Heated and humidified high flow therapy (HHHFT) in extreme and very preterm neonates with respiratory distress syndrome (RDS): a retrospective cohort from a tertiary care setting in Pakistan

OBJECTIVE

To determine the role of heated humidified high flow therapy (HHHFT) as primary respiratory support in spontaneously breathing moderate-late, very and extreme preterm neonates with respiratory distress syndrome (RDS) at a tertiary care hospital from a developing country.

DESIGN

Retrospective cohort study.

SETTING

Neonatal intensive care unit of Indus Hospital and Health Network, Karachi, Pakistan.

PATIENTS

All preterm neonates with RDS and who received HHHFT as primary respiratory support were included retrospectively, while neonates with orofacial anomalies, congenital heart and lung diseases other than RDS, abdominal wall defects, encephalopathy, congenital pneumonia and received continuous positive airway pressure or invasive ventilation were excluded.

INTERVENTIONS

HHHFT as primary respiratory support for RDS.

MAIN OUTCOME MEASURES

Effectiveness, duration, failure rate and complications of HHHFT as a primary respiratory support in moderate-late, very and extremely preterm neonates were evaluated.

RESULTS

The cohort included 138 neonates during a period of 12 months. The median gestational age was 32 weeks, and the median birth weight was 1607 g. Grade 1-2 RDS was seen in 97%, surfactant instillation was done in 10.8% and HHHFT was provided in all the neonates as primary respiratory support. The total duration of HHHFT support was <1 week in 94% of neonates. Bronchopulmonary dysplasia and pneumothorax until discharge or death were observed in one neonate, haemodynamically significant Patent Ductus Artriosus (HsPDA) in two neonates and intraventricular haemorrhage Grade ≥2 in five neonates, while only one neonate died.

CONCLUSION

This study appears to show that HHHFT is a simple, safe, efficient and cheap mode of primary respiratory support that can be given to spontaneously breathing moderate-late, very and extremely preterm neonates with RDS, especially in low- or middle-income countries.

Effects of 7-day polyphenol powder supplementation on cycling performance and lung function in an ozone-polluted environment

PURPOSE

Polluted environments can adversely affect lung function and exercise performance. Evidence suggests that some nutrient supplements may offset pollution's detrimental effects. This study examined the effect of polyphenol supplementation on lung function and exercise performance in an ozone-polluted environment.

METHODS

Ten male cyclists (mean ± SD: age, 43.8 ± 12.4 years; height, 177.8 ± 7.1 cm; weight, 76.03 ± 7.88 kg; VO2max 4.12 ± 0.72 L min-1) initially completed a baseline maximal incremental test and maximal effort 4 km time trial in ambient air. Thereafter cyclists completed two trials in an ozone-polluted environment (0.25 ppm) following seven days of supplementation with either polyphenol (PB) or placebo (PL). Experimental trials consisted of a three-stage submaximal test (50%, 60% and 70% incremental peak power) followed by a 4 km time trial. Lung function was measured pre- and post-exercise via spirometry and adverse respiratory symptoms with a Likert scale.

RESULTS

Ozone exposure significantly reduced (p < 0.05) lung function relative to ambient air. There were no significant differences (p > 0.05) in measured variables across the three submaximal intensities. There was a small (d = 0.31) non-significant difference (p = 0.09) in 4 km performance in PB (406.43 ± 50.29 s) vs. PL (426.20 ± 75.06 s). Oxygen consumption during the time trial was greater in PB (3.49 ± 0.71 L min-1) vs PL (3.32 ± 0.71 L min-1, p = 0.01, d = 0.24). Cough severity (SOC) was lower (p = 0.03) with PB relative to PL.

CONCLUSION

PB supplementation may provide small benefits to performance and reduce cough symptoms during high-intensity exercise in ozone-polluted environments.

