Intravenous magnesium sulfate for asthma exacerbations in children: Systematic review with meta-analysis

BACKGROUND

Asthma is the most prevalent chronic disease in children and constitutes a significant healthcare burden. First-line therapy for acute asthma exacerbations is well established. However, secondary treatments, including intravenous magnesium sulfate (IV-MgSO4), remain variable due to scarcity of data on its efficacy and safety.

OBJECTIVE

To assess the effectiveness and safety of IV-MgSO4 as a second line of treatment in managing children with asthma exacerbations.

METHODS

We searched five databases from inception until April 2023 on randomized clinical trials of IV-MgSO4 in children with acute asthma exacerbations. The primary outcomes were hospitalization rate and length, and change in the severity score. Secondary outcomes included percentage increase in peak expiratory flow rate (PEFR), hospital re-admission rate, need and length for pediatric intensive care unit (PICU) treatment, and adverse effects. Meta-analysis was performed for three outcomes with estimated odds ratios (ORs) or mean differences (MDs) and 95% confidence intervals (CIs).

RESULTS

Eleven studies met the final criteria. In comparison to control, administration of IV-MgSO4 was associated with a reduced hospitalization risk (OR 0.15; 95%CI: 0.03, 0.73) in four studies, and improvement of lung function (MD 26.77% PEFR; 95%CI: 18.41, 54.79) in two studies. There were no significant differences in the length of stay between groups. Due to heterogeneity, a narrative synthesis of other outcomes was performed.

CONCLUSION

The use of IV-MgSO4 demonstrated a reduction in the hospitalization rate and PEFR improvement in children with asthma exacerbations. Adverse effects were rare. Further well-designed studies are needed to better determine the efficacy and safety profile of IV-MgSO4.

Acuity of asthma exacerbations in Alberta, Canada is increasing: a population-based study

BACKGROUND

Asthma is a common respiratory illness affecting 2.8 million Canadians, including 9.7% of Albertans. Prior studies showed a substantial decrease in ED visits for asthma in the decade preceding 2010, followed by a stabilization. This was attributed to improvements in the pharmacologic and non-pharmacologic treatments for asthma during that period followed by a balance between epidemiologic drivers and protective factors in the population.

METHODS

We assessed whether this trend continued in Alberta from 2010 to 2022 using population level data for the volume of daily ED visits, acuity of asthma exacerbations in the ED, and hospitalization rate.

RESULTS

The mean number of ED visits decreased from 4.5 to 2.2 per million persons per day, but the acuity of exacerbations and the proportion requiring hospitalization increased. The number of patients presenting with the highest level of acuity increased by over 300%, and the percentage of patients requiring hospitalization increased from 6.8 to 11.3%.

CONCLUSION

Total ED visits for asthma exacerbations continues to decline in Alberta. The reasons for an increase in more severe exacerbations requires further attention.

Incidence and causative agent distribution of viral-induced paediatric asthma exacerbations under strict infection control measures: a single-centre retrospective study in Japan

BACKGROUND

The prevalence of respiratory viruses in children changed under strict infection control measures during the coronavirus disease 2019 (COVID-19) outbreak. In this study, we investigated the frequency of viral detection in the nasopharynx of paediatric patients with asthma exacerbations requiring hospitalization during the COVID-19 pandemic, as well as the distribution of causative viruses.

METHODS

We included paediatric patients admitted for asthma exacerbations between November 2020 and December 2022 at a single centre in Kobe, Japan. Demographic, clinical, and laboratory data were collected from their medical records and using additional questionnaires. All patients enrolled in this study met the diagnostic criteria for asthma exacerbations outlined in the Japanese Pediatric Guideline for the Treatment and Management of Bronchial Asthma 2020. Statistical differences were calculated using univariate analyses (chi-square or Mann‒Whitney U test).

RESULTS

We enrolled 203 children hospitalized for asthma attacks and collected nasopharyngeal samples from 189 patients. The median patient age was 3.0 years. Asthma severity was classified as mild (4.0%), moderate (82.3%), or severe (13.8%). The proportion of viral respiratory infections was 95.2% (180/189). The rate of patients with multiple viral infections was 20.6% (39/189). The most frequently detected pathogens were rhinovirus and enterovirus (RV/EV) at 69.3% (131/189), allowing for duplicate detection, followed by respiratory syncytial virus (RSV) at 28.6% (54/189). We also detected RV/EV almost every month compared to RSV and other viruses. In addition, RV/EV-positive patients were significantly older (p = 0.033), exhibited higher WBC counts (p < 0.001) and higher Eos counts (p < 0.001), had elevated total IgE levels (p < 0.001) and house dust mite-specific IgE levels (p = 0.019), had a shorter duration of hospitalization (p < 0.001), and had a shorter duration of oxygen therapy (p < 0.001). In patients positive for RV/EV, the use of ICSs significantly reduced the severity of the condition (p < 0.001).

CONCLUSION

Even under strict infection control measures, respiratory viruses were detected in the nasopharynx of almost all paediatric patients who had asthma exacerbations requiring hospitalization.

Achieving clinical outcomes with benralizumab in severe eosinophilic asthma patients in a real-world setting: orbe II study

BACKGROUND

The ORBE II study aimed to describe the characteristics and clinical outcomes of adult patients with severe eosinophilic asthma (SEA) treated with benralizumab in a real-world setting in Spain.

METHODS

ORBE II (NCT04648839) was an observational, retrospective cohort study in adult SEA patients who had been prescribed benralizumab. Demographic and clinical data of 204 SEA patients were collected 12 months prior to benralizumab initiation (baseline) and at follow-up. Exacerbation rate, asthma symptoms, maintenance oral corticosteroid (OCS) use and lung function were evaluated, among other variables.

RESULTS

A total of 204 SEA patients were evaluated. Mean (standard deviation, SD) age of the study population was 56.4 (12.4) years, 62.3% were women and mean (SD) duration of asthma was 15.1 (12.7) years. Median (Q1-Q3) follow-up duration was 19.5 (14.2-24.2) months. At baseline, 72.6% of the overall population (OP) presented blood eosinophil counts ≥ 300 cells/µL; 36.8% had comorbid chronic rhinosinusitis with nasal polyps (CRSwNP); 84.8% reported at least one severe exacerbation, and 29.1% were OCS-dependent. At 1 year of follow-up, patients receiving benralizumab treatment had a 85.6% mean reduction in exacerbations from baseline, and 81.4% of patients achieved zero exacerbations. We also found a clinically relevant mean (SD) increase in pre-bronchodilator (BD) FEV1 of 331 (413) mL, with 66.7% of patients achieving a pre-BD FEV1 increase ≥ 100 mL, and 46.3% of patients achieving a pre-BD FEV1 ≥ 80% of predicted. Regarding symptom control, 73.8% of the OP obtained an ACT score ≥ 20 points. After 1 year of follow-up, mean reduction in the daily OCS dose was 70.5%, and complete OCS withdrawal was achieved by 52.8% of the OCS-dependent patients. Almost half (43.7%) of the OP on benralizumab met all four criteria for clinical remission. Patients with concomitant CRSwNP obtained similar or enhanced outcomes.

CONCLUSIONS

These data support the real-world benefits of benralizumab in SEA patients, and particularly in those with concomitant CRSwNP.

TRIAL REGISTRATION

NCT04648839.

Triple Therapy with Mometasone/Indacaterol/Glycopyrronium or Doubling the ICS/LABA Dose in GINA Step 4: IRIDIUM Analyses

INTRODUCTION

GINA guidelines recommend increasing the dose of inhaled corticosteroids (ICS) as a step-up option for patients with inadequately controlled asthma at GINA step 4 [inadequately controlled asthma on medium-dose ICS/long-acting beta-2 agonist (LABA)]. The aim of this study was to compare the efficacy and safety of long-acting muscarinic antagonists (LAMA) add-on to medium-dose ICS/LABA in patients at GINA 2022 step 4.

METHODS

This post hoc analysis of the IRIDIUM study evaluated the change from baseline in trough forced expiratory volume (FEV1 ) in patients receiving medium-dose MF/IND/GLY versus high-dose MF/IND and high-dose FLU/SAL at Week 26. Other outcomes included improvement in lung functions [peak expiratory flow (PEF), forced vital capacity (FVC), forced expiratory flow between 25% and 75% of the FVC (FEF)25-75%)], asthma control [Asthma Control Questionnaire (ACQ-7)], responder analysis (≥ 0.5 unit improvement in ACQ-7), and reduction in asthma exacerbations at Weeks 26 and 52.

RESULTS

A total of 1930 patients were included in this analysis. Medium-dose MF/IND/GLY improved trough FEV1 versus high-dose MF/IND (Δ 41 mL; 95% CI - 7-90) and high-dose FLU/SAL (Δ 88 mL; 95% CI 39-137) at Week 26 which were sustained until Week 52. Exacerbation rates were 16% lower with medium-dose MF/IND/GLY versus high-dose MF/IND for all (mild, moderate, and severe) exacerbations and 21-30% lower versus high-dose FLU/SAL for all (mild, moderate, and severe), moderate or severe, and severe exacerbations over 52 weeks. Further improvements in other lung functions were observed with medium-dose MF/IND/GLY. No new safety signals were identified.

