Guideline-recommended fractional exhaled nitric oxide is a poor predictor of health-care use among inner-city children and adolescents receiving usual asthma care

Association of fractional exhaled nitric oxide with asthma morbidity in urban minority children

OBJECTIVE

Fractional exhaled nitric oxide (FeNO) is a well-established measure of allergic airway inflammation and possible useful adjunct disease management tool. We investigated the association of baseline and follow-up FeNO measurements with disease burden in minority children with persistent asthma.

METHODS

A retrospective chart review was conducted on 352 African American and Hispanic children seen at an urban Asthma Center in Bronx, NY. Demographic, clinical characteristics, and pulmonary function tests (PFTs) were compared between children with low, intermediate, and high baseline FeNO levels. Among 95 children with subsequent follow up visits, associations of change in FeNO with demographics, clinical characteristics, and PFTs were examined using mixed effects linear regression models.

RESULTS

A higher proportion of children with intermediate (54%) and high FeNO (58%) levels had lower airways obstruction compared to those with low FeNO levels (33%). Children with intermediate FeNO levels had more annual hospitalizations (2.8 ± 6.2) compared to those with low and high FeNO levels (1.3 ± 2.8 and 1.3 ± 2.5). These associations did not differ between ethnicities. An increase in FeNO over time was associated with higher BMI z-scores (β = 6.2, 95% CI: 1.0 to 11.4) and two or more hospitalizations in the past year (β = 16.1, 95% CI: 1.5 to 30.8).

CONCLUSIONS

Intermediate and high FeNO levels are associated with lower airways obstruction and hospitalizations. Initial and serial FeNO measurements can be a useful adjunctive tool in identifying asthma-related morbidity in urban African American and Hispanic children.

Understanding the Updates in the Asthma Guidelines

Asthma is a chronic inflammatory lung disease that affects millions of Americans, with variable symptoms of bronchospasm and obstruction among individuals over time. The National Heart, Lung, and Blood Institute (NHLBI) published the 2020 Focused Updates to the Asthma Management Guidelines based on the latest research since the 2007 Expert Panel Report-3 (EPR-3). The following article reviews the 21 new recommendations on the six core topics in asthma: use of intermittent inhaled corticosteroids, long-acting muscarinic antagonist therapy, use of the fractional exhaled nitric oxide test in asthma diagnosis and monitoring, indoor allergen mitigation, immunotherapy, and bronchial thermoplasty. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to rate recommendations as strong or conditional based on the evidence. The recommendations were based on systematic reviews of the literature and focused on patient-centered critical outcomes of asthma exacerbations, asthma control, and asthma-related quality of life. Understanding the recommendations with consideration of individual values through shared decision-making may improve asthma outcomes.

CT Features of Lymphatic Plastic Bronchitis in Adults: Correlation with Multimodality Lymphatic Imaging

Purpose

To distinguish CT patterns of lymphatic and nonlymphatic causes of plastic bronchitis (PB) through comparison with lymphatic imaging.

Materials and Methods

In this retrospective study, chest CT images acquired prior to lymphatic workup were assessed in 44 patients with PB from January 2014 to August 2020. The location and extent of ground-glass opacity (GGO) was compared with symptoms and lymphatic imaging. Statistical analysis was performed using descriptive statistics, logistic regression, Pearson correlation coefficient, and unweighted κ coefficient for interobserver agreement. Sensitivity and specificity of GGO for lymphatic PB were calculated.

Results

Lymphatic imaging was performed in 44 patients (median age, 52 years ± 21 [IQR]; 23 women): 35 with lymphatic PB and nine with nonlymphatic PB. GGO was more frequently observed in patients with lymphatic PB than in those with nonlymphatic PB (91% [32 of 35] vs 33% [three of nine]; P < .001). Univariate logistic regression confirmed this result by showing that GGO was a significant predictor of lymphatic PB (odds ratio, 21 (95% CI: 3.8, 159.7). The model areas under the receiver operating characteristic curve (AUCs) of GGO unadjusted and adjusted for demographics were 0.79 and 0.86, respectively. The location of GGO correlated with lymphatic imaging and bronchoscopic findings. Overall sensitivity and specificity of GGO for lymphatic PB were 91% (32 of 35; 95% CI: 76, 98) and 67% (six of nine; 95% CI: 30, 93), respectively.

