary disease from the NHANES 2007-2012: A large-scale cross-sectional study

BACKGROUND

The occurrence of chronic obstructive pulmonary disease (COPD) is associated with oxidative stress. Oxidation Balance Score (OBS) can evaluate the oxidation and antioxidant status of the body. However, we found no studies that examined the association between the two.

OBJECTIVE

To assess the association between OBS and COPD prevalence, and to explore dietary and lifestyle patterns aimed at preventing and delay COPD in adults.

METHOD

We included 13,909 participants using data from the NHANES. Weighted logistic regression model and weighted restricted cubic spline curve were used to explore the relationship between OBS and COPD. Subgroup analysis and sensitivity analysis were used to determine the stability of results. Mediation analysis was employed to assess the effect of inflammatory factors.

RESULT

In logistic regression model, compared with the lowest quartile of OBS, the highest quartile of OBS, diet OBS, lifestyle OBS and COPD had odd ratios OR(95%CI)=0.67 (0.51, 0.89), OR (95% CI) = 0.71 (0.55, 0.93), and OR (95% CI) = 0.39 (0.26, 0.58) respectively. The restricted cubic spline curve reveals that OBS and dietary OBS exhibit an L-shaped curve in relation to COPD prevalence, while lifestyle OBS shows a negative correlation curve with COPD prevalence. Subgroup analysis and sensitivity analysis proved the robustness of the association. Mediation analysis demonstrated that inflammatory factors mediate the association of OBS on the prevalence of COPD.

CONCLUSION

The increase of OBS, dietary OBS, and lifestyle OBS was associated with a decrease in the prevalence of COPD, but excessive OBS and dietary OBS were associated with an inapparent decrease or even increased risk of COPD.

Applications and advancements of nanoparticle-based drug delivery in alleviating lung cancer and chronic obstructive pulmonary disease

Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) are among the leading causes of mortality worldwide. Cigarette smoking is among the main aetiologic factors for both ailments. These diseases share common pathogenetic mechanisms including inflammation, oxidative stress, and tissue remodelling. Current therapeutic approaches are limited by low efficacy and adverse effects. Consequentially, LC has a 5-year survival of < 20%, while COPD is incurable, underlining the necessity for innovative treatment strategies. Two promising emerging classes of therapy against these diseases include plant-derived molecules (phytoceuticals) and nucleic acid-based therapies. The clinical application of both is limited by issues including poor solubility, poor permeability, and, in the case of nucleic acids, susceptibility to enzymatic degradation, large size, and electrostatic charge density. Nanoparticle-based advanced drug delivery systems are currently being explored as flexible systems allowing to overcome these limitations. In this review, an updated summary of the most recent studies using nanoparticle-based advanced drug delivery systems to improve the delivery of nucleic acids and phytoceuticals for the treatment of LC and COPD is provided. This review highlights the enormous relevance of these delivery systems as tools that are set to facilitate the clinical application of novel categories of therapeutics with poor pharmacokinetic properties.

Occupational status and chronic respiratory diseases: a cross-sectional study based on the data of the Rafsanjan Cohort Study

BACKGROUND

The aim of the present study was to investigate the possible connection between occupational status and chronic respiratory diseases (CRDs) among the Iranian population.

METHODS

The present cross-sectional study was conducted on 9934 individuals aged 35-70 years enrolled in the Rafsanjan Cohort Study (RCS), a component of the Prospective Epidemiological Research Studies in Iran (PERSIAN). Detailed questionnaires were used to collect information on various factors, such as occupation, sociodemographic characteristics, medical history, anthropometric measurements, physical activity, cigarette and hookah smoking, opium use, and alcohol consumption. The association between occupational class and CRD was evaluated using logistic regression models for rare events.

RESULTS

In the present study, 4624 (46.55%) participants were male, and 5310 (53.45%) were female. The prevalence of CRD among all participants was 2.61%. Occupational activities were classified into two categories: In class I, the largest group was the homemaker and unemployment category (41.73%), followed by self-employment (34.39%), employment (13.03%), and retired individuals (10.84%). In class II, there were pistachio farmers (12.61%), copper miners (3.62%), and others in various occupations (83.76%). Subjects with CRD were significantly more likely to be homemakers, unemployed, elderly, female, less educated, and obese. There was no significant relationship between CRD and job type/occupational status after adjusting for some potential confounding variables.

CONCLUSIONS

There was no significant relationship between CRD and job type/occupational status. However, longitudinal studies are needed to assess the impact of job type/occupational status on the risk of CRD.

First Molecular Evidence of Emerging Lophomonas Pathogen Among Patients Suspected of Having Pulmonary Tuberculosis in Mazandaran Province, Northern Iran

PURPOSE

Lophomoniasis is a chronic protozoan respiratory disease in humans with main clinical symptoms such as chronic cough, productive sputum, breath shortness, and occasionally hemoptysis. Differentiation diagnosis of lophomoniasis from tuberculosis (TB) and asthma is crucial.

METHODS

In this study, 210 participants with suspected TB referred to tuberculosis laboratories in Mazandaran province, northeastern Iran, were enrolled during 2021. All patients showed low grade fever, chronic cough or sputum on referral. Sputum specimens were collected from the participants, and Lophomonas DNA was detected through a conventional genus-specific polymerase chain reaction (PCR).

RESULTS

Out of 210 participants, 67 (31.9%) had Lophomonas spp., infection, 38 (18.1%) had TB (Smear and culture-positive), and 20 (9.5%) had both TB and Lophomonas co-infection.

CONCLUSION

Based on our results, a relatively high occurrence of Lophomonas infection was found among patients suspected of having TB. Accordingly, due to the high similarity of clinical symptoms between both pulmonary diseases, it is highly recommended to accurately and early diagnose the parasite in the sputum specimen.

The effect of breathing hypoxic gas (15% FIO2 ) on physiological and behavioral outcomes during simulated driving in healthy subjects

Hypoxia is mainly caused by cardiopulmonary disease or high-altitude exposure. We used a driving simulator to investigate whether breathing hypoxic gas influences driving behaviors in healthy subjects. Fifty-two healthy subjects were recruited in this study, approved by the Science and Engineering Ethical Committee. During simulated driving experiments, driving behaviors, breathing frequency, oxygen saturation (SpO2 ), and heart rate variability (HRV) were analyzed. Each subject had four driving sessions; a 10-min practice and three 20-min randomized interventions: normoxic room air (21% FIO2 ) and medical air (21% FIO2 ) and hypoxic air (equal to 15% FIO2 ), analyzed by repeated measures ANOVA. Driving behaviors and HRV frequency domains showed no significant change. Heart rate (HR; p < 0.0001), standard deviation of the RR interval (SDRR; p = 0.03), short-term HRV (SD1; p < 0.0001), breathing rate (p = 0.01), and SpO2 (p < 0.0001) were all significantly different over the three gas interventions. Pairwise comparisons showed HR increased during hypoxic gas exposure compared to both normoxic interventions, while SDRR, SD1, breathing rate, and SpO2 were lower. Breathing hypoxic gas (15% FiO2 , equivalent to 2710 m altitude) may not have a significant impact on driving behavior in healthy subjects. Furthermore, HRV was negatively affected by hypoxic gas exposure while driving suggesting further research to investigate the impact of breathing hypoxic gas on driving performance for patients with autonomic dysfunction.