Systemic Inflammation but not Oxidative Stress Is Associated with Physical Performance in Moderate Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) patients manifest muscle dysfunction and impaired muscle oxidative capacity, which result in reduced exercise capacity and poor health status. The aim of this study was to compare the physical performance, systemic inflammation, and oxidative stress of patients with moderate COPD, and to associate physical performance with inflammatory and oxidative stress plasma markers. Twenty CONTROL (n = 10) and moderate COPD (n = 10) patients participated in this study. Systematic inflammation and oxidative stress plasma markers, maximal aerobic capacity (VO2peak), and maximal isometric strength (MVIC) of the knee extensor (KE) muscles were measured. VO2peak was 31.3% greater in CONTROL compared to COPD (P = 0.006). The MVIC strength of the KE was 43.9% greater in CONTROL compared to COPD (P = 0.002). Tumor necrosis factor-alpha (TNF-α) was 79.6% greater in COPD compared to CONTROL (P < 0.001). Glutathione peroxidase activity (GPx) activity was 27.5% lesser in COPD compared to CONTROL (P = 0.05). TNF-α concentration was correlated with KE MVC strength (R = -0.48; P = 0.045) and VO2peak (R = -0.58; P = 0.01). Meanwhile, malondialdehyde (MDA) and GPx activity were not associated with KE strength or VO2peak (P = 0.74 and P = 0.14, respectively). COPD patients showed lesser muscle strength and aerobic capacity than healthy control individuals. Furthermore, patients with COPD showed greater systemic inflammation and lesser antioxidant capacity than healthy counterparts. A moderate association was evident between levels of systemic inflammation and physical performance variables.

An overview of atmospheric aerosol and their effects on human health

Epidemiologic investigations have previously been published in more than 200 papers, and several studies have examined the impacts of particle air pollution on health. The main conclusions now being made about the epidemiological evidence of particle pollution-induced health impacts are discussed in this article. Although there is no universal agreement, most reviewers conclude that particulate air pollution, particularly excellent combustion-cause contamination prevalent in many municipal and manufacturing environments, is a significant risk for cardiopulmonary sickness and mortality. Most epidemiological research has concentrated on the impacts of acute exposure, although the total public health implications of chronic acquaintance's outcome may be more extraordinarily significant. According to some reviewers, prolonged, repeated exposure raises the risk of cardiorespiratory death and chronic respiratory illness. A more general (but still universal) agreement is that short-term particle pollution exposure has been shown to aggravate pre-existing pulmonary and cardiovascular diseases and increase the number of community members who become sick, require medical treatment, or die. Several in-depth studies conducted in the global and Indian regions are addressed.

Human airway tuft cells influence the mucociliary clearance through cholinergic signalling

BACKGROUND

Airway tuft cells, formerly called brush cells have long been described only morphologically in human airways. More recent RNAseq studies described a chemosensory cell population, which includes tuft cells, by a distinct gene transcription signature. Yet, until which level in the tracheobronchial tree in native human airway epithelium tuft cells occur and if they function as regulators of innate immunity, e.g., by regulating mucociliary clearance, remained largely elusive.

METHODS

We performed immunohistochemistry, RT-PCR and immunoblotting analyses for various tuft cell markers to confirm the presence of this cell type in human tracheal samples. Immunohistochemistry was conducted to study the distribution of tuft cells along the intrapulmonary airways in humans. We assessed the influence of bitter substances and the taste transduction pathway on mucociliary clearance in mouse and human tracheal samples by measuring particle transport speed.

RESULTS

Tuft cells identified by the expression of their well-established marker POU class 2 homeobox 3 (POU2F3) were present from the trachea to the bronchioles. We identified choline acetyltransferase in POU2F3 expressing cells as well as the transient receptor potential melastatin 5 (TRPM5) channel in a small population of tracheal epithelial cells with morphological appearance of tuft cells. Application of bitter substances, such as denatonium, led to an increase in mucociliary clearance in human tracheal preparations. This was dependent on activation of the TRPM5 channel and involved cholinergic and nitric oxide signalling, indicating a functional role for human tuft cells in the regulation of mucociliary clearance.

CONCLUSIONS

We were able to detect tuft cells in the tracheobronchial tree down to the level of the bronchioles. Moreover, taste transduction and cholinergic signalling occur in the same cells and regulate mucociliary clearance. Thus, tuft cells are potentially involved in the regulation of innate immunity in human airways.

Interactions and clinical implications of serological and respiratory variables 3 months after acute COVID-19

Medical follow-up of symptomatic patients after acute Coronavirus Disease 2019 (COVID-19) results in major burdens on patients and healthcare systems. The value of serological markers as part of this follow-up remains undetermined. We aimed to evaluate the clinical implications of serological markers for follow-up of acute COVID-19. For this purpose, we conducted an observational cohort study of patients 3 months after acute COVID-19. Participants visited a respiratory-clinic between October 2020 and March 2021, and completed pulmonary function tests (PFTs), serological tests, symptom-related questionnaires, and chest CT scans. Overall, 275 patients were included at a median of 82 days (IQR 64-111) post infection. 162 (59%) patients had diffusing capacity for carbon monoxide corrected for hemoglobin (DLCOc) below 80%, and 69 (25%) had bilateral chest abnormalities on CT scan. In multivariate analysis, anti-S levels were an independent predictor for DLCOc (β = - 0.14, p = 0.036). Anti-S levels were also associated with severe COVID-19 and older age, and correlated with anti-nucleocapsid (r = 0.30, p < 0.001) and antibodies to receptor binding domain (RBD, r = 0.37, p < 0.001). Other serological variables were not associated with clinical outcomes. In conclusion, symptomatic patients 3-months after COVID-19 had high respiratory symptomatic burden, in which anti-S levels were significantly associated with previous severe COVID-19 and DLCOc.