Conclusion

Patients with lymphatic PB predominantly had multifocal GGO with or without a "crazy paving" pattern; identification of GGO should prompt lymphatic workup in this frequently misdiagnosed condition.Keywords: Lymphography, Lymphatic, CT, Tracheobronchial Tree, Thorax© RSNA, 2022See also commentary by Kligerman and White in this issue.

2020 Focused Updates to the Asthma Management Guidelines: A Report from the National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group

The 2020 Focused Updates to the Asthma Management Guidelines: A Report from the National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group was coordinated and supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health. It is designed to improve patient care and support informed decision making about asthma management in the clinical setting. This update addresses six priority topic areas as determined by the state of the science at the time of a needs assessment, and input from multiple stakeholders:A rigorous process was undertaken to develop these evidence-based guidelines. The Agency for Healthcare Research and Quality's (AHRQ) Evidence-Based Practice Centers conducted systematic reviews on these topics, which were used by the Expert Panel Working Group as a basis for developing recommendations and guidance. The Expert Panel used GRADE (Grading of Recommendations, Assessment, Development and Evaluation), an internationally accepted framework, in consultation with an experienced methodology team for determining the certainty of evidence and the direction and strength of recommendations based on the evidence. Practical implementation guidance for each recommendation incorporates findings from NHLBI-led patient, caregiver, and clinician focus groups. To assist clincians in implementing these recommendations into patient care, the new recommendations have been integrated into the existing Expert Panel Report-3 (EPR-3) asthma management step diagram format.

Immunological biomarkers in severe asthma

Severe asthma is heterogeneous in its clinical presentation, underlying pathophysiology, course and response to therapy. Clinical and physiological assessment of severe asthma is often inadequate in predicting underlying disease mechanisms and or response to medications. With the emergence of novel targeted therapies in severe asthma, the need for reproducible, easily measured biomarkers became obvious but only few are currently available for clinical use. These biomarkers along with the clinical presentation of the patient play an important role in identifying phenotypes and endotypes, predicting the clinical course and prognosis and improving the precision therapeutic approach to asthma.

Phenotypes favoring fractional exhaled nitric oxide discordance vs guideline-based uncontrolled asthma

BACKGROUND

Despite potential value of identification of allergic inflammation with fractional exhaled nitric oxide (FeNO) in managing asthma, randomized clinical trials have not consistently shown better outcomes compared with guideline management alone.

OBJECTIVE

To assess the effectiveness of FeNO vs non-FeNO-based therapeutic algorithms in managing asthma, and the phenotypic profile associated with FeNO >35 ppb yet well controlled by guidelines, as a potential model to predict better FeNO-based algorithm outcomes.

METHODS

This is a randomized controlled study (RCT) in 88 high-risk children with asthma 7 to 18 years of age across 352 visits over a 1-year period. Generalized estimating equations analysis assessed algorithm group differences in outcomes and characteristics associated with higher odds uncontrolled by FeNO alone in the treatment decision algorithm.

RESULTS

The FeNO treatment algorithm did not show superiority in reducing exacerbations and morbidity (P > .05). Phenotypes that more than doubled the odds FeNO alone identified uncontrolled asthma included adolescence, non-adherence, high atopy (>6+), and baseline FeNO >35 ppb, whereas obesity, FEF_25-75% < 65% predicted, and bronchodilator response >10% decreased the odds. Uncontrolled asthma by FeNO alone (F) vs guidelines alone (G) showed overall F/G > 1.0 in adolescents, but <1.0 in younger patients unless the FeNO threshold was reduced to >20 ppb.

CONCLUSION

Our study suggests that age and phenotypes play a key role in FeNO discordance compared with the conventional guideline-based uncontrolled asthma. The FeNO-based therapeutic algorithm, if confirmed further, could provide the clinician with an effective asthma management tool. The clinical implication could improve future FeNO-based RCTs and treatment decision algorithms in managing asthma by considering phenotypes and age-dependent FeNO thresholds.

At-risk children with asthma (ARC): a systematic review

Introduction

Asthma attacks are responsible for considerable morbidity and may be fatal. We aimed to identify and weight risk factors for asthma attacks in children (5–12 years) in order to inform and prioritise care.