The diagnostic value of bronchial provocation testing combined with fractional exhaled nitric oxide (FeNO) in children with chest tightness-variant asthma (CTVA)

BACKGROUND

Chest tightness-variant asthma (CTVA) is a novel atypical asthma characterized by chest tightness as the sole or primary symptom.

OBJECTIVES

To investigate the value of bronchial provocation testing combined with fractional exhaled nitric oxide (FeNO) in the diagnosis of CTVA in children.

METHODS

This study included 95 children aged 6-14 years with chest tightness as the sole symptom, with a duration of symptoms exceeding 4 weeks. All subjects underwent FeNO measurement, pulmonary function testing, and bronchial provocation testing using the Astograph method. Subjects with positive bronchial provocation testing were classified as the CTVA group, while those with negative results served as the non-CTVA control group.

RESULTS

The lung function of children in both groups was normal. The FeNO level in the CTVA group was (22.35 ± 9.91) ppb, significantly higher than the control group (14.85 ± 5.63) ppb, with a statistically significant difference (P < 0.05). The value of FeNO in diagnosing CTVA was analyzed using an ROC curve, with an area under the curve of 0.073 (P < 0.05). The optimal cutoff point for diagnosing CTVA using FeNO was determined to be 18.5 ppb, with a sensitivity of 60.3 % and specificity of 77.8 %. There was a negative correlation between FeNO and Dmin as well as PD15 (P = 0.006).

CONCLUSION

FeNO can serve as an adjunctive diagnostic tool for CTVA, with the optimal cutoff point for diagnosing CTVA being 18.5 ppb. However, FeNO is not a specific diagnostic marker for CTVA and should be used in conjunction with bronchial provocation testing to enhance its diagnostic value.

Efficacy and Mechanisms of Natural Products as Therapeutic Interventions for Chronic Respiratory Diseases

Chronic respiratory diseases are long-term conditions affecting the airways and other lung components that are characterized by a high prevalence, disability rate, and mortality rate. Further optimization of their treatment is required. Natural products, primarily extracted from organisms, possess specific molecular and structural formulas as well as distinct chemical and physical properties. These characteristics grant them the advantages of safety, gentleness, accessibility, and minimal side effects. The numerous advances in the use of natural products for treating chronic respiratory diseases have provided a steady source of motivation for new drug research and development. In this paper, we introduced the pathogenesis of chronic respiratory diseases and natural products. Furthermore, we classified natural products according to their mechanism for treating chronic respiratory diseases and describe the ways in which these products can alleviate the pathological symptoms. Simultaneously, we elaborate on the signal transduction pathways and biological impacts of natural products' targeting. Additionally, we present future prospects for natural products, considering their combination treatment approaches and administration methods. The significance of this review extends to both the research on preventing and treating chronic respiratory diseases, as well as the advancement of novel drug development in this field.

Aspherical, Nano-Structured Drug Delivery System with Tunable Release and Clearance for Pulmonary Applications

Addressing the challenge of efficient drug delivery to the lungs, a nano-structured, microparticulate carrier system with defined and customizable dimensions has been developed. Utilizing a template-assisted approach and capillary forces, particles were rapidly loaded and stabilized. The system employs a biocompatible alginate gel as a stabilizing matrix, facilitating the breakdown of the carrier in body fluids with the subsequent release of its nano-load, while also mitigating long-term accumulation in the lung. Different gel strengths and stabilizing steps were applied, allowing us to tune the release kinetics, as evaluated by a quantitative method based on a flow-imaging system. The micro-cylinders demonstrated superior aerodynamic properties in Next Generation Impactor (NGI) experiments, such as a smaller median aerodynamic diameter (MMAD), while yielding a higher fine particle fraction (FPF) than spherical particles similar in critical dimensions. They exhibited negligible toxicity to a differentiated macrophage cell line (dTHP-1) for up to 24 h of incubation. The kinetics of the cellular uptake by dTHP-1 cells was assessed via fluorescence microscopy, revealing an uptake-rate dependence on the aspect ratio (AR = l/d); cylinders with high AR were phagocytosed more slowly than shorter rods and comparable spherical particles. This indicates that this novel drug delivery system can modulate macrophage uptake and clearance by adjusting its geometric parameters while maintaining optimal aerodynamic properties and featuring a biodegradable stabilizing matrix.

The causality between systemic inflammatory regulators and chronic respiratory diseases: A bidirectional Mendelian-randomization study

INTRODUCTION

Accumulative evidence suggests the associations between systemic inflammatory regulators and chronic respiratory diseases (CRDs). However, the intrinsic causation remains implicit. Therefore, this study aimed to examine causative associations by mendelian randomization (MR) and to identify valuable active factors.

METHODS

Based on data from the GWAS database, we performed MR analyses of 41 serum cytokines from 8,293 Finnish and European descent cohorts from GBMI and UKBB for five major CRDs. We mainly applied inverse variance weighted regression, supplemented by MR-Egger regression, weighted median, maximum likelihood, weighted mode, and simple mode algorithms. Moreover, sensitivity analyses were conducted using Cochrane's Q test, MR-Egger intercept, MR-PRESSO Global test and MR-Steiger filtering. Eventually, the consistency of MR results was assessed by leave-one-out.

RESULTS

Our results suggest that 12 genetically predicted systemic inflammatory regulators probably participate in the progression of CRDs, including four risk factors (IL-1RA, IL-4, MIP-1A, PDGF-BB) and one protective factor (IL-6) in IPF, two protective factors (SCF, SDF-1A) in COPD, and two protective factors (SCF, SDF-1A) in asthma, two protective factors (GROA, IL-2RA) were also included in asthma, whereas only one factor (HGF) was protective against bronchiectasis. Additionally, two protective factors (FGF-BASIC, G-CSF) were identified in sarcoidosis. Sensitivity analyses showed no horizontal pleiotropy and significant heterogeneity. Finally, based on the findings of inverse MR analysis, no inverse causal association was uncovered, confirming the robustness of results.

CONCLUSION

Our study unearths potential associations between systemic inflammatory modulators and common CRDs, providing new insights for inflammation-mediated CRD prevention and therapeutic approaches.