CONCLUSION

Medium-dose MF/IND/GLY improved lung function and reduced asthma exacerbations compared to high-dose ICS/LABA and may be an undervalued option in patients at GINA 2022 step 4.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02571777.

Rhinovirus infection induces secretion of endothelin-1 from airway epithelial cells in both in vitro and in vivo models

BACKGROUND

Rhinovirus (RV) infection of airway epithelial cells triggers asthma exacerbations, during which airway smooth muscle (ASM) excessively contracts. Due to ASM contraction, airway epithelial cells become mechanically compressed. We previously reported that compressed human bronchial epithelial (HBE) cells are a source of endothelin-1 (ET-1) that causes ASM contraction. Here, we hypothesized that epithelial sensing of RV by TLR3 and epithelial compression induce ET-1 secretion through a TGF-β receptor (TGFβR)-dependent mechanism.

METHODS

To test this, we used primary HBE cells well-differentiated in air-liquid interface culture and two mouse models (ovalbumin and house dust mite) of allergic airway disease (AAD). HBE cells were infected with RV-A16, treated with a TLR3 agonist (poly(I:C)), or exposed to compression. Thereafter, EDN1 (ET-1 protein-encoding gene) mRNA expression and secreted ET-1 protein were measured. We examined the role of TGFβR in ET-1 secretion using either a pharmacologic inhibitor of TGFβR or recombinant TGF-β1 protein. In the AAD mouse models, allergen-sensitized and allergen-challenged mice were subsequently infected with RV. We then measured ET-1 in bronchoalveolar lavage fluid (BALF) and airway hyperresponsiveness (AHR) following methacholine challenge.

RESULTS

Our data reveal that RV infection induced EDN1 expression and ET-1 secretion in HBE cells, potentially mediated by TLR3. TGFβR activation was partially required for ET-1 secretion, which was induced by RV, poly(I:C), or compression. TGFβR activation alone was sufficient to increase ET-1 secretion. In AAD mouse models, RV induced ET-1 secretion in BALF, which positively correlated with AHR.

CONCLUSIONS

Our data provide evidence that RV infection increased epithelial-cell ET-1 secretion through a TGFβR-dependent mechanism, which contributes to bronchoconstriction during RV-induced asthma exacerbations.

Clinical Implications of Longitudinal Blood Eosinophil Counts in Patients With Severe Asthma

BACKGROUND

The stability and variability of blood eosinophil counts (BECs) to phenotype patients with severe asthma is not fully understood.

OBJECTIVE

This post hoc, longitudinal, pooled analysis of placebo-arm patients from 2 phase 3 studies evaluated the clinical implications of BEC stability and variability in moderate-to-severe asthma.

METHODS

This analysis included patients from SIROCCO and CALIMA who received maintenance medium- to high-dosage inhaled corticosteroids plus long-acting β2-agonists; 2:1 patients with BECs of 300 cells/μL or higher and less than 300 cells/μL were enrolled. The BECs were measured 6 times over 1 year in a centralized laboratory. Exacerbations, lung function, and Asthma Control Questionnaire 6 scores were documented across patients grouped by BEC (<300 cells/μL or ≥300 cells/μL) and variability (<80% or ≥80% BECs less than or greater than 300 cells/μL).

RESULTS

Among 718 patients, 42.2% (n = 303) had predominantly high, 30.9% (n = 222) had predominantly low, and 26.9% (n = 193) had variable BECs. Prospective exacerbation rates (mean ± SD) were significantly greater in patients with predominantly high (1.39 ± 2.20) and variable (1.41 ± 2.09) BECs versus predominantly low (1.05 ± 1.66) BECs. Similar results were observed for the number of exacerbations while on placebo.

CONCLUSIONS

Although patients with variable BECs had intermittently high and low BECs, they experienced similar exacerbation rates to the predominantly high group, which were greater than those in the predominantly low group. A high BEC supports an eosinophilic phenotype in clinical settings without additional measurements, whereas a low BEC requires repeated measurements because it could reflect intermittently high or predominantly low BECs.

Asthma Exacerbations: The Genes Behind the Scenes

The clinical and socioeconomic burden of asthma exacerbations (AEs) constitutes a major public health problem. In the last 4 years, there has been an increase in ethnic diversity in candidate-gene and genome-wide association studies of AEs, which in the latter case led to the identification of novel genes and underlying pathobiological processes. Pharmacogenomics, admixture mapping analyses, and the combination of multiple "omics" layers have helped to prioritize genomic regions of interest and/or facilitated our understanding of the functional consequences of genetic variation. Nevertheless, the field still lags behind the genomics of asthma, where a vast compendium of genetic approaches has been used (eg, gene-environment nteractions, next-generation sequencing, and polygenic risk scores). Furthermore, the roles of the DNA methylome and histone modifications in AEs have received little attention, and microRNA findings remain to be validated in independent studies. Likewise, the most recent transcriptomic studies highlight the importance of the host-airway microbiome interaction in the modulation of risk of AEs. Leveraging -omics and deep-phenotyping data from subtypes or homogenous subgroups of patients will be crucial if we are to overcome the inherent heterogeneity of AEs, boost the identification of potential therapeutic targets, and implement precision medicine approaches to AEs in clinical practice.

Urinary metabolites of polycyclic aromatic hydrocarbons and short-acting beta agonist or systemic corticosteroid asthma medication use within NHANES

BACKGROUND

Within cross-sectional studies like the U.S. National Health and Nutritional Examination Survey (NHANES), researchers have observed positive associations between polycyclic aromatic hydrocarbon (PAH) exposure and asthma diagnosis. It is unclear whether similar relationships exist for measures of acute asthma outcomes, including short-term asthma medication use to alleviate symptoms. We examined the relationship between markers of recent PAH exposure and 30-day short-acting beta agonist (SABA) or systemic corticosteroid use, an indicator for recent asthma symptoms.

MATERIALS AND METHODS

For 16,550 children and adults across multiple waves of NHANES (2005-2016), we fit quasi-Poisson multivariable regression models to describe the association between urinary 1-hydroxypyrene (a metabolite of PAH) and SABA or systemic corticosteroid use. We assessed for effect modification by age group and asthma controller medication use. All models were adjusted for urinary creatinine, age, female/male designation, race/ethnicity, poverty, insurance coverage, and serum cotinine.

RESULTS

After controlling for confounding, an increase of one standard deviation of 1-hydroxypyrene was associated with greater prevalence of recent SABA or systemic corticosteroid use (PR: 1.06, 95% CI: 1.03-1.10). The results were similar among those with ever asthma diagnosis and across urine creatinine dilution methods. We did not observe effect modification by age group (p-interaction = 0.22) or asthma controller medication use (p-interaction = 0.73).

CONCLUSION

Markers of recent PAH exposure was positively associated with SABA or systemic corticosteroid use, across various urine dilution adjustment methods. It is important to ensure appropriate temporality between exposures and outcomes in cross-sectional studies.

"As-Needed" Inhaled Corticosteroids for Patients With Asthma

Prevention of severe asthma exacerbations is a primary management goal for asthma across the severity spectrum. Inhaled corticosteroids (ICSs) decrease the risk of asthma exacerbations, but patient adherence to ICS-containing medications as a daily maintenance therapy is poor, and many patients overuse short-acting beta2-agonist relievers; both are associated with increased risk of severe exacerbations and death. Airway inflammation also varies over time, influenced by exposures such as viral infections and allergen. As-needed ICS strategies, in which patients receive ICSs (or additional ICSs, if already taking controller therapy) whenever they take their reliever inhaler, empower patients to adjust their ICS intake in response to symptom fluctuation. These strategies can improve asthma morbidity outcomes, particularly by reducing severe exacerbations and reducing the risk of adverse effects of oral corticosteroids. In this review, the evidence for combination ICS-formoterol in a single inhaler, ICS and short-acting beta2-agonists in separate inhalers, and combination ICS-albuterol in a single inhaler is presented, along with practical considerations, evidence gaps, and implications for clinical practice for each strategy, presented by level of asthma severity and age group. Improving access to such strategies on a global scale is imperative to improve asthma outcomes and achieve equity across populations.

A parametric model to jointly characterize rate, duration, and severity of exacerbations in episodic diseases

BACKGROUND

The natural history of many chronic diseases is characterized by periods of increased disease activity, commonly referred to as flare-ups or exacerbations. Accurate characterization of the burden of these exacerbations is an important research objective.

METHODS

The purpose of this work was to develop a statistical framework for nuanced characterization of the three main features of exacerbations: their rate, duration, and severity, with interrelationships among these features being a particular focus. We jointly specified a zero-inflated accelerated failure time regression model for the rate, an accelerated failure time regression model for the duration, and a logistic regression model for the severity of exacerbations. Random effects were incorporated into each component to capture heterogeneity beyond the variability attributable to observed characteristics, and to describe the interrelationships among these components.

RESULTS

We used pooled data from two clinical trials in asthma as an exemplary application to illustrate the utility of the joint modeling approach. The model fit clearly indicated the presence of heterogeneity in all three components. A novel finding was that the new therapy reduced not just the rate but also the duration of exacerbations, but did not have a significant impact on their severity. After controlling for covariates, exacerbations among more frequent exacerbators tended to be shorter and less likely to be severe.