A unique case of intralobar pulmonary sequestration in an elderly patient: A case report

Pulmonary sequestration (PS) is a rare congenital anomaly characterized by non-functional lung tissue receiving blood supply from an abnormal source. PS is typically diagnosed in young individuals but is uncommon in the elderly. This abstract describes a case of PS in a 62-year-old male patient presenting with recurrent fever, chronic cough, and difficulty breathing. Imaging revealed abnormal lung tissue disconnected from the bronchial tree, with blood supply from the descending thoracic aorta. Surgical intervention successfully treated the condition. The case emphasizes the need to consider PS as a possible diagnosis, even in older patients, and suggests further research into its possible etiologies.

A fatal respiratory complication of malaria caused by Plasmodium vivax

BACKGROUND

Malaria is endemic and represents an important public health issue in Brazil. Knowledge of risk factors for disease progression represents an important step in preventing and controlling malaria-related complications. Reports of severe forms of Plasmodium vivax malaria are now becoming a common place, but respiratory complications are described in less than 3% of global literature on severe vivax malaria.

CASE PRESENTATION

A severe respiratory case of imported vivax malaria in a previously healthy 40-year-old woman has been reported. The patient died after the fifth day of treatment with chloroquine and primaquine due to acute respiratory distress syndrome.

CONCLUSIONS

Respiratory symptoms started 48 h after the initiation of anti-malarial drugs, raising the hypothesis that the drugs may have been involved in the genesis of the complication. The concept that vivax malaria is a benign disease that can sometimes result in the development of serious complications must be disseminated. This report highlights, once more, the crucial importance of malaria early diagnosis, a true challenge in non-endemic areas, where health personnel are not familiar with the disease and do not consider its diagnosis promptly.

Regulation of vagally-evoked respiratory responses by the lateral parabrachial nucleus in the mouse

Vagal sensory inputs to the brainstem can alter breathing through the modulation of pontomedullary respiratory circuits. In this study, we set out to investigate the localised effects of modulating lateral parabrachial nucleus (LPB) activity on vagally-evoked changes in breathing pattern. In isoflurane-anaesthetised and instrumented mice, electrical stimulation of the vagus nerve (eVNS) produced stimulation frequency-dependent changes in diaphragm electromyograph (dEMG) activity with an evoked tachypnoea and apnoea at low and high stimulation frequencies, respectively. Muscimol microinjections into the LPB significantly attenuated eVNS-evoked respiratory rate responses. Notably, muscimol injections reaching the caudal LPB, previously unrecognised for respiratory modulation, potently modulated eVNS-evoked apnoea, whilst muscimol injections reaching the intermediate LPB selectively modulated the eVNS-evoked tachypnoea. The effects of muscimol on eVNS-evoked breathing rate changes occurred without altering basal eupneic breathing. These results highlight novel roles for the LPB in regulating vagally-evoked respiratory reflexes.

Recovery from COVID-19 in athletes and impact on sporting participation

Insight regarding the impact of COVID-19 on return to sporting participation is a key issue for many athletes. We report time-loss following respiratory tract infection (RTI), over the pandemic, in UK athletes preparing for international competition. During the study, 566 athletes developed COVID-19 and 217 developed other causes of RTI. Time-loss from COVID-19 reduced from a median (interquartile range) of 27 days (13- 40) in April-June 2020 to 10 days (8-13) from October-December 2022 (P<0.001). There was no change in time-loss following RTi (P=0.13). The time-loss period following COVID-19 has shortened over the pandemic. Further work is needed to explore why some athletes still have prolonged sporting time-loss.

Sugammadex Is Associated With Reduced Pulmonary Complications in Patients With Respiratory Dysfunction

INTRODUCTION

Use of sugammadex is associated with fewer postoperative pulmonary complications (PPCs). This study investigated the relationship between sugammadex and PPCs in specific patients with respiratory dysfunction.