The secretory leukocyte protease inhibitor (SLPI) in pathophysiology of non-communicable diseases: Evidence from experimental studies to clinical applications

Non-communicable diseases (NCDs) are a worldwide health issue because of their prevalence, negative impacts on human welfare, and economic costs. Protease enzymes play important roles in viral and NCD diseases. Slowing disease progression by inhibiting proteases using small-molecule inhibitors or endogenous inhibitory peptides appears to be crucial. Secretory leukocyte protease inhibitor (SLPI), an inflammatory serine protease inhibitor, maintains protease/antiprotease balance. SLPI is produced by host defense effector cells during inflammation to prevent proteolytic enzyme-induced tissue damage. The etiology of noncommunicable illnesses is linked to SLPI's immunomodulatory and tissue regeneration roles. Disease phases are associated with SLPI levels and activity changes in regional tissue and circulation. SLPI has been extensively evaluated in inflammation, but rarely in NCDs. Unfortunately, the thorough evaluation of SLPI's pathophysiological functions in NCDs in multiple research models has not been published elsewhere. In this review, data from PubMed from 2014 to 2023 was collected, analysed, and categorized into in vitro, in vivo, and clinical studies. According to the review, serine protease inhibitor (SLPI) activity control is linked to non-communicable diseases (NCDs) and other illnesses. Overexpression of the SLPI gene and protein may be a viable diagnostic and therapeutic target for non-communicable diseases (NCDs). SLPI is also cytoprotective, making it a unique treatment. These findings suggest that future research should focus on these pathways using advanced methods, reliable biomarkers, and therapy approaches to assess susceptibility and illness progression. Implications from this review will help pave the way for a new therapeutic target and diagnosis marker for non-communicable diseases.

Exploring knowledge gaps and research needs in respiratory therapy: a qualitative description study

Background

Respiratory therapists (RTs) are expected to stay updated on technology, treatments, research, and best practices to provide high-quality patient care. They must possess the skills to interpret, evaluate, and contribute to evidence-based practices. However, RTs often rely on research from other professions that may not fully address their specific needs, leading to insufficient guidance for their practice. Additionally, there has been no exploration of knowledge gaps and research needs from RTs' perspectives to enhance their practice and patient outcomes. The research questions guiding this study were: (i) what are the perceived practice-oriented knowledge gaps? and (ii) what are the necessary research priorities across the respiratory therapy profession according to experts in respiratory therapy?

Methods

A qualitative description study was conducted using semi-structured focus groups with 40 expert RTs from seven areas of practice across Canada. Data was analyzed using qualitative content analysis.

Results

We identified four major themes relating to what these experts perceive as the practice-oriented gaps and necessary research priorities across the respiratory therapy profession: 1) system-level impact of RTs, 2) optimizing respiratory therapy practices, 3) scholarship on the respiratory therapy profession and 4) respiratory therapy education.

Discussion

The findings establish a fundamental understanding of the current gaps and the specific needs of RTs that require further investigation. Participants strongly emphasized the significance of research priorities that consider the breadth and depth of the respiratory therapy profession, which underscores the complex nature of respiratory therapy and its application in practice.

Conclusion

The unique insights garnered from this study highlight the knowledge gaps and research needs specific to RTs. These findings pave the way for further exploration, discourse, and research aimed at understanding the specific contributions and requirements of RTs.

Genetic association and bidirectional Mendelian randomization for causality between gut microbiota and six lung diseases

Purposes

Increasing evidence suggests that intestinal microbiota correlates with the pathological processes of many lung diseases. This study aimed to investigate the causality of gut microbiota and lung diseases.

Methods

Genetic information on intestinal flora and lung diseases [asthma, chronic bronchitis, chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD), lower respiratory tract infection (LRTI), pulmonary arterial hypertension (PAH)] and lung function was obtained from UK Biobank, FinnGen, and additional studies. A Mendelian randomization (MR) analysis was conducted to explore the causal association between gut microbiota and lung diseases.

Results

The genetic liability to lung diseases may be associated with the abundance of certain microbiota taxa. Specifically, the genus Prevotella (p = 0.041) was related to a higher risk of asthma; the family Defluviitaleaceae (p = 0.002) and its child taxon were identified as a risk factor for chronic bronchitis; the abundance of the genus Prevotella (p = 0.020) was related to a higher risk of ILD; the family Coriobacteriaceae (p = 0.011) was identified to have a positive effect on the risk of LRTI; the genus Lactobacillus (p = 0.0297) has been identified to be associated with an increased risk of PAH, whereas the genus Holdemanella (p = 0.0154) presented a causal decrease in COPD risk; the order Selenomonadales was identified to have a positive effect on the risk of FEV1(p = 0.011). The reverse TSMR analysis also provided genetic evidence of reverse causality from lung diseases to the gut microbiota.

Conclusion

This data-driven MR analysis revealed that gut microbiota was causally associated with lung diseases, providing genetic evidence for further mechanistic and clinical studies to understand the crosstalk between gut microbiota and lung diseases.

Educational Interventions in Immigrants for Asthma and COPD: A Systematic Review

Objective

Asthma and COPD are prevalent respiratory conditions among immigrants, yet many individuals in this population do not effectively utilize available therapies, resulting in exacerbations and limitations in their daily lives. This systematic review seeks to describe asthma/COPD educational interventions specifically tailored for immigrant patients and assess their variability and outcomes, with the ultimate goal of improving self-management and achieving better asthma or COPD control in this population.

Design

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. A comprehensive literature search was conducted using four electronic databases (CINAHL, PubMed, Embase and PsycInfo). Articles were included if they focused on asthma or COPD interventions conducted in immigrant populations. The Mixed Methods Appraisal Tool was used to assess the quality of included articles.

Results

Out of the initial 1173 articles identified, 812 were assessed for eligibility. Six articles met the inclusion criteria for educational interventions targeting immigrants with asthma or COPD. These studies explored the effectiveness of interventions on various immigrant populations using different methodologies including group discussion of photographs and classroom-based interventions. The interventions varied in terms of settings, educational materials, and delivery methods. Positive outcomes were observed in areas such as knowledge, understanding of instructions, and inhaler technique. However, the included studies had limitations in assessing the impact on asthma and COPD self-management and sustainability.

Conclusion

More research is needed on asthma and COPD management in immigrants. The interventions included in this review had positive effects on outcomes like inhaler technique and asthma knowledge. However, due to variability in outcome measures, it is difficult to directly compare the interventions. Future studies should include diverse immigrant populations, consider the specific migration status of the immigrants, long-term sustainability of the intervention and use culturally tailored approaches to improve respiratory health in this population.