CONCLUSIONS

We conclude that a joint modeling framework, programmable in available software, can provide novel insights about how the rate, duration, and severity of episodic events interrelate, and enables consistent inference on the effect of treatments on different disease outcomes. Trial registration Ethics approval was obtained from the University of British Columbia Human Ethics Board (H17-00938).

Effect of an Asthma Exacerbation on Medication Adherence

BACKGROUND

Few studies have looked at the effect of an asthma exacerbation on asthma medication adherence.

OBJECTIVE

To measure asthma medication adherence in the 12 months after an asthma exacerbation and the influence of care type (specialist vs primary care provider) as well as social economic status on adherence.

METHODS

We measured portion of days covered (PDC) during the 12 months before and after an exacerbation in a cohort of patients with asthma who were aged 18 years and older. Subanalyses looked at PDC in those who had more than one exacerbation after the sentinel exacerbation, by type of care received (primary care, allergist or pulmonologist, or no care) during both periods and by socioeconomic status (SES), defined as the lower quartile of annual income for the group.

RESULTS

In a cohort of 1,697 patients, PDC improved significantly (from 0.44 to 0.53; P < .001) after an asthma exacerbation. Improvement in PDC was even greater (from 0.45 to 0.57; P < .001) if they had more than one exacerbation after the sentinel exacerbation. Being seen by a specialist after the exacerbation but not before it, resulted in the greatest improvement in PDC (0.17 mean change). Patients not seen by a specialist either before the exacerbation or after had a mean change of just 0.07. Those with a lower SES had an overall lower PDC before the exacerbation (0.37 vs 0.43) but saw a similar improvement in the PDC compared with those in a higher SES (0.09 vs 0.10).

CONCLUSIONS

An asthma exacerbation is associated with a significant and sustained effect on medication adherence.

Impact of exacerbations on lung function, resource utilization, and productivity: results from an observational, prospective study in adults with uncontrolled asthma

Exacerbations have a major impact on the well-being of patients with uncontrolled asthma. This study evaluated lung function, healthcare resource utilization (HCRU), and productivity loss following asthma exacerbations. This single-center, observational, prospective cohort study recruited US patients with an acute asthma exacerbation; a reference group without exacerbations was included for comparison. Lung function (forced expiratory volume in 1 second [FEV₁]), reported as FEV₁ percent predicted (FEV₁pp), was collected at baseline, daily during Month 1, and monthly for Months 2-5. HCRU (outpatient visits to a healthcare practitioner, emergency room [ER] visits, and hospitalizations for asthma), oral corticosteroid (OCS) use, and asthma-related work/school absence were collected monthly for 6 months. Overall, 150 patients were recruited (exacerbation: n = 102; reference: n = 48; mean [SD] age: 42.7 [15.2] and 49.6 [12.4] years; female: 73% and 71%). In both groups, similar trends were observed in FEV₁, with significant improvement from baseline to Week 1 (p < 0.05), followed by a continuous decline. FEV₁pp was 7.7% lower at baseline and 8.9% lower at Month 5 in the exacerbation versus reference group. The exacerbation group had significantly higher rates of OCS prescriptions (p = 0.04) and increased work absences (p = 0.001) during follow-up versus reference group. There were no significant differences in other HCRU measures (e.g., outpatient visits, ER visits, and hospitalizations). Although patients with exacerbations had rapid recovery of lung function, this was not maintained and declined faster than in patients without exacerbations. The results suggest that intensive disease management and monitoring are important in patients with asthma who experience an exacerbation.

REALITI-A Study: Real-World Oral Corticosteroid-Sparing Effect of Mepolizumab in Severe Asthma

BACKGROUND

Patients with severe asthma may require maintenance oral corticosteroids (mOCS) for disease control as well as systemic corticosteroid (SCS) bursts for clinically significant exacerbations. However, mOCS and SCS use are associated with adverse effects, which increases patient disease burden.

OBJECTIVE

To assess the real-world corticosteroid-sparing effect of mepolizumab in patients with severe asthma.

METHODS

REALITI-A was a 24-month international, prospective, observational cohort study involving 84 centers across Europe, Canada, and the United States, with a 1-year pre-post mepolizumab treatment preplanned interim analysis. A total of 822 adults with a clinical diagnosis of asthma and a physician decision to initiate mepolizumab treatment (100 mg subcutaneously) were included. End points included daily mOCS dose at baseline (penultimate 28 days of pretreatment) and 1 year after treatment; percent reduction from baseline in mOCS dose; patients discontinuing mOCS 1 year after treatment; and the rate of clinically significant exacerbations (those requiring OCS for 3 days or more [or parenteral administration], emergency room visit, and/or hospital admission) before and after treatment.

RESULTS

A total of 319 patients received mOCS at baseline (median [interquartile range]: 10.0 [5.0-15.0] mg/d). At 1 year after treatment, median mOCS dose was reduced by 75% (2.5 [0.0-5.0] mg/d); 64% of patients had a reduction in mOCS dose of 50% or greater compared with baseline and 43% discontinued mOCS. Clinically significant exacerbations decreased between pretreatment and posttreatment (rate ratio [95% confidence interval] 0.29 [0.26-0.32]; P < .001).

CONCLUSION

This 1-year analysis demonstrates that real-world mepolizumab treatment is clinically effective in patients with severe asthma, providing disease control while reducing the need for mOCS and SCS bursts.

Transition to Virtual Asthma Care During the COVID-19 Pandemic: An Observational Study

BACKGROUND

The COVID-19 pandemic increased reliance on virtual care for patients with persistent asthma.

OBJECTIVE

This retrospective cohort study assessed changes from in-person to virtual care during the pandemic. In patients with persistent asthma, compared with the same period before the pandemic.

METHODS

Kaiser Permanente Colorado members aged 18 to 99 years with persistent asthma were evaluated during two periods (March to October 2019 and March to October 2020). Comparison of asthma exacerbations (hospitalizations, emergency department visits, and courses of oral prednisone) and asthma medication metrics were evaluated between the two periods and by type of care received during the pandemic (no care, virtual care only, in-person care only, or a mix of virtual and in-person care). Population characteristics by type of care received during the pandemic were also evaluated.

RESULTS

Among 7,805 adults with persistent asthma, those who used more virtual care or sought no care during the pandemic were younger and had fewer comorbidities, mental health diagnoses, or financial barriers. Exacerbations decreased (0.264 to 0.214; P <.001) as did courses of prednisone (0.213 to 0.169). Asthma medication adherence (0.53 to 0.54; P <.001) and the asthma medication ratio, a quality-of-care metric (0.755 to 0.762; P = .019), increased slightly. Patients receiving a mix of in-person and virtual care had the highest rate of exacerbations (0.83) and a lower asthma medication ratio (0.74) despite having the highest adherence (.57).

CONCLUSIONS

Despite an increase in virtual care, asthma exacerbations decreased except among individuals who received both in-person and virtual care, likely because they had more severe disease.

Severe lactic acidosis and persistent diastolic hypotension following standard dose of intermittent nebulized salbutamol in a child: a case report

Background

Salbutamol is a selective β2-receptor agonist widely used to treat asthma in both emergency and outpatient settings. However, it has been associated with a broad spectrum of side effects. Lactic acidosis and diastolic hypotension are rarely reported together following intermittent salbutamol nebulization in children, even less so at standard therapeutic doses.

Case presentation

We present the case of a 12-year-old Italian boy, 34 kg body weight, who experienced a serious drug reaction during a moderate asthma exacerbation with associated dehydration (blood urea nitrogen/creatinine 0.25), following intermittent inhaled (0.2 mg at 3-hour intervals—overall 1.4 mg in 24 hours before arrival) and nebulized treatment (3.25 mg at 20-minute intervals in 60 minutes, overall 11.25 mg in our emergency department). The patient developed hyperglycemia (peak concentration 222 mg/dL), hypokalemia (lowest concentration 2.6 mEq/L), electrocardiogram alterations (corrected QT interval 467 ms), long-lasting arterial hypotension despite fluid boluses (lowest value 87/33 mmHg), and elevated blood lactate levels (peak concentration 8.1 mmol/L), following the third nebulized dose. Infections, liver dysfunction, and toxicity following other medications were ruled out. The aforementioned alterations improved within 24 hours after discontinuation of salbutamol.

Conclusions

We reinforce the message that even the use of intermittent nebulized salbutamol for acute moderate asthma can lead to severe transient complications in children. Then, healthcare providers should pay attention not only in emergency settings, to achieve prompt recognition and proper management of this adverse reaction. Careful reassessment could prevent similar reactions.

Diet, Asthma, and Severe Asthma Exacerbations in a Prospective Study of Puerto Rican Youth

BACKGROUND

Poor diet quality may contribute to the disproportionate asthma burden in Puerto Rican youth.

OBJECTIVE

To examine whether an unhealthy diet at one or two study visits conducted over about 5 years was associated with asthma, severe asthma exacerbations, and worse lung function in Puerto Rican youth.

