Assessment of adherence to corticosteroids in asthma by drug monitoring or fractional exhaled nitric oxide: A literature review.

BACKGROUND: Although the efficacy of corticosteroid treatment in controlling asthma is widely accepted, its effectiveness is undermined by poor adherence. However, the optimal method for measuring adherence to asthma therapy remains unclear. OBJECTIVE: To perform a review of the literature reporting biological, objective methods for assessing adherence to inhaled or oral corticosteroids in asthma; we included studies reporting direct measurement of exogenous corticosteroids in blood, or the effect of adherence on exhaled nitric oxide. DESIGN: We searched three databases MEDLINE (using both PubMed and Ovid), the Cumulative Index of Nursing and Allied Health Literature (CINAHL) and Web of Science for articles published between January 1975 and July 2020. Quality of the studies was assessed using the National Institute of Health checklist. RESULTS: From 2850 screened articles, 26 fulfilled the inclusion criteria. Measurement of blood prednisolone with or without cortisol was used in eight studies as a measure of oral corticosteroid adherence, and fractional exhaled nitric oxide (FeNO) in 17 studies for inhaled corticosteroid adherence. Inhaled corticosteroids were measured directly in the blood in one study. By direct measurement of drug levels in the blood, adherence rates to oral corticosteroids ranged from 47% to 92%, although the performance and timing of the test were often not known, making interpretation of findings and serum prednisolone concentrations difficult. FeNO is generally lower in adherent than non-adherent patients, but no absolute cut-off can be proposed based on the available data. However, a fall in FeNO following supervised inhaled corticosteroid dosing could indicate previous poor adherence. CONCLUSIONS AND CLINICAL RELEVANCE: Despite prednisolone and cortisol levels commonly being used as adherence markers in clinical practice, further work is required to assess the influence of the dose and timing on blood levels. The promising findings of FeNO suppression testing should be explored in further prospective studies.

Clinical presentation, assessment, and management of inducible laryngeal obstruction.

PURPOSE OF REVIEW: Many aspects of inducible laryngeal obstruction (ILO) are still poorly understood. However, in recent years there have been advances made and an international consensus has achieved a standardized taxonomy. This review will synthesize recent research; specifically, relating to clinical presentation, assessment, and therapeutic interventions. RECENT FINDINGS: The evidence base is growing but still limited for ILO and mostly comprises retrospective reviews, case studies, and anecdotal reports. The proposed relationship between ILO and other manifestations of laryngeal dysfunction via laryngeal hypersensitivity and hyperresponsiveness warrants further investigation. Progress has been made with guidelines published on laryngoscopy reporting procedures and validated symptom questionnaires produced for clinical use, although diagnostic algorithms are yet to be established. Emerging conservative and surgical interventions show promise, although as yet there are no randomized controlled trials investigating treatment efficacy. SUMMARY: The field is in an embryonic state and key research priorities, acknowledged in the current literature, need to be addressed to positively impact patient care.

Laryngeal Dysfunction: Assessment and Management for the Clinician.

The larynx is one of the most highly innervated organs in humans and serves a number of vitally important, complex, and highly evolved biological functions. On a day-to-day basis, the larynx functions autonomously, addressing several roles including airway protection, swallowing, and phonation. In some situations the larynx appears to adopt a functional state that could be considered maladaptive or "dysfunctional." This laryngeal dysfunction can underpin and account for a number of respiratory symptoms that otherwise appear incongruous with a clinical disease state and/or contribute to the development of symptoms that appear "refractory" to treatment. These include conditions associated with a heightened tendency for inappropriate laryngeal closure (e.g., inducible laryngeal obstruction), voice disturbance, and chronic cough. Recognition of laryngeal dysfunction is important to deliver targeted treatment and failure to recognize the condition can lead to repeated use of inappropriate treatment. Diagnosis is not straightforward, however, and many patients appear to present with symptoms attributable to laryngeal dysfunction, but in whom the diagnosis has been overlooked in clinical work-up for some time. This review provides an overview of the current state of knowledge in the field of laryngeal dysfunction, with a focus on pragmatic clinical assessment and management.