Prospective clinical validation of the Empatica EmbracePlus wristband as a reflective pulse oximeter

Introduction

Respiratory diseases such as chronic obstructive pulmonary disease, obstructive sleep apnea syndrome, and COVID-19 may cause a decrease in arterial oxygen saturation (SaO2). The continuous monitoring of oxygen levels may be beneficial for the early detection of hypoxemia and timely intervention. Wearable non-invasive pulse oximetry devices measuring peripheral oxygen saturation (SpO2) have been garnering increasing popularity. However, there is still a strong need for extended and robust clinical validation of such devices, especially to address topical concerns about disparities in performances across racial groups. This prospective clinical validation aimed to assess the accuracy of the reflective pulse oximeter function of the EmbracePlus wristband during a controlled hypoxia study in accordance with the ISO 80601-2-61:2017 standard and the Food & Drug Administration (FDA) guidance.

Methods

Healthy adult participants were recruited in a controlled desaturation protocol to reproduce mild, moderate, and severe hypoxic conditions with SaO2 ranging from 100% to 70% (ClinicalTrials.gov registration #NCT04964609). The SpO2 level was estimated with an EmbracePlus device placed on the participant's wrist and the reference SaO2 was obtained from blood samples analyzed with a multiwavelength co-oximeter.

Results

The controlled hypoxia study yielded 373 conclusive measurements on 15 subjects, including 30% of participants with dark skin pigmentation (V-VI on the Fitzpatrick scale). The accuracy root mean square (Arms) error was found to be 2.4%, within the 3.5% limit recommended by the FDA. A strong positive correlation between the wristband SpO2 and the reference SaO2 was observed (r = 0.96, P < 0.001), and a good concordance was found with Bland-Altman analysis (bias, 0.05%; standard deviation, 1.66; lower limit, -4.7%; and upper limit, 4.8%). Moreover, acceptable accuracy was observed when stratifying data points by skin pigmentation (Arms 2.2% in Fitzpatrick V-VI, 2.5% in Fitzpatrick I-IV), and sex (Arms 1.9% in females, and 2.9% in males).

Discussion

This study demonstrates that the EmbracePlus wristband could be used to assess SpO2 with clinically acceptable accuracy under no-motion and high perfusion conditions for individuals of different ethnicities across the claimed range. This study paves the way for further accuracy evaluations on unhealthy subjects and during prolonged use in ambulatory settings.

Curcumin and PCI-34051 combined treatment ameliorates inflammation and fibrosis by affecting MAP kinase pathway

OBJECTIVE

Bronchoconstriction, along with inflammation and hyperresponsiveness is the characteristic feature associated with asthma, contributing to variable airflow obstruction, which manifests shortness of breath, cough and wheeze, etc. Histone deacetylases 8 (HDAC8) is the member of class I HDAC family and known to regulate microtubule integrity and muscle contraction. Therefore, we aimed to investigate the effects of HDAC8 inhibition in murine model of asthma using Pan-HDAC inhibitor curcumin (CUR) and HDAC8-specific inhibitor PCI-34051 (PCI), alone and in combination.

MATERIALS AND METHODS

To develop asthmatic mouse model, Balb/c mice were sensitized and challenged with ovalbumin (OVA). CUR (10 mg/kg, pre, post, alone and combined treatment) and PCI (0.5 mg/kg), were administered through intranasal (i.n) route, an hour before OVA aerosol challenge. Effects of HDAC8 inhibition by CUR and PCI pretreatments were evaluated in terms of inflammation, oxidative stress and fibrosis markers. Efficacy of curcumin post-treatment (CUR(p)) was also evaluated simultaneously.

RESULTS

Inflammatory cell recruitment, oxidative stress (reactive oxygen species, nitric oxide), histamine and Immunoglobulin E (IgE) levels and expression of fibrosis markers including hydroxyproline, matrix metalloproteinases-9 and alpha smooth muscle actin (MMP-9 and α-SMA) were significantly reduced by CUR, CUR(p), PCI-alone and combined treatments. Protein expressions of HDAC8, Nuclear factor-κB (NF-κB) accompanied by MAPKs (mitogen-activated protein kinases) were significantly reduced by the treatments. Structural alterations were examined by histopathological analysis and linked with the fibrotic changes.

CONCLUSIONS

Present study indicates protective effects of HDAC8 inhibition in asthma using HDAC8 using CUR and PCI alone or in combination, attenuates airway inflammation, fibrosis and remodeling; hence, bronchoconstriction was accompanied through modulation of MAP kinase pathway.

Enabling Continuous Breathing-Phase Contextualization via Wearable-Based Impedance Pneumography and Lung Sounds: A Feasibility Study

Chronic respiratory diseases affect millions and are leading causes of death in the US and worldwide. Pulmonary auscultation provides clinicians with critical respiratory health information through the study of Lung Sounds (LS) and the context of the breathing-phase and chest location in which they are measured. Existing auscultation technologies, however, do not enable the simultaneous measurement of this context, thereby potentially limiting computerized LS analysis. In this work, LS and Impedance Pneumography (IP) measurements were obtained from 10 healthy volunteers while performing normal and forced-expiratory (FE) breathing maneuvers using our wearable IP and respiratory sounds (WIRS) system. Simultaneous auscultation was performed with the Eko CORE stethoscope (EKO). The breathing-phase context was extracted from the IP signals and used to compute phase-by-phase (Inspiratory (I), expiratory (E), and their ratio (I:E)) and breath-by-breath acoustic features. Their individual and added value was then elucidated through machine learning analysis. We found that the phase-contextualized features effectively captured the underlying acoustic differences between deep and FE breaths, yielding a maximum F1 Score of 84.1 ±11.4% with the phase-by-phase features as the strongest contributors to this performance. Further, the individual phase-contextualized models outperformed the traditional breath-by-breath models in all cases. The validity of the results was demonstrated for the LS obtained with WIRS, EKO, and their combination. These results suggest that incorporating breathing-phase context may enhance computerized LS analysis. Hence, multimodal sensing systems that enable this, such as WIRS, have the potential to advance LS clinical utility beyond traditional manual auscultation and improve patient care.

A critical assessment of the cellular defences of the avian respiratory system: are birds in general and poultry in particular relatively more susceptible to pulmonary infections/afflictions?