MATERIALS AND METHODS

We reviewed the electronic medical and anesthesia records of patients with respiratory dysfunction who underwent laparoscopic gastric or intestinal surgery at a single center between May 1, 2018 and December 31, 2019. The patients were divided into the sugammadex group and the nonsugammadex group, based on whether they received sugammadex or neostigmine. Binary logistic regression analyses were used to characterize the differences in incidence of PPC.

RESULTS

A total of 112 patients were included, of which 46 patients (41.1%) received sugammadex. In the logistic regression analysis, the incidences of PPC were fewer in the sugammadex group. Postoperative fever (odds ratio [OR] 0.330; 95% confidence interval [CI] 0.137-0.793, P = 0.0213), postoperative intensive care unit admission (OR 0.204; 95% CI 0.065-0.644, P = 0.007), cough (OR 0.143; 95% CI 0.061- 0.333, P < 0.001), pleural effusion (all) (OR: 0.280; 95% CI 0.104- 0.759, P = 0.012), pleural effusion (massive) (OR: 0.142; 95% CI 0.031- 0.653, P = 0.012), and difficulty in breathing (OR: 0.111; 95% CI 0.014-0.849, P = 0.039) showed significant differences between the two groups.

CONCLUSIONS

Sugammadex is associated with a reduction in PPC in patients with respiratory dysfunction.

Exposure to cooking fumes is associated with perturbations in nasal microbiota composition: A pilot study

Air pollution is one of the leading causes of overall mortality globally. Cooking emissions are a major source of fine particulate matter (PM2.5). However, studies on their potential perturbations on the nasal microbiota as well as their association with respiratory health are lacking. This pilot study aims to assess the environmental air quality among occupational cooks and its associations with nasal microbiota and respiratory symptoms. A total of 20 cooks (exposed) and 20 unexposed controls (mainly office workers), were recruited in Singapore from 2019 to 2021. Information on sociodemographic factors, cooking methods, and self-reported respiratory symptoms were collected using a questionnaire. Personal PM2.5 concentrations and reactive oxygen species (ROS) levels were measured using portable sensors and filter samplers. DNA was extracted from nasal swabs and sequenced using 16s sequencing. Alpha-diversity and beta-diversity were calculated, and between-group variation analysis of species was performed. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between exposure groups and self-reported respiratory symptoms. Higher daily mean PM2.5 (P = 2 × 10-7) and environmental ROS exposure (P = 3.25 × 10-7) were observed in the exposed group. Alpha diversity of the nasal microbiota between the two groups was not significantly different. However, beta diversity was significantly different (unweighted UniFrac P = 1.11 × 10-5, weighted UniFrac P = 5.42 × 10-6) between the two exposure groups. In addition, certain taxa of bacteria were slightly more abundant in the exposed group compared to unexposed controls. There were no significant associations between the exposure groups and self-reported respiratory symptoms. In summary, the exposed group had higher PM2.5 and ROS exposure levels and altered nasal microbiotas as compared to unexposed controls, though further studies are required to replicate these findings in a larger population.

Prenatal dietary exposure to chemicals and allergy or respiratory diseases in children in the EDEN mother-child cohort

INTRODUCTION

Maternal exposure to food chemicals may increase the risk of allergy and respiratory disorders in offspring. We aimed to assess the association of prenatal dietary exposure to single chemicals and chemical mixtures with allergy or respiratory events reported before age 8 y in children.

METHODS

We included 1428 mother-child pairs enrolled in the EDEN mother-child cohort. Maternal dietary exposure to 209 chemicals and eight associated mixtures was investigated. Allergic and respiratory diseases (wheezing, asthma, allergic rhinitis, eczema and food allergy) were reported by parents between birth and age 8 y. Associations with the studied outcomes were evaluated with three approaches based on adjusted logistic regression, estimating odds ratios (ORs) and 95 % confidence intervals (CIs). First, food chemicals were considered individually, with correction for multiple testing. Second, chemicals selected by elastic net regression were considered simultaneously in a multiple exposure model. Third, predefined mixtures were introduced in the same adjusted logistic regression. Results are expressed as odds ratio (OR[95 % CI]).

