The Psychosocial Impact of Indwelling Pleural Catheters: A Scoping Review.

We aimed to identify research on the psychosocial impact of Indwelling Pleural Catheters (IPC); report on the extent, range, and nature of studies; and summarize the findings. A secondary aim was to capture reports on patient support needs and/or self-management of IPC. A systematic literature search was undertaken, with evidence synthesis planned if sufficient literature was identified. We searched ten databases available through the United Kingdom National Health Service Knowledge and Library Hub: the British Nursing Index (BNI), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane, Excerpta Medica Database (Embase), Exerpta Medica Care (Emcare), E-thesis Online Service (EThOS), Medical Literature Analysis and Retrieval System Online (Medline), National Grey Literature Collection, Psychological Information Database (PsycInfo), and PubMed. We included studies reporting on the psychosocial impact of indwelling pleural catheters or their effect on quality of life (QoL). The latter was limited to those studies using qualitative research methods from which we could identify psychosocial impacts. The evaluation of psychosocial factors was not the primary objective of any identified study, and we found no studies in which quality of life was assessed using qualitative methods. Two studies met the inclusion criteria but only tangentially. While indwelling pleural catheters may improve the quality of life in patients with pulmonary effusion when assessed quantitatively, there is a dearth of research examining their psychosocial impact.

Changes in exhaled volatile organic compounds following indirect bronchial challenge in suspected asthma.

BACKGROUND: Inhaled mannitol provokes bronchoconstriction via mediators released during osmotic degranulation of inflammatory cells, and, hence represents a useful diagnostic test for asthma and model for acute attacks. We hypothesised that the mannitol challenge would trigger changes in exhaled volatile organic compounds (VOCs), generating both candidate biomarkers and novel insights into their origin. METHODS: Participants with a clinical diagnosis of asthma, or undergoing investigation for suspected asthma, were recruited. Inhaled mannitol challenges were performed, followed by a sham challenge after 2 weeks in participants with bronchial hyper-responsiveness (BHR). VOCs were collected before and after challenges and analysed using gas chromatography-mass spectrometry. RESULTS: Forty-six patients (mean (SD) age 52 (16) years) completed a mannitol challenge, of which 16 (35%) were positive, and 15 of these completed a sham challenge. Quantities of 16 of 51 identified VOCs changed following mannitol challenge (p<0.05), of which 11 contributed to a multivariate sparse partial least square discriminative analysis model, with a classification error rate of 13.8%. Five of these 16 VOCs also changed (p<0.05) in quantity following the sham challenge, along with four further VOCs. In patients with BHR to mannitol distinct postchallenge VOC signatures were observed compared with post-sham challenge. CONCLUSION: Inhalation of mannitol was associated with changes in breath VOCs, and in people with BHR resulted in a distinct exhaled breath profile when compared with a sham challenge. These differentially expressed VOCs are likely associated with acute airway inflammation and/or bronchoconstriction and merit further investigation as potential biomarkers in asthma.

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.

Volatile organic compounds associated with diagnosis and disease characteristics in asthma - A systematic review.

BACKGROUND: Metabolomics refers to study of the metabolome, the entire set of metabolites produced by a biological system. The application of metabolomics to exhaled breath samples - breathomics - is a rapidly growing field with potential application to asthma diagnosis and management. OBJECTIVES: We aimed to review the adult asthma breathomic literature and present a comprehensive list of volatile organic compounds identified by asthma breathomic models. METHODS: We undertook a systematic search for literature on exhaled volatile organic compounds in adult asthma. We assessed the quality of studies and performed a qualitative synthesis. RESULTS: We identified twenty studies; these were methodologically heterogenous with a variable risk of bias. Studies almost universally reported breathomics to be capable of differentiating - with moderate or greater accuracy - between samples from healthy controls and those with asthma; and to be capable of phenotyping disease. However, there was little concordance in the compounds upon which discriminatory models were based. CONCLUSION: Results to-date are promising but validation in independent prospective cohorts is needed. This may be challenging given the high levels of inter-individual variation. However, large-scale, multi-centre studies are underway and validation efforts have been aided by the publication of technical standards likely to increase inter-study comparability. Successful validation of breathomic models for diagnosis and phenotyping would constitute an important step towards personalised medicine in asthma.

The role of measuring exhaled breath biomarkers in sarcoidosis: a systematic review.