In commercial poultry farming, respiratory diseases cause high morbidities and mortalities, begetting colossal economic losses. Without empirical evidence, early observations led to the supposition that birds in general, and poultry in particular, have weak innate and adaptive pulmonary defences and are therefore highly susceptible to injury by pathogens. Recent findings have, however, shown that birds possess notably efficient pulmonary defences that include: (i) a structurally complex three-tiered airway arrangement with aerodynamically intricate air-flow dynamics that provide efficient filtration of inhaled air; (ii) a specialised airway mucosal lining that comprises air-filtering (ciliated) cells and various resident phagocytic cells such as surface and tissue macrophages, dendritic cells and lymphocytes; (iii) an exceptionally efficient mucociliary escalator system that efficiently removes trapped foreign agents; (iv) phagocytotic atrial and infundibular epithelial cells; (v) phagocytically competent surface macrophages that destroy pathogens and injurious particulates; (vi) pulmonary intravascular macrophages that protect the lung from the vascular side; and (vii) proficiently phagocytic pulmonary extravasated erythrocytes. Additionally, the avian respiratory system rapidly translocates phagocytic cells onto the respiratory surface, ostensibly from the subepithelial space and the circulatory system: the mobilised cells complement the surface macrophages in destroying foreign agents. Further studies are needed to determine whether the posited weak defence of the avian respiratory system is a global avian feature or is exclusive to poultry. This review argues that any inadequacies of pulmonary defences in poultry may have derived from exacting genetic manipulation(s) for traits such as rapid weight gain from efficient conversion of food into meat and eggs and the harsh environmental conditions and severe husbandry operations in modern poultry farming. To reduce pulmonary diseases and their severity, greater effort must be directed at establishment of optimal poultry housing conditions and use of more humane husbandry practices.

Development and validation of risk prediction nomograms for acute respiratory failure in elderly patients with hip fracture

BACKGROUND

Hip fractures in the elderly often lead to acute respiratory failure, but there is currently no tool to assess the prognosis of such patients. This study aims to develop a risk prediction model for respiratory failure in these patients.

METHODS

A retrospective cross-sectional study was conducted using the Medical Information Mart for Intensive Care (MIMIC)-IV database, incorporating data from 3,266 patients with hip fractures aged over 55 years from 2008 to 2019. Data included demographic information, laboratory indicators, comorbidities, and treatment methods. Patients were divided into a training group (70%) and a validation group (30%). Least Absolute Shrinkage and Selection Operator (LASSO) regression was applied to select prognostic predictors, and a visualized nomogram model was constructed using multivariate logistic regression analysis. Model performance and clinical applicability were assessed. Statistical analyses were done using R4.2.2, with P < 0.05 deemed significant.

RESULTS

Seven key factors, including age, height, albumin, chloride, pneumonia, acute kidney injury (AKI), and heparin use, were associated with respiratory failure risk. The model demonstrated good performance with area under the curve (AUC) values of 0.77 and 0.73 in the training and validation sets, respectively. The calibration curve showed good agreement, and decision curve analysis (DCA) indicated the model's clinical benefit.

CONCLUSIONS

This risk prediction model can effectively predict respiratory failure in hip fracture patients, assisting clinicians in identifying high-risk individuals and providing evidence-based references for treatment strategies.

Real-time counting of wheezing events from lung sounds using deep learning algorithms: Implications for disease prediction and early intervention

This pioneering study aims to revolutionize self-symptom management and telemedicine-based remote monitoring through the development of a real-time wheeze counting algorithm. Leveraging a novel approach that includes the detailed labeling of one breathing cycle into three types: break, normal, and wheeze, this study not only identifies abnormal sounds within each breath but also captures comprehensive data on their location, duration, and relationships within entire respiratory cycles, including atypical patterns. This innovative strategy is based on a combination of a one-dimensional convolutional neural network (1D-CNN) and a long short-term memory (LSTM) network model, enabling real-time analysis of respiratory sounds. Notably, it stands out for its capacity to handle continuous data, distinguishing it from conventional lung sound classification algorithms. The study utilizes a substantial dataset consisting of 535 respiration cycles from diverse sources, including the Child Sim Lung Sound Simulator, the EMTprep Open-Source Database, Clinical Patient Records, and the ICBHI 2017 Challenge Database. Achieving a classification accuracy of 90%, the exceptional result metrics encompass the identification of each breath cycle and simultaneous detection of the abnormal sound, enabling the real-time wheeze counting of all respirations. This innovative wheeze counter holds the promise of revolutionizing research on predicting lung diseases based on long-term breathing patterns and offers applicability in clinical and non-clinical settings for on-the-go detection and remote intervention of exacerbated respiratory symptoms.

Association of cesarean section with asthma in children/adolescents: a systematic review and meta-analysis based on cohort studies

BACKGROUND

Whether cesarean section (CS) is a risk factor for asthma in offspring is controversial. The purpose of this study was to investigate the association between CS and asthma in children/adolescents.

METHODS

Pubmed, Embase, Web of Science, and Cochrane Library electronic databases were searched for cohort studies on the relationship between mode of delivery and asthma in children/adolescents up to February 2023. Birth via CS was considered an exposure factor. Asthma incidence was taken as a result.

RESULTS

Thirty-five cohort studies (thirteen prospective and twenty-two retrospective cohort studies) were included. The results showed that the incidence of asthma was higher in CS offspring (odds ratio (OR) = 1.18, P < 0.001) than in the vaginal delivery (VD) group. Partial subgroup analyses showed a higher incidence of asthma in female offspring born via CS (OR = 1.26, P < 0.001) compared with the VD group, while there was no difference in males (OR = 1.07, P = 0.325). Asthma incidence was higher in CS offspring than in the VD group in Europe (OR = 1.20, P < 0.001), North America (OR = 1.15, P < 0.001), and Oceania (OR = 1.06, P = 0.008). This trend was not found in the Asian population (OR = 1.17, P = 0.102). The incidence of atopic asthma was higher in offspring born via CS (OR = 1.14, P < 0.001) compared to the VD group. The CS group had a higher incidence of persistent asthma, but the difference did not reach statistical significance (OR = 1.15, P = 0.063).

CONCLUSION

In this meta-analysis, CS may be a risk factor for asthma in offspring children/adolescents compared with VD. The relationship between CS and asthma was influenced by sex and region.

Quantitative CT Scan Imaging of the Airways for Diagnosis and Management of Lung Disease

CT scan imaging provides high-resolution images of the lungs in patients with chronic respiratory diseases. Extensive research over the last several decades has focused on developing novel quantitative CT scan airway measurements that reflect abnormal airway structure. Despite many observational studies demonstrating that associations between CT scan airway measurements and clinically important outcomes such as morbidity, mortality, and lung function decline, few quantitative CT scan measurements are applied in clinical practice. This article provides an overview of the relevant methodologic considerations for implementing quantitative CT scan airway analyses and provides a review of the scientific literature involving quantitative CT scan airway measurements used in clinical or randomized trials and observational studies of humans. We also discuss emerging evidence for the clinical usefulness of quantitative CT scan imaging of the airways and discuss what is required to bridge the gap between research and clinical application. CT scan airway measurements continue to improve our understanding of disease pathophysiologic features, diagnosis, and outcomes. However, a literature review revealed a need for studies evaluating clinical benefit when quantitative CT scan imaging is applied in the clinical setting. Technical standards for quantitative CT scan imaging of the airways and high-quality evidence of clinical benefit from management guided by quantitative CT scan imaging of the airways are required.