RESULTS

Prenatal single exposure to 74 food chemicals was associated with higher risk of allergic rhinitis. Prenatal single exposure to 11 chemicals was associated with higher risk of wheezing. In the multi-exposure approach, risk of wheezing was associated with the pesticides diazinon and triadimenol, and polycyclic aromatic hydrocarbon 5-methylchrysene. Phytoestrogen resveratrol was negatively associated with lower risk of both wheezing and allergic rhinitis, and mycotoxin monoacetoxyscirpenol was negatively associated with risk of eczema. Finally, a chemical mixture composed mainly of trace elements, furans and polycyclic aromatic hydrocarbons, was associated with higher risk of allergic rhinitis (1.33 [1.02;1.73]).

CONCLUSION

Prenatal dietary exposure to chemicals was associated with risk of allergic rhinitis or wheezing up to age 8 y. A few chemicals were associated with other allergic and respiratory diseases. Larger prospective studies are needed to confirm these findings.

A retrospective review of the utility of chest X-rays in diving and submarine medical examinations

Introduction

Performance of routine Chest X-rays (CXRs) in asymptomatic individuals to assess hyperbaric exposure risk is controversial. The radiation risk may overshadow the low yield in many settings. However, the yield may be higher in certain settings, such as tuberculosis-endemic countries. We evaluated the utility of routine CXR in diving and submarine medical examinations in South Africa.

Methods

Records of 2,777 CXRs during 3,568 fitness examinations of 894 divers and submariners spanning 31 years were reviewed to determine the incidence of CXR abnormality. Associated factors were evaluated using odds ratios and a binomial logistic regression model, with a Kaplan-Meier plot to describe the duration of service until first abnormal CXR.

Results

An abnormal CXR was reported in 1.1% per person year of service, yielding a cumulative incidence of 6.5% (58/894) of the study participants. Only four individuals had a clinical indication for the CXR in their medical history. A range of potential pathologies were seen, of which 15.5% were declared disqualifying and the rest (84.5%) were treated, or further investigation showed that the person could be declared fit.

Conclusions

In South Africa, a routine CXR has a role to play in detecting abnormalities that are incompatible with pressure exposures. The highest number of abnormalities were found during the initial examinations and in individuals with long service records. Only four individuals had a clinical indication for their CXR during the 31-year span of our study. Similar studies should be performed to make recommendations in other countries and settings.

A multi-organ, lung-derived inflammatory response following in vitro airway exposure to cigarette smoke and next-generation nicotine delivery products

Despite increasing use of in vitro models that closely resemble in vivo human biology, their application in understanding downstream effects of airway toxicity, such as inflammation, are at an early stage. In this study, we used various assays to examine the inflammatory response induced in MucilAir™ tissues and A549 cells exposed to three products known to induce toxicity. Reduced barrier integrity was observed in tissues following exposure to each product, with reduced viability and increased cytotoxicity also shown. Similar changes in viability were also observed in A549 cells. Furthermore, whole cigarette smoke (CS) induced downstream phenotypic THP-1 changes and endothelial cell adhesion, an early marker of atherosclerosis. In contrast, exposure to next-generation delivery product (NGP) aerosol did not induce this response. Cytokine, histological and RNA analysis highlighted increased biomarkers linked to inflammatory pathways and immune cell differentiation following exposure to whole cigarette smoke, including GM-CSF, IL-1β, cleaved caspase-3 and cytochrome P450 enzymes. As a result of similar observations in human airway inflammation, we propose that our exposure platform could act as a representative model for studying such events in vitro. Furthermore, this model could be used to test the inflammatory or anti-inflammatory impact posed by inhaled compounds delivered to the lung.

The age-related association between serum creatinine and cardiorespiratory morbidity and mortality and fractures among adults with cerebral palsy

PURPOSE

Serum creatinine may be an objective biomarker of salient health issues in adults with cerebral palsy (CP). The objective was to assess the age-related association between serum creatinine with 3-year risk of cardiorespiratory morbidity/mortality and fracture among adults with CP.

PATIENTS AND METHODS

This retrospective cohort study used medical records between Jan. 1, 2012 and Oct. 2, 2022 from adults ≥18 years old with CP. The association between baseline serum creatinine with the 3-year risk of all-cause mortality, respiratory/cardiovascular morbidity/mortality, and fracture was assessed by age and sex using logistic regression. The discriminative ability of serum creatinine alone and in conjunction with other variables was assessed.

RESULTS

Over the 3-year follow-up, 8.3% of 1368 adults with CP had all-cause mortality, 25.6% had respiratory morbidity/mortality, 12.4% had cardiovascular morbidity/mortality, and 8.9% sustained a fracture. The association between serum creatinine with outcomes was dependent on age. For younger adults, lower creatinine had a higher odds ratio (OR) for all-cause mortality, respiratory morbidity/mortality, and fracture. For 51-60 year olds, higher creatinine had a higher OR for cardiovascular morbidity/mortality. Serum creatinine alone had modest prediction of outcomes, and generally improved prediction when added to models that included sex and co-occurring intellectual disabilities and epilepsy (c-statistic range, 0.54-0.84).