Methods

We systematically searched six databases (May 2016; updated with forward citations January 2017) with no language/date restrictions. Two reviewers independently selected studies for inclusion, assessed study quality and extracted data. Heterogeneity precluded meta-analysis. Weighting was undertaken by an Expert Panel who independently assessed each variable for degree of risk and confidence in the assessment (based on study quality and size, effect sizes, biological plausibility and consistency of results) and then achieved consensus by discussion. Assessments were finally presented, discussed and agreed at a multidisciplinary workshop.

Results

From 16 109 records, we included 68 papers (28 cohort; 4 case-control; 36 cross-sectional studies). Previous asthma attacks were associated with greatly increased risk of attack (ORs between 2.0 and 4.1). Persistent symptoms (ORs between 1.4 and 7.8) and poor access to care (ORs between 1.2 and 2.3) were associated with moderately/greatly increased risk. A moderately increased risk was associated with suboptimal drug regimen, comorbid atopic/allergic disease, African-American ethnicity (USA), poverty and vitamin D deficiency. Environmental tobacco smoke exposure, younger age, obesity and low parental education were associated with slightly increased risk.

Discussion

Assessment of the clinical and demographic features identified in this review may help clinicians to focus risk reduction management on the high-risk child. Population level factors may be used by health service planners and policymakers to target healthcare initiatives.

Trial registration number

CRD42016037464.

Seasonal risk factors for asthma exacerbations among inner-city children

BACKGROUND

Asthma exacerbations remain common, even in children and adolescents, despite optimal medical management. Identification of host risk factors for exacerbations is incomplete, particularly for seasonal episodes.

OBJECTIVE

We sought to define host risk factors for asthma exacerbations unique to their season of occurrence.

METHODS

This is a retrospective analysis of patients aged 6 to 20 years who comprised the control groups of the Asthma Control Evaluation study and the Inner City Anti-IgE Therapy for Asthma study. Univariate and multivariate models were constructed to determine whether patients' demographic and historical factors, allergic sensitization, fraction of exhaled nitric oxide values, spirometric measurements, asthma control, and treatment requirements were associated with seasonal exacerbations.

RESULTS

The analysis included 400 patients (54.5% male; 59.0% African American; median age, 13 years). Exacerbations occurred in 37.5% of participants over the periods of observation and were most common in the fall (28.8% of participants). In univariate analysis impaired pulmonary function was significantly associated with greater odds of exacerbations for all seasons, as was an exacerbation in the previous season for all seasons except spring. In multivariate analysis exacerbation in the previous season was the strongest predictor in fall and winter, whereas a higher requirement for inhaled corticosteroids was the strongest predictor in spring and summer. The multivariate models had the best predictive power for fall exacerbations (30.5% variance attributed).

CONCLUSIONS

Among a large cohort of inner-city children with asthma, patients' risk factors for exacerbation vary by season. Thus information on individual patients might be beneficial in strategies to prevent these seasonal events.

The importance of atopy on exhaled nitric oxide levels in African American children

BACKGROUND

For physicians to be maximally effective in managing asthma in minority populations, a better understanding of the factors that affect fractional exhaled nitric oxide (FeNO) measurements in African Americans is needed.

OBJECTIVE

To examine demographic, environmental, and physiologic factors that influence FeNO measurements in African American children with and without asthma.

METHODS

A cross-sectional study of 128 African American children aged 7 to 18 years (44% with asthma) was conducted. FeNO measurements, skin prick tests (as a measure of atopy), spirometry, and questionnaire data were obtained from all participants. Regression models were constructed after identifying factors significantly associated on univariate analysis.

RESULTS

Among all study participants, the mean FeNO measurement at baseline was 24.4 ppb. Children with asthma had a higher level than those without (30.9 vs 19.3 ppb, P = .002). When examining all children through logistic regression analysis, an elevated FeNO level was significantly associated with atopy, lower spirometric values, and current asthma (P < .05 for all). Among asthmatic children, univariate analysis revealed that an elevated FeNO level was associated with inhaled corticosteroid use, recent respiratory infection, and atopy (P < .05 for all). However, only atopy remained significant after regression analysis. For asthmatic and nonasthmatic children, FeNO levels were directly correlated with the number of positive skin test results.

CONCLUSION

In African American children with and without asthma, FeNO levels are strongly influenced by atopy. Guidelines for FeNO measurements that incorporate atopic status are needed.