The therapeutic role of inspiratory muscle training in the management of asthma: a narrative review

Asthma is a disorder of the airways characterized by chronic airway inflammation, hyperresponsiveness, and variable recurring airway obstruction. Treatment options for asthma include pharmacological strategies, whereas nonpharmacological strategies are limited. Established pharmacological approaches to treating asthma may cause unwanted side effects and do not always afford adequate protection against asthma, possibly because of an individual's variable response to medications. A potential nonpharmacological intervention that is most available and cost effective is inspiratory muscle training (IMT), which is a technique targeted at increasing the strength and endurance of the diaphragm and accessory muscles of inspiration. Studies examining the impact of IMT on asthma have reported increases in inspiratory muscle strength and a reduction in the perception of dyspnea and medication use. However, because of the limited number of studies and discordant methods between studies more evidence is required to elucidate in individuals with asthma the efficacy of IMT on inspiratory muscle endurance, exercise capacity, asthma control, symptoms, and quality of life as well as in adolescents with differing severities of asthma. Large randomized controlled trials would be a significant step forward in clarifying the effectiveness of IMT in individuals with asthma. Although IMT may have favorable effects on inspiratory muscle strength, dyspnea, and medication use, the current evidence that IMT is an effective treatment for asthma is inconclusive.

Health Status of US Patients With One or More Health Conditions: Using a Novel Electronic Patient-reported Outcome Measure Producing Single Metric Measures

BACKGROUND

Most existing research studying health status impacted by morbidity has focused on a specific health condition, and most instruments used for measuring health status are neither patient-centered nor preference-based. This study aims to report on the health status of patients impacted by one or more health conditions, measured by a patient-centered and preference-based electronic patient-reported outcome measure.

METHODS

A cross-sectional study was conducted among patients with one or more health conditions in the United States. A novel generic, patient-centered, and preference-based electronic patient-reported outcome measure: Château Santé-Base, was used to measure health status. Individual health state was expressed as a single metric number (value). We compared these health-state values between sociodemographic subgroups, between separate conditions, between groups with or without comorbidity, and between different combinations of multimorbidity.

RESULTS

The total sample comprised 3913 patients. Multimorbidity was present in 62% of the patients. The most prevalent health conditions were pain (50%), fatigue/sleep problems (40%), mental health problems (28%), respiratory diseases (22%), and diabetes (18%). The highest (best) and lowest health-state values were observed in patients with diabetes and mental health problems. Among combinations of multimorbidity, the lowest values were observed when mental health problems were involved, the second lowest values were observed when fatigue/sleep problems and respiratory diseases coexisted.

CONCLUSIONS

This study compared health status across various single, and multiple (multimorbidity and comorbidity) health conditions directly, based on single metric health-state values. The insights are valuable in clinical practice and policy-making.

Assessment of In Vitro Airway Smooth Muscle Relaxant Activity of Rhus coriaria L. Fruit Ethanolic Extract and Its Possible Mechanisms

Rhus coriaria L. (Anacardiaceae), also known as Sumac, is commonly used as a spice, flavoring agent, and as a traditional medicinal herb. This includes also the traditional use for treating asthma, catarrh, and common colds. The accumulating evidence supports its cardioprotective, antidiabetic, neuroprotective, anticancer, gastroprotective, antibacterial, anti-inflammatory, antiviral, antioxidant, and respiratory effects. However, there are no previous studies that have shown its effects and mechanism in the airway smooth muscle tone, and therefore, the aim of our study was to investigate the in vitro pharmacological action of R. coriaria L. extract (RCE) on the rat isolated tracheal and bronchial preparations by exploring its relaxant activity and mechanism of action. The direct relaxant effect of RCE (0.1-0.7 mg/mL) was tested in the rat bronchi and trachea rings precontracted by carbachol (CCh). In addition, the pretreatment with RCE (1 mg/mL) was tested on the bronchial and tracheal reactivity induced by CCh, potassium chloride (KCl), or CaCl2. In addition, the cyclooxygenase inhibitor indomethacin and the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME), respectively, were used for exploring the mechanisms of RCE-induced relaxation and reduction of reactivity. Our findings demonstrated that RCE induced a concentration-dependent relaxation and a significant reduction of reactivity, significantly reduced with either indomethacin or L-NAME. In addition, RCE decreased the responsiveness to KCl and affected the extracellular Ca2+-induced contraction in the tissues with added CCh or KCl in Ca2+-free Krebs-Henseleit solution. In summary, we have shown that RCE displayed relaxant activities in the in vitro airway smooth muscles, and the possible mechanisms seems to involve the prostaglandin, nitric oxide, and Ca2+ pathways. Taken together, our findings indicate the potential role of RCE in the treatment of respiratory diseases with limited airflow, or obstructive respiratory diseases, and could justify its traditional use in the respiratory diseases.

Barriers to adherence to home-based pulmonary rehabilitation among patients with chronic obstructive pulmonary disease in Iran: a descriptive qualitative study

OBJECTIVES

Chronic obstructive pulmonary disease is a chronic disease with numerous complications. Therefore, its effective management depends on home-based pulmonary rehabilitation. The effectiveness of home-based pulmonary rehabilitation programmes in turn depends on patient adherence to them. The aim of this study was to explore the barriers to adherence to home-based pulmonary rehabilitation among patients with chronic obstructive pulmonary disease.

DESIGN

Qualitative descriptive design.

SETTING

The lung care wards of Al-Zahra and Khorshid teaching hospitals and the comprehensive lung care clinic of Khorshid hospital, Isfahan, Iran.

PARTICIPANTS

Participants patients with chronic obstructive pulmonary disease (n=20), their family caregivers (n=15) and healthcare providers (n=14) recruited via purposive sampling.

RESULTS

The five main categories of the barriers to adherence to home-based pulmonary rehabilitation among patients with chronic obstructive pulmonary disease were patient-related barriers, caregivers' caregiving burden, limited support for patients, healthcare providers' limited professional competence and ineffective home-based pulmonary rehabilitation planning.

CONCLUSION

Different and complex factors related to patients, families and healthcare providers can affect adherence to home-based pulmonary rehabilitation among patients with chronic obstructive pulmonary disease. Healthcare authorities can use the findings of this study to develop strategies to support patients with chronic obstructive pulmonary disease and their family caregivers and thereby reduce the physical and mental complications of Chronic obstructive pulmonary disease.