CONCLUSIONS

Lower serum creatinine may reflect frailty while higher levels may reflect kidney dysfunction, helping to explain the differential associations by age. Serum creatinine may be a useful biomarker as part of risk prediction models for these salient health issues for adults with CP.

Climate Change, Air Quality, and Pulmonary Health Disparities

Climate change will alter environmental risks that influence pulmonary health, including heat, air pollution, and pollen. These exposures disproportionately burden populations already at risk of ill health, including those at vulnerable life stages, with low socioeconomic status, and systematically targeted by oppressive policies. Climate change can exacerbate existing environmental injustices by affecting future exposure, as well as through differentials in the ability to adapt; this is compounded by disparities in rates of underlying disease and access to health care. Climate change is therefore a dire threat not only to individual and population health but also to health equity.

Environmental exposures and pulmonary function among adult residents of rural Appalachian Kentucky

BACKGROUND

Estimated residential exposures of adults to roadway density and several metrics of resource extraction, including coal mining and oil and gas drilling, were hypothesized to contribute to the prevalence of respiratory disease in rural Appalachia.

OBJECTIVE

Determine how small-area geographic variation in residential environmental exposures impacts measures of pulmonary function among adults in a community-based study.

METHODS

We examined associations between residential environmental respiratory exposures and pulmonary function among 827 adult participants of the "The Mountain Air Project", a community-based, cross-sectional study in Southeastern Kentucky during 2016-2018. Exposures characterized the density of roadways, oil/gas wells, or current/past surface and underground coal mining at the level of 14-digit hydrologic unit code (HUC), or valley "hollow" where participants resided. Each participant completed an in-person interview to obtain extensive background data on risk factors, health history, and occupational and environmental exposures, as well as a spirometry test administered by experienced study staff at their place of residence. Multivariable linear regression was used to model the adjusted association between each environmental exposure and percent predicted forced expiratory volume in one second (FEV1PP) and forced vital capacity (FVCPP).

RESULTS

Adjusted regression models indicate persons living in HUCs with the highest level of roadway density experienced a reduction in both FEV1PP (-4.3: 95% CI: -7.44 -1.15;) and FVCPP (-3.8: 95% CI: -6.38, -1.21) versus persons in HUCs with the lowest roadway density. No associations were detected between the metrics associated with mining and oil and gas operations and individual pulmonary function.

IMPACT STATEMENT

Our work demonstrates the potential adverse impact of roadway-related exposures on the respiratory health of rural Appalachia residents. We employed a novel method of small-area exposure classification based on the hydrologic unit code (HUC), representing potential exposure levels per hollow occurring  in proximity to the residence, and controlled for individual-level risk factors for reduced respiratory health. We highlight an overlooked yet ubiquitous source of residential exposure from motor vehicles that may contribute to the regionally high prevalence of respiratory disease in rural Appalachia.

SIgA in various pulmonary diseases

Secretory immunoglobulin A (SIgA) is one of the most abundant immunoglobulin subtypes among mucosa, which plays an indispensable role in the first-line protection against invading pathogens and antigens. Therefore, the role of respiratory SIgA in respiratory mucosal immune diseases has attracted more and more attention. Although the role of SIgA in intestinal mucosal immunity has been widely studied, the cell types responsible for SIgA and the interactions between cells are still unclear. Here, we conducted a wide search of relevant studies and sorted out the relationship between SIgA and some pulmonary diseases (COPD, asthma, tuberculosis, idiopathic pulmonary fibrosis, COVID-19, lung cancer), which found SIgA is involved in the pathogenesis and progression of various lung diseases, intending to provide new ideas for the prevention, diagnosis, and treatment of related lung diseases.