INTRODUCTION: Sarcoidosis is a chronic granulomatous disease of unknown aetiology with a variable clinical course and prognosis. There is a growing need to identify non-invasive biomarkers to differentiate between clinical phenotypes, identify those at risk of disease progression and monitor response to treatment. OBJECTIVES: We undertook a systematic review and meta-analysis to evaluate the utility of breath-based biomarkers in discriminating sarcoidosis from healthy controls, alongside correlation with existing non breath-based biomarkers used in clinical practice, radiological stage, markers of disease activity and response to treatment. METHODS: Electronic searches were undertaken during November 2017 using PubMed, Ebsco, Embase and Web of Science to capture relevant studies evaluating breath-based biomarkers in adult patients with sarcoidosis. RESULTS: 353 papers were screened; 21 met the inclusion criteria and assessed 25 different biomarkers alongside VOCs in exhaled breath gas or condensate. Considerable heterogeneity existed amongst the studies in terms of participant characteristics, sampling and analytical methods. Elevated biomarkers in sarcoidosis included 8-isoprostane, carbon monoxide, neopterin, TGF-ß1, TNFα, CysLT and several metallic elements including chromium, silicon and nickel. Three studies exploring VOCs were able to distinguish sarcoidosis from controls. Meta-analysis of four studies assessing alveolar nitric oxide showed no significant difference between sarcoidosis and healthy controls (2.22 ppb; 95% CI -0.83, 5.27) however, a high degree of heterogeneity was observed with an I 2 of 93.4% (p < 0.001). Inconsistent or statistically insignificant results were observed for correlations between several biomarkers and radiological stage, markers of disease activity or treatment. CONCLUSIONS: The evidence for using breath biomarkers to diagnose and monitor sarcoidosis remains inconclusive with many studies limited by small sample sizes and lack of standardisation. VOCs have shown promising potential but further research is required to evaluate their prognostic role.

Safety of 80% vs 30-35% fraction of inspired oxygen in patients undergoing surgery: a systematic review and meta-analysis.

BACKGROUND: Evidence-based guidelines from the World Health Organization (WHO) have recommended a high (80%) fraction of inspired oxygen (FiO2) to reduce surgical site infection in adult surgical patients undergoing general anaesthesia with tracheal intubation. However, there is ongoing debate over the safety of high FiO2. We performed a systematic review to define the relative risk of clinically relevant adverse events (AE) associated with high FiO2. METHODS: We reviewed potentially relevant articles from the WHO review supporting the recommendation, including an updated (July 2018) search of EMBASE and PubMed for randomised and non-randomised controlled studies reporting AE in surgical patients receiving 80% FiO2 compared with 30-35% FiO2. We assessed study quality and performed meta-analyses of risk ratios (RR) comparing 80% FiO2 against 30-35% for major complications, mortality, and intensive care admission. RESULTS: We included 17 moderate-good quality trials and two non-randomised studies with serious-critical risk of bias. No evidence of harm with high FiO2 was found for major AE in the meta-analysis of randomised trials: atelectasis RR 0.91 [95% confidence interval (CI) 0.59-1.42); cardiovascular events RR 0.90 (95% CI 0.32-2.54); intensive care admission RR 0.93 (95% CI 0.7-1.12); and death during the trial RR 0.49 (95% CI 0.17-1.37). One non-randomised study reported that high FiO2 was associated with major respiratory AE [RR 1.99 (95% CI 1.72-2.31)]. CONCLUSIONS: No definite signal of harm with 80% FiO2 in adult surgical patients undergoing general anaesthesia was demonstrated and there is little evidence on safety-related issues to discourage its use in this population.

Biomarkers in adult asthma: a systematic review of 8-isoprostane in exhaled breath condensate.

OBJECTIVES: We aimed to assess the evidence for the use of 8-isoprostane in exhaled breath condensate (EBC) as a biomarker in adult asthma. DESIGN: A systematic review and meta-analysis of EBC 8-isoprostane. METHODS: We searched a number of online databases (including PubMed, Embase and Scopus) in January 2016. We included studies of adult non-smokers with EBC collection and asthma diagnosis conducted according to recognised guidelines. We aimed to pool data using random effects meta-analysis and assess heterogeneity using I 2. RESULTS: We included twenty studies, the findings from which were inconsistent. Seven studies (n = 329) reported 8-isoprostane levels in asthma to be significantly higher than that of control groups, whilst six studies (n = 403) did not. Only four studies were appropriate for inclusion in a random effects meta-analysis of mean difference. This found a statistically significant between-groups difference of 22 pg ml-1. Confidence in the result is limited by the small number of studies and by substantial statistical heterogeneity (I 2 = 94). CONCLUSION: The clinical value of EBC 8-isoprostane as a quantitative assessment of oxidative stress in asthma remains unclear due to variability in results and methodological heterogeneity. It is essential to develop a robust and standardised methodology if the use of EBC 8-isoprostane in asthma is to be properly evaluated.