Machine Learning for Automated Classification of Abnormal Lung Sounds Obtained from Public Databases: A Systematic Review

Pulmonary auscultation is essential for detecting abnormal lung sounds during physical assessments, but its reliability depends on the operator. Machine learning (ML) models offer an alternative by automatically classifying lung sounds. ML models require substantial data, and public databases aim to address this limitation. This systematic review compares characteristics, diagnostic accuracy, concerns, and data sources of existing models in the literature. Papers published from five major databases between 1990 and 2022 were assessed. Quality assessment was accomplished with a modified QUADAS-2 tool. The review encompassed 62 studies utilizing ML models and public-access databases for lung sound classification. Artificial neural networks (ANN) and support vector machines (SVM) were frequently employed in the ML classifiers. The accuracy ranged from 49.43% to 100% for discriminating abnormal sound types and 69.40% to 99.62% for disease class classification. Seventeen public databases were identified, with the ICBHI 2017 database being the most used (66%). The majority of studies exhibited a high risk of bias and concerns related to patient selection and reference standards. Summarizing, ML models can effectively classify abnormal lung sounds using publicly available data sources. Nevertheless, inconsistent reporting and methodologies pose limitations to advancing the field, and therefore, public databases should adhere to standardized recording and labeling procedures.

Berberine-loaded engineered nanoparticles attenuate TGF-β-induced remodelling in human bronchial epithelial cells

Airway remodelling occurs in chronic respiratory diseases (CRDs) such as asthma and chronic obstructive pulmonary disease (COPD). It is characterized by aberrant activation of epithelial reparation, excessive extracellular matrix (ECM) deposition, epithelial-to-mesenchymal transition (EMT), and airway obstruction. The master regulator is Transforming Growth Factor-β (TGF-β), which activates tissue repair, release of growth factors, EMT, increased cell proliferation, and reduced nitric oxide (NO) secretion. Due to its fundamental role in remodelling, TGF-β is an emerging target in the treatment of CRDs. Berberine is a benzylisoquinoline alkaloid with antioxidant, anti-inflammatory, and anti-fibrotic activities whose clinical application is hampered by poor permeability. To overcome these limitations, in this study, berberine was encapsulated in monoolein-based liquid crystalline nanoparticles (BM-LCNs). The potential of BM-LCNs in inhibiting TGF-β-induced remodelling features in human bronchial epithelial cells (BEAS-2B) was tested. BM-LCNs significantly inhibited TGF-β-induced migration, reducing the levels of proteins upregulated by TGF-β including endoglin, thrombospondin-1, basic fibroblast growth factor, vascular-endothelial growth factor, and myeloperoxidase, and increasing the levels of cystatin C, a protein whose expression was downregulated by TGF-β. Furthermore, BM-LCNs restored baseline NO levels downregulated by TGF-β. The results prove the in vitro therapeutic efficacy of BM-LCNs in counteracting TGF-β-induced remodelling features. This study supports the suitability of berberine-loaded drug delivery systems to counteract airway remodelling, with potential application as a treatment strategy against CRDs.

Regenerative and translational medicine in COPD: hype and hope

COPD is a common, preventable and usually progressive disease associated with an enhanced chronic inflammatory response in the airways and lung, generally caused by exposure to noxious particles and gases. It is a treatable disease characterised by persistent respiratory symptoms and airflow limitation due to abnormalities in the airways and/or alveoli. COPD is currently the third leading cause of death worldwide, representing a serious public health problem and a high social and economic burden. Despite significant advances, effective clinical treatments have not yet been achieved. In this scenario, cell-based therapies have emerged as potentially promising therapeutic approaches. However, there are only a few published studies of cell-based therapies in human patients with COPD and a small number of ongoing clinical trials registered on clinicaltrials.gov Despite the advances and interesting results, numerous doubts and questions remain about efficacy, mechanisms of action, culture conditions, doses, timing, route of administration and conditions related to homing and engraftment of the infused cells. This article presents the state of the art of cell-based therapy in COPD. Clinical trials that have already been completed and with published results are discussed in detail. We also discuss the questions that remain unanswered about cell-based regenerative and translational medicine for COPD.

Innovative three-dimensional models for understanding mechanisms underlying lung diseases: powerful tools for translational research

Chronic lung diseases result from alteration and/or destruction of lung tissue, inevitably causing decreased breathing capacity and quality of life for patients. While animal models have paved the way for our understanding of pathobiology and the development of therapeutic strategies for disease management, their translational capacity is limited. There is, therefore, a well-recognised need for innovative in vitro models to reflect chronic lung diseases, which will facilitate mechanism investigation and the advancement of new treatment strategies. In the last decades, lungs have been modelled in healthy and diseased conditions using precision-cut lung slices, organoids, extracellular matrix-derived hydrogels and lung-on-chip systems. These three-dimensional models together provide a wide spectrum of applicability and mimicry of the lung microenvironment. While each system has its own limitations, their advantages over traditional two-dimensional culture systems, or even over animal models, increases the value of in vitro models. Generating new and advanced models with increased translational capacity will not only benefit our understanding of the pathobiology of lung diseases but should also shorten the timelines required for discovery and generation of new therapeutics. This article summarises and provides an outline of the European Respiratory Society research seminar "Innovative 3D models for understanding mechanisms underlying lung diseases: powerful tools for translational research", held in Lisbon, Portugal, in April 2022. Current in vitro models developed for recapitulating healthy and diseased lungs are outlined and discussed with respect to the challenges associated with them, efforts to develop best practices for model generation, characterisation and utilisation of models and state-of-the-art translational potential.

Beginning to Address an Implementation Gap in Asthma: Clinicians' Views of Prescribing Reliever Budesonide-Formoterol Inhalers and SMART in the United States

BACKGROUND

The Global Initiative for Asthma and National Asthma Education and Prevention Program recently made paradigm-shifting recommendations regarding inhaler management in asthma. The Global Initiative for Asthma now recommends that combination inhaled corticosteroid (ICS)-formoterol inhalers replace short-acting β-agonists as the preferred reliever therapy at all steps of asthma management. Although the most recent guidelines of the National Asthma Education and Prevention Program did not review reliever ICS-formoterol usage in mild asthma, they similarly recommended single maintenance and reliever therapy (SMART) at steps 3 and 4 of asthma management. Despite these recommendations, many clinicians-particularly in the United States-are not prescribing new inhaler paradigms. Clinician-level reasons for this implementation gap remain largely unexplored.

OBJECTIVE

To gain an in-depth understanding of the facilitators and barriers to prescribing reliever ICS-formoterol inhalers and SMART in the United States.

METHODS

Community and academic primary care providers, pulmonologists, and allergists who reported regularly caring for adults with asthma were interviewed. Interviews were recorded, transcribed, qualitatively coded, and analyzed using the Consolidated Framework for Implementation Research. Interviews were continued until theme saturation.