Nine human epidemiological studies on synthetic amorphous silica and respiratory health

The respiratory health effects of Synthetic Amorphous Silica (SAS) have been studied in human epidemiological research. This article presents a historical overview and review of nine occupational worker studies that have been conducted so far on this topic. The combined study population of all of these studies included 1172 employees, and exposure concentrations ranged from < 1 mg/m3 to 100 mg/m3. In two studies with a total of 293 workers, the incidence of silicosis was investigated after long-term exposure to precipitated SAS, and no cases of silicosis were found (Plunkett and Dewitt, 1962; Volk, 1960). In another study, the spirometry results of 40 workers were normal (Vitums et al., 1977). In a study of 28 workers, 4 cases of silicosis were identified, but it is possible that contamination with cristobalite occurred and detailed information about the amorphous silica origin was not provided (Mohrmann and Kahn, 1985). Ferch et al. (1987) found that lung impairment was associated with confounding factors (smoking) but not with exposure to precipitated SAS in a study of 143 workers. Choudat et al. (1990) reported a reduction in forced expiratory flow in a group exposed to precipitated SAS compared to a control group. Still, they found no correlation between the extent of exposure and pulmonary function was found in a study of 131 workers. Wilson et al. (1979) also failed to show a significant association between the degree of exposure to precipitated SAS and annual changes in lung function in a study of 165 workers. In the most recent and most extensive study (Taeger et al., 2016; Yong et al., 2022) in Germany, involving 462 factory workers, no association between inhalable or respirable SAS dust exposure and respiratory health was reported. Based on the available data, there is no evidence-base to support a relationship between SAS and respiratory health in humans.

Associations of U.S. state-level COVID-19 policies intensity with cannabis sharing behaviors in 2020

Background

Cannabis use before the COVID-19 pandemic for many involved sharing prepared cannabis for inhalation, practices that were less prevalent during the pandemic. State-level COVID-19 containment policies may have influenced this decrease. This study examined the extent to which the intensity of state-level COVID-19 policies were associated with individual-level cannabis sharing. Findings have the potential to guide harm reduction policies for future respiratory pandemics and seasonal respiratory virus waves.

Methods

This study used cross-sectional individual-level data from the COVID-19 Cannabis Study, an anonymous U.S.-based web survey on cannabis use disseminated during the early phase of the pandemic (Full sample N = 1,883). We combined individual-level data with state-level policy data from Kaiser Family Foundation's State COVID-19 Data and Policy Actions for three time-points from June to August 2020 that overlapped with the survey period. Cannabis sharing was dichotomized as any versus no sharing. We adapted a previously published coding framework to score the intensity of COVID-19 policies implemented in each U.S. state and averaged the policy score across the time period. We then used logistic regression models to quantify the associations of the average state-level COVID-19 policy score with cannabis sharing during the pandemic.

Results

Participants (n = 975) reporting using inhalation as a mode for cannabis use were included in this analysis. Most respondents were male (64.1%), non-Hispanic White (54.3%), with a mean age of 33.7 years (SD 8.8). A large proportion (75.1%) reported sharing cannabis during the pandemic. Those who shared cannabis more commonly lived in states with a lower average policy score (15.3, IQR 11.3-19.0) compared to those who did not share (16.3, IQR 13.7-22.7). In adjusted models, the odds of any cannabis sharing per every 5-unit increase in the average COVID-19 policy score were 0.78 (95% CI 0.58, 1.04).

Conclusions

Fewer individuals shared cannabis in states with more intense COVID-19 containment policies compared to those in states with less intense policies. Individuals who use cannabis may be willing to make changes to their behavior and may further benefit from specific and directed public health messaging to avoid sharing during respiratory infection outbreaks.

Changes in the patterns of respiratory support and incidence of bronchopulmonary dysplasia; a single center experience

BACKGROUND

With the advances in neonatal intensive care, the survival rate of extremely preterm infants is increasing. However, bronchopulmonary dysplasia (BPD) remains a major cause of morbidity among infants in this group. This study examined the changes in respiratory support modalities, specifically heated humidified high-flow nasal cannula (HHHFNC), and their association with BPD incidence among preterm infants born at < 29 weeks of gestation.

METHOD

This population-based retrospective cohort study included infants born at < 29 weeks of gestation between 2016 and 2020. Data regarding the use and duration of respiratory support modalities were obtained, including mechanical ventilation, continuous positive airway pressure, HHHFNC, and low-flow oxygen therapy. Additionally, the incidence of BPD was determined in the included infants. Trend analysis for each respiratory support modality and BPD incidence rate was performed to define the temporal changes associated with changes in BPD rates. In addition, a logistic regression model was developed to identify the association between BPD and severity grade using HHHFNC.

RESULTS

Three Hundred and sixteen infants were included in this study. The use and duration of HHHFNC therapy increased during the study period. Throughout the study period, the overall incidence of BPD was 49%, with no significant trends. The BPD rate was significantly higher in the infants who received HHHFNC than in those who did not (52% vs. 39%, P = 0.03). Analysis of BPD severity grades showed that both grade 1 BPD (34% vs. 21%, P = 0.03) and grade 2 BPD (12% vs. 1%, P < 0.01) were significantly more common among infants who received HHHFNC than among those who did not. In contrast, the incidence of grade 3 BPD was lower in infants who received HHFNC (6% vs. 17%, P < 0.01). The duration in days of HHHFNC was found to significantly predict BPD incidence (OR 1.04 [95%CI: 1.01-1.06], P < 0.01) after adjusting for confounding variables.

CONCLUSION

The use of HHHFNC in extremely preterm infants born at < 29 weeks of gestation is increasing. There was a significant association between the duration of HHHFNC therapy and the development of BPD in extremely preterm infants born at < 29 weeks of gestation.

Evaluating Adult Idiopathic Scoliosis as an Independent Risk Factor for Critical Illness in SARS-CoV-2 Infection

BACKGROUND

Thoracic spinal deformities may reduce chest wall compliance, leading to respiratory complications. The first SARS-CoV-2 (L-variant) strain caused critical respiratory illness, especially in vulnerable patients. This study investigates the association between scoliosis and SARS-CoV-2 (COVID-19) disease course severity.

METHODS

Clinical data of 129 patients treated between March 2020 to June 2021 who received a positive COVID-19 polymerase chain reaction result from Mount Sinai and had a scoliosis ICD-10 code (M41.0-M41.9) was retrospectively analyzed. Degree of coronal plane scoliosis on imaging was confirmed by 2 independent measurers and grouped into no scoliosis (Cobb angle <10°), mild (10°-24°), moderate (25°-39°), and severe (>40°) cohorts. Baseline characteristics were compared, and a multivariable logistic regression controlling for clinically significant comorbidities examined the significance of scoliosis as an independent risk factor for hospitalization, intensive care unit (ICU) admission, acute respiratory distress syndrome (ARDS), mechanical ventilation, and mortality.

RESULTS

The no (n = 42), mild (n = 14), moderate (n = 44), and severe scoliosis (n = 29) cohorts differed significantly only in age (P = 0.026). The percentage of patients hospitalized (P = 0.59), admitted to the ICU (P = 0.33), developing ARDS (P = 0.77), requiring mechanical ventilation (P = 1.0), or who expired (P = 0.77) did not significantly differ between cohorts. The scoliosis cohorts did not have a significantly higher likelihood of hospital admission (mild P = 0.19, moderate P = 0.67, severe P = 0.98), ICU admission (P = 0.97, P = 0.94, P = 0.22), ARDS (P = 0.87, P = 0.74, P = 0.94), mechanical ventilation (P = 0.73, P = 0.69, P = 0.70), or mortality (P = 0.74, P = 0.87, P = 0.66) than the no scoliosis cohort.

CONCLUSIONS

Scoliosis was not an independent risk factor for critical COVID-19 illness. No trends indicated any consistent effect of degree of scoliosis on increased adverse outcome likelihood.

Cross-country skiers often experience respiratory symptoms during and after exercise but have a low prevalence of prolonged cough

Background

Cross-country skiers train and compete during the winter for long periods of time in subfreezing conditions, which strains the airways and provokes respiratory symptoms. This study aimed to compare the prevalence of exercise-related symptoms and prolonged cough in competitive cross-country skiers versus the general population and to investigate the association between these symptoms and asthma.

Methods

A questionnaire was sent to Finnish cross-country skiers (n=1282) and a random sample of the general population (n=1754), with response rates of 26.9% and 19.0%, respectively.

Results

Both groups were mostly asymptomatic at rest, but symptoms were increased in both groups during and after exercise. Cough was more prevalent after exercise in skiers and phlegm production was more common during and after exercise in skiers. Asthma did not provoke specific symptoms, but symptom prevalence was higher in asthmatic individuals. Skiers had a higher prevalence of cough after exercise (60.6% vs 22.8%, p<0.001) compared with controls, but controls had a higher prevalence of prolonged cough (4.1% vs 9.6%, p=0.004). In participants without asthma, cold air triggered symptoms more often in skiers than controls, while strong odours triggered symptoms more often in asthmatic controls than skiers. Chronic cough lasting more than 8 weeks was rare, reported by 4.8% of controls and 2.0% of skiers.

Conclusion

Cross-country skiers, especially those with asthma, experience a higher burden of exercise-related respiratory symptoms compared with controls. However, repeated exposure to cold air does not appear to result in long-term hypersensitivity of the cough reflex arc.