METHODS

This was a prospective study of 406 Puerto Rican youth aged 6 to 14 years at a baseline visit and 9 to 20 years at a follow-up visit. As in prior work, diet was assessed using a dietary score ranging from -2 to +2. The exposure of interest was an unhealthy diet, defined as a nonpositive dietary score (0 to -2) at one or both visits. Outcomes of interest were asthma (defined as physician-diagnosed asthma and one of more episode of wheeze in the year before the second visit), one or more severe asthma exacerbation in the year before the second visit, and change in percent predicted lung function measures (FEV₁, FVC, and FEV₁/FVC) between the first and second visits.

RESULTS

In a multivariable analysis, an unhealthy diet at both visits was associated with increased odds of asthma (adjusted odds ratio = 3.38; 95% confidence interval, 1.74-6.57) and severe asthma exacerbations (adjusted odds ratio = 2.65; 95% confidence interval, 1.16-6.03), but not with change in lung function.

CONCLUSIONS

An unhealthy diet at both visits was associated with increased odds of asthma and severe asthma exacerbations, compared with a healthy diet at both visits. Our findings support health policies promoting a healthy diet in Puerto Rican youth, a population at high risk for asthma.

Carbon footprint and associated costs of asthma exacerbation care among UK adults

INTRODUCTION

Asthma exacerbations are a primary driver of costs and health impacts from asthma. Despite research suggesting that asthma care has a disproportionate carbon footprint, emissions costs are not considered when evaluating its societal burden. To advance the understanding of greenhouse gas (GHG) emissions associated with asthma, we estimated the carbon footprint and associated costs of asthma exacerbation care by severity level among UK adults.

METHODS

Guidelines for asthma exacerbation treatment in UK adults were reviewed by severity level: mild, moderate, and severe/life-threatening. Components of care for each severity were evaluated for GHG emission potential and key drivers were identified. Carbon dioxide equivalent (CO₂e) emissions of drivers were sourced from published literature and combined to estimate the carbon footprint per exacerbation, by severity level. Emissions were scaled up to the annual UK adult population based on the annual number of exacerbations at each severity. Costs associated with emissions were estimated using the UK government's 2020 nontraded price of carbon, at ₤71 per tonne CO₂e (tCO₂e).

RESULTS

Overall, emissions drivers for exacerbations were medical services, including patient-travel, and quick-relief inhalers. The annual number of mild, moderate, and severe/life-threatening asthma exacerbations among UK adults were 118.9 M, 5.5 M, and 2.4 M. Associated annual carbon footprints were estimated to be 83,455 tCO₂e, 192,709 tCO₂e, and 448,037 tCO₂e for mild, moderate, and severe/life-threatening exacerbations, respectively, with a total of 724,201 tCO₂e. Total annual emissions costs from exacerbation care were £51.3 M; ₤5.9 M, ₤13.6 M, and ₤31.7 M for mild, moderate, and severe/life-threatening exacerbations, respectively.

CONCLUSION

GHG emissions from asthma exacerbation management were the highest for severe/life-threatening events, followed by moderate exacerbations. Treatment to reduce the severity and occurrence of exacerbations, such as effective, long-term control therapy via lower-emission dry powder inhalers (DPIs), can help mitigate asthma care emissions. For mild exacerbations, the use of DPIs can eliminate associated emissions.

Outdoor air pollution and the risk of asthma exacerbations in single lag0 and lag1 exposure patterns: a systematic review and meta-analysis

Objective: To synthesize evidence regarding the relationship between outdoor air pollution and risk of asthma exacerbations in single lag0 and lag1 exposure patterns.Methods: We performed a systematic literature search using PubMed, Embase, Cochrane Library, Web of Science, ClinicalTrials, China National Knowledge Internet, Chinese BioMedical, and Wanfang databases. Articles published until August 1, 2020 and the reference lists of the relevant articles were reviewed. Two authors independently evaluated the eligible articles and performed structured extraction of the relevant information. Pooled relative risks (RRs) and 95% confidence intervals (CIs) of lag0 and lag1 exposure patterns were estimated using random-effect models.Results: Eighty-four studies met the eligibility criteria and provided sufficient information for meta-analysis. Outdoor air pollutants were associated with increased risk of asthma exacerbations in both single lag0 and lag1 exposure patterns [lag0: RR (95% CI) (pollutants), 1.057(1.011, 1.103) (air quality index, AQI), 1.007 (1.005, 1.010) (particulate matter of diameter ≤ 2.5 μm, PM_2.5), 1.009 (1.005, 1.012) (particulate matter of diameter, PM₁₀), 1.010 (1.006, 1.014) (NO₂), 1.030 (1.011, 1.048) (CO), 1.005 (1.002, 1.009) (O₃); lag1:1.064(1.022, 1.106) (AQI), 1.005 (1.002, 1.008) (PM_2.5), 1.007 (1.004, 1.011) (PM₁₀), 1.008 (1.004, 1.012) (NO₂), 1.025 (1.007, 1.042) (CO), 1.010 (1.006, 1.013) (O₃)], except SO₂ [lag0: RR (95% CI), 1.004 (1.000, 1.007); lag1: RR (95% CI), 1.003 (0.999, 1.006)]. Subgroup analyses revealed stronger effects in children and asthma exacerbations associated with other events (including symptoms, lung function changes, and medication use).Conclusion: Outdoor air pollution increases the asthma exacerbation risk in single lag0 and lag1 exposure patterns.Trial registration: PROSPERO, CRD42020204097. https://www.crd.york.ac.uk/.Supplemental data for this article is available online at https://doi.org/10.1080/02770903.2021.2008429 .

Exacerbation-Prone Asthma: A Biological Phenotype or a Social Construct

Asthma is a complex syndrome with multiple phenotypes and endotypes. Asthma exacerbations are not only the clearest indictor of the morbidity of asthma and of the risk for mortality due to asthma, but also comprise a significant amount of the cost to care for poorly controlled asthma. There continues to be significant disparity in the prevalence, mortality, and morbidity due to asthma. Patients with asthma who suffer recurrent exacerbations are considered to have exacerbation-prone asthma (EPA). Efforts to characterize patients with frequent exacerbations show that the etiology is likely multifactorial. Research to determine the intrinsic risk factors for EPA include studies of both genetic and inflammatory biomarkers. External factors contributing to exacerbations have been extensively reviewed and include viral infection, environmental exposures, air pollution, and psychosocial and economic barriers to optimizing health. It is likely that EPA occurs when patients who have an increased underlying intrinsic/biological risk are placed in a given exposome (environments with a variety of exposures and triggers including allergens, pollution, stress, barriers, and occupational exposures). It is the social construct combined with underlying biology that frequently drives an EPA phenotype.

Assessment and Management of Occupational Asthma

Exposures at work can give rise to different phenotypes of "work-related asthma." The focus of this review is on the diagnosis and management of sensitizer-induced occupational asthma (OA) caused by either a high- or low-molecular-weight agent encountered in the workplace. The diagnosis of OA remains a challenge for the clinician because there is no simple test with a sufficiently high level of accuracy. Instead, the diagnostic process combines different procedures in a stepwise manner. These procedures include a detailed clinical history, immunologic testing, measurement of lung function parameters and airway inflammatory markers, as well as various methods that relate changes in these functional and inflammatory indices to workplace exposure. Their diagnostic performances, alone and in combination, are critically reviewed and summarized into evidence-based key messages. A working diagnostic algorithm is proposed that can be adapted to the suspected agent, purpose of diagnosis, and available resources. Current information on the management options of OA is summarized to provide pragmatic guidance to clinicians who have to advise their patients with OA.

Predicting Severe Asthma Exacerbations in Children: Blueprint for Today and Tomorrow

Severe asthma exacerbations are the primary cause of morbidity and mortality in children with asthma. Accurate prediction of children at risk for severe exacerbations, defined as those requiring systemic corticosteroids, emergency department visit, and/or hospitalization, would considerably reduce health care utilization and improve symptoms and quality of life. Substantial progress has been made in identifying high-risk exacerbation-prone children. Known risk factors for exacerbations include demographic characteristics (ie, low income, minority race/ethnicity), poor asthma control, environmental exposures (ie, aeroallergen exposure/sensitization, concomitant viral infection), inflammatory biomarkers, genetic polymorphisms, and markers from other "omic" technologies. The strongest risk factor for a future severe exacerbation remains having had one in the previous year. Combining risk factors into composite scores and use of advanced predictive analytic techniques such as machine learning are recent methods used to achieve stronger prediction of severe exacerbations. However, these methods are limited in prediction efficiency and are currently unable to predict children at risk for impending (within days) severe exacerbations. Thus, we provide a commentary on strategies that have potential to allow for accurate and reliable prediction of children at risk for impending exacerbations. These approaches include implementation of passive, real-time monitoring of impending exacerbation predictors, use of population health strategies, prediction of severe exacerbation responders versus nonresponders to conventional exacerbation management, and considerations for preschool-age children who can be especially high risk. Rigorous prediction and prevention of severe asthma exacerbations is needed to advance asthma management and improve the associated morbidity and mortality.

Season-stratified effects of meteorological factors on childhood asthma in Shanghai, China

OBJECTIVES

There has been increasing interest in identifying the adverse effects of ambient environmental factors on asthma exacerbations (AE), but season-stratified effects of meteorological factors on childhood asthma remain unclear. We explored the season-stratified effects of meteorological factors on childhood AE in Shanghai, China.

METHODS

Poisson generalized linear regression model combined with a distributed lag nonlinear model was used to examine the lagged and nonlinear effects of meteorological factors on childhood AE after adjustment for putative confounders. We also performed a season-stratified analysis to determine whether the season modified the relationship between meteorological factors and childhood AE.

RESULTS

There were 23,103 emergency department visits (EDVs) for childhood AE, including 15,466 boys and 7637 girls during 2008-2017. Most meteorological factors (e.g., temperature, diurnal temperature range (DTR), relative humidity (RH) and wind speed (WS)) were significantly associated with EDVs for childhood AE, even after adjustment for the confounding effects of air pollutants. In the whole year, extreme cold, moderate heat, higher DTR, lower RH and WS increased the relative risk (RR) for childhood AE. In the cold season, lower RH and wind speed increased the risks of childhood AE (RR_lag0-28 for the 5th percentile (p5) of RH: 9.744, 95% CI: 3.567, 26.616; RR_lag0-28 for the p5 of wind speed: 10.671, 95% CI: 1.096, 103.879). In the warm season, higher temperature and DTR, lower RH and WS increased the RR for childhood AE (RR_lag0-5 for the p95 of temperature: 1.871, 95% CI: 1.246, 2.810; RR_lag0-2 for the p95 of DTR: 1.146, 95% CI: 1.010, 1.300; RR_lag0-5 for the p5 of RH: 1.931, 95% CI: 1.191, 3.128; RR_lag0-2 for the p5 of WS: 1.311, 95% CI: 1.005, 1.709).

CONCLUSIONS

Extreme meteorological factors appeared to be triggers of EDVs for childhood AE in Shanghai and the effects modified by season. These findings provide evidence for developing season-specific and tailored strategies to prevent and control childhood AE.

Paediatric asthma deaths in Ireland: 2006-2016

BACKGROUND

Asthma is the commonest chronic condition in childhood but mortality from asthma during childhood is a rare occurrence. No national review into asthma deaths in children in Ireland has been performed to date.

AIM

The aim of this study was to review all cases of mortality from asthma in the paediatric population over a 10-year period in Ireland. The objective was to identify risk factors contributing to asthma deaths in children.

METHODS

A retrospective chart review was performed on cases reported to the National Paediatric Mortality Register (NPMR) with asthma as the primary cause of death.

RESULTS

Eleven cases were reported. Consent was obtained for six cases. Median age at death was 11.8 years. All patients presented to the Emergency Department (ED) in asystole. Fifty percent of patients had acute symptoms prior to the fatal episode. None of the patients was attending secondary services. Only 60% had a written personalised asthma action plan (PAAP).

CONCLUSION

Our data suggests that most patients present in extremis and have little warning signs of severity of the attack. Better education on recognition of symptoms and initiation of action plans is required.

Effects of ambient ozone concentrations with different averaging times on asthma exacerbations: A meta-analysis

BACKGROUND

Mounting evidence suggests that short-term exposure to ozone increases the risk of asthma exacerbations. However, ozone exposures have been assessed using ambient ozone concentrations averaged over different time periods in different studies.

OBJECTIVE

To evaluate the risks for asthma exacerbations related to ambient ozone measured as 1-hour or 8-hour daily maximum and 24-hour average concentrations.

METHODS

Based on a literature search in PubMed, EMBASE and Web of Science, we identified all time-series studies as of December 4th, 2018 and included 47 eligible studies in our analyses. Asthma exacerbation is defined as the risk for emergency room visits or hospital admissions. Pooled relative risks (RRs) and 95% confidence intervals (95%CIs) for a 10 μg/m3 increase in daily ozone concentration were estimated using random effect models. Subgroup analyses and sensitivity analyses were also performed to examine the risks for different seasons, regions and age groups and for the robustness of our main findings.

RESULTS

Significant and similar associations were found for O3-1 h max (RR,1.012; 95%CI, 1.005-1.019) and O3-8 h max (RR, 1.011; 95%CI, 1.007-1.014), while marginal effect was identified for O3-24 h average (RR, 1.005; 95%CI, 0.996-1.014). No significant publication bias but high heterogeneities were observed. During the warm season, ozone was significantly associated with asthma exacerbation. O3-1 h max had the highest RR of 1.014 (95%CI, 1.005-1.024), followed by O3-8 h max (RR, 1.012; 95%CI, 1.009-1.016), while marginal association was identified for O3-24 h avg (RR, 1.008; 95%CI, 0.998-1.017). During the cold season, null associations were identified for all the three averaging times. Variations were also observed in region and age.

CONCLUSION

Ozone exposure measured as 1-hour or 8-hour daily max were more consistently associated with asthma exacerbations than 24-hour average exposure during the warm season.

Molecular detection of respiratory pathogens and typing of human rhinovirus of adults hospitalized for exacerbation of asthma and chronic obstructive pulmonary disease

Background

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and asthma are associated with a variety of precipitating factors including infection. This study assessed the infective viral etiologies by real-time multiplex polymerase chain reaction of patients hospitalized with AECOPD and asthma exacerbations. In addition, infective etiologies were assessed for association with the clinical outcome of the patients.

Methods

Adults admitted with AECOPD and asthma exacerbations between August 2016 and July 2017 were recruited. Nasopharyngeal aspirate (NPA) samples were obtained from the patients within 1–2 days of admission and subjected to pathogen detection and human rhinovirus (HRV) typing.

Results

Altogether 402 patients with AECOPD, 80 stable COPD, 100 asthma exacerbation and 21 stable asthma subjects were recruited. Among those admitted for AECOPD and asthma exacerbations, 141(35.1%) and 45(45.0%) respectively had pathogens identified in the NPA specimens. The commonest virus identified was influenza A followed by HRV. HRV typing identified HRV-A and HRV-C as the more common HRV with a wide variety of genotypes. Identification of pathogens in NPA or HRV typing otherwise did not affect clinical outcomes including the hospital length of stay, readmission rates and mortality except that identification of pathogens in asthma exacerbation was associated with a lower rate of readmissions at 30 and 60 days.

Conclusions

Many respiratory viruses were associated with AECOPD and asthma exacerbation. HRV-A and HRV-C were the more common HRV associated with exacerbations. Identification of pathogens in NPA was associated with less readmissions for asthma patients at 30 and 60 days.

Trial registration

ClinicalTrials.gov NCT02866357.

Supplementary information

Supplementary information accompanies this paper at10.1186/s12931-019-1181-0.

Cross-sectional associations of vitamin D status with asthma prevalence, exacerbations, and control in New Zealand adults

BACKGROUND

Previous studies, mostly with children, have reported inconsistent findings on the associations of vitamin D status with asthma prevalence, exacerbations, and control. Because of limited research with adults, we examined these associations in a large community-based sample of New Zealand adults.

METHODS

5110 participants, aged 50-84 years, were recruited from the community into a clinical trial of vitamin D supplementation. The current analysis is based on baseline blood sample collection to measure serum 25-hydroxyvitamin D (25(OH)D), which was deseasonalized for data analyses; and baseline asthma assessment, which included questions on asthma prevalence, urgent medical care for asthma in the previous 12 months, and control of asthma symptoms in the previous 4 weeks.

RESULTS

702 (13.2%) of 5088 participants reported having doctor-diagnosed asthma. There was no difference in mean (SE) 25(OH)D concentration between participants with and without asthma: 66 (0.9) and 66 (0.4) nmol/L, respectively, adjusting for sex (p = 0.71). However, in multivariable analyses restricted to participants who reported having asthma, mean (SE) 25(OH)D concentration was 6.3 (2.6) nmol/L lower in those who reported having urgent medical care for asthma in the previous 12 months compared to others (p = 0.02), and 10.4 (3.9) nmol/L lower in those with very poor asthma control compared to those who were well-controlled (p = 0.03).

CONCLUSION

These cross-sectional results suggest that asthmatic adults with lower vitamin D status are more likely to receive urgent asthma medical care and to experience poor asthma control. Clinical trials are needed to determine the role of vitamin D supplementation in asthma management.

Severe Occupational Asthma: Insights From a Multicenter European Cohort

BACKGROUND

Although sensitizer-induced occupational asthma (OA) accounts for an appreciable fraction of adult asthma, the severity of OA has received little attention.

OBJECTIVE

The aim of this study was to characterize the burden and determinants of severe OA in a large multicenter cohort of subjects with OA.

METHODS

This retrospective study included 997 subjects with OA ascertained by a positive specific inhalation challenge completed in 20 tertiary centers in 11 European countries during the period 2006 to 2015. Severe asthma was defined by a high level of treatment and any 1 of the following criteria: (1) daily need for a reliever medication, (2) 2 or more severe exacerbations in the previous year, or (3) airflow obstruction.

RESULTS

Overall, 162 (16.2%; 95% CI, 14.0%-18.7%) subjects were classified as having severe OA. Multivariable logistic regression analysis revealed that severe OA was associated with persistent (vs reduced) exposure to the causal agent at work (odds ratio [OR], 2.78; 95% CI, 1.50-5.60); a longer duration of the disease (OR, 1.04; 95% CI, 1.00-1.07); a low level of education (OR, 2.69; 95% CI, 1.73-4.18); childhood asthma (OR, 2.92; 95% CI, 1.13-7.36); and sputum production (OR, 2.86; 95% CI, 1.87-4.38). In subjects removed from exposure, severe OA was associated only with sputum production (OR, 3.68; 95% CI, 1.87-7.40); a low education level (OR, 3.41; 95% CI, 1.72-6.80); and obesity (OR, 1.98; 95% CI, 0.97-3.97).

CONCLUSIONS

This study indicates that a substantial proportion of subjects with OA experience severe asthma and identifies potentially modifiable risk factors for severe OA that should be targeted to reduce the adverse impacts of the disease.

Asthma Exacerbations in the Pediatric Emergency Department at a Tertiary Hospital: Association With Environmental Factors

INTRODUCTION

Children with asthma experience recurrent respiratory symptoms and exacerbations due to multiple environmental factors. The aim of this study was to describe the prevalence and triggers of asthma exacerbations and their management in a cohort of pediatric patients attended in an emergency department (ED).

METHODS

We performed an observational, retrospective, single-center study in the pediatric ED of Hospital Universitario La Paz, Madrid, Spain in 2015. Children with asthma exacerbations attending the ED were included after a thorough search using our institutional computer database. Pollen and atmospheric mold spore counts and pollution data were collected for that period from official websites. Multiple logistic regression was used to assess the association between daily pollution (NO2, PM10, ozone, pollen, and molds) and admissions to the ED because of asthma.

RESULTS

During 2015, a total of 50 619 patients were attended in the ED of our hospital. Of these, 2609 (5%) were diagnosed with asthma exacerbation/bronchospasm. The patient had to be admitted to hospital in 21.7% of cases. The main triggers of asthma exacerbations were respiratory infection in 1841 cases (70.6%). A significant correlation was found between grass pollen counts and ED admissions (P<.0001). A positive correlation was also found between ED admissions and NO2 0.58 (95%CI, 0.02-0.87) and PM10 0.75 (95%CI, 0.31-0.93) (P<.05).

CONCLUSION

Environmental factors such as grass pollen counts and pollution (NO2 and PM10) are associated with a higher frequency of admission to the ED.

Intranasal curcumin protects against LPS-induced airway remodeling by modulating toll-like receptor-4 (TLR-4) and matrixmetalloproteinase-9 (MMP-9) expression via affecting MAP kinases in mouse model

OBJECTIVE

Bacterial infections can exacerbate asthmatic inflammation depending on lipopolysaccharide (LPS) composition, the outermost component of cell wall, its exposure timings as well as host's immune status. In present study, Balb/c mice were exposed to antigen (ovalbumin) and LPS simultaneously to establish an asthmatic model. Curcumin (diferuloylmethane), well known for its anti-inflammatory potential, was administered through intranasal route 1 h before LPS and OVA (ovalbumin) exposure to evaluate its efficacy against airway structural changes.

METHODS

Inflammatory cell infiltration in lungs was measured by flow cytometry and further eosinophils were especially measured by immunofluorescence detection of major basic protein (MBP) as marker of eosinophilc granule protein. We also measured reactive oxygen species (ROS) in BALF by spectrofluorometry. MMP-9 activity was evaluated by gelatin zymography and mRNA expressions of MMP-9, TIMP-1, TGF-β1, IL-13, Collagen-1 and TLR-4 were measured in lungs. Protein expression of MAP kinases (P-ERK, P-JNK, P-p38), TLR-4, Cox-2, Lox-5 and Eotaxin was measured by western blotting. Hydroxyproline level and masson's trichrome staining were used to evaluate collagen deposition in lung.

RESULTS

Exposure to LPS (0.1 µg) exacerbates airway inflammation and induces structural changes in lungs by enhanced ROS production, collagen deposition, expression of genes involved in airway remodeling and activation of MAP kinases pathway enzymes. Intranasal curcumin pretreatment had significantly suppressed inflammatory mediators and airway remodeling proteins.

CONCLUSION

Our results strongly suggest that intranasal curcumin effectively protects LPS-induced airway inflammation and structural changes by modulating genes involved in airway remodeling in safer way; hence, it can be considered as supplementary alternative towards asthma treatments.

Relationship of Inhaled Corticosteroid Adherence to Asthma Exacerbations in Patients with Moderate-to-Severe Asthma

BACKGROUND

Patients with asthma and elevated blood eosinophils are at increased risk of severe exacerbations. Management of these patients should consider nonadherence to inhaled corticosteroid (ICS) therapy as a factor for increased exacerbation risk.

OBJECTIVE

The objective of this study was to investigate whether poor adherence to ICS therapy explains the occurrence of asthma exacerbations in patients with elevated blood eosinophil levels.

METHODS

This historical cohort study identified patients within the Optimum Patient Care Research Database, aged 18 years or more, at Global Initiative for Asthma step 3 or 4, with 2 or more ICS prescriptions during the year before the clinical review. Patient characteristics and adherence (based on prescription refills and patient self-report) for ICS therapy were analyzed for those with elevated (>400 cells/μL) or normal (≤400 cells/μL) blood eosinophils.

RESULTS

We studied 7195 patients (66% female, mean age 60 years) with median eosinophil count of 200 cells/μL and found 81% to be not fully adherent to ICS therapy. A total of 1031 patients (14%) had elevated blood eosinophil counts (58% female, mean age 60 years), 83% of whom were not fully adherent to ICS. An increased proportion of adherent patients in the elevated blood eosinophil group had 2 or more exacerbations (14.0% vs 7.2%; P = .003) and uncontrolled asthma (73% vs 60.8%; P = .004) as compared with non-fully adherent patients.

CONCLUSIONS

Approximately 1 in 7 patients had elevated eosinophils. Adherence to ICS therapy was not associated with decreased exacerbations for these patients. Additional therapy should be considered for these patients, such as biologics, which have been previously shown to improve control in severe uncontrolled eosinophilic asthma.

Pediatric severe asthma: a case series report and perspectives on anti-IgE treatment

Background

The primary goal of asthma management is to achieve disease control for reducing the risk of future exacerbations and progressive loss of lung function. Asthma not responding to treatment may result in significant morbidity. In many children with uncontrolled symptoms, the diagnosis of asthma may be wrong or adherence to treatment may be poor. It is then crucial to distinguish these cases from the truly “severe therapy-resistant” asthmatics by a proper filtering process. Herein we report on four cases diagnosed as difficult asthma, detail the workup that resulted in the ultimate diagnosis, and provide the process that led to the prescription of omalizumab.

Case presentation

All children had been initially referred because of asthma not responding to long-term treatment with high-dose inhaled steroids, long-acting β₂-agonists and leukotriene receptor antagonists. Definitive diagnosis was severe asthma. Three out four patients were treated with omalizumab, which improved asthma control and patients’ quality of life. We reviewed the current literature on the diagnostic approach to the disease and on the comorbidities associated with difficult asthma and presented the perspectives on omalizumab treatment in children and adolescents. Based on the evidence from the literature review, we also proposed an algorithm for the diagnosis of pediatric difficult-to-treat and severe asthma.

Conclusions

The management of asthma is becoming much more patient-specific, as more and more is learned about the biology behind the development and progression of asthma. The addition of omalizumab, the first targeted biological treatment approved for asthma, has led to renewed optimism in the management of children and adolescents with atopic severe asthma.

Phenotype-Driven Therapeutics in Severe Asthma

Inhaled corticosteroids are the mainstay of asthma treatment using a step-up approach with incremental dosing and additional controller medications in order to achieve symptom control and prevent exacerbations. While most patients respond well to this treatment approach, some patients remain refractory despite high doses of inhaled corticosteroids and a long-acting β-agonist. The problem lies in the heterogeneity of severe asthma, which is further supported by the emergence of severe asthma phenotypes. This heterogeneity contributes to the variability in treatment response. Randomized controlled trials involving add-on therapies in poorly controlled asthma have challenged the idea of a "one size fits all" approach targeting specific phenotypes in their subject selection. This review discusses severe asthma phenotypes from unbiased clustering approaches and the most recent scientific evidence on novel treatments to provide a guide in personalizing severe asthma treatment.

The Role of Human Parainfluenza Virus Infections in the Immunopathology of the Respiratory Tract

Viral infections are leading causes of both upper and lower airway acute illness in all age groups of healthy persons, and have also been implicated in the acute exacerbations of chronic respiratory disorders like asthma and COPD. Human rhinovirus, respiratory syncytial virus, influenza virus and coronavirus have been considered as the most important respiratory pathogens and relatively little attention has been paid to the role of parainfluenza viruses (hPIVs). Human parainfluenza viruses are single-stranded RNA viruses belonging to the paramyxovirus family that may evoke lower respiratory infections in infants, children and immunocompromised individuals. Among non-immune compromised adults, hPIV infection typically causes mild disease manifested as upper respiratory tract symptoms and is infrequently associated with severe croup or pneumonia. Moreover, hPIV infection may be associated with viral exacerbations of chronic airway diseases, asthma or COPD or chronic rhinosinusitis. In this review, we summarized the basic epidemiology and immunology of hPIVs and addressed the more recent data implicating the role of parainfluenza viruses in the exacerbation of chronic airway disorders.

The effect of nebulised magnesium sulphate in the management of childhood moderate asthma exacerbations as adjuvant treatment

BACKGROUND

After the bronchodilator effect of magnesium was shown, the use of magnesium in treatment of asthma exacerbations became common. With the results of recent studies, the use of intravenous magnesium in severe asthma exacerbations took its place. We aimed to examine the effects of adding isotonic magnesium sulphate instead of isotonic saline into nebulised salbutamol on the Modified Pulmonary Index Score (MPIS) and the hospitalisation rate in moderate asthma exacerbations.

METHODS

Our study population included 100 children age between 3 and 15 years with asthma admitted to emergency department due to moderate asthma exacerbations. The patients were randomised to placebo or magnesium, with 50 patients in each arm. All patients received 1mg/kg of systemic methylprednisolone at the beginning of treatment and thereafter received either nebulised salbutamol (0.15mg/kg/dose) and 1ml magnesium sulphate (15%)+1.5ml isotonic saline on three occasions at roughly 20min intervals (Magnesium group) or nebulised salbutamol (0.15mg/kg/dose) and 2.5ml isotonic saline mixture on three occasions at roughly 20min intervals (Placebo group). The MPIS of patients on 0th min, 20th min, 40th and 120th min were calculated and compared. The primary outcome was to compare MPIS values at the end of 120th min.

RESULTS

Both groups have similar demographic, allergic characteristics and baseline MPIS scores. When the MPIS scores in the 120th min and admission rates in the 200th min, there was no significant difference between the two groups.

CONCLUSIONS

The use of nebulised magnesium sulphate in moderate asthma exacerbation as adjuvant treatment showed no benefit to standard treatment in our study.

Seasonal and geographic variations in the incidence of asthma exacerbations in the United States

BACKGROUND

Exacerbations drive the burden of asthma and lead to significant morbidity and consumption of health care resources. Many prior studies of the epidemiology of asthma exacerbations have relied upon data from hospital care.

OBJECTIVE

The objective of this study was to determine US patterns of geographic and seasonal variations of asthma exacerbations being defined as asthma episodes requiring hospital care and/or a prescription for oral steroid.

METHODS

The study was a retrospective observational cohort study using administrative claims data for insured individuals from the HealthCore Integrated Research Database, including around 43 million members in the United States. Analyses examined 3 age groups, 6-17, 18-64, and ≥65 years and four US regions, Northeast, Southeast, Central, and Western.

RESULTS

Monthly rates of asthma exacerbations showed the greatest variation over the year in children, less so in adults and in the elderly. Clinically important differences in rates of asthma exacerbation were observed between regions with the Western Region having the lowest in all three age groups followed by the Northeast, Central, and Southeast regions. Peaks in children occurred in the early fall following troughs in the summer months, and peaks at year-end occurred in adults, particularly in those over 65 years.

CONCLUSIONS

There is a striking seasonal variation in asthma exacerbations in the United States. Substantial differences between regions of the United States in asthma exacerbation rates cannot readily be explained and invite further investigation.

Fatal asthma; is it still an epidemic?

BACKGROUND

Asthma mortality has declined since the 1980s. Nevertheless the World Health Organization (WHO) identified asthma as responsible for 225.000 deaths worldwide in 2005, and 430.000 fatal cases are expected by 2030. Some unexpected and concentrated fatal asthma events all occurred between 2013 and 2015 in Veneto, a North Eastern region of Italy, which prompted a more in-depth investigation of characteristics and risk factors.

METHODS

A web search including key words related to fatal asthma in Italy between 2013 and 2015 has been performed. Concerning the cases that occurred in Veneto, subjects' clinical records have been evaluated and details about concomitant weather conditions, pollutants and pollen count have been collected.

RESULTS

Twenty-three cases of asthma deaths were found in Italy; 16 of them (69%) occurred in the Veneto Region. A prevalence of male and young age was observed. Most of patients were atopic, died in the night-time hours and during the weekends. The possible risk factors identified were the sensitization to alternaria, previous near fatal asthma attacks and the incorrect treatment of the disease. Weather condition did not appear to be related to the fatal exacerbations, whereas among the pollutants only ozone was detected over the accepted limits. Smoking habits, possible drug abuse and concomitant complementary therapies might be regarded as further risk factors.

DISCUSSION

Although not free from potential biases, our web search and further investigations highlight an increasing asthma mortality trend, similarly to what other observatories report. The analysis of available clinical data suggests that the lack of treatment more than a severe asthma phenotype characterizes the fatal events.

CONCLUSIONS

Asthma mortality still represents a critical issue in the management of the disease, particularly in youngsters. Once more the inadequate treatment and the lack of adherence seem to be not only related to the uncontrolled asthma but also to asthma mortality.

The lag-time approach improved drug-outcome association estimates in presence of protopathic bias

OBJECTIVES

Protopathic bias is a systematic error which occurs when measured exposure status may be affected by the latent onset of the target outcome. In this article, we aimed to discuss the benefits and drawbacks of the lag-time approach to address this type of bias.

STUDY DESIGN AND SETTING

The lag-time approach consists in excluding from exposure assessment the period immediately preceding the outcome detection date. With the help of simple causal diagrams, we illustrate the rationale and limitations of such strategy. The lag-time approach was illustrated in a case-crossover study, based on the health care utilization databases of the Italian Lombardy Region, on the real-world effectiveness of some respiratory drugs (exposure) in preventing asthma exacerbations (outcome).

RESULTS

A total of 7,300 of patients who were admitted to an emergency department (ED) for asthma during 2010-2012 (cases) were included. Use (vs. nonuse) of short-acting beta-agonists (SABAs, an asthma reliever medication) during the 90 days before the ED admission date was associated with an increased risk of the outcome [odds ratio (OR): 1.95; 95% confidence interval (CI): 1.72, 2.22]. This paradoxical finding may be explained by protopathic bias, as SABA use prior the ED admission may be affected by preceding respiratory distress. Indeed, when a 120-day period preceding the ED admission was ignored from drug exposure assessment (lag time), SABAs were found to be associated with a reduced risk of the outcome (OR: 0.81; 95% CI: 0.84, 0.92), as expected.

CONCLUSIONS

The lag-time approach can be a useful strategy to circumvent protopathic bias in observational studies.

Virus and Mycoplasma pneumoniae prevalence in a selected pediatric population with acute asthma exacerbation

OBJECTIVE

To determine the prevalence of viral and atypical bacteria Mycoplasma pneumoniae infection in children experiencing asthma exacerbation and compare positive and negative subjects with regard to exacerbation severity, need for hospitalization, and treatment.

METHODS

One hundred sixty-nine asthmatic children aged 2-15 years old who were admitted to emergency rooms in Bogota, Colombia for acute asthma exacerbation were interviewed. Nasopharyngeal aspirates were taken for DNA and RNA extraction. M. pneumoniae and virus were detected by PCR using specific primers.

RESULTS

The prevalence of M. pneumoniae and viral infection in the study population was 12.4% and 83.7%, respectively. All subjects positive for M. pneumoniae were also positive for viral infection. Rhinovirus was the most frequently detected viral agent. No significant differences in severity of asthma exacerbations or in need for hospitalization between the virus or M. pneumoniae positive and negative groups were observed. A significantly lower percentage of M. pneumoniae positive subjects had used inhaled steroids over the six months prior to asthma exacerbation compared to M. pneumoniae negative subjects (38.1% vs. 68.2%), suggesting that inhaled corticosteroids may have a protective effect against M. pneumoniae infections.

CONCLUSIONS

The M. pneumoniae and virus prevalence found in this study were similar to those described in the literature. The 100% co-infection rate observed suggests that viral infection can predispose patients to M. pneumoniae infection, and that this interaction may trigger asthmatic exacerbation. Further studies should be done to confirm the protective effect of inhaled corticosteroids on M. pneumoniae infection in patients with asthma exacerbations.

Childhood Asthma Management and Environmental Triggers

Asthma is the most common chronic disease among children. It cannot be prevented but can be controlled. Industrialized countries experience high lifetime asthma prevalence that has increased over recent decades. Asthma has a complex interplay of genetic and environmental triggers. Studies have revealed complex interactions of lung structure and function genes with environmental exposures such as environmental tobacco smoke and vitamin D. Home environmental strategies can reduce asthma morbidity in children but should be tailored to specific allergens. Coupled with education and severity-specific asthma therapy, tailored interventions may be the most effective strategy to manage childhood asthma.

Lipopolysaccharide (LPS) exposure differently affects allergic asthma exacerbations and its amelioration by intranasal curcumin in mice. Cytokine. 2015;76:334-342. [PMID: 26239413 DOI: 10.1016/j.cyto.2015.07.022]

AIM

Lipopolysaccharide (LPS) is ubiquitous in the environment and can therefore, exacerbate allergic responses. Studies have suggested immunoregulatory effects of LPS according to route, dose and stage of exposure. Present study has examined whether dose and stage of LPS exposure (during sensitization and challenge with OVA) exacerbates airway inflammations, antigen specific-IgE level, histamine release, Th1/Th2 cytokine response. Further, anti-asthmatic potential of curcumin, through intranasal route has been evaluated for the first time in LPS induced airway inflammation in an ovalbumin (OVA)-challenged mouse asthma model.

METHODS

Balb/c mice were first sensitized with OVA on 1st and 8th day and exposed to two LPS doses (0.1/1.0 μg) separately on 2nd day and then further exposed to LPS with OVA-aerosol (from 9 to 14 day). Further, lower LPS dose (0.1 μg) was chosen for OVA exposed mouse model of asthma exacerbation study. Intranasal curcumin was administered from 9th to 14th day before every LPS exposure.

RESULTS

Exposure to LPS (0.1 μg) exacerbates airway inflammations in terms of IgE level, Th2-cytokine response (IL-4 and IL-5), histamine release, EPO and MPO activities and oxidative stress. Intranasal curcumin has effectively ameliorated airway exacerbations whereas dexamethasone, a known glucocorticosteroid, was not promising as compared to intranasal curcumin.

CONCLUSION

Schedule and dose of LPS exposure determines asthma exacerbations and intranasal curcumin could be better immunomodulatory agent in LPS exposed asthma exacerbations.

The Effect of Viral Infection on Exhaled Nitric Oxide in Children with Acute Asthma Exacerbations

BACKGROUND

Fraction of exhaled nitric oxide (Feno) level is used as an aid in the diagnosis and management of chronic asthma. Its role in acute asthma remains to be studied.

OBJECTIVE

To determine whether Feno levels are elevated in children with asthma exacerbations compared with baseline, and whether there is a difference in Feno levels based on PCR positive (+) (respiratory virus isolated by PCR analysis) versus PCR negative (-) (respiratory virus not isolated by PCR analysis) status.

METHODS

Children with a previous Feno level measurement while stable and who presented to an urgent care facility with an asthma exacerbation were enrolled. Feno levels, spirometry, and nasal swabs for viral PCR were obtained at the time of the exacerbation and following a course of prednisone. Data were available on 66 children. Linear mixed models were used to regress the outcomes of interest (FEV1, FEV1/forced vital capacity, forced expiratory flow at 25% to 75% of forced vital capacity, and natural log Feno) on detected virus (yes/no), visit (baseline, exacerbation, follow-up), and the interaction between the detected virus and visit.

RESULTS

Compared with baseline, higher Feno values and lower lung function were found at the time of an exacerbation. A respiratory virus was detected in 59% of the exacerbations. The interaction between PCR (+) and PCR (-) groups and visit on log Feno was marginally significant (P = .07). There was no difference in log Feno between the PCR (+) and PCR (-) groups at baseline, while higher log Feno was found in the PCR (-) group at the time of exacerbation and following prednisone (P = .05 and .001, respectively).

CONCLUSIONS

Higher Feno concentration in PCR (-) exacerbations suggests an eosinophilic predominance in nonviral compared with viral exacerbations.

Prospective Study on the Relationship of Obesity to Asthma Impairment and Risk

BACKGROUND

Although studies consistently show an association between obesity and increased asthma incidence, the role of obesity in asthma control is less clear.

OBJECTIVE

The objective of this study was to evaluate the association between baseline body mass index (BMI) and measures of subsequent asthma control in a large real-world cohort of adults with persistent asthma.

METHODS

In Kaiser Permanente Southern California (KPSC), a large managed care organization, we identified adults with persistent asthma in 2006, continuous health plan enrollment in 2007 and 2008, and a BMI measurement in 2006 or 2007. Each patient's last BMI measure in 2006 or 2007 was categorized into a BMI group: normal (<25 kg/m(2)), overweight (25-29.9 kg/m(2)), or obese (≥30 kg/m(2)). Asthma control outcomes in 2008 included asthma hospitalizations or emergency department visits (EDHO), oral corticosteroid dispensings linked to an asthma encounter (OCS), and dispensing of ≥7 short-acting beta-agonist canisters (SABA7). Multivariable analyses were conducted to assess the relationships of BMI categories with the risk of the asthma control outcomes after controlling for potential confounders.

RESULTS

In the 10,233 eligible adults-after adjusting for potential demographic, comorbidity, and prior utilization confounders-we found an increased relative risk (RR) of EDHO in overweight and obese (RR 1.40, 95% CI 1.10-1.78) individuals. Only obesity was associated in adjusted analyses with a significant increased relative risk of SABA7 (RR 1.27, 95% CI 1.15-1.40).

CONCLUSIONS

Elevated BMI, particularly obesity, is associated with subsequent poor asthma control, especially in the risk domain (exacerbations). These findings further support the importance of facilitating weight loss in overweight and obese adults with asthma.

Incidence and Triggers of Asthma Exacerbations Attended in the Emergency Department as a Level of Care Indicator (ASMAB III, 2005 and ASMAB IV, 2011)

INTRODUCTION

The identification of asthma exacerbations (AE) seen in emergency departments and in the home is proposed as a parameter of asthma control and for monitoring environmental triggers.

PATIENTS AND METHODS

All AEs seen in 2005 and 2011 in the reference hospital of the region and in the patients' homes by the Emergency Medical Services were identified.

RESULTS

The incidence of AE was 1.93/10(6)inhabitants/day during 2005, and 2/10(6)inhabitants/day in 2011. The most common triggers were slow onset common cold of more than 24h duration in 104/219 (47%) AEs in 2005 and 107/220 (49%) in 2011; prior bronchial symptoms with cough, expectoration and fever were recorded in 41/219 (19%) in 2005 and in 57/220 (26%) AEs in 2011. In total, 49% (2005) and 74% (2011) of the AEs had onset more than 24h before admission.

CONCLUSIONS

No significant differences were observed in the rate of attendance in the emergency department due to AE between 2005 and 2011. The most common triggers were common cold and bronchial symptoms with expectoration and fever. AE had begun more than 24h previously in at least half of cases. These findings appear to suggest that there may be a scope for improvement in the outpatient care of the asthmatic patient.

Intermittent and episode-driven use of pranlukast to reduce the frequency of wheezing in atopic children: a randomized, double-blind, placebo-controlled trial

Background

Leukotriene receptor antagonist (LTRA) therapy reduces asthma exacerbations in children older than 2 years. However, whether early intervention using LTRA in atopic smaller children aged 1 to 2 years who had experienced episodic wheezing can reduce the frequency of wheezing is unknown.

Methods

A randomized, double-blind, placebo-controlled, multi-center trial of episode-driven intermittent use of pranlukast for 12 months, one of the LTRAs, was conducted by enrolling children who had two, but not more than two, episodes of wheezing prior to entry and were allergen-specific IgE-positive (≥class 2). The primary outcome was increased episodes of wheezing more than once a month for 3 months.

Results

Seventy-seven children were randomly assigned to receive pranlukast (n = 37) or placebo (n = 40). The primary outcome occurred in 10 of 36 (28%) of the pranlukast group and 14 of 39 (36%) in the placebo group, which was not significantly different (P = 0.45). Even though the study period was extended to a maximum of >5 years, there was no significant difference in the Kaplan-Meier curves in the occurrence of the primary outcome between the two groups.

Conclusions

These results suggest that intermittent and episode-driven use of pranlukast in small children with a prior history of wheezing and atopic sensitization may not reduce the frequency of wheezing later in life. However, the sample size was too small to make a definitive conclusion.

Trial registration

UMIN000000634

The impact of asthma exacerbations and preventive strategies

OBJECTIVE

To review the pathophysiologic mechanisms underlying asthma exacerbations, the impact of exacerbations, and both current and future treatment strategies to establish asthma control and reduce the risk of future exacerbations.

RESEARCH DESIGN AND METHODS

Relevant adult data were identified via PubMed, with additional references obtained by reviewing bibliographies from selected articles.

RESULTS

Asthma exacerbations or 'attacks' are acute episodes of progressive worsening of symptoms which occur in patients with all degrees of asthma severity and are an important cause of morbidity and mortality. For patients, these asthma attacks constitute a considerable part of the disease burden in terms of both personal suffering and economic impact. Exacerbations are characterized in part by decreases in expiratory flow or lung function. The pathophysiologic mechanism underlying these changes is likely to be different depending on the specific asthma phenotype. Asthma exacerbations are commonly initiated by upper respiratory tract infections and/or environmental allergens, although there are other known factors which increase the risk of a patient developing exacerbations, such as cigarette smoking. Establishing asthma control and reducing the risk of future exacerbations is the main goal of asthma treatment. Inhaled corticosteroids alone or in combination with long-acting β2-agonists, in addition to other step-up strategies such as leukotriene receptor antagonists and theophylline, are recommended. The anti-immunoglobulin E monoclonal antibody omalizumab should also be considered in difficult-to-treat allergic asthma.

CONCLUSIONS

Despite the currently available treatments, many patients with asthma remain symptomatic and experience exacerbations regardless of disease severity. New therapies, including long-acting anticholinergics, anti-cytokines, and chemoattractant receptor-homologous molecules, are under investigation with some promising results. In addition to increased education and use of self-management plans, these novel therapies are essential to help improve asthma control and reduce exacerbation risk.