RESULTS

Among 20 interviewed clinicians, only 6 clinicians described regularly prescribing ICS-formoterol inhalers as a reliever inhaler (either alone or within SMART). Significant barriers to new inhaler approaches included concerns surrounding a lack of Food and Drug Administration labeling for ICS-formoterol as a reliever therapy, a lack of awareness regarding a patient's formulary-preferred ICS-long-acting β-agonist choices, the high cost of combination inhalers, and time constraints. Facilitators to using new inhaler approaches included clinicians' beliefs that the latest inhaler recommendations are simpler and more congruent with real-world patients' behavior, and that a potential change in management strategy would offer a valuable opportunity for shared decision making.

CONCLUSIONS

Although new guidelines exist in asthma, many clinicians described significant barriers to using them including medicolegal issues, pharmaceutical formulary confusion, and high drug costs. Nonetheless, most clinicians believed that the latest inhaler approaches would be more intuitive for their patients and would offer an opportunity for patient-centered collaboration and care. Stakeholders may find these results useful in future attempts to increase the real-world adoption of recent asthma recommendations.

From gene identifications to therapeutic targets for asthma: Focus on great potentials of TSLP, ORMDL3, and GSDMB

Asthma is a chronic respiratory disease, and clinically, asthma exacerbations remain difficult to treat. The disease is caused by combinations of and interactions between genetic and environmental factors. Genomic and genetic approaches identified many novel genes to treat asthma and brought new insights into the disease. The products of the genes have functional roles in regulating physiological or pathophysiological processes in airway structural cells and immune system cells. Genetic factors also interact with environmental factors such as air pollutants, and bacterial and viral infections to trigger the disease. Thymic stromal lymphopoietin (TSLP), orosomucoid-like 3 (ORMDL3), and gasdermin B (GSDMB) are three genes identified by genetic studies to have a great potential as therapeutic targets of asthma. TSLP is an important driver of type 2 inflammation. ORMDL3 mediates cell stress, sphingolipid synthesis, and viral and bacterial infections. GSDMB regulates cell pyroptosis through its N and C terminals and can bind sulfatides to influence inflammatory response. Investigating inhibitors or modulators for these pathways would bring a new landscape for therapeutics of asthma in future.

Asthma hospitalisations and heat exposure in England: a case-crossover study during 2002-2019

BACKGROUND

Previous studies have reported an association between warm temperature and asthma hospitalisation. They have reported different sex-related and age-related vulnerabilities; nevertheless, little is known about how this effect has changed over time and how it varies in space. This study aims to evaluate the association between asthma hospitalisation and warm temperature and investigate vulnerabilities by age, sex, time and space.

METHODS

We retrieved individual-level data on summer asthma hospitalisation at high temporal (daily) and spatial (postcodes) resolutions during 2002-2019 in England from the NHS Digital. Daily mean temperature at 1 km×1 km resolution was retrieved from the UK Met Office. We focused on lag 0-3 days. We employed a case-crossover study design and fitted Bayesian hierarchical Poisson models accounting for possible confounders (rainfall, relative humidity, wind speed and national holidays).

RESULTS

After accounting for confounding, we found an increase of 1.11% (95% credible interval: 0.88% to 1.34%) in the asthma hospitalisation risk for every 1°C increase in the ambient summer temperature. The effect was highest for males aged 16-64 (2.10%, 1.59% to 2.61%) and during the early years of our analysis. We also found evidence of a decreasing linear trend of the effect over time. Populations in Yorkshire and the Humber and East and West Midlands were the most vulnerable.

CONCLUSION

This study provides evidence of an association between warm temperature and hospital admission for asthma. The effect has decreased over time with potential explanations including temporal differences in patterns of heat exposure, adaptive mechanisms, asthma management, lifestyle, comorbidities and occupation.

Pulmonary Rehabilitation for Adults with Chronic Respiratory Disease: An Official American Thoracic Society Clinical Practice Guideline

Background: Despite the known benefits of pulmonary rehabilitation (PR) for patients with chronic respiratory disease, this treatment is underused. Evidence-based guidelines should lead to greater knowledge of the proven benefits of PR, highlight the role of PR in evidence-based health care, and in turn foster referrals to and more effective delivery of PR for people with chronic respiratory disease. Methods: The multidisciplinary panel formulated six research questions addressing PR for specific patient groups (chronic obstructive pulmonary disease [COPD], interstitial lung disease, and pulmonary hypertension) and models for PR delivery (telerehabilitation, maintenance PR). Treatment effects were quantified using systematic reviews. The Grading of Recommendations, Assessment, Development and Evaluation approach was used to formulate clinical recommendations. Recommendations: The panel made the following judgments: strong recommendations for PR for adults with stable COPD (moderate-quality evidence) and after hospitalization for COPD exacerbation (moderate-quality evidence), strong recommendation for PR for adults with interstitial lung disease (moderate-quality evidence), conditional recommendation for PR for adults with pulmonary hypertension (low-quality evidence), strong recommendation for offering the choice of center-based PR or telerehabilitation for patients with chronic respiratory disease (moderate-quality evidence), and conditional recommendation for offering either supervised maintenance PR or usual care after initial PR for adults with COPD (low-quality evidence). Conclusions: These guidelines provide the basis for evidence-based delivery of PR for people with chronic respiratory disease.

A Transcutaneous Carbon Dioxide Monitor Based on Time-Domain Dual Lifetime Referencing

The partial pressure of arterial carbon dioxide plays a critical role in assessing the acid-base and respiratory status of the human body. Typically, this measurement is invasive and can only be taken momentarily when an arterial blood sample is drawn. Transcutaneous monitoring is a noninvasive surrogate method that provides a continuous measure of arterial carbon dioxide. Unfortunately, current technology is limited to bedside instruments mainly used in intensive care units. We developed a first-of-its-kind miniaturized transcutaneous carbon dioxide monitor that utilizes a luminescence sensing film and a time-domain dual lifetime referencing method. Gas cell experiments confirmed the monitor's ability to accurately identify changes in the partial pressure of carbon dioxide within the clinically significant range. Compared to the luminescence intensity-based technique, the time-domain dual lifetime referencing method is less prone to measurement errors caused by changes in excitation strength, reducing the maximum error from  ∼ 40% to  ∼ 3% and resulting in more reliable readings. Additionally, we analyzed the sensing film by investigating its behavior under various confounding factors and its susceptibility to measurement drift. Finally, a human subject test demonstrated the effectiveness of the applied method in detecting even slight changes in transcutaneous carbon dioxide, as small as  ∼ 0.7%, during hyperventilation. The prototype, which consumes 30.1 mW of power, is a wearable wristband with compact dimensions of 37 mm× 